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Review of Artificial Production of Anadromous and Resident Fish in the
Columbia River Basin
(part 3 of 3)
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VI. Impacts Associated with Artificial Production
As evidenced from the historical overview, Columbia Basin hatchery
programs have been motivated by several goals, with the most recent
perhaps incompatible with those of previous years. Attainment of some
goals may even be considered detrimental to others, and not merely because
of competition for programmatic resources, but because of conflicting
outcomes. To address this problem, risk management is an option that needs
to be considered, but this may prove ineffective, unless the goals are
ranked, so that priorities can be established to adopt measures that
address the resolution of competing risks.
Risks Associated with Failure and Success - Originally,
the goal of the hatchery programs was production for harvest, so the
measure of success was the numbers of returning harvestable adults of
hatchery origin. However, in actual practice over the years, and perhaps
as a matter of convenience, hatcheries tended to report their performance
in terms of numbers of smolts released rather than adults returning, with
the assumption that adult return responsiveness was in proportion. The
problem with this criterion is that the rate of adult return for number of
smolts released varies enormously from hatchery to hatchery and from year
to year, leaving smolt production actually an unreliable indicator of
expected harvest. Concentrating on smolt production and not adult return
diverts attention from the central issue and results in the risk of not
succeeding in reaching the harvest goal, or the risk of increasing
failure. One component of the present review, therefore, is to assess the
effectiveness of hatcheries in meeting production goals for harvest,
attempting to find patterns that might account for the success of some and
the failure of others.
Unfortunately, with the passage of time, native runs of Columbia Basin
salmon have declined to such low levels that local extinctions have taken
place, and many others are presently at risk. In this new era of concern
for wild fish the question naturally arises whether the operation of
hatcheries is a contributing factor in their decline. In addition to the
pessimism raised about even new state-of-the-art production hatcheries,
these concerns also apply to supplementation operations as well as captive
broodstock programs. Ironically, there are some plausible scenarios in
which the greater the success of the hatcheries in producing harvestable
fish under the original set of goals, the greater the damage they would
cause to the affected wild stocks which are the focus of new goals
consistent with ecological health. These are the risks of success.
Accordingly, the second component of the present review is to assess the
magnitudes and likelihood of the various negative effects that hatchery
operations might have on wild stocks.
Contrasting the Evidence with the Theory - The practical
science of hatchery management is more than 100 years old. During that
time hatchery technology has progressed to the point that success rate of
the "hatchery phase" in the life cycle of salmon and steelhead
is very high. In fact, it is expected that a hatchery program will produce
more smolts per spawner than in natural production. The magnitude of this
relative advantage is in the order of 10 fold, but this advantage is
restricted to the hatchery phase. It is quite a different story when
considering success in the post-release phase of the life cycle. Hatchery
fish experience substantially less survival success in the wild. This is
another issue of concern in the present assessment. In particular, what is
the relative survival of the hatchery bred fish, their reproductive
ability, their ecological costs, and their genetic impacts on wild fish.
In nearly all cases, when hatchery production rationale is assessed
under ecological, genetic, and evolutionary theory, the result is
unequivocally negative, but of an unknown magnitude. There are some
limited experimental data, generally from other taxa and in specific
situations, which demonstrates the mechanisms that theory is based on, but
relevant empirical information related to salmonids is generally
anecdotal, lacking in adequate controls, and insufficient in quantity to
be conclusive. Thus, while we are confident that such mechanisms can apply
to hatchery produced salmonids, there is limited empirical evidence on
hatchery impacts in the Columbia Basin. Although some are tempted to
attribute the decline of wild stocks in the Basin on interaction with
hatchery fish, as well as even the poor success of hatchery fish on
hatchery practices, such evidence, at best, is indirect and neglectful of
the other major environmental perturbances in the system. The task of
making linkages is a formidable one, but necessary in the fair resolution
of hatchery assessment.
Risk Analysis and Risk Management - Fishery scientists
must deal with two major factors in making decisions about how to assess
and manage risks of hatcheries: (1) the uncertainty in predicting success
or failure and (2) the potential conflicts between multiple attributes of
success. One major attribute of success is the increase of fish for
harvest; another is the impact on wild stocks.
Depending on how the fisheries managers and the public value the
probability of success in terms of producing fish for harvest, the annual
investment in the hatchery system might be considered worthwhile. There is
a probability that this investment will deliver a return in harvestable
fish, and a probability that it will not, in which case the odds may
justify making the investment. Evidence demonstrating that hatcheries
contribute to harvest continues to stimulate interest in the use of
hatcheries for harvest augmentation and mitigation.
At the same time, there are probabilities that hatchery fish may have
negative impacts on wild stocks, which can occur even when hatcheries are
managed for supplementation or recovery of wild stocks. Negative effects
could overwhelm the positive effects of increased survival in the hatchery
during the wild phase of the life cycle. Here, the gamble is on wild stock
recovery. Managers must not only assess biological uncertainties but also
the trade-offs. In a recovery program, balancing may involve the
probability of decreasing the risk of extinction during the hatchery phase
versus the probability of increasing mortality during the wild phase of
the life cycle. On a broader scale, managers must take into account both
the harvest goals and goals to protect wild stocks. However, from a
strictly ecological perspective to preserve and recover wild fish, there
can be no such compromise.
The critical uncertainties that dominate decision making are amenable
to empirical resolution if the right things are measured in a controlled,
systematic, and powerful experimental design. To get the information
needed to answer hard questions, it would mean a major reorganization of
how hatchery programs are conducted, including interim changes and
re-prioritization in hatchery production goals. Hatchery research,
focusing on programmed study plans around appropriate experiments to
quantify the effects of hatcheries and hatchery practices, would need to
be the initial priority. The long-term priority would be to return to
production goals with management and technologies reconditioned to
maximize the benefits of artificial production in a manner that
complements the ecological health of the system.
A. Management Impacts on Artificial Production Effectiveness Although
controversy about the effectiveness and impact of anadromous fish
hatcheries has existed since hatcheries first appeared on the Columbia
River, there needs to be a distinction in the object and substance of such
controversy between those factors associated with hatchery technology and
those associated with hatchery management. Hatchery technology occurs in
many different forms, from juvenile rearing on formulated diets in
concrete raceways to unfed fry releases from incubation in artificial
substrate. The chinook hatchery on Sooes River, Washington; pink salmon
hatcheries in Prince William Sound, Alaska; and the Weaver Creek sockeye
spawning channel in British Columbia, are examples of successful hatchery
programs resulting in significant enlargement of their respective salmon
populations. In contrast, and yet with similar technology, sockeye
production at the Leavenworth hatchery on Icicle Creek, Washington; coho
and chinook production at Grays River hatchery on the lower Columbia
River; and the Priest Rapids chinook spawning channel in the mid-Columbia,
are examples of hatchery programs that have demonstrated no success, and
may have had negative impacts on returns. The point is that hatchery
propagation takes many different forms, and each can demonstrate highly
variable performance, even when the same technology is used. Most
certainly, present technology can be improved, and advancements associated
with reduced fish density, natural-type habitat, and measures to reduce
conditioning of fish to circumstances associated with culture operations,
offers promise of producing fish more similar in behavior and performance
with that of wild fish.
However, the overriding influence on hatchery performance, and the
basis of the long-term controversy, is related more to hatchery management
practices of the fisheries agencies than to fish culture practices.
Variability in hatchery performance is not so much related to technology,
as it is to the manner in which that technology has been applied. The
consistent oversight in hatchery propagation is that management has not
been careful to provide for the biological needs of the young salmon after
release to the natural environment. Hatcheries are generally managed from
the central office, well displaced from the fish and the streams being
stocked, with little appreciation of the fact that these fish must
integrate into a very complex environmental system. A disregard for stock
structure and the synchrony between genetic attributes of populations and
the environment associated with their natal systems has generally
characterized hatchery management policy over the past. Moreover,
objectives such as producing the maximum number of smolts possible with
the flow available, and fish release programming based on space needs
among competing species or year classes, contributed significantly to poor
quality of fish, and negative impacts on fish in the receiving
environment. More recently concern about these issues have altered some
hatchery operations in an attempt to address problems with fish quality
and wild/hatchery fish interaction. The existing track record, however, is
dominated by former management practices, many of which are still
represented among Columbia River hatcheries.
To assess Columbia Basin hatcheries, technology such as lack of cover
in raceways or training on artificial diets may be issues, but the
compelling questions deal with the potential impact of the hatchery
program. That is a very different matter. Management policy dictates the
manner in which hatcheries are employed. Management policy affects what
genetic stocks are used, the breeding protocol, and where and in what
numbers hatchery fish are planted. Management policy is what motivates
knowing the status of the endemic stock where hatchery fish are planted,
making sure the genetics are complementary, and knowing the carrying
capacity of the target streams. Technology can be available to meet the
objectives required of artificial production to be compatible with native
stocks, but management must assure that it is applied. The impact of
management on the application of artificial production is the overwhelming
and decisive factor that determines the effectiveness of hatchery
programs. Good management is the key to successful integration of
hatcheries into a functioning and dynamic ecosystem.
B. Genetic Impacts of Artificial Production Better
understanding of nutrition, disease, stress, and water quality, has given
aquaculturists increasing control over the unpredictable nature of raising
fish. Only recently, however, have salmon aquaculturists become aware of
genetic concerns. Artificial production can lead to unwanted or
unanticipated genetic changes in wild and hatchery populations. These
changes are a concern because the productivity and resiliency of
populations to environmental change depend on the genetic diversity they
contain. Unlike disease or nutritional problems, which can be controlled
nearly immediately, the impacts of unwanted genetic changes can effect
productivity for many years.
In recent years, a variety of authors have cataloged the potential
genetic impacts of artificial production (Hindar et al. 1991, Waples 1991,
Busack and Currens 1995, Campton 1995, Waples 1995, Allendorf and Waples
1996). These impacts can be classified into four major types: (1)
extinction, (2) loss of within-population genetic variability, (3) loss of
among-population variability, and (4) domestication (Busack and Currens
1995). The impacts are not necessarily independent. For example,
domestication-or loss of fitness in the wild of a population adapted to a
captive environment-may also be associated with loss of genetic diversity
within that population. This has led to increasing awareness that managing
genetic impacts will require assessing the trade-offs between the major
types of impacts or between using artificial production or not (Hard et
al. 1992, Currens and Busack 1995).
In this section, we review the evidence for genetic impacts of
artificial production. For each of the four impacts, we ask two basic
questions that are important to decision-makers: (1) What is the evidence
that the impact occurs? (2) What is the evidence that the effects be
managed or mitigated?
Extinction
Definition-Extinction is the complete loss of a population and all its
genetic information.
Theory-Unlike other genetic impacts, extinction is usually associated
with three nongenetic causes of large changes in population abundance
(Shaffer 1981). These include demographic or random changes in survival
and reproductive success, fluctuations in the environment, and
catastrophes.
Captive environments, such as hatcheries, offer greater control over
environmental variation and the potential for increased reproductive
success. These should counter natural risks of extinction. Consequently,
artificial propagation could theoretically reduce the short-term risk of
extinction (Hard et al. 1992). In certain circumstances, however, hatchery
programs can increase the demographic and catastrophic risks of
extinction. Hatchery programs may mine small, natural populations, if they
take fish for brood stock but are unable to replace them. For example,
hatcheries that take female salmon with 4,000 eggs would be mining the
wild stock if they have much less than 0.05% egg-to-adult survival.
Inbreeding, a genetic phenomenon, can theoretically contribute to
irreversible declines in abundance in very small or wild populations (Gilpin
1987). When most or all of a population is taken into captivity, disease,
power failures, predation, and dewatering in the hatchery could be
catastrophic.
Evidence for Extinction-We found evidence of conditions that could
contribute to extinction caused by hatcheries (Flagg et al. 1995a). To
date, however, there are no records of hatcheries directly causing the
extinction of stocks. In contrast, artificial propagation has been used to
reduce short-term risk of extinction for sockeye salmon (Flagg et al.
1995b), chinook salmon (Bugert et al. 1995, Carmichael and Messmer 1995,
Appleby and Keown 1995, Shiewe et al. 1997), and steelhead (Brown 1995).
Ability to Mitigate-Evidence suggests that the probability of extinction
caused by artificial production can be mitigated, if the reproductive
success of naturally spawning and hatchery spawning fish are monitored and
adequate safeguards are established to prevent catastrophes in hatcheries.
We did not conclude whether the lack of hatchery-caused extinction
indicates that these safeguards are in place or simply a fortuitous turn
of events.
Loss of Genetic Diversity Within Populations
Definition-Loss of within-population diversity is the reduction in
the quantity, variety, and combinations of alleles in a population. It is
associated with two genetic phenomena, genetic drift and inbreeding. Both
of these are most important in small or declining populations: the smaller
the effective population size, the greater the rate of inbreeding and loss
of genetic information through genetic drift.
Theory-The relationship between small population size, loss of genetic
diversity, and increased inbreeding is one of the cornerstones of
theoretical population genetics. Considerable theory has been developed to
explain the generality of this relationship (Wright 1938, Crow and Kimura
1970, Goodnight 1987, 1988; Caballero 1994) and its importance for
short-term and long-term survival (Lande 1988, Mitton 1993, Burger and
Lynch 1995, Lande and Shannon 1996, Lynch 1996). In addition, general
population genetic theories have been refined to fit the specific
life-histories of Pacific salmon (Waples 1990a, 1990b, Waples and Teel
1990). They have also been extended to examine the effect of increasing
natural population size through artificial production (Ryman and Laikre
1991, Ryman et al. 1995).
Evidence for Genetic Drift-Many years of experimental work have
demonstrated the relationship between population size and loss of genetic
diversity (reviewed by Wright 1977, Rich et al. 1979, Leberg 1992) in many
varieties of laboratory animals.
Support for theory from natural populations is less available, because
fewer opportunities have existed to measure levels of genetic diversity as
population sizes changed. Low levels of genetic diversity have been
measured in animals that have undergone known drastic reductions in
population size. These include elephant seals (Lehman et al. 1993), koalas
(Houlden et al. 1996), prairie chickens (Bouzat et al. 1998a, 1998b), and
chinook salmon transplanted to New Zealand (Quinn et al. 1996). Island
populations of many different taxa, which were presumably founded and
maintained by few individuals, also have lower levels of genetic
variability than mainland counterparts (Frankham 1997, 1998). Where
barrier dams have fragmented the range of steelhead, rainbow trout that
survive above barrier dams have levels of genetic diversity that are lower
than anadromous populations and that are often comparable to small
populations isolated above ancient barriers (Currens, in prep.). Lower
levels of genetic variation in hatchery stocks compared to their
counterparts in the wild (Allendorf and Phelps 1980, Ryman and Stahl 1980,
Vuorinen 1984, Waples et al. 1990) suggest that genetic variation has been
lost under some kinds of artificial propagation. Conditions necessary for
genetic drift exist in many Pacific salmon hatcheries and evidence is
growing that it occurs (Gharrett and Shirley 1985, Simon et al. 1986,
Withler 1988, Waples and Teel 1990). Salmon aquaculture effects nearly all
of the factors that theoretically influence genetic drift and inbreeding.
