The article below was published in SCIENCE by the members of the
National Research Council panel convened to assess the hatchery
fish vs. ESA issue. Most of these guys are in the National Academy
of Science and are NOT salmon biologists. This panel was
chartered to address the question at hand with an outside,
independent view. The article summarizes their conclusion (note
the last paragraph of the article).

Science, Vol 303, Issue 5666, 1980 , 26 March 2004

Hatcheries and Endangered Salmon

Ransom A. Myers, Simon A. Levin, Russell Lande, Frances C.
James, William W. Murdoch, Robert T. Paine

The role of hatcheries in restoring threatened and endangered
populations of salmon to sustainable levels is one of the most
controversial issues in applied ecology (1). The central issue has
been whether such hatcheries can work, or whether, instead, they
may actually harm wild populations (2, 3). A new and overriding
issue, however, has arisen because of a recent judicial decision.

On 10 September 2001, U.S. District Court Judge Michael Hogan
revoked the listing, by the National Marine Fisheries Service
(NMFS), of all Oregon coast coho salmon under the Endangered
Species Act (4). He ruled that, if hatchery fish were included in the
same distinct population segment as the wild fish with which they
are genetically associated, then they must be listed together. This
approach could have devastating consequences: Wild salmon could
decline or go extinct while only hatchery fish persist. Petitions are
now pending to delist 15 other evolutionarily significant units
(ESUs) (5).

An ESU is defined as a genetically distinct segment of a species,
with an evolutionary history and future largely separate from other
ESUs (6). For taxonomic purposes, one could use genetic similarity
to classify hatchery fish as part of the ESU from which they were
derived. However, for assessing ESU extinction risk and/or
potential listing under the Endangered Species Act, including
hatchery fish in an ESU confounds risk of extinction in the wild
with ease of captive propagation and ignores important biological
differences between wild and hatchery fish.

We define "hatchery fish" as fish fertilized and/or grown artificially
in a production or conservation hatchery. Inevitably, hatchery
brood stock show domestication effects, genetic adaptations to
hatchery environments that are generally maladaptive in the wild.
Hatchery fish usually have poor survival in the wild and altered
morphology, migration, and feeding behavior (7). On release,
hatchery fish, which are typically larger, compete with wild fish (1).
Their high local abundance may mask habitat degradation, enhance
predator populations, and allow fishery exploitation to increase,
with concomitant mortality of wild fish (1, 8). The absence of
imprinting to the natal stream leads to greater straying rates, and
that spreads genes not adapted locally (1). Also, hybrids have
poor viability, which may take two generations to be detected (9).

Interagency draft criteria (10) describe hatchery fish most
appropriate for inclusion in an ESU as those founded within two
generations or those that had regular infusions of fish from the
wild population. However, fish grown in hatcheries for even two
generations may not assist population recovery; their rate of
survival in the wild is much lower than that of wild fish (11).
Regularly infusing hatchery stocks with natural fish may also be a
drain on the natural system. Hence, even these hatchery fish
should not be included in an ESU, even if they are indistinguishable
at the quasi-neutral molecular genetic loci typically used to identify
an ESU.

Much evidence exists that hatcheries cannot maintain wild salmon
populations indefinitely (7). In the inner Bay of Fundy in Eastern
Canada, hatchery supplementation of Atlantic salmon occurred for
more than a century (12). Despite the longevity of this program, it
failed to maintain viable natural populations. Hatcheries effectively
disguised long-term problems, which probably contributed to the
near extirpation of native Atlantic salmon. Moreover, as
recommended by the World Conservation Union (IUCN), long-term
reliance on artificial propagation is imprudent, because of the
impossibility of its maintenance in perpetuity (13).

Although their effectiveness has not been shown (14),
conservation hatcheries may play a role in future salmon recovery.
However, to avoid the dysgenic effects of domestication, even
conservation hatcheries should be strictly temporary and should
not prevent protection of wild populations under the Endangered
Species Act.

To address one of the subsidiary lawsuits, NMFS has pledged to
complete a review of eight ESUs by 31 March 2004. NMFS should
continue to pursue its current recovery goal of establishing
self-sustaining, naturally spawning populations. The danger of
including hatchery fish as part of any ESU is that it opens the legal
door to the possibility of maintaining a stock solely through
hatcheries. However, hatcheries generally reduce current fitness
and inhibit future adaptation of natural populations. Hence, the
legal definition of an ESU must be unambiguous and must
reinforce what is known biologically. Hatchery fish should not be
included as part of an ESU.

References and Notes

1. National Research Council, Upstream: Salmon and Society in the
Pacific Northwest (National Academy Press, Washington, DC,
1996).
2. R. Hilborn, J. Winton, Can. J. Fