Pacific salmon (Oncorhynchus spp.) are organized into distinct
populations because of homing behavior (Rich and Holmes 1939,
Ricker 1972). The alternative to homing is straying, in which
fish do not return to their natal streams to spawn but spawn elsewhere
(Bams 1976). Even though some straying occurs among wild populations
(usually less than 5%; Lindsey et al. 1959, Vernon 1957, Rich
and Holmes 1928), the amount of straying between natural and hatchery
stocks is of concern because it can reduce the fitness of natural
populations (Fleming and Gross 1993, Meffe 1992, Leider et al.
1990, Waples 1991). Evidence shows that some transplanted stocks
are less productive than locally adapted populations, and that
hatchery populations are generally less productive in nature than
native locally adapted populations (Leider et al. 1990, Reisenbichler
1996, Chilcote et al. 1986). Introductions of hatchery fish into
a river system can also displace wild fish or reduce their abundance
(Nickelson et al. 1986). The effects of hatchery fish on wild
populations are well documented (see Can. J. Fish. Aquat. Sci.
1981, 38(12), Aquaculture 1991, 98(1-3)).
Much of my effort has been to get salmon management and Indian
tribal agencies to pay attention to the results of these studies
in their efforts to develop and manage salmonid fisheries. Given
the documented effects that hatchery strays can have on wild populations,
hatchery policies and funding should be subject to a scientific
review process, and that is what this workshop is about. Hatcheries,
however, are often treated as 'sacred cows' by fishery agencies,
and attempts to correct problems with straying are sometimes met
with accusations of 'hatchery bashing.' The problem is that a
formal process of hatchery evaluation is lacking in formulating
budgets. For example, in fiscal 1992, the NMFS budget for its
hatchery program was $13.4 million, whereas the combined funding
for fishery resource management, protected species management,
and habitat restoration and conservation was only $1.8 million
(R. Schmitten, NMFS Headquarters, 1315 East West Highway, Silver
Spring, MD 20910. Pers. commun., March 1992). The states of
Oregon and Washington have similar policies for funding hatcheries,
as does the U.S. Fish and Wildlife Service. Since hatchery programs
constitute a large proportion of the agencies' budgets, it is
reasonable for these agencies to avoid questions about hatchery
programs and their influences on wild stocks.
Discussions of hatchery straying are often seen as attacks on
hatchery programs, rather than as constructive criticisms intended
to make things work better. Present policies inadequately regulate
fish hatchery practices. Even the recent effort on the part of
fish agencies to develop an integrated hatchery policy in the
Columbia River Basin does not evaluate the effects of hatchery
fish on the ecosystem once they are released. It deals chiefly
with the coordination of protocols among hatcheries. An institutional
mechanism to identify hatchery-related ecosystem problems is entirely
lacking. Consequently, even though there are ample scientific
studies on the problems hatchery strays cause, an institutional
means of addressing and resolving these problems is not in place
because funds for a review and evaluation are not available.
Additional funds are required to acclimate juvenile hatchery fish
so they imprint adequately during their down-river migration,
to mark them, and to inventory spawning streams for them as adults.
To reduce the rate of straying of hatchery fish, the trucking
of juveniles will also have to be discontinued. Truck-transported
juveniles are not imprinted well enough to find their way back
up a river to their point of capture, so they tend to stray to
other areas (Slatick et al. 1982) and can introduce such diseases
as IHN to previously uninfected rivers. But we continue to truck
juveniles because it is more economical than barging them. To
deal with hatchery straying, a policy must be developed and implemented
to determine if any rates of straying are acceptable, especially
for small populations because they are at the greatest risk.
Traps will have to be placed in streams so that marked hatchery
fish can be removed.
Two primary kinds of hatchery strays include 1) hatchery fish
that do not return to their release site, but stray into other
streams, and 2) non-native hatchery fish used for fishery enhancement
or mitigation that are transplanted from non-local populations.
Both kinds of hatchery strays place native fish at risk through
interbreeding and ecological interactions, and any policy on straying
of non-native fish must be designed to protect the fitness and
evolutionary potential of wild populations. This may mean closing
a hatchery facility when it becomes too expensive or impractical
to control the straying of non-native fish. Straying may also
be induced when juveniles are transported for release to rivers
where the hatchery fish are non-native. Examples, among many
others, include the non-local release of Alsea Hatchery winter
steelhead, Skamania Hatchery summer-run steelhead, Lower Columbia
River hatchery coho salmon, and Rogue River chinook salmon (reared
in net-pens in the Lower Columbia River). Adults returning to
a release site may stray uncontrollably when they encounter unfavorable
conditions. This occurred in the Umatilla River.
Converting hatcheries to raise only native brood stock may greatly
reduce the effects of hatchery straying, but this hypothesis must
be evaluated before it can be applied broadly to a river system.
Captive brood stock may also diverge genetically from local wild
stocks in traits that are important in local adaptation. Even
with the use of only native brood stocks, hatchery strays may
still adversely affect natural populations. Any policy on strays
should also consider ecological interactions of juvenile hatchery
fish with wild fish, especially in the large-scale use of non-native
fish for mitigating run losses or for run enhancement.
Conserving genetic variability within and among native wild salmonid
populatons is key to the success of fishery management. At this
time, it is impossible to prevent selection for traits that favor
survival in a hatchery environment, so hatchery fish will diverge
from wild forms and become less fit for survival in nature. Thus,
hatchery fish can be a form of biological pollution that must
be controlled to maintain not only native salmon, but ultimately
the consumptive fisheries.