These include the number and proportion of founders or broodstock taken
from the wild, sex ratios, age-structure, and variation in family size as
measured on adult progeny. Recent increased monitoring of genetic
diversity in many hatcheries will help resolve this question further.
Evidence for Inbreeding and Inbreeding Depression-Considerable
experimental evidence shows that inbreeding can reduce fitness (reviewed
in Wright 1977, Thornhill 1993, Roff 1997, Lynch and Walsh 1998). Tave
(1993) compiled evidence for fish, including trout and salmon, which shows
that that they respond to inbreeding similarly to other organisms.
In natural populations, concerns arise when estimated levels of
inbreeding are comparable to inbreeding that led to depression in
experimental environments. For example, estimates of increased inbreeding
have been associated with reduced fitness in Sonoran and Mexican
poeciliids (Quattro and Vrijenhoek 1989, Vrijenhoek 1996), white-footed
mice (Jimenez et al. 1994), butterflies (Saccheri et al. 1998), and the
evening primrose (Newman and Pilson 1997) in natural environments.
Frankham (1998) estimated levels of inbreeding in 210 island populations
of birds, mammals, insects and plants and observed that based on
inbreeding in laboratory studies these levels of inbreeding could explain
the higher extinction rates on islands.
Evidence for Loss of Fitness from Artificial Propagation-There is
little direct evidence of significant losses of fitness from genetic drift
and inbreeding associated with salmon hatcheries. Theory and observation,
however, indicate that the ability to predict or measure the effects of
fitness using existing tools would be limited. Consequently, such losses,
if they occurred, may not have been detectable. First of all, enzyme or
DNA markers, which have been used most often to measure loss of genetic
variation, are not the best ones to show the effects on fitness (Lynch
1996). No studies of salmon have attempted to document the loss of
multilocus, adaptive genetic variation and its consequences on fitness as
have been done for experimental animals (e.g., Bryant et al. 1986, Bryant
and Meffert 1991). Furthermore, logistical difficulties of maintaining a
powerful, experimental design may prohibit many such studies (Roff 1997).
Second, changes in fitness in small populations may also reflect the
confounding effects of inbreeding depression or accumulation of
deleterious mutations. Leberg (1990), for example, found that mosquito
fish populations founded from small numbers of related founders grew at
much slower rates than control populations. Similar scrutiny has not been
applied to salmon hatcheries. Using evidence from fruit flies, Lynch
(1996) argued that under some kinds of artificial propagation, the
accumulation of deleterious effects and random genetic drift would
interact to reduce fitness even in moderately large populations. This has
not been examined in Pacific salmon.
Ability to Mitigate-Theory suggests that managing brood fish number,
sex ratios, and age structure can control loss of genetic diversity and
inbreeding in hatchery populations (Falconer and Mckay 1996). For
integrated programs, where brood stock are taken from the wild and some
hatchery fish spawn naturally, theory suggests that controlling loss of
genetic diversity may be much more difficult (Ryman and Laikre 1991, Ryman
et al. 1995). Logistically, controlling loss of genetic diversity and
inbreeding in captive hatchery programs or integrated programs will be
difficult. Monitoring the genetic parameters effecting loss of genetic
diversity is also difficult. Few programs have attempted to directly
monitor the effective breeding size of the population (Hedrick et al.
1995). Variation in family size, which theory shows as being critical for
determining the rate at which genetic diversity is lost, cannot be
directly estimated without a pedigree of all the fish in the population.
These are currently unavailable and unlikely to become available in the
future for most populations.
Loss of Genetic Diversity Among Populations
Definition-Loss of among-population genetic diversity is the
reduction in differences in the quantity, variety, and combinations of
alleles among populations. In artificial production situations, it is
caused by unusually high levels gene flow that arise when fish or eggs
from different populations are transferred between hatcheries, when fish
are stocked in non-native waters, or when phenotypic changes in hatchery
fish cause them to stray at greater rates or to different streams than
normal.
Theory-The relationship between gene flow and population
differentiation is another of the cornerstones of evolutionary biology
(reviewed in Slatkin 1985). Mathematical models show that unless gene flow
rates are low, differences among populations will be lost (Haldane 1930,
Wright 1931, 1943; Hanson 1966, Barton 1983). Evolutionary theory predicts
that loss of genetic diversity among populations can decrease the
evolutionary potential of the species. In addition, theory indicates that
extensive interbreeding of genetically differentiated populations (outbreeding)
may lead to more immediate losses of fitness or outbreeding depression (Dobzhansky
1948, Shields 1982, Templeton 1986, Lynch 1991). Documentation of the
genetic mechanisms remains elusive (Lynch and Walsh 1998). At least one
model of outbreeding depression is available for salmon (Emlen 1991). An
important conclusion of basic theory is that some forms of outbreeding
depression will not be predictable. Consequently, the importance of
outbreeding depression may need to be solved empirically (Roff 1997).
Evidence of Loss of Genetic Diversity-Evidence of loss of genetic
diversity among natural populations from gene flow is extensive. It is
especially important in western North America, where extensive hatchery
programs have spread cultured forms of Pacific salmon and trout into
watersheds where they have interbred with local populations (reviewed in
Behnke 1992, Leary et al. 1995, Waples 1995). Loss of genetic diversity
from interbreeding with introduced fish has been inferred for populations
of the same species (Allendorf et al. 1980, Campton and Johnston 1985,
Gyllensten et al. 1985, Reisenbichler and Phelps 1989, Currens et al.
1990, 1997a, Forbes and Allendorf 1991, Reisenbichler et al. 1992,
Williams et al. 1996, 1997; Currens 1997) and different species (Busack
and Gall 1981, Leary et al. 1984, Allendorf and Leary 1988). Lack of
extensive interbreeding in some areas where hatchery fish have been
introduced (Wishard et al. 1984, Currens et al. 1990, Waples 1991, Currens
1997) indicates that loss of genetic variation cannot be predicted simply
from knowledge of hatchery stocking rates or migration.
Evidence for Loss of Fitness-Evidence of outbreeding depression from
populations in natural habitats is available from a variety of organisms,
including marine copepods (Burton 1987, 1990a, 1990b), plants (reviewed in
Waser 1993), Daphnia (Deng and Lynch 1996), and fish (Leberg 1993). Most
concern about outbreeding depression in Pacific salmon is based on
evidence that Pacific salmon are locally adapted (reviewed in Ricker 1972,
Taylor 1991) and theoretical and experimental results from other animals
that demonstrate that interbreeding of different locally adapted
populations could result in outbreeding depression. Limited evidence
suggests that outbreeding depression can occur in Pacific salmon, but
rigorous experiments designed to detect outbreeding depression in Pacific
salmon are missing from the scientific literature. Gharrett and Smoker
(1991) reported that F2 crosses of pink salmon from odd and even-year runs
had lower survivals and greater morphological asymmetry than F1 crosses,
which is consistent with outbreeding depression. Currens et al. (1997)
found that a hybrid swarm of introduced coastal rainbow trout and native
inland rainbow trout had lower levels of resistance to a lethal disease,
ceratomyxosis, than native populations. They attributed that to
interbreeding with introduced coastal rainbow trout, which lacked genetic
resistance to the disease. Ability to Mitigate-Two of the three major
sources of loss of genetic diversity-transfer of fish or eggs from
different populations between hatcheries and stocking fish in non-native
waters can be mitigated by management measures such as developing local
brood stocks or building fish sorting barriers where marked, non-native
returning adults can be removed from a population. Control of straying
that is promoted by hatchery practices is more difficult. Although
increased straying is correlated with a variety of hatchery practices
(Quinn 1993, 1997), modifying these practices may not always be easy or
desirable. For example, transportation of fish to increase post-release
survival may also increase straying (McCabe et al. 1983, Solazzi et al.
1991). Monitoring the potential loss of genetic diversity from straying
can be accomplished with existing genetic techniques. Monitoring potential
outbreeding depression is much more difficult and probably logistically
possible for only a few experimental situations.
Domestication Definition-Domestication is the adaptation of a captive
population to its captive environment. It reflects the changes in
quantity, variety, and combination of alleles within a captive population
or between a captive population and its natural complement. Selection is
the primary genetic mechanism, although it does not occur independently of
genetic drift and mutation. We include both intentional (artificial
selection) and unintentional selection (natural selection in a new
environment) as domestication. Others have limited domestication selection
to unintentional selection (Campton 1995).
Theory-The theoretical and empirical basis for selection is the
foundation of biology (reviewed by Bell 1997). The main principles were
described in the early part of this century (reviewed in Wright 1968,
1977). The fundamental theory predicts that organisms will respond to
selection when they have adequate genetic variation for selection to act
on (measured as heritability) and when there is a selection differential.
For over 60 years, these principles have provided the theoretical basis
for modern plant and animal breeding programs (Lush 1937, Falconer and
Mackay 1996) and our understanding of domestication. Theory has not yet
been refined to answer genetics questions about interbreeding of hatchery
salmon and natural populations
Evidence for Domestication-Even before modern genetics, animal breeders
recognized and promoted domestication. Darwin (1898) considered
domestication inevitable for captive animals. The development of captive
populations for experimental genetics in the early 1900s, however,
provided the first documentation of the genetic mechanisms of how
organisms adapt to captive environments (reviewed in Wright 1977). Concern
about domestication in Pacific salmonids comes from two sources. First,
considerable evidence shows that many behavioral and physiological traits
would respond to selection if selection differentials also existed. Tave
(1993) compiled estimated heritabilities of many traits. A variety of
authors have argued that strong selection differentials exist in novel,
captive environments such as hatcheries (Doyle 1983, Frankham et al. 1986,
Kohane and Parsons 1988). Together these would lead to domestication.
Second, evidence of behavioral and physiological changes in hatchery
populations compared to wild populations is increasing. Few data are
available, however, to examine the fitness effects on a natural population
of interbreeding with hatchery fish that have undergone different levels
of domestication. Early studies of domestication found evidence of
behavioral change in captive brook and brown trout populations (Vincent
1960, Green 1964, Moyle 1969, Bachman 1984). More recently, Petersson et
al. (1996) documented the change in morphology and life history of a
hatchery strain of Atlantic salmon over 23 years. Likewise, Kallio-Nyberg
and Koljonen (1997) found that growth rate and age of maturation in
Atlantic salmon changed over several generations in a hatchery. In Pacific
salmon, Reisenbichler and McIntyre (1977) found that progeny of hatchery
fish only two generations removed from the wild had about 80% survival of
wild, but the opposite pattern was true in the hatchery. Fleming and Gross
(1989, 1992, 1993, 1994) and Fleming et al. (1996) documented changed
behavior and decreased reproductive success of hatchery Atlantic salmon
and coho salmon in artificial spawning channels compared to wild fish.
Swain and Riddell (1990) concluded that greater aggressive behavior of
juvenile hatchery coho salmon than wild fish reared under the same
environment was because of domestication selection. Berejikian (1995),
however, found that hatchery steelhead raised in the same controlled
environment as the wild counterparts were more likely to be eaten by a
native predator. Compared to naturally spawning wild steelhead in the same
stream, Chilcote et al. (1986) and Leider et al. (1990) found that
naturally spawning hatchery steelhead were about 10-30% as successful in
producing surviving smolts and adult progeny as wild fish. The hatchery
stock used in this study, however, was not native to the stream and was of
mixed ancestry. Consequently, the reproductive success of this stock
reflects more than domestication effects.
Ability to Mitigate-Theory indicates that controlling domestication
selection may be very difficult. Busack and Currens (1995) reviewed
domestication and concluded that it is one of the costs of using
hatcheries. The only way to remove domestication selection is to remove
the selection differential. In practical terms this translates to removing
the differences between the hatchery and wild environments. This is
presently unimaginable. Hatcheries are successful because they offer a
better environment in which early survival is greater than in the wild. It
may be possible to reduce selection for key traits if we could identify
the traits, how they were correlated with fitness, and what environmental
conditions led to selection. This knowledge is not currently available.
C. Ecological Effects of Artificial Production
A healthy ecosystem is often equated with conditions that
characterized river basins prior to encroachment of modern civilization.
Ecosystems are dynamic and any point in time is only a snapshot in the
geophysiographic transition in environmental circumstances over time, and
in many cases return to historical conditions is not possible, even if
human influences could be eliminated. Descriptive reconstructions of
historical conditions, however, are invaluable in helping to explain
current observations that are the outcome of past processes (Lichatowich
et al., 1995). Contemporary ecological theory recognizes the importance of
considering not only the biology of organisms, but also the biogeochemical
processes that control the distribution and production of biota, and human
influences on those processes (Stanford et al, in press). Such historical
reconstructions viewed under the guidelines of ecological theory provide
the descriptive fingerprint through which present population structure can
be understood.
In Return to the River (Williams et al., in press), the ISG developed a
conceptual foundation for restoration of Columbia River salmonids, in
which the "normative ecosystem" was defined as a mix of natural
and cultural features that typifies modern society. It was implicit,
however, and consistent with ecological theory, that environmental equity
in the "normative ecosystem" would have to be sufficient to
sustain all life stages of a diverse mixture of healthy wild anadromous
salmonids, concurrent with cultural and economic development of water
resources. ISG stated "Restoration requires detailed understanding of
the interactive, biophysical attributes and processes that control the
survival of salmonids rather than a simple accounting of numbers of fish
at various points and time in the ecosystem". Ecosystem health infers
that whatever changes occur through man-made alterations of the river
system that define the "normative ecosystem", maximum effort is
exerted to maintain existing habitat for the full exploitation of
anadromous salmonids. Restoration, therefore, refers to measures that
enhance the natural production of native salmonids, even to their fullest
diversity possible within the potential of the "normative
ecosystem".
Diversity is inherent to the stability of the species in the larger
context of the river basin. The sub-basin environments, with their
component population networks, are the sanctuaries of variability from
which recolonization and extension take place, and which are referred to
as core populations by Williams et al. (in press). When viewed from the
basin wide perspective, the member populations within the river system
form a aggregation of unique populations, identified by their return
times, return destinations, spawning times, incubation periods, rearing
strategies and migratory behavior (Brannon in press). When these member
populations are taken in combination, they are what is referred to as a
metapopulation within the context of the basin they inhabit (Hanski and
Gilpin 1991). Major basins such as the Columbia River are massive enough
to represent nearly the entire range of the wide spectrum of environmental
extremes tolerated by salmonids. Moreover, the extent to which population
structure is represented, is not simply the extension of common forms to a
wider array of habitat types. Representatives of the composite Basin
populations exist as unique forms of the species in synchrony with the
environmental attributes that have been responsible for the evolution of
the life history strategies they demonstrate. Without that habitat, that
diversity will not survive. Moreover, the strategies they demonstrate
reflect the optimum behavior in the complexity of selective pressures
exerted on them. Proper management, therefore, must include only measures
that are consistent with those life histories, or severe impacts on the
native populations will occur.
Return spawners within a population usually represent less than five
percent of the broodyear potential. That level of mortality already
exemplifies a tenuous balance that swings several percentage points in
either direction in response to environmental variability that occurs
naturally in biological systems. Each of these populations that have
evolved their unique strategy for maximum benefit, has a different level
of fitness based on the restraints each has experienced, and articulate a
different level of tolerance to perturbation based on the phenotype. Major
influences on wild fish can be realized from management scenarios that do
not take into consideration the biological and ecological realities of
wild stocks sympatric with hatchery releases. Relatively small changes can
have major influences if wild stock fitness is already approaching a
maintenance threshold. Moreover, life history strategies, such as
ocean-type and stream-type chinook salmon forms, have evolved around
environmental parameters in which size and number of conspecifics are part
of the selective pressures responsible for the strategy expressed, and the
survival success to the point of adult return.
Ecological effects of artificial production, therefore, are not simply
competitive in scope, but rather can represent major alterations in the
selective environment affecting population structure. For example, there
is a positive relationship between smolt size and survival of hatchery
fish, which has encouraged hatchery managers to release larger smolts to
maximize hatchery returns. The problem is that wild chinook life history
strategies have evolved based on the sizes they have been able to achieve
under the temperature and nutrient limitations of the natural environment.
Potentially negative impacts of such hatchery management scenarios on
survival success of wild fish can be translated in two separate but major
avenues. One is the immediate impact on the ability of wild fish to avoid
competition and predation pressures compounded by the presence of
abundant, larger hatchery fish. The other, and perhaps more serious, is
the long-term selective pressure being exerted on wild fish to accommodate
the "new" compromising force of larger conspecifics in the
ecosystem.
Another potential negative impact is asynchrony in timing of hatchery
and wild fish smoltification. Closely related to the size issue around
hatchery fish survival is management efforts to optimize release times for
hatchery survival benefits. Here again this is in stark conflict with life
history evolution of wild fish. The number and timing of hatchery releases
can disrupt the synchrony that has evolved in life history strategy of
anadromous wild salmonids to minimize losses from predation while
maximizing growth opportunity. Hatchery releases are not insignificant,
and the overwhelming numbers from hatcheries entering the migratory
ecosystem can disrupt the timing patterns that have evolved in the wild
counterpart by altering the selective pressures that have identified the
optimum window of opportunity for migration. The "new" forms are
a force that has not been accommodated in the adaptive evolution of the
species, and the magnitude of hatchery releases at times asynchronous to
wild migration timing has not been given appropriate consideration as a
potential hatchery threat to wild fish success.
Of course the more obvious impact of hatchery management on ecological
status of wild fish is the pre-smolt releases on stream carrying capacity
through competition. Hatchery fish are seldom released in numbers that are
related to the carrying capacity of the receiving stream. Whether as
smolts or pre-smolt juveniles, these fish will compete and, in most cases,
stress the native stock when numbers released approach or exceed the
carrying capacity of the stream. Smolt releases are based on the
assumption that only the transit system is being used, but not all of the
fish released are at the smolt transit stage, and some won't smolt at all.
These residuals and pre-smolt juveniles will compete with their wild
counterparts and lower the wild fish success by changing optimum habitat
utilization of the wild fish. As stressed above, restoration requires
detailed understanding of the interactive, biophysical attributes and
processes that control the survival of salmonids. Management policy has
been negligent in assessing even the competitive impacts of hatchery fish
on wild populations. This is a prime example where historical
reconstruction of population structure and contemporary ecological theory
need to be employed in management planning. This should be done even when
applied evidence is lacking or is unattainable without commitment to years
of applied research. The risk of failure in reaching wild fish production
goals is certain where such wild fish management priorities are not
considered.
The original management goal of maximizing harvest has created other
examples of ecological impacts of artificial production. With reduced
escapement needs to sustain hatchery programs, harvest has been given a
greater share of the return, generally associated with the management
concept of Maximum Sustained Yield (MSY). This has not only impacted
escapements of wild fish in mixed stock fisheries, but it has affected
nutrient recruitment from carcasses that enriched otherwise nutrient
impoverished systems. Carcasses were undoubtedly an important source of
nutrients to freshwater systems that habitually export nutrients
downstream. The dependence on artificial production has exaggerated the
deficit in nutrient transfer caused by management around MSY from that
historically experienced, because of even further limited escapements
required to sustain hatchery production. Consequently, reduction of
carcass contribution to nutrient loads in salmon spawning streams is an
indirect, but significant ecological impact of hatchery management.
D. Populations and Production Trends Over time As
referenced above in the history of the early hatcheries, hatcheries were
started in response to the decline of returns from overfishing. Whether or
not early hatchery production made any contribution, hatcheries were still
viewed as the solution to mitigate for the anticipated loss in harvest
resulting from river development. With successive construction of the dams
beginning in the 1930s (Figure 16), habitat was not only totally
eliminated upstream from the barriers of Chief Joseph/Grand Coulee and
Hells Canyon dams. Spawning and rearing habitat were also altered and lost
below these points from the nearly continuous line of reservoirs that now
represent the portions of the mainstem rivers "accessible" to
anadromous salmonids.
Figure 16. Dams on the Columbia and Snake rivers.
In response to the anticipated reduction in natural production from
loss of habitat, hatchery construction went forward with major facilities
designed to replace the anticipated loss in harvest. Hatchery production
responded with a consistent and growing contribution over the years
(Figure 17). Since 1950, the contribution from hatcheries increased from
38 million to 150 million by 1979, and has remained around 120 million
since that time.
Figure 17. Hatchery contribution to Columbia Basin juvenile salmonid
emigration. (Mahnken et al, 1997: Fish Passage Center)
In the meantime, the results of the increased hatchery production were
equivocal in terms of influencing the returning numbers of adult salmon
and steelhead. Salmonid populations entering the Columbia River have shown
a fluctuating range in escapement from 420,000 to 650,000 fish from counts
over Bonneville Dam (Figure 18). Peak return was in 1987, following a weak
but general trend with increased hatchery production. However, while
hatchery production surged to an increase of over 100% from 1969 to 1980,
returning adults are shown to have simultaneously decreased about 30% over
the same time period.
Figure 18. The trend in returning anadromous salmonid populations counted
over Bonneville Dam on the Columbia River. (SteamNet 1996)
The contrasting trends between artificial production and return over
these years makes it uncertain what portion of the return can be
attributed to hatchery production, and underscores the need to complete
the intensive examination of hatchery performance. The loss of habitat
from dam construction reduced the natural production potential for which
hatcheries were built to overcome. Total return of all anadromous
salmonids, including commercial landing, have shown a relatively level
trend up to the 1990s, and a significant dropping off after that point
(Figure 19), while hatchery production remained the same.
Figure 19. The trend in total return production of returning anadromous
salmonid populations to the Columbia River plus commercial landings.
(SteamNet 1996)
In retrospect, returning numbers of salmon have been maintained over
the years up to the 1990's. The precipitous loss of returning chinook
entering the Snake River (Figure 20) accounts for a major share of the
decline that has occurred in total return to the Columbia.
A serious impact on the recent returns to the Columbia River Basin,
therefore, appears to have been from the construction of the four lower
Snake River dams. Mitigation has not maintained adult returns to the Snake
River at the level that existed prior to the construction of Ice Harbor
dam. However, there has been a high mortality of emigrating juveniles
while making their migratory journeys through the altered mainstem
corridor. The cumulative effects of the successive developments along the
corridor impacted the hatchery fish as well as the wild fish, creating a
more complex problem as developments expanded than what was probably
anticipated. If there is any hope of reaching the mitigation objective of
replacement, the corridor passage in the Snake River will have to be
resolved.
The ascendancy of the ecosystem management in the Columbia has further
complicated the problem on addressing the mitigation responsibilities on
the river. Mitigation with hatchery production was not founded on the
paradigm of ecosystem management, but simply one of replacing fish for
fish in the harvest. Under the new concept, ecosystem health is a priority
of equal importance as mitigation for lost harvest, which means the
original process of satisfying mitigation will have to change. Hatchery
success is no longer viewed soley by the number of adults returning. Part
of the problem in the decline of wild fish production is attributed to the
impact of the very hatchery fish meant to mitigate for harvest reduction
through over harvest of wild fish in mixed stock fisheries. Hatchery fish
can sustain higher harvest rates because of lower escapement needs
(<10%) to supply production requirements. Wild fish, requiring higher
escapements (30% to 60%) for adequate production, suffer the same rate of
exploitation in mixed stock fisheries targeting hatchery fish. The
cumulative effect, uncontrolled, is to drive natural populations down to
eventual extinction. That was not an issue before ecosystem health became
a fisheries management objective, as demonstrated by the willingness to
extirpate runs above Grand Coulee and Hells Canyon dams.
Figure 20. Chinook salmon returns to the Snake River related to the years
when Lower Snake Dams were built.
The ecological impacts of hatchery fish reviewed above is an issue of
equal importance to mixed stock fisheries with regard to the long-term
health of natural populations. Although there is little evidence to
support some of the more theoretical concerns about hatchery fish altering
the fitness of wild populations (Campton 1998), the premise is not
disputed, only the direction and degree to which such effects are
manifest.
E. Management Response to Impacts of Artificial Production
There is no doubt among fisheries managers that there is a crisis of major
proportions confronting anadromous salmon and steelhead runs in the
Pacific Northwest. That crisis is characterized by depleted populations
especially in Oregon, Washington, Idaho and California, massive shrinking
of the salmon's range, collapsed fisheries and large scale protection
under the federal Endangered Species Act, and nowhere in such proportions
as the Columbia River Basin. Hatcheries play a unique role in this
predicament. They have been identified as one of the causes of the current
crisis, while at the same time they are also considered part of the
solution. Many salmon biologists and culturists recognize this dual role
of artificial propagation. They resolve the apparent contradiction by
declaring that the hatchery programs made mistakes in the past, but things
are different now.
At the present time hatcheries consume about 40 percent of the annual
budget for the Council's Fish and Wildlife Program (ISRP 1997). If
artificial propagation is going to consume such a large proportion of the
tens of millions of dollars spent on salmon restoration, it is critical
that there be specific answers to the questions: what problems did the
programs have in the past and specifically how were those problems
resolved? Because of the unique, dual role of hatcheries, we have to be
sure that the past is really past, and that hatchery products are able to
fit in the larger picture of ecosystem function that is being advocated as
the new management paradigm.
Hatchery technology has continuously changed over the past 120 years.
Improvements include: a) Better operational design, b) Increased
nutritional value of feeds, c) Better disease treatments, d) Development
of tagging technology to allow monitor the contribution and survival of
hatchery reared fish, e) Control over hatchery environments such as water
temperature and pathogens has increased, and f) Integration of genetic
principles in fish husbandry practices.
In short, many of the operational problems that plagued hatchery
operations in the past have been resolved. However, the distinction
between intrinsic hatchery operations and management of hatcheries must be
addressed separately. Included in management resolution is the effect of
sustained fisheries on adult salmon of hatchery origin (Campton 1995). It
is the latter, Campton argues, that is the source of most genetic effects
of hatcheries on wild stocks. Moreover, management is the major source of
ecological impact of hatchery fish on wild stocks, and the object of
controversy regarding poor survival of artificially propagated fish. If
the manner in which hatcheries are used is, in fact, contributing to poor
performance of hatchery fish, the negative effects of hatcheries due to
poor management decisions can be resolved by changing the philosophy and
priorities of management (Campton 1995).
To determine if changes in management philosophy and priorities have
corrected the past problems of hatcheries, we have to look beyond the
changes in technology that have occurred over the past century. Changes in
philosophy are directly related to changes in fundamental assumptions that
underlie hatchery and fisheries management. To determine if things really
are different, it is critical to identify the fundamental assumptions that
guided hatchery management in the past and compare them to the assumptions
that guide hatchery management today. That can only be done through a
historical analysis. Culturists who believe that "things are
different now" often see little value in such analyses, with the
result that fishery scientists have produced few analytical studies of
earlier program performance (Smith 1994). Consequently, the specifics that
would clarify past programs and the assumptions that guided them are not
well known. Information is generally good with regard to hatchery
operations. Hatchery population inventory, health status, feeding levels,
condition and outplanting dates are in the archives of daily logs kept by
the agencies. The missing detail is the rationale behind their hatchery
programs. Understandably, the objective was increased production for
harvest, but what motivated the approach undertaken to secure that
objective is primarily anecdotal
Restoration programs that intend to produce a new future for the river
and its salmon must be historically informed, because in a sense the past
is never really past. Programs and their philosophical underpinnings
evolve which means "new " programs carry in them strands of
ideas and assumptions that have their roots in the distant past. We cannot
merely assume that hatchery programs today are detached from their
historical roots without a review of those roots and their influence on
current assumptions that drive the program.
VII. Concluding Recommendations
The Scientific Review Team was formed to review artificial production
in the Columbia River Basin to assist the Council in making recommending
to Congress regarding a set of policies to guide the use of federally
funded hatcheries. Artificial production in this review refers
specifically to the standard production hatcheries of the state, tribal,
and federal agencies charged with the responsibility of augmenting harvest
and mitigating for loss of natural anadromous salmonid production caused
from the economic development of the river.
The committee was made up of seven scientists in the fields of
fisheries management, fish culture, population dynamics, genetics,
ecology, and salmonid life history. The seven members bring with them
backgrounds in fisheries management, artificial production, academia,
Native Americans, and the angling public; providing a balance of interests
typically associated with hatchery production on the Columbia.
The review process includes three parts, each of which will culminate
in a report to the Council; a review of the science associated with
artificial production, the preparation of the database, and the analysis
of hatchery performance, finalizing the recommendations on policy. The
present report is the first phase of the review, the state of the science
on artificial production.
A. Scientific Framework
Hatchery production on the Columbia River started before the turn
of the century for the purpose of augmenting harvest of chinook salmon in
the commercial fishery. By providing optimum incubation conditions in the
protection of a hatchery environment, contribution of fry from single
females increased five-fold over natural productivity. However, this had
little or no impact on overall production in the system. The relative
number of fish spawned was small compared to natural spawners, limiting
the magnitude of hatchery contribution. Moreover the fry they produced
were poorly timed and planted in strange environments showing little
reciprocal augmentation. The effort failed because the limiting factor for
a stream dwelling species such as chinook salmon is not poor egg survival,
but the carrying capacity of the rearing area. When hatcheries switched
from egg incubation to rearing of fingerlings for release, production
suffered from different problems related to health, habitat, and poor
preconditioning for residence in natural streams. Rearing to the smolt
stage appears to have been the most promising, but health and
preconditioning were also factors in their poor success through a
migratory corridor congested with barriers, altered water quality, and
exotic species.