I conclude with a quote by Yu. P. Altukhov and Salmenkova (1991,
p. 28, 35-36): ". . . many anadromous fish are now reproduced
artificially in hatcheries and reared and released into the rivers--but
the method is insufficiently effective. This is because the species'
population genetic structure has not been taken into account .
. . . These data testify to the negative genetic effects of existing
salmonid exploitation and management practices. Artificial reproduction,
commercial fisheries, and transfers result in the impairment of
gene diversity in salmon populations, and so cause their biological
degradation."
Altukhov, Y. P, and E. A. Salmenkova. 1991. The genetic structure
of salmon populations. Aquaculture 98:11-40.
Bams, R. A. 1976. Survival and propensity for homing as affected
by presence or absence of locally adapted paternal genes in two
transplanted populations of pink salmon. J. Fish. Res. Board
Can. 33:2716-2725.
Chilcote, M. W., S. A. Leider, and J. J. Loch. 1986. Differential
reproductive success of hatchery and wild summer-run steelhead
under natural conditions. Trans. Am. Fish. Soc. 115:726-735.
Fleming, I. A., and M. R. Gross. 1993. Breeding success of hatchery
and wild coho salmon in competition. Ecol. Appls. 3:230-245.
Leider, S. A., P. L. Hulett, J. J. Loch, and M. W. Chilcote.
1990. Electrophoretic comparison of reproductive success of naturally
spawning transplanted and wild steelhead trout through the returning
adult stage. Aquaculture 88:239-252.
Lindsey, C. C., T. G. Northcote, and G. F. Hartmann. 1959. Homing
of rainbow trout into inlet and outlet spawning streams at Loon
Lake, British Columbia. J. Fish. Res. Board Can. 16:695-719.
Meffe, G. K. 1992. Techno-arrogance and halfway technologies:
salmon hatcheries on the Pacific coast of North America. Conserv.
Biol. 6:350-354.
Nickelson, T. E., M. F. Solazzi, and S. L. Johnson. 1986. Use
of hatchery coho salmon presmolts to rebuild wild populations
in Oregon coastal streams. Can. J. Fish. Aquat. Sci. 43:2443-2449.
Reisenbichler, R. R. 1996. Genetic factors contributing to declines
of anadromous salmonids in the Pacific Northwest. In D. J. Stouder,
P. A. Bisson and R. J. Naiman (editors), Pacific Salmon and their
Ecosystems, p. 223-244. Chapman Hall, New York.
Rich, W. H., and H. B. Holmes. 1928. Experiments in marking
young chinook salmon on the Columbia River, 1916-1927. Bull.
Bur. Fish. 44:215-264.
Rich, W. H., and H. B. Holmes. 1939. Local populations and migration
in relation to conservation of Pacific salmon in the western states
and Alaska. Amer. Assoc. Adv. Sci. Publ. 8:45-50.
Ricker, W. E. 1972. Hereditary and environmental factors affecting
certain salmonid populations. In:
R. C. Simon and P. A. Larkin (editors), The Stock Concept in Pacific
Salmon, p. 19-160. MacMillan Lectures on Fisheries. Univ. British
Columbia, Vancouver, B.C.
Slatick, E., L. G. Gilbreath, J. R. Harmon, and K. A. Walch.
1982. Imprinting salmon and steelhead trout for homing. Report
to the U.S. Bonneville Power Administration, Division of Fish
and Wildlife, Contract DE-A179-81-BP27891, 52 p. with appendices.
(Available from Northwest Fisheries Science Center, 2725 Montlake
Blvd. E., Seattle, WA 98112.)
Vernon, E. H. 1957. Morphometric comparison of three races of
kokanee within a large British Columbia lake. J. Fish. Res. Board
Can. 14:573-598.
Waples, R. S. 1991. Genetic interactions between hatchery and
wild salmonids: lessons from the Pacific Northwest. Can. J.
Fish. Aquat. Sci. 48(suppl. 1):124-133.
Question: Dave Johnson (Nez Pierce Tribal Fisheries): The peoples
in the Pacific Northwest have eaten salmon for thousands of years,
and the United States government made promises when the land was
taken from Indian peoples. Among these promises was the ability
to live off salmon. If, as you suggest, we manage for a particular
population of salmon, we in effect lose our treaty rights and
our means of subsistence is taken away. For thousands of years
we have lived on salmon, and now within 100-150 years salmon have
practically disappeared. We are not so concerned with the genetics
of these fish, we just want the fish to eat and we support whatever
hatchery programs are needed to give us those fish.
Answer: Bill Bakke: I understand your point of view, but are
artificially propagated salmon as good as natural fish "from
the creator" for your spiritual and cultural well-being?
The Snake River has been pressed into many different uses that
adversely affect salmon populations, and I hope that the tribes
and others can begin to correct the problems causing the decline
of salmon populations. Sustainable artificial propagation of
salmon in the long term has its own problems. For example, we
have a shrinking supply of eggs for the lower Snake River hatcheries
and are forced to import non-native eggs. It does not appear
that hatchery technology is solving the problem.
Comment: Robin Waples: I think it is good to get these ideas out, because they show the complexity of the issue and the strong feelings on all sides. The panel, however, has not been asked to deal with these social and cultural issues, but will deal only with scientific issues.