The role of science in this process varied from very little in the
beginning, apart from the development of fish husbandry, to more formal
attention to nutrition, genetics and pathology in recent years. That
attention, however, was again centered primarily in the technology of fish
husbandry, with little coupling of the concerns about hatchery fish
interaction with wild fish, or with the natural (post-release)
environment. With the new paradigm of ecosystem function, and the
development of the ecological framework, science articulated a refreshed
interest in community balance, food chain dynamics, population structure,
and integration of hatchery fish as a functional component of the
ecosystem. Standard hatchery procedures were no longer an accepted
template for addressing augmentation or mitigation needs of the resource,
and much greater emphasis is placed on the new conceptual foundation under
which artificial propagation should proceed.
The architects of the conceptual foundation that guides the use of
hatcheries in the Columbia Basin, however, cannot be oblivious of the fact
that the Columbia and Snake rivers are systems substantially altered from
the historical conditions in which anadromous salmonids evolved. Given
that natural populations were assumed to have been highly fit, changes in
the migratory corridor will have already disrupted the synchronies
critical to survival in the anadromous species. No one doubts the
influences of the developed corridor on the survival success of the
anadromous populations, which has to be taken into consideration assessing
hatchery performance. What isn't recognized, however, and even more
serious than the physically induced mortality, is the disarray those
influences are having on the biological dynamics of fitness. Not only has
the physical habitat markedly changed around flow regimes, velocities, and
water temperatures, but community composition of competing and predating
species has undergone substantial changes also. All of these factors,
apart from any hatchery effect, have major impacts on the reproductive
success of wild runs through their disruptive effects on fitness. Those
processes carry a heavy toll on performance, especially when the effects
of hatchery propagation and barging could retard the adaptive processes
wild fish must undergo in the altered ecosystem. Some differences in
survival success of Columbia Basin wild and hatchery fish compared with
observed success outside the Basin can be attributed to the physical
conditions the migrants must face in the altered mainstem of the river.
Further, some of the survival differences could also be attributed to a
fitness level of hatchery produced fish that is discordant with phenotypic
needs presented by the present system.
B. Recommendations
This is not a commentary establishing the role of artificial
production in Columbia River fisheries management, or recommending the
degree to which hatchery production should contribute in the Basin. That
is the responsibility of the state and tribal fisheries managers. This
report is on the state of the science that relates to artificial
production, and in that regard presents recommendations on the appropriate
measures to take when artificial production is undertaken in the system.
These recommendations, taken with the results of the Phase 2 analysis of
hatchery performance, will constitute substantive contribution in the
development of policy to guide the use of federally funded hatcheries in
the Basin. The recommendations within the scope of Phase 1, the science
around artificial production, is in three parts; in the first SRT derived
recommendations from three recent reviews (ISG, NRC, NFHRP). The second is
based on the SRT's scientific assessment of artificial production. The
third addresses what is considered the necessary research to resolve
problems with both the technology and management of hatchery programs.
(1) Points of General Agreement with Recent Reviews.
The three recent independent reviews of hatcheries collectively
represent a concerted effort to assess hatchery production from the
scientific perspective. There was consensus among the three panels, which
underscores the importance of their contributions in revision of hatchery
policy. The ten general conclusions made by the three panels are listed
below.
- Hatcheries have generally failed to meet their objective.
- Hatcheries have imparted adverse effects on natural populations. q
Managers have failed to evaluate hatchery programs.
- Rationale justifying hatchery production was based on untested
assumptions.
- Supplementation should be linked with habitat improvements.
- Genetic considerations have to be included in hatchery programs. q
More research and experimental approaches are required.
- Stock transfers and introductions of non-native species should be
discontinued.
- Artificial production should have a new role in fisheries
management.
- Hatcheries should be used as temporary refuges, rather than for
long-term production.
The SRT agrees with the first seven of the ten conclusions, and
therefore recommends to the NPPC that those seven elements should be
considered in the development of the hatchery policies.
Recommendation
1. Linking supplementation with habitat improvements, and
monitoring of hatchery programs are required through formal studies and
increased emphasis on hatchery related research.
Justification: It is understood that the goals sought by
hatcheries have changed over the years, and the most recent efforts of
supplementation and captive broodstock production may have succeeded in
their numerical production objectives, as had earlier hatcheries with
regard to juvenile releases. The issue is that the result of that
production on increased return has generally not been demonstrated.
Agencies have evaluated some hatchery procedures, such as the effect of
size and time of release on return success, but there has been a general
lack of effort at the programmatic level. Only recently has natural
production in the Columbia Basin been given priority. Previously, the
approach of concentrating artificial production below the lower Columbia
dams was considered an option for providing the necessary production from
the system, based on general trends in hatchery production returns.
However, if evaluations demonstrating the consistent production benefits
of hatcheries have been undertaken, they have not been published in the
refereed literature, which is needed to provide fair analyses of programs.
Issues around genetics, stock transfers, and limited effort to avoid
overfishing wild stocks mixed with hatchery fish, are symptomatic of the
previous philosophy minimizing natural production. Given the present
emphasis on the ecosystem approach, these issues are now important and are
given priority in the development of the new conceptual foundation for
artificial production.
Of the remaining three conclusions, the SRT concedes that stock
transfers and introductions of non-native species is a practice that can
place serious risk on native stocks of fish and should be discontinued
except in those situations where a stock of fish has gone extinct and
restoration is the objective.
Recommendation
2. Stock transfer should be eliminated from hatchery programs,
except in those situations where the purpose is to restore an extirpated
run.
Justification: Weak native runs have been scheduled for
replacement in the development of hatchery programs, such as the original
plan regarding Sooes River fall chinook salmon. Such action must not be
tolerated. Diversity is the key to the long-range success of salmonid
populations, and adaptive traits should never be willfully abandoned. In
those situations where a stock has been extirpated, managers need to have
the option of introducing non-native fish to establish the nucleus on
which restoration can take place. Even in this situation, however, the
donor stock chosen should not be based simply on egg availability, but
careful analysis is required to assure environmental relationships between
donor and target streams are as compatible as possible for the stock
selected.
Conclusions that artificial production should have a new role in
fisheries management, and hatcheries should be used as temporary refuges,
rather than for long-term production, are considerations that require
assessment or research on the specific issue before such conclusions
should be part of a policy recommendation. The primary role of hatcheries
in the Basin is mitigation for the loss of harvest as a result of
reduction of habitat. Given the extent of habitat loss from economic
development of the Columbia and Snake rivers, and the present encroachment
of man into the riparian and adjacent lands of these river systems, it is
unlikely that natural production in a recovered ecosystem would satisfy
commercial, tribal, and sports harvest interests. The options, therefore,
are (1) to be content with lower production from managed natural
populations, and use hatcheries in a more temporary role for
rehabilitation, or (2) to manage for greater harvest potential from a
combination of natural production and hatcheries mitigating for habitat no
longer accessible. Mitigation hatcheries are a long-term commitment
involving significant cost. Although Columbia Basin hatcheries have not
satisfied their objective of sustaining production thus far, none-the-less
they account for the majority of production in the Basin.
Changing the role of hatcheries is probably not an option, but changing
the manner in which hatcheries address their role is the hope sustaining
the conviction that hatcheries can succeed. Based on the past performance
of hatcheries in the Basin such expectation is bereft of proof, but
abrogation of the concept based only on the past is also imprudent when
hatchery management has made such serious mistakes and the fish still
persist. As Reisenbichler (1998) reasoned after observing fish in the
hatchery environment ".. substantial adaptation to hatchery
conditions (occurs)... and holds promise that modifying hatchery
conditions can reduce deleterious genetic differences between hatchery and
wild fish". The expectation is that with care given to appropriate
changes in the hatchery environment, the response of hatchery fish can be
compatible and complementary to the natural population structure of the
native species. The "normative ecosystem" is an equitable mix of
natural and cultural features with environmental equity to sustain all
life stages of a diverse mixture of healthy wild anadromous salmonids,
concurrent with cultural and economic development of water resources.
Hatcheries can have a mitigation role in the "normative
ecosystem". These may become rehabilitation programs that secure the
endurance of native runs. They may also become perpetual programs to
supply commercial or angling opportunities. The challenge is to redevelop
the concept of a hatchery to assure enhanced production meets both
ecological and economic objectives.
(2) Recommendations from Scientific Analysis It is
imperative that priority be given to the development of a set of
scientific principles that serve as a conceptual foundation for the
Columbia Basin hatchery program. These principles must also be consistent
with the eight elements of the basin-wide ecological framework (NPPC issue
paper 98-6) that is to guide management of the Columbia River as an
ecological system. The eight ecologically based elements are listed below.
- The abundance and productivity of fish and wildlife reflect the
conditions they experience in their ecosystem over the course of their
life cycle.
- Natural ecosystems are dynamic, evolutionary, and resilient.
- Ecosystems are structured hierarchically.
- Ecosystems are defined relative to specific communities of plant and
animal species.
- Biological diversity accommodates environmental variation.
- Ecosystem conditions develop primarily through natural processes.
- Ecological management is adaptive and experimental.
- Human actions can be key factors structuring ecosystems.
The set of scientific principles that relate to artificial production,
and emphasized by the latter two elements listed, are meant to minimize
unintentional human influences on ecosystem structure. These principles
can be divided along technological and managerial lines, differentiating
between how hatchery fish are produced and how hatchery fish are used.
(a) Technological Principles Present technology is
bringing into application measures that improve the quality of fry at the
time of emergence and at readiness of juveniles to enter the migratory
phase. Providing required nutritional needs in a form available in
artificial diets were some of the first advancements in hatchery
technology (Hublou 1963), and nutritional develops have continued (Forster
and Hardy 1995). Some of the items listed in recommendation 3 are already
practiced at some hatcheries. Substrate and darkness during incubation to
maximize energy efficiency for growth are now employed routinely . These
conditions were found to more accurately simulate natural incubation
environments and produce larger fry at emergence than open tray or basket
incubators (Brannon 1965). Other technologies are also being employed, and
their appearance in the list only reaffirms the importance placed on them.
Recommendation
3. Continue using and developing technology to more closely
resemble natural incubation and rearing conditions in hatchery
propagation to include:
a. incubation in substrate and darkness
b. incubation at lower densities
c. rearing at lower densities
d. rearing with shade cover available
e. exposure to in-pond, natural-like habitat
f. rearing in variable, higher velocity habitat
g. non-demand food distribution during rearing
h. exposure to predator training
i. minimize fish-human interaction
j. acclimation ponds at release sites
k. volitional emigration from release sites
Justification: Lower rearing densities, minimum exposure to humans, and
shade cover over raceways enhances fish quality and maintain a behavior
more similar to that of wild fish. Also, volitional migration when the
fish are ready to begin their journey to sea is a technology practiced at
some hatcheries, promoting natural transit behavior and less impact on the
carrying capacity of the receiving stream. These are positive advancements
in hatchery production operations that are applauded and encouraged to
continue. Although accelerated rearing can easily overcome any size
deficiency of the fry experienced at the time of emergence, what isn't
known are the other potential requirements natural incubation conditions
impart to the normal ontogeny from embryo to fingerling.
Recommendation
4. New hatchery facilities need to be incorporated in hatchery
programs that are designed and engineered to represent natural
incubation and rearing habitat, simulating incubation and rearing
experiences complementary with expectations of wild fish in natural
habitat.
Justification: Hatchery technology in the Columbia has been
based primarily on standard tray incubation, concrete raceway design
technology based on engineering designs around efficiency and convenience
for culture operations. Qualities associated with natural habitat have not
been incorporated in such designs, and fish reared in standard concrete
raceways learn behavior (conditioned) conducive to those situations, and
out of harmony with what they will experience when released into natural
conditions. Comparatively poor survival success of hatchery fish is
attributed in part to such experiences atypical of natural conditions.
Technology needs to incorporate new facilities that utilize engineered
earthen stream channels that represent natural habitat with cover, glides
and pools, woody debris, and flow patterns mimicking natural habitat.
Incubation and rearing could take place in the same channel facility, at
densities appropriate to encourage natural feed (supplemented with
formulated diets) and provide learning opportunities under simulated
natural conditions. Training would include exposure to conspecific size
variability and exposure (limited) to predation.
Recommendation
5. New hatchery technology for improving fish quality and
performance needs to have a plan for implementation and review at all
hatchery sites, where appropriate, to assure its application.
Justification: Assuring that technological advances in hatchery
propagation are part of hatchery operational plans is critical to the
implementation of changes meant to improve the quality and performance of
hatchery fish in the natural environment. Often such implementation occurs
only among those hatcheries where a willingness to make changes exists,
given that information on new technology is even transmitted. It is
important that technological advancements are first verified and the
mechanism through which such technology enhances quality or performance is
well understood. Then there needs to be a process for implementing the
technology, with accountability for its installation and review to make it
as routine as feed delivery, assuring its application and evaluation.
(b) Management Principles
Management of all hatcheries should be consistent with the life
history of the cultured stock and the environmental conditions of the
watershed, especially the annual temperature regime of the relevant
section of native habitat represented in the stock of fish propagated.
Life history strategies demonstrate the optimum course of action in the
complexity of selective pressures exerted on them (Brannon in press).
Proper management, therefore, must include only measures that are
consistent with those life histories, or severe impacts on the native
populations are to be expected. Management policy on such conventions as
stock introductions (listed above), size and time of release, magnitude of
release, genetic agenda, and recovery strategies, are of major importance
to the success of hatchery programs. Detail on these issues are in the
following resolutions, but it needs to be understood that in many cases
where scientific principles are advocated, applied evidence is not
available to demonstrate the precept. Theory and the forthcoming
principles to address problems they exemplify are safeguards against
unforeseen events that could destroy the viability of the runs managers
are attempting to conserve. Some theories are troublesome to practitioners
because their experiences do not support the axiom. Concerns about
inbreeding are an example. May populations of salmonids are small and
inbred by the nature of the environment describing their habitat. In fact,
where certain traits are critical to their survival, such as an innate
complex orientation pattern to reach a destination, specificity rather
than diversity defines fitness. This appears contrary to the theory, but
in the broader range of the species, diversity is still the key to species
stability. Measures taken to maintain the diversity present, or to prevent
potentially negative effects of induced inbreeding, even within naturally
inbred lines, are precautions that safeguard against artificially imposing
a deleterious artifact of hatchery production on a population.
The several recommendations pertaining to management principles are listed
below.
Recommendation
6. Genetic and breeding protocols consistent with local stock
structure need to be developed and faithfully adhered to as a mechanism
to minimize potential negative hatchery effects on wild populations and
to maximize the positive benefits that hatcheries can contribute to the
recovery and maintenance of salmonids in the Columbia ecosystem.
Justification: As an integral component in a complex ecological
system, salmonid stocks have evolved in synchrony with their environments.
Spawning time, emergence timing, juvenile distribution, marine orientation
and distribution are not random, but rather occur in specific patterns of
time and space for each population (Brannon 1984), and include behavior
that evolved under historical abundance constraints in natural
populations. The appropriate seed stock is key to producing viable,
healthy fish for the respective system. Given the ecosystem concept for
management protocol in the Columbia Basin, population genetics and the
natural environment salmonid stocks have evolved under have to become
blueprints in hatchery programming. Differences between the genetics of
wild stocks and hatchery fish (Ryman and St?l 1980; Allendorf and Utter
1979) are considered by the SRT as a major source of poor hatchery fish
performance in the wild. Development and adherence to strict genetic
guidelines and breeding protocols consistent with local population
structure is essential for effective hatchery contribution to wild
production and maintenance of local genetic diversity.
Recommendation
7. Hatchery propagation should use large breeding populations
to minimize inbreeding effects and maintain what genetic diversity is
present within the population.
Justification: One of the potential negative effects of
artificial production is that relatively small breeding populations are
involved in hatchery programs. Even when a hundred thousand fingerlings
are scheduled for supplementation, that number represents a little over 25
females for broodstock, and a relatively limited representation of the
gene pool. In the Idaho captive rearing project where juveniles are
intercepted and reared to maturity as a means to avoid demographic risks
of cohort extinction, only enough parr are captured to provide 20 spawners
for each population, which is even a smaller representation of the gene
pool. The risk in using small breeding populations is loss of diversity,
and also magnifying the effect of deleterious genes. Hatchery survival can
increase the contribution of the artificially propagated fish out of
proportion with number, with the result that over time the hatchery
population will become increasingly more represented among the natural
spawners. The issue is not just inbreeding because many healthy natural
populations are very site specific in unique environments and represent
inbred lines. The risk is that hatchery production can accelerate the
potential harmful effects of inbreeding by involving only a small portion
of the returning adults in the artificial breeding population. To avoid
these negative effects of hatchery production, a large number of spawners
should be included in the breeding protocol. When the run is relatively
small, this may require live spawning, and removing only a portion of the
eggs from each female, and subsequently releasing the fish to continue
spawning naturally.
Recommendation
8. To mimic natural populations, hatchery production strategy
should target natural population parameters in size and timing among
emigrating juveniles to synchronize with environmental selective forces
shaping natural population structure.
Justification: Hatchery programs have tended to concentrate on
large size fish at the time of release, as well as varying the timing of
release, to facilitate higher return success. Although such rationale is
understandable from the standpoint of improving hatchery fish survival,
such practices introduce atypical migrants that create an alteration in
the natural continuity of events around which population strategies have
evolved. With the exception of fall chinook that normally show variation
in migratory distribution patterns, such practices with other anadromous
salmonids are believed to have negative effects on fitness of wild fish,
and may perturb population structure to the disadvantage of natural
populations. Based on interpretations of population structure and life
history patterns (Brannon, in press), avoiding atypical size and time at
migration among hatchery fish is desirable, even with the immediate
disadvantage it may have on hatchery return success. The point is that
hatcheries should focus on mimicking the natural environmental selective
forces within the target watershed so hatchery-produced emigrating
juveniles exhibit the same size distributions as juveniles from the
natural population.
Recommendation
9. Hatchery policy should utilize ambient natal stream habitat
temperatures to reinforce genetic compatibility with local environments
and provide the temporal synchrony between stock and habitat that is
responsible for population structure of stocks from which hatchery fish
are generated.
Justification: Temperature unequivocally is argued as the factor
determining adult salmonid return timing and spawning (Brannon, 1987), and
is an important factor affecting the length of time juveniles spend in
stream residence before migrating to sea. This fundamental influence has
formed the framework around the evolution of salmonid population
structure. Temperature demonstrates its pivotal effect on the evolution of
life history forms through temporal influences on egg incubation and
juvenile growth as the basis for differentiation of adult timing and
juvenile residence behavior, respectively. It is argued, therefore, that
temperature is the most critical environmental factor affecting life
history forms peculiar to their respective stream system. Temperature is
the environmental parameter motivating the evolution of stock
predispositions selectively reinforced over time to represent genetically
distinct units. Temperature regimes during early life history are
typically altered from the natural pattern by hatchery use of ground water
for incubation. Hatchery management policy should adhere to using the
ambient temperature regime of their natal environments to maintain the
compatibility of hatchery fish with the natural system and the
effectiveness of hatchery contribution to the natural spawning population.
In some cases, wild fish spawn on spring fed reaches of streams and the
appropriate incubation temperatures in those situations would be
incubation substrate temperatures. However, when it comes to the rearing
phase where the growth rate is determined by temperature (Brett et al,
1969), it is the daily ambient mean temperature that is important to
follow.
Recommendation
10. Hatchery incubation and rearing experiences should use the
natal stream water source whenever possible, to enhance homestream
recognition when supplementation projects are designed for natural
populations.
Justification: Another factor associated with the natal habitat
and homing accuracy is the homestream odor profile that provides the
fingerprint ultimately identified with the homestream spawning and
incubation site. Hatchery programs not only use ground water for
incubation, but hatcheries are usually away from the natal environment to
which local stocks have adapted. The assumption is that by planting the
fish in the proper location, hatchery fish will home to that stream on
return. While this is true, imprinting is sequential (Brannon and Quinn
1990; Quinn et al. 1990), and the incubation environment is the first odor
cue on which alevins imprint and the ultimate identity sought by returning
fish (Brannon 1982). Strays are common in some hatchery populations and
lack of having imprinted during the incubation phase is suggested as being
responsible for higher stray rates. To assure the continuity between
hatchery fish genetics and local stream habitat, the water sources closely
linked with the natal environment are most desirable. This recommendation
is most difficult to incorporate with present hatcheries because the
capital structure and water system have been established without those
priorities. New facilities, however, should be located on sites where
access to appropriate water sources is available.
Recommendation
11. Hatchery release strategies need to follow standards that
accommodate reasonable numerical limits determined by the carrying
capacity of the receiving stream to accommodate residence needs of
non-migrating members of the release population. Standards should
include impact considerations on the wild fish residing in the system,
and should be based on life history requirements of the cultured stock.
Justification: Hatchery releases of cultured fish into receiving
streams occur under the assumption that the river is used primarily as a
migratory conduit to the estuary. This is true for only those fish
(smolts) at emigration readiness. Fish not ready to migrate will take up
transitional residence in the stream, causing the potential negative
interactions with wild fish present. Care should be taken to limit release
numbers consistent with the estimated rearing capacity of the system to
minimize impacts on wild fish. Moreover, the practice of releasing fish to
make space for other broods should be discontinued. Release of hatchery
fish must fit a schedule consistent with life history requirements of
natural population from which the brood lot was derived.
Recommendation
12. New hatchery programs should dedicate significant effort in
developing small facilitates designed for specific stream sites where
supplementation and enhancement objectives are sought, using local
stocks and ambient water in the facilities designed around engineered
habitat to simulate the natural stream, whenever possible.
Justification: Hatcheries are most often developed around the
concept of a central facility from which fish are outplanted to many other
streams or acclimation ponds, not always using native stocks in each
instance. The rationale is usually related to the major capital
expenditures for hatcheries under the old hatchery concept. It is much
more desirable to locate smaller, stream specific operations to maintain
stock identity with the particular stream targeted. Nothing larger than a
station capacity of 100,000 eggs or 25,000 fingerlings would be required
on smaller tributary systems. This would require no more than a rearing
channel to accommodate such small inventories, but small numbers in
natural-like habitat is the ideal for supplementation of native salmonids.
Even fry releases can be a feasible option to consider under these
circumstances associated with the natural habitat, when conditions for
supplementation can call for such limited, and perhaps temporary,
artificial application. Again, this recommendation is impossible with
present facilities located where they are and with capital commitments in
water and concrete. However, with new artificial production facilities,
part-time stations of this nature would address both the biological and
ecological requirements that future operations must satisfy.
Recommendation
13. Hatchery supplementation programs must avoid using strays
in breeding operations with returning fish. Stock hybridization breaks
down genetic homeostasis and disrupts adaptive linkages which lowers the
fitness of the local stock and defeats the objective.
Justification: In situations where strays constitute a
substantial proportion of hatchery return populations, care should be
taken to avoid inter-stock hybridization because of the loss of adaptive
traits in the resulting progeny. Reisenbichler (1998) demonstrated
examples of reduced fitness from hybridization. Stock hybridization breaks
down genetic homeostasis and disrupts co-adaptive gene complexes, which
lowers the fitness of the local stock. A policy needs to be developed to
minimize the contribution of strays to the local hatchery stock. In the
situation where a hatchery is supplementing a native population,
inter-stock hybridization should be avoided to prevent loss of adaptive
fitness.
Recommendation
14. Restoration of extirpated populations should follow genetic
guidelines to maximize the potential for re-establishing self-sustaining
populations. Once initiated, subsequent effort must concentrate on
allowing selection to work, by discontinuing introductions.
Justification: When undertaking restoration projects where
populations have been extirpated, restoration strategies need to be given
careful consideration and reference to genetic guidelines. Where
neighboring populations represent appropriate characteristics, stock
transfer may be the best strategy. When suitable stocks are not available,
or when information is insufficient with which to match a donor stock,
then inter-stock hybridization may be an alternative. Inter-stock
hybridization breaks down co-adapted gene complexes and releases genetic
variability on which selection can re-work to establish specificity with
the environmental conditions. Restoration can use different genetic-based
approaches, depending on the situation, but the characteristics of the
donor stock(s) are critical. The key is to follow through with the
strategy selected and allow sufficient time for the founders to be
selectively established by avoiding continued introductions in the target
stream.
Recommendation
15. Germ plasm repositories be developed to preserve genetic
diversity for application in future recovery and restoration projects in
the Basin, and to maintain a gene bank to reinforce diversity among
small inbred natural populations.
Justification: One of the most important considerations in the
Columbia Basin fisheries management plan is to preserve the genetic
diversity that presently exists. Diversity is inherent to the stability of
the species and the various systems, with their component population
networks, are the sanctuaries of variability. Recovery and enhancement of
natural production in the Basin will not be a rapid process, and in the
meantime further loss of diversity may occur, with some populations
becoming extinct. It is critical, therefore, to launch an immediate
program to preserve germ plasm by collecting and cryopreserving milt from
all naturally spawning populations that can be reached. The technology is
available and presently being employed with some ESA listed salmonid
stocks. This effort needs to be expanded, and given greater priority. Germ
plasm should be collected from each population on more than one broodyear
to develop as complete a repository as possible. The availability of germ
plasm for future use in maintenance of diversity or restoration of
extirpated runs will be invaluable in the long-term ecological framework
of the managed river.
Recommendation
16. The physical and genetic status of all natural populations
of anadromous and resident salmonids need to be understood and routinely
reviewed as the basis of management planning for artificial production.
Information should include life history, population structure, and the
habitat utilized.
Justification: Knowing the status of the endemic stock where
hatchery fish are involved is imperative under the ecological framework of
fisheries management. This knowledge must include, in addition to the
traditional numerical status of the run, details on its population
structure, distribution patterns, size and timing of migration, and the
level of genetic specificity and diversity within the population. The
habitat status associated with the population must also be known,
including the area available, the condition of the habitat, new areas that
can be developed, and the carrying capacity. This information is essential
to the management of all native anadromous and resident species in the
Basin, which will require ecological expertise at the programmatic and
hatchery levels.
(3) Recommendations on Research and Monitoring
Good management is the key to successful integration of hatcheries
into a functioning and dynamic ecosystem. Research to improve artificial
production, the extent of its application, and its limitations, is basic
to the effective management of hatcheries in the Basin. In this regard,
monitoring is also a critical element in the management process. Knowing
what is successful and what must change is impossible without appropriate
monitoring programs. The following recommendations address the research
and monitoring needs associated with management under the ecological
framework.
Recommendation
17. An in-hatchery fish monitoring program needs to be
developed on performance of juveniles under culture, including genetic
assessment to ascertain if breeding protocol is maintaining wild stock
genotypic characteristics.
Justification: The NPPC needs to design a scientifically valid
monitoring program for the basin hatcheries. Special attention should be
paid to the collection of valid data that applies to routine assessment of
juvenile performance in the hatchery incubation and rearing phase, up to
the point of release. Genetic monitoring of the stock inventory would
include descriptive evaluation at first feeding and at release time to
assess if hatchery propagation is altering genotypes from that of the wild
population.
Recommendation
18. A hatchery fish monitoring program needs to be developed on
performance from release to return, including information on survival
success, interception distribution, behavior, and genotypic changes
experienced from selection between release and return.
Justification: The NPPC needs to design a scientifically valid
monitoring program for hatchery fish performance after release from the
culture facilities. In addition to return success, attention should be
paid to relative interception distribution (tag analysis) of hatchery fish
to compare performance parameters with native fish. Special attention
should also be given to descriptive genetic assessment at time of return
to determine if genotypes surviving are representative of genotypes
released, and compatible with the native stock. With the advent of the PIT
tag system, opportunities to gather more specific information exists.
Significant insights can be gained on straying, migratory route, and
timing that is key to honing hatchery programs.
Recommendation
19. A study is required to determine cost of monitoring
hatchery performance, and source of funding.
Justification: A study should be undertaken to consider how much
monitoring programs will cost and what reallocation of effort in the
production programs would be required to fund adequate monitoring efforts
where additional funds cannot be secured.
Recommendation
20. Regular performance audits of artificial production
objectives should be undertaken, and where they are not successful,
research should be initiated to resolve the problem.
Justification: Routine audits of hatchery production objectives
should be established (for example, every five years) to determine if they
are achieving their objectives. In those cases where programs or
hatcheries are not showing any production benefit, they should be
re-prioritized to research only, until the problems can be resolved. In
some cases research may disclose that the objectives are not attainable.
In those situations, emphasis can then be redirected, programs changed, or
discontinued.
Recommendation
21. The NPPC should appoint an independent peer review panel,
to develop a Basin-wide artificial production program plan to meet the
ecological framework goals for hatchery management.
Justification: With the development of the broad ecological
framework in the Basin placing emphasis on hatchery management in the
arena of conservation fisheries and ecosystem function, it will be
necessary for practitioners and fisheries scientists to work together in
developing the appropriate hatchery program plans to achieve the ecosystem
goal. Problems that have prevented hatcheries from achieving their goals,
or insights on what may be impossible to achieve in the ecosystem approach
at the hatchery level, cannot be ascertained without major contribution
from hatchery managers experienced in the system. Also, the inherent
conflict between the concept of ecosystem management and the concept of
management for harvest mitigation has to be resolved within the ecosystem
framework. Those resolutions, and the development of the hatchery program
plan addressing specific actions needed to achieve the goal, is an
essential element early in the planning process. The responsibility will
require an appointment of an independent peer review panel that through
solicitation of agency, tribal, public interests, can give careful and
appropriate consideration to the experience represented in the management
community.
The SRT has identified the minimum scientific basis in the conceptual
foundation on artificial production in the Columbia River Basin. With
review of the hatchery program and production data, more hatchery specific
assessment will be provided as a broader treatment of artificial
production for hatchery policy recommendations to the Council.
LITERATURE CITED
Allendorf, F. W., and R. F. Leary. 1988. Conservation and distribution
of genetic variation in a polytypic species, the cutthroat trout.
Conservation Biology 2:170-184.
Allendorf, F. W., and R. S. Waples. 1996. Conservation and genetics of
salmonid fishes. Pages 238-280 in J. C. Avise and J. L. Hamrick, editors.
Conservation genetics: case histories from nature. Chapman and Hall, New
York.
Allendorf, F. W., and S. R. Phelps. 1980. Loss of genetic variation in
a hatchery stock of cutthroat trout. Transactions of the American
Fisheries Society 109:537-543.
Allendorf, F. W., D. M. Espeland, D. T. Scow, and S. Phelps. 1980.
Coexistence of native and introduced rainbow trout in the Kootenai River
drainage. Proceedings of the Montana Academy of Sciences 39:28-36.
Allendorf, F. W., and F. M. Utter. 1979. Population genetics. Pages
407-454 in W. F. Hoar and D. J. Randall, editors. Fish Physiology, volume
8. Academic Press, NY.
Anderson, D. A., G. Cristofferson, R. Beamesdefer, B. Woodard, M. Rowe,
and J. Hanson. 1996. StreamNet the Northwest aquatic resource information
network: Report on the status of salmon and steelhead in the Columbia
River basin - 1995. Pacific States Marine Fisheries Commission, Oregon
Department of Fish and Wildlife, Washington Department of Wildlife,
Shoshone-Bannock Tribes, and Idaho Department of Fish and Game for
Northwest Power Planning Council and U.S. Department of Energy, Bonneville
Power Administration. Project number 88-108-04.
Appleby, A., and K. Keown. 1995. History of White River spring chinook
broodstocking and captive broodstock rearing efforts. Pages 6.1-6.32 in T.
A. Flagg and C. V. W. Mahnken, editors. An assessment of the status of
captive broodstock technology for Pacific salmon. Bonneville Power
Administration Report DOE/BP-55064-1.
Bachman, R. A. 1984. Foraging behavior of free-ranging wild and
hatchery brown trout in a stream. Transactions of the American Fisheries
Society 113:1-32.
Baird, S. 1875. Salmon fisheries of Oregon. Oregonian, March 3, 1875,
Portland, Oregon.
Barton, N. H. 1983. Multilocus clines. Evolution 37:454-471.
Behnke, R. J. 1992. Native trout of western North America. American
Fisheries Society Monograph 6.
Beiningen, K. T. 1976. Fish runs. Section E. in Investigative Reports
of Columbia River Fisheries Project. Pacific Northwest Regional
Commission, Vancouver, Washington.
Berejikian, B. A. 1995. The effects of hatchery and wild ancestry and
experience on the relative ability of steelhead trout fry (Oncorhynchus
mykiss) to avoid a benthic predator. Canadian Journal of Fisheries and
Aquatic Sciences 52:2476-2482.
Bottom, D. L. 1997. To till the water: A history of ideas in fisheries
conservation. Pages 569-597 in D. J. Stouder, P. A. Bisson and R. J.
Naiman, editors. Pacific salmon and their ecosystem: status and future
options, Chapman and Hall, New York, New York.
Bouzat, J. L., H. A. Lewin, and K. N. Paige. 1998a. The ghost of
genetic diversity past: historical DNA analysis of the greater prairie
chicken. American Naturalist 152:1-6.
Bouzat, J. L., H. H. Cheng, H. A. Lewin, R. L. Westemeier, J. D. Brown,
and K. N. Paige. 1998b. Genetic evaluation of a demographic bottleneck in
the greater prairie chicken. Conservation Biology 12:836-843.
Brannon, E. L. 1965. The influence of physical factors on the
development and weight of sockeye salmon embryos and alevins.
International Pacific Salmon Fisheries Commission. Progress Report 12. 26
p.
Brannon, E. L. 1972. Mechanisms controlling migration of sockeye salmon
fry. International Pacific Salmon Fisheries Commission. Bulletin XXI. 86
p.
Brannon, E. L. 1982. Orientation mechanisms of homing salmonids. Pages
219-227 in E. L. Brannon and E. O. Salo, editors. Proceedings of salmon
and trout migratory behavior symposium School of Fisheries, University of
Washington, Seattle, Washington.
Brannon, E. L. 1984. Influence of stock origin on salmon migratory
behavior. Pages 103-112 in, J. D. McCleave, G. P. Arnold, J. J. Dodson,
and W. H. Neill, editors. Mechanisms of Migration in Fishes. Plenum Press,
New York.
Brannon, E. L. 1987. Mechanisms stabilizing salmonid fry emergence
timing. Pages 120-124 in H. D. Smith, L. Margolis, and C. C. Wood,
editors. Sockeye salmon (Oncorhynchus nerka) populations biology and
future management. Canadian Special Publication of Fisheries Aquatic
Sciences 96.
Brannon, E. L., and T. P. Quinn. 1990. Field test of the pheromone
hypothesis for homing by Pacific salmon. Journal of Chemical Ecology
16(2):603-609.
Brett, J. R., J. E. Shelborn, and C. T. Shoop. 1969. Growth rate and
body composition of fingerling sockeye salmon, Oncorhynchus nerka, in
relation to temperature and ration size. Journal of Fisheries Research
Board of Canada 26:2363-2394.
Brown, L. G. 1995. Mid-Columbia River summer steelhead stock
assessment: a summary of the Priest Rapids steelhead sampling project
1986-1994 cycles. Washington Department of Fish and Wildlife Progress
Report No. AF95-02.
Bryant, E. H., and L. M. Meffert. 1991. The effects of bottlenecks on
genetic variation, fitness, and quantitative traits in the housefly. Pages
591-601 in E. C. Dudley, editor. The unity of evolutionary biology, volume
2. Dioscorides Press, Portland, Oregon.
Bryant, E. H., S. A. McCommas, and L. M. Combs. 1986. The effect of an
experimental bottleneck upon quantitative genetic variation in the
housefly. Genetics 114:1191-1211.
Bugert, R. M., C. W. Hopley, C. A. Busack, and G. W. Mendel. 1995.
Pages 267-276 in H. L. Schramm, Jr., and R. G. Piper, editors. Uses and
effects of cultured fishes in aquatic ecosystems. American Fisheries
Society, Bethesda, Maryland.
Burger, R., and M. Lynch. 1995. Evolution and extinction in changing
environment: a quantitative genetic analysis. Evolution 49:151-163.
Burton, R. S. 1987. Differentiation and integration of the genome in
populations of Tigriopus californicus. Evolution 41:504-513.
Burton, R. S. 1990a. Hybrid breakdown in physiological response: a
mechanistic approach. Evolution 44:1806-1813.
Burton, R. S. 1990b. Hybrid breakdown in developmental time in copepod
Tigriopus californicus. Evolution 44:1814-1822.
Busack, C. A., and G. A. E. Gall. 1981. Introgressive hybridization in
populations of Paiute cutthroat trout (Salmo clarki seleniris). Canadian
Journal of Fisheries and Aquatic Sciences 38:939-951.
Busack, C. A., and K. P. Currens. 1995. Genetic risks and hazards in
hatchery operations: fundamental concepts and issues. Pages 71-80 in H. L.
Schramm, Jr. and R. G. Piper, editors. Uses and effects of cultured fishes
in aquatic ecosystems. American Fisheries Society, Bethesda, Maryland.
Caballero, A. 1994. Developments in the prediction of effective
population size. Heredity 73:657-679.
Calkins, R. , W. Durand, and W. Rich. 1939. Report of the board of
consultants on the fish problems of the upper Columbia River. Stanford
University. Stanford, California.
Campton, D. E. 1995. Genetic effects of hatchery fish on wild
populations of Pacific salmon and steelhead: what do we really know? Pages
337-353 in H. L. Schramm, Jr. and R. G. Piper, editors. Uses and effects
of cultured fishes in aquatic ecosystems. American Fisheries Society 15,
Bethesda, Maryland.
Campton, D.E. 1998. Genetic effects of hatcheries on wild populations
of Pacific salmon and steelhead: Overview of fact and speculation. Pages
1-18 in E. Brannon and W. Kinsel, editors. Proceedings of Columbia River
anadromous rehabilitation and passage symposium. Aquaculture Research
Institute, University of Idaho, Moscow, Idaho and Mechanical Engineering,
Washington State University, Richland Washington.
Campton, D. E., and J. M. Johnston. 1985. Electrophoretic evidence for
a genetic admixture of native and nonnative rainbow trout in the Yakima
River, Washington. Transactions of the American Fisheries Society
114:782-793.
Carmichael, R. W., and R. T. Messmer. 1995. Status of supplementing
chinook salmon natural production in the Imnaha River Basin. Pages 284-291
in H. L. Schramm, Jr., and R. G. Piper, editors. Uses and effects of
cultured fishes in aquatic ecosystems. American Fisheries Society,
Bethesda, Maryland.
Chilcote, M. W., S. A. Leider, and J. J. Loch. 1986. Differential
reproductive success of hatchery and wild summer-run steelhead under
natural conditions. Transactions of the American Fisheries Society
115:726-735.
Cobb, J. N. 1930. Pacific salmon fisheries. Bureau of Fisheries
Document, number 1092. Washington, DC.
Columbia Basin Fish and Wildlife Authority (CBFWA). 1990. Review of the
history, development, and management of anadromous fish production
facilities in the Columbia River Basin. Columbia Basin Fish and Wildlife
Authority, Portland, Oregon.
Craig, J. A., and R. L. Hacker. 1940. The history and development of
the fisheries of the Columbia River. Bulletin of the Bureau of Fisheries,
number 32, Washington, DC.
Cross, T.S., and J. King. 1983. Genetic effects of hatchery rearing in
Atlantic salmon. Aquaculture 33:33-40.
Crow, J., and M. Kimura. 1970. An introduction to population genetics
theory. Harper and Row, New York, New York.
Currens, K. P. 1997. Evolution and risk in conservation of Pacific
salmon. Ph.D. dissertation. Oregon State University, Corvallis, Oregon.
Currens, K. P., and C. A. Busack. 1995. A framework for assessing
genetic vulnerability. Fisheries 20(12):24-31.
Currens, K. P., A. R. Hemmingsen, R. A. French, D. V. Buchanan, C. B.
Schreck, and H. W. Li. 1997. Introgression and susceptibility to disease
in a wild population of rainbow trout. North American Journal of Fisheries
Management 17:1065-1078.
Currens, K. P., C. B. Schreck, and H. W. Li. 1990. Allozyme and
morphological divergence of rainbow trout (Oncorhynchus mykiss) above and
below waterfalls in the Deschutes River, Oregon. Copeia 1990:730-746.
Darwin, C. 1898. The variation of animals and plants under
domestication, volume 2. Appleton, New York, New York.
Dehart, D. A. 1997. Comments on return to the river. Oregon Department
of Fish and Wildlife, Portland, Oregon. Delarm, M. R., E. Wold, and R. Z.
Smith. 1987. Columbia river fisheries development program annual report
for FY 1986. NOAA Technical Memorandum NMFS F/NWR - 21, Seattle,
Washington. Deng, H. -W., and M. Lynch. 1996. Change of genetic
architecture in response to sex. Genetics 143:203-212.
Dobzhansky, T. 1948. Genetics of natural populations. XVIII.
Experiments on chromosomes of Drosophila pseudoobscura from different
geographical regions. Genetics 33:588-602.
Doyle, R. W. 1983. An approach to the quantitative analysis of
domestication in aquaculture. Aquaculture 33:167-185.
Dyson, F. 1997. Imagined worlds. Harvard University Press, Cambridge,
Massachusetts.
Emlen, J. M. 1991. Heterosis and outbreeding depression: a multilocus
model and an application to salmon production. Fisheries Research
12:187-212.
Falconer, D. S., and T. F. C. Mackay. 1996. Introduction to
quantitative genetics. 4th edition. Longman, Harlow, United Kingdom.
Fish, F. F., and M. G. Hanavan. 1948. A Report upon the Grand Coulee
fish-maintenance project 1939-1947. U. S. Fish and Wildlife Service,
Washington, DC.
Flagg, T. A., C. V. W. Mahnken, and K. A. Johnson. 1995b. Captive
broodstocks for recovery of Snake River sockeye salmon. Pages 81-90 in H.
L Schramm, Jr. and R. G. Piper, editors. Uses and effects of cultured
fishes in aquatic ecosystems. American Fisheries Society Symposium 15,
Bethesda, Maryland
Flagg, T. A., F. W. Waknitz, D. J. Maynard, G. B. Milner, and C. V. W.
Mahken. 1995a. The effect of hatcheries on native coho salmon populations
in the lower Columbia River. Pages 366-375 in H. L. Schramm, Jr., and R.
G. Piper. Uses and effects of cultured fishes in aquatic ecosystems.
American Fisheries Society Symposium 15, Bethesda, Maryland.
Fleming, I. A., and M. R. Gross. 1989. Evolution of adult female life
history and morphology in a Pacific salmon coho (Oncorhynchus kisutch).
Evolution 43:141-157.
Fleming, I. A., and M. R. Gross. 1992. Reproductive behavior of
hatchery and wild coho salmon (Oncorhynchus kisutch)- does it differ?
Aquaculture 103:101-121.
Fleming, I. A., and M. R. Gross. 1993. Breeding success of hatchery and
wild coho salmon (Oncorhynchus kisutch) in competition. Ecological
Applications 3:230-245.
Fleming, I. A., and M .R. Gross. 1994. Breeding competition in a
Pacific salmon (coho: Oncorhynchus kisutch): measures of natural and
sexual selection. Evolution 48:637-657.
Fleming, I. A., B. Jonsson, M. R. Gross, and A. Lamberg. 1996. An
experimental study of the reproductive behavior and success of farmed and
wild Atlantic salmon. Journal of Applied Ecology 33:893-905.
Forster, I.P., and R.W. Hardy. 1995. Captive salmon broodstock
nutrition literature in review. Pages 4-1 to 4-38 in T.A. Flagg and C.V.
Mahnken, editors. An assessment of the status of captive broodstock
technology for Pacific salmon. Final report, U.S. Department of Energy,
Bonneville Power Administration, Environment, Fish and Wildlife, Portland,
Oregon. Project 93-56.
Forbes, S. H., and F. W. Allendorf. 1991. Associations between
mitochondrial and nuclear genotypes in cutthroat trout hybrid swarms.
Evolution 45:1332-1349.
Frankham, R. 1997. Do island populations have lower genetic variation
than mainland populations? Heredity 78:311-327.
Frankham, R. 1998. Inbreeding and extinction: island populations.
Conservation Biology 12:665-675.
Frankham, R., H. Hemmer, O. A. Ryder, E. G. Cothran, M. E. Soule, N. D.
Murrray, and M. Snyder. 1986. Selection in captive populations. Zoo
Biology 5:127-138
Fuss, H.J. 1998. Hatcheries are a tool: They are as food or as bad as
the management goals that guide them. Pages 19-28 in E. Brannon and W.
Kinsel, editors. Proceedings of Columbia River anadromous rehabilitation
and passage symposium. Aquaculture Research Institute, University of
Idaho, Moscow, ID and Mechanical Engineering, Washington State University,
Richland, Washington.
Gharrett, A. J., and S. M. Shirley. 1985. A genetic examination of
spawning methodology in a salmon hatchery. Aquaculture 47:245-256.
Gharrett, A. J., and W. W. Smoker. 1991. Two generations of hybrids
between even- and odd-year pink salmon (Oncorhynchus gorbuscha): a test
for outbreeding depression? Canadian Journal of Fisheries and Aquatic
Sciences 48:1744-1749.
Gilbert, C. H. 1913. Age at maturity of the Pacific coast salmon of the
genus Oncorhynchus. (1910-1914). Bulletin of the Bureau of Fisheries,
volume 32, Washington, DC.
Gilpin, M. E. 1987. Spatial structure and population vulnerability.
Pages 87-124 in M. E. Soule, editor. Viable populations for conservation.
Cambridge University Press, New York, New York.
Goodnight, C. J. 1987. On the effect of founder events on epistatic
genetic variance. Evolution 41:80-91.
Goodnight, C. J. 1988. Epistasis and the effect of founder events on
the additive genetic variance. Evolution 42:441-454.
Green, D. M., Jr. 1964. A comparison of stamina of brook trout from
wild and domestic parents. Transactions of the American Fisheries Society
93:96-100.
Gyllensten, U., R. F. Leary, F. W. Allendorf, and A. C. Wilson. 1985.
Introgression between two cutthroat trout subspecies with substantial
karyotypic, nuclear, and mitochondrial genomic divergence. Genetics
111:905-915.
Hagger, R.C., and R.E. Noble. 1976. Relation of size at time of release
study. Columbia River study analysis and documentation completion report.
Salmon Culture Division. Washington Department of Fisheries, Olympia,
Washington
Harden, J. B. S. 1930. A mathematical theory of natural and artificial
selection. Part 4. Isolation. Proceedings of the Cambridge Philosophical
Society 26:220-230.
Hanski, I., and M. Gilpin. 1991. Metapopulation dynamics: Brief history
and conceptual domain. Biological Journal of Linnean Society 42:3-16.
Hanson, W. D. 1966. Effects of partial isolation (distance), migration,
and different fitness requirements among environmental pockets upon steady
state gene frequencies. Biometrics 22:453-468.
Hard, J. J., R. P. Jones, Jr., M. R. Delarm, and R. S. Waples. 1992.
Pacific salmon and artificial propagation under the Endangered Species
Act. U.S. Department of Commerce, NOAA Technical Memorandum NMFS-NWFSC-2.
Hayden, M. V. 1930. History of the salmon industry of Oregon. Master's
Thesis University of Oregon, Eugene, Oregon.
Hedrick, P. W., D. Hedgecock, and S. Hamelberg. 1995. Effective
population size in winter-run chinook salmon. Conservation Biology
9:615-624.
Herrig, D. 1998. Lower Snake River compensation Plan Background. Pages
14-20 in Lower Snake River compensation plan status review symposium. U.
S. Fish and Wildlife Service, Boise, Idaho.
Hindar, K., N. Ryman, and F. Utter. 1991. Genetic effects of cultured
fish on natural fish populations. Canadian Journal of Fisheries and
Aquatic Sciences 48:945-957.
Houlden, B. A., P. R. England, A. C. Taylor, W. D. Grenville, and W. B.
Sherwin. 1996. Low genetic variability of the koala Phascolarctos cinereus
in south-eastern Australia following a severe population bottleneck.
Molecular Ecology 5:269-281.
Hublou, W. F. 1963. Oregon pellets. Progressive Fish Culturist
23:175-180.
Hume, R. D. 1893. Salmon of the Pacific coast. Schmidt Label &
Lithographic Co., San Francisco, California.
Independent Scientific Group. 1996. Return to the river. Northwest
Power Planning Council, Portland, Oregon.
Independent Scientific Review Panel. 1997. Review of the Columbia River
Basin Fish and Wildlife Program as directed by the 1996 amendment to the
Power Act. Report of the Independent Scientific Review Panel for the
Northwest Power Planning Council, Portland, Oregon.
International Pacific Salmon Fisheries Commission. Annual Reports. New
Westminster, British Columbia, Canada.
Jimenez, J., H. Kimberly, G. Alaks, L. Graham, and R. Lacy. 1994. An
experimental study of inbreeding depression in a natural habitat. Science
266:271-273.
Johnson, S. L. 1984. Freshwater environmental problems and coho
production in Oregon. Oregon Department of Fish and Wildlife, Information
Report 84-11, Corvallis, Oregon.
Kallio-Nyberg, I., and M. -L. Koljonen. 1997. The genetic consequences
of hatchery-rearing on life-history traits of Atlantic salmon (Salmo salar
L.): a comparative analysis of sea-ranched salmon with wild and reared
parents. Aquaculture 153:207-224.
Kohane, M. J., and P. A. Parsons. 1988. Domestication: evolutionary
change under stress. Evolutionary Biology 23:31-48.
Lande, R. 1988. Genetics and demography in biological conservation.
Science 241:1455-1460.
Lande, R., and S. Shannon. 1996. The role of genetic variation in
adaptation and population persistence in a changing environment. Evolution
50:434-437.
Lavier, D. C. 1976. Major dams on Columbia River and tributaries.
Investigative Reports of Columbia River Fisheries Project, Pacific
Northwest Regional Commission, Vancouver, Washington.
Laythe, L. L. 1948. The fishery development program in the Lower
Columbia River. Transactions of the American Fisheries Society, 78th
Annual Meeting September 13-15, 1948, Atlantic City, New Jersey.
Leary, R. F., F. W. Allendorf, S. R. Phelps, and K. L. Knudsen. 1984.
Introgression between westslope cutthroat and rainbow trout in the Clark
Fork River drainage, Montana. Proceedings of the Montana Academy of
Sciences 43:1-18.
Leary, R. F., F. W. Allendorf, and G. K. Sage. 1995. Hybridization and
introgression between introduced and native fish. Uses and defects of
cultured fishes in aquatic ecosystems. Pages 91-101 in H. L. Schramm and
R. G. Piper. American Fisheries Society Symposium 15. Bethesda, Maryland.
Leberg, P. L. 1990. Influence of genetic variability on population
growth: implications for conservation. Journal of Fish Biology
37(Supplement A):193-195.
Leberg, P. L. 1992. Effects of population bottlenecks on genetic
diversity as measured by allozyme electrophoresis. Evolution 46:477-494.
Leberg, P. L. 1993. Strategies for population reintroduction: effects
of genetic variability on population growth and size. Conservation Biology
7:194-199.
Lehman, M., R. K. Wayne, and B. S. Stewart. 1993. Comparative levels of
genetic variability in harbour seals and northern elephant seals as
determined by genetic fingerprinting. Symposium of the Zoological Society
London 66:49-60.
Leider, S. A., P. L. Hulett, J. J. Loch, and M. W. Chilcote. 1990.
Electrophoretic comparison of the reproductive success of naturally
spawning transplanted and wild steelhead trout through the returning adult
stage. Aquaculture 88:239-252.
Lichatowich, J. A., L. E. Mobrand, L. Lestelle, and T. S. Vogel. 1995.
An approach to the diagnosis and treatment of depleted Pacific Salmon
populations in Pacific Northwest watersheds. Fisheries 20:10-18.
Lichatowich, J. A., L. E. Mobrand, R. J. Costello, and T. S. Vogel.
1996. A history of frameworks used in the management of Columbia River
chinook salmon. A report prepared for Bonneville Power Administration
included in Report DOE/BP 33243-1, Portland, Oregon.
Lush, J. L. 1937. Animal breeding plans. Iowa State University Press,
Ames, Iowa.
Lynch, M. 1991. The genetic interpretation of inbreeding depression and
outbreeding depression. Evolution 45:622-629.
Lynch, M. 1996. A quantitative-genetic perspective on conservation
issues. Page 471-501 in J. C. Avise and J. L. Hamrick, editor.
Conservation genetics: case histories from nature. Chapman & Hall, New
York, New York. Lynch, M., and B. Walsh. 1998. Genetics and the analysis
of quantitative traits. Sinauer Associates, Sunderland, Massachusetts.
Mahnken, C., G. Ruggerone, W. Waknitz, and T. Flagg. In press(1997). A
historical perspective on salmonid production from north rim hatcheries.
Proceedings of the NPAFC, Bulletin Number 1, "Assessment and status
of Pacific rim salmonid stocks."
Maitland, J. R. G. 1884. The culture of salmonidae and the
acclimatization of fish. In The Fisheries Exhibition Literature,
International Fisheries Exhibition, London, 1883. William Clowes and Sons,
Limited, London, England.
McCabe, G. T., Jr., C. W. Long, and S. L. Leek. 1983. Survival and
homing of juvenile coho salmon, Oncorhynchus kisutch, transported by
barge. Fishery Bulletin 81:412-415.
McDonald, M. 1894. Address of the Chairman of the General Committee on
the World's Fisheries Congress. Bulletin of the United States Fish
Commission, volume 13 (1893), Washington, DC.
McIntosh, R. 1985. The background of ecology, concept and theory.
Cambridge Studies in Ecology. Cambridge University Press, New York, New
York.
McNeil, W. J. 1991. Sea ranching of coho salmon (Oncorhynchus kisutch)
in Oregon. Pages 1-10 inT. Pedersen and E. Kj?svik, editors. Proceedings
from the symposium and workshop 21-23 October, 1990, Bergen, Norway.
Norwegian Society for Aquaculture Research and Institute of Marine
Research, Division of Aquaculture, Bergen, Norway.
Messmer, R. T., R. W. Carmichael, M. W. Flesher, and T. A. Whitesel.
1992. Evaluation of Lower Snake River compensation plan facilities in
Oregon. Oregon Department of Fish and Wildlife, Portland, Oregon.
Mitton, J. B. 1993. Theory and data pertinent to the relationship
between heterozygosity and fitness. Pages 17-41 in T. W. Thornhill,
editor. The natural history of inbreeding and outbreeding. University of
Chicago Press, Chicago, Illinois.
Moyle, P. B. 1969. Comparative behavior of young brook trout of wild
and hatchery origin. Progressive Fish-Culturist 31:51-56.
Mullan, J. W., K. R. Williams, G. Rhodus, T. W. Hillman, and J. D.
McIntyre. 1992. Production and habitat of salmonids in mid-Columbia River
tributary streams. U.S. Fish and Wildlife Service, Monograph I,
Washington, DC.
National Fish Hatchery Review Panel (NFHRP). 1994. Report of the
National Fish Hatchery Review Panel. The Conservation Fund, Arlington,
Virginia.
National Research Council (NRC). 1996. Upstream: salmon and society in
the Pacific Northwest. Committee on Protection and Management of Pacific
Northwest Anadromous Salmonids, National Academy of Science, Washington,
D.C.
Neitzel, D. 1998. Preliminary IHOT database information. Submitted to
the SRT on July 30, 1998. Pacific Northwest National Laboratory, Richland,
Washington.
Newman, D., and D. Pilson. 1997. Increased probability of extinction
due to decreased genetic effective population size: experimental
population of Clarkia pulchella. Evolution 51:354-362.
Oregon Department of Fish and Wildlife and Washington Department of
Fisheries (ODFW and WDF). 1993. Status report: Columbia River fish runs
and fisheries 1938-92. Portland, Oregon.
Oregon Fish and Game Commission (OFGC). 1919. Biennial report of the
Fish and Game Commission of the State of Oregon. Salem, Oregon.
Oregon State Board of Fish Commissioners (OSBFC). 1888. First report of
the State Board of Fish Commissioners to the Governor of Oregon. Salem,
Oregon.
Oregon State Board of Fish Commissioners (OSBFC). 1890. Fourth annual
report of the State Board of Fish Commissioners for 1890. Salem, Oregon.
Oregon State Fish and Game Protector (OSFGP). 1896. Third and fourth
annual reports of the State Fish and Game Protector of the State of
Oregon, 1895-1896. State of Oregon, Salem, Oregon.
Pacific Salmon Commission. Annual Reports. Vancouver, British Columbia,
Canada.
Petersson, E., T. Jarvi, N. G. Steffner, and B. Ragnarsson. 1996. The
effect of domestication selection on some life history traits of sea trout
and Atlantic salmon. Journal of Fish Biology 48:776-791.
Quattro, J. M., and R. C. Vrijenhoek. 1989. Fitness differences among
remnant populations of the Sonoran topminnow, Poeciliopsis occidentalis.
Science 245:976-978.
Quinn, T. P. 1993. A review of homing and straying of wild and
hatchery-produced salmon. Fisheries Research 18:29-44.
Quinn, T. P. 1997. Homing, straying, and colonization. Pages 73-85 in
W. S. Grant, editor. Genetic effects of straying of non-native hatchery
fish into natural populations: proceedings of the workshop. U. S.
Department of Commerce, NOAA Technical Memorandum NMFS-NWFSC-30.
Quinn T. P., E. L. Brannon, and A. H. Dittman. 1990. Spatial aspects of
imprinting and homing in coho salmon, Oncorhynchus kisutch. Fishery
Bulletin, U.S. 87:769-774.
Quinn, T. P., J. L. Nielsen, C. Gan, M. J. Unwin, R. Wilmot, C.
Guthrie, and F. M. Utter. 1996. Origin and genetic structure of chinook
salmon, Oncorhynchus tshawytscha, transplanted from California to New
Zealand: allozyme and mtDNA evidence. Fishery Bulletin 94:506-521.
Reisenbichler, R. R. 1998. Questions and partial answers about
supplementation - genetic differences between hatchery fish and wild fish.
Pages 29-38 in E. Brannon and W. Kinsel editors. Proceedings of Columbia
river Anadromous rehabilitation and Passage Symposium. Aquaculture
Research Institute, University of Idaho, Moscow, Idaho and Mechanical
Engineering, Washington State University, Richland, Washington.
Reisenbichler, R. R., and J. D. McIntyre. 1977. Genetic differences in
growth and survival of juvenile hatchery and wild steelhead trout. Journal
of the Fisheries Research Board of Canada 34:123-128.
Reisenbichler, R. R., and S. R. Phelps. 1989. Genetic variation in
steelhead (Salmo gairdneri) from the north coast of Washington. Canadian
Journal of Fisheries and Aquatic Sciences 46:66-73.
Reisenbichler, R. R., J. D. McIntyre, M. F. Solazzi, and S. W. Landino.
1992. Genetic variation in steelhead of Oregon and Northern California.
Transactions of the American Fisheries Society 121:158-169.
Rich, S. S., A. E. Bell, and S. P. Wilson. 1979. Genetic drift in small
populations of Tribolium. Evolution 33:579-584.
Rich, W. H. 1920. Early history and seaward migration of chinook salmon
in the Columbia and Sacramento Rivers. Bulletin of U. S. Bureau of
Fisheries Number 37, Washington, DC.
Rich, W. H. 1922. A statistical analysis of the results of artificial
propagation of chinook salmon. Document located in the manuscript library,
Northwest and Alaska Fisheries Science Center, National Marine Fisheries
Service, Seattle, Washington.
Rich, W. H. 1941. The present state of the Columbia River salmon
resources. Department of Research, Fish Commission of the State of Oregon,
Contribution Number 3, 425-430, Salem, Oregon.
Rich, W. H. 1948. A survey of the Columbia River and its tributaries
with special reference to the management of its fishery resources. U. S.
Fish and Wildlife Service, Special Scientific Report Number 51,
Washington, DC.
Rich, W. H., and H. B. Holmes. 1929 . Experiments in marking young
chinook salmon on the Columbia River, 1916 to 1927. Bulletin of the Bureau
of Fisheries, Document Number 1047, Washington, DC.
Ricker, W. E. 1972. Hereditary and environmental factors affecting
certain salmonid populations. Pages 19-160 in R. C. Simon and P. A.
Larkin, editors. The stock concept in Pacific salmon. H. R. McMillan
Lectures in Fisheries, University of British Columbia, Vancouver.
Roff, D. A. 1997. Evolutionary quantitative genetics. Chapman and Hall,
New York, New York.
Ryman, N., and G. Stahl. 1980. Genetic changes in hatchery stocks of
brown trout (Salmo trutta). Canadian Journal of Fisheries and Aquatic
Sciences 37:82-87.
Ryman, N., and L. Laikre. 1991. Effects of supportive breeding on the
genetically effective population size. Conservation Biology 5:325-329.
Ryman, N., P. E. Jorde, and L. Laikre. 1995. Supportive breeding and
variance effective population size. Conservation Biology 9:1619-1628.
Saccheri, M. K., M. Kuussaari, M. Kankare, P. Vikman, W. Fortelius, and
I. Hanski. 1998. Inbreeding and extinction in a butterfly metapopulation.
Nature 392:491-494. Shaffer, M. L. 1981. Minimum viable population sizes
for species conservation. Bioscience 31:131-134.
Shields, W. M. 1982. Philopatry, inbreeding, and the evolution of sex.
State University of New York Press, Albany, New York.
Shiewe, M. H., T. A. Flagg, and B. A. Berejikian. 1997. The use of
captive broodstocks for gene conservation of salmon in the western United
States. Bulletin of Natural Resource Institute Aquaculture Supplement
3:29-34.
Simon, R. C., J. D. McIntyre, and A. R. Hemmingsen. 1986. Family size
and effective population size in a hatchery stock of coho salmon
(Oncorhynchus kisutch). Canadian Journal of Fisheries and Aquatic Sciences
43:2434-2442.
Slatkin, M. 1985. Gene flow in natural populations. Annual Review of
Ecology and Systematics 16:393-430.
Smith, E. V. 1919. Fish culture methods in the hatcheries of the State
of Washington. Washington State Fish Commissioner, Olympia, Washington.
Smith, T. D. 1994. Scaling fisheries: the science of measuring the
effects of fishing, 1855-1955. Cambridge University Press, New York, New
York.
Solazzi, M. F., T. E. Nickelson, and S. L. Johnson. 1991. Survival,
contribution, and return of hatchery coho salmon (Oncorhynchus kisutch)
released into freshwater, estuarine, and marine environments. Canadian
Journal of Fisheries and Aquatic Sciences 48:248-253.
Stone, L. 1879. Report of operations at the salmon-hatching station on
the Clackamas River, Oregon, in 1877. Part 11 in Part 5, Report of the
Commissioner for 1877. U. S. Commission of Fish and Fisheries, Washington,
DC.
Stone, L. 1884. The artificial propagation of salmon in the Columbia
River basin. Transactions of the American Fish-Cultural Association. 13th
annual meeting May 13-14, 1884, New York, New York.
Swain, D. P., and B. E. Riddell. 1990. Variation in agonistic behavior
between newly emerged juveniles from hatchery and wild populations of coho
salmon, Oncorhynchus kisutch. Canadian Journal of Fisheries and Aquatic
Sciences 47:566-577.
Tave, D. 1993. Genetics for fish hatchery managers, second edition.
AVI, New York, New York.
Taylor, E. B. 1991. A review of local adaptation in Salmonidae, with
particular reference to Pacific and Atlantic salmon. Aquaculture
98:185-207.
Templeton, A. R. 1986. Coadaptation, local adaptation, and outbreeding
depression. Pages 105-116 in M. E. Soule, editor. Conservation biology:
the science of scarcity and diversity. Sinauer Associates, Sunderland,
Massachusetts.
Thompson, W. F. 1951. An outline for salmon research in Alaska.
Fisheries Research Institute, University of Washington. Seattle,
Washington.
Thornhill, N. W. (editor). 1993. The natural history of inbreeding and
outbreeding. University of Chicago Press, Chicago, Illinois.
Utter, F. M., D. W. Chapman, and A. R. Marshall. 1995. Genetic
population structure and history of chinook salmon of the Upper Columbia
River. American Fisheries Society Symposium 17:149-165.
Van Cleve, R., and R. Ting. 1960. The condition of salmon stocks in the
John Day, Umatilla, Walla Walla, Grande Ronde, and Imnaha Rivers as
reported by various fisheries agencies. University of Washington,
Department of Oceanography, Seattle, Washington.
Vincent, R. E. 1960. Some influences of domestication upon three stocks
of brook trout (Salvelinus fontinalis Mitchell). Transactions of the
American Fisheries Society 89:35-52.
Vreeland, R. R. 1989. Evaluation of the contribution of fall chinook
salmon reared at Columbia River hatcheries to the Pacific salmon
fisheries. Bonneville Power Administration, Report No. DOE/BP-39638-4,
Portland, Oregon.
Vrijenhoek, R. C. 1996. Conservation genetics of North American desert
fishes. Pages 367-397 in J. C. Avise and J. L. Hamrick, editors.
Conservation genetics: case histories from nature. Chapman and Hall, New
York, New York.
Vuorinen, J. 1984. Reduction of genetic variability in a hatchery stock
of brown trout, Salmo trutta. Journal of Fish Biology 24:339-348.
Wahle, R.J., and R.R. Vreeland. 1978. Bioeconomic contribution to
Columbia River hatchery fall chinook salmon, 1961 and 1964 broods, to the
Pacific salmon fisheries. Fisheries Bulletin 76:179-208.
Wahle, R.J., R.R. Vreeland, and R.H. Lander. 1974. Bioeconomic
contribution of Columbia River hatchery coho salmon, 1965 and 1966 broods,
to the Pacific salmon fisheries. Fisheries Bulletin 72(1):139-169.
Wallis, J. 1964. An evaluation of the Bonneville salmon hatchery.
Oregon Fish Commission Research Laboratory, Clackamas, Oregon.
Waples, R. S. 1990a. Conservation genetics of Pacific salmon. II.
Effective population size and rate of loss of genetic variability. Journal
of Heredity 81:267-276.
Waples, R. S. 1990b. Conservation genetics of Pacific salmon. III.
Estimating effective population size. Journal of Heredity 81:277-289.
Waples, R. S. 1991. Genetic interactions between hatchery and wild
salmonids: lessons from the Pacific Northwest. Canadian Journal of
Fisheries and Aquatic Sciences 48:124-133.
Waples, R. S. 1995. Genetic effects of stock transfers of fish. Pages
51-69 in D. Philipp, editor. Protection of aquatic biodiversity:
Proceedings of the World Fisheries Congress, Theme 3. Oxford and IBH, New
Delhi.
Waples, R. S., and D. J. Teel. 1990. Conservation genetics of Pacific
salmon. I. Temporal changes in allele frequency. Conservation Biology
4:144-155. Waples, R. S., G. A. Winans, F. M. Utter, and C. Mahnken. 1990.
Genetic monitoring of Pacific salmon hatcheries. NOAA Technical Report
NMFS 92.
Waser, N. M. 1993. Population structure, optimal outcrossing, and
assortative mating in angiosperms. Pages 1-13 in N. W. Thornhill, editor.
The natural history of inbreeding and outbreeding: theoretical and
empirical perspectives. University of Chicago Press, Chicago, Illinois.
Washington Department of Fisheries (WDF). 1953. Biannual Report to the
Legislature. Olympia, Washington.
Washington Department of Fisheries and Game (WDFG). 1921. Thirtieth and
thirty-first annual reports of the State Fish Commissioner to the Governor
of the State of Washington. Olympia, Washington.
Washington Department of Fisheries (WDF). 1960. Fisheries, fish
farming, fisheries management: conservation-propagation-regulation.
Olympia, Washington.
Willette, M. 1992. Effects of ocean temperatures and zooplankton
abundance on the growth and survival of juvenile pink salmon in Prince
William Sound. report to Prince William Sound Aquaculture Corporation,
Alaska Department or Fish and Game, Cordova, Alaska.
Williams, R. N., D. K. Shiozawa, J. E. Carter, and R. F. Leary. 1996.
Genetic detection of putative hybridization between native and introduced
rainbow trout populations of the upper Snake River. Transactions of the
American Fisheries Society 125:387-401.
Williams, R. N., R. F. Leary, and K. P. Currens. 1997. Localized
genetic effects of a long-term hatchery stocking program on resident
rainbow trout in the Metolius River, Oregon.
Wishard, L. N., J. E. Seeb, F. M. Utter, and D. Stefan. 1984. A genetic
investigation of suspected redband trout populations. Copeia 1984:120-132.
Withler, R. E. 1988. Genetic consequences of fertilizing chinook salmon
(Oncorhynchus tshawytscha) eggs with pooled milt. Aquaculture 68:15-25.
Wood, E. M. 1953. A century of American fish culture, 1853-1953. The
Progressive Fish Culturist, 15:(4)147-160.
Wright, S. 1931. Evolution in Mendelian populations. Genetics
16:111-123.
Wright, S. 1938. Size of population and breeding structure in relation
to evolution. Science 87:430-431.
Wright, S. 1943. Isolation by distance. Genetics 28:114-138.
Wright, S. 1968. Evolution and the genetics of populations. Volume 1.
Genetic and biometric foundations. University of Chicago Press, Chicago,
Illinois.
Wright, S. 1977. Evolution and the genetics of populations. Volume 3.
Experimental results and evolutionary deductions. University of Chicago
Press, Chicago, Illinois.
APPENDIX
Regional Scientific Questions on Artificial Production
1. What are the ecological impacts of artificial production in the
Columbia River Basin?
General
- What are the positive biological/ecological contributions of
artificial production in the Columbia River?
- What are the negative biological/ecological impacts of artificial
production in the Columbia River?
- Does it not make sense to alter stock composition in hatcheries
based on ocean conditions?
Fitness
- Can hatcheries be used to rebuild wild, native salmonid populations
and maintain their genetic and life history attributes, their fitness
and the evolutionary capacity of the populations?
- Are hatchery salmonids less fit for survival in the natural
freshwater and ocean environments? If they are, what are the changes
that must be made in the hatchery operation to make hatchery fish as
fit as wild fish?
- Is there a differential survival between hatchery and wild salmonids
throughout their life cycle stages? Is there a differential survival
rate for hatchery and wild fish as they encounter the human changes in
the system? For example, do wild and hatchery fish survive dam
passage, barging, predation at different rates? If they do, then
should the agencies and tribes in their management program acknowledge
this differential survival rate?
- Where have hatchery stocks caused the decline or extinction of wild
stocks? Where have hatcheries enhanced the restoration of a wild
stock?
- Can the biological diversity, fitness and productivity of a wild,
native salmonid population be maintained with a hatchery?
- Do hatchery programs exist in the Columbia Basin or the region that
have been shown to do a good job supporting biological diversity,
genetic and life history attributes, fitness and productivity of the
native population they interact with? Can they serve as a model for
the basin and region?
- Should a coordinated gene flow management policy be developed to
control stray hatchery fish in the basin?
Disease
- Are hatchery disease treatment programs likely to create resistant
pathogens that could pose a health risk to wild salmonids? What should
be done to eliminate or manage this risk?
2. What is scientific context for the use of artificial production in
the Columbia Basin?
- What are the major research questions associated with artificial
production?
- How does the existing level of scientific uncertainty affect the use
and management of artificial production?
- What are the priority research questions that need to be answered to
integrate hatchery and wild production so that there is no loss of
fitness and productivity in either the hatchery or wild populations?
- What is the historic relationship between natural production and
harvest?
3. How has artificial production performed relative to its management
goals?
General
- How effective has artificial production been relative to stated
objectives in the Columbia River?
Harvest
- How does artificial production affect harvest regimes and vice
versa? What has been the affect of this relationship on natural
production?
- How do we mitigate fisheries with the least impact on wild fish?
- As the proportion of hatchery fish increases and harvests are
targeted on them a mixed stock harvest problem is created where the
wild, native population is exposed to high harvest rates. In this way
the hatchery program fuels the harvest management program and wild
fish are over harvested. What are your recommendations for reducing or
terminating this problem? Can hatchery fish be used as a buffer to
protect wild fish or is this a rationalization to justify not making
changes in fishery management?
- If harvest rates are constrained by natural production, then how can
we alter hatcheries to meet compensation goals?
Mitigation
- Can hatcheries be used to double the runs and, at the same time,
maintain the biological diversity, fitness and productivity of the
individual subbasin populations or is there a conflict between these
two goals set forth by the fish agencies and tribes through the Power
Council? What are your recommendations for resolving this conflict, if
it exists?
- Mitigation has been carried out in such a way that the effect is the
replacement of wild, native salmonids with hatchery fish. Is this
effective mitigation? Have the mitigation agreements and goals been
met in each relevant case in the Columbia? If hatchery mitigation is
not working what should it be replaced with that would protect wild
populations?
- Given that hatcheries are a necessary tool to mitigate for lost
natural production, where does is make most sense, (i.e. most
effective in production and cost) to locate production facilities?
- Have mitigation hatcheries been successful in replacing numerical
losses in the basin? Have they been successful in replacing the
biological diversity and fitness of the wild, native runs that were
lost?
4. What is the scientific basis for the use of supplementation?
- What is the potential and associated risks for artificial production
to augment or supplement natural production in a biologically sound
and sustainable manner?
- What are the hatchery protocols needed to prevent a hatchery
population from diverging from the wild donor population?
- Can it be assumed that a hatchery population derived from a wild
donor population will not diverge from the donor population in
genetic, life history traits, and fitness?
- How should a hatchery program be operated when reintroducing a
salmonid population into a stream where the species has gone extinct
if the goal is to promote a healthy, self-reproducing new population?
- Does hatchery supplementation of wild salmonids work? Is there
evidence in the scientific literature that shows hatchery
supplementation is able to maintain the biological diversity,
abundance, distribution, productivity and fitness of the original
wild, native population? If not should the region continue to fund new
hatchery supplementation projects?
- Can these wild native populations be recovered using supplementation
where wild brood stocks are used in the hatchery program?
- Can hatchery supplementation increase the numbers of fish while
maintaining the productivity (fitness) of the affected population over
time?
- Should hatchery and wild salmonids be integrated so that they
function as single reproductive unit within a subbasin or should the
two be kept separate, including the separation of spawning time to
reduce crossbreeding between hatchery and wild fish?
5. What is the application to resident fish?
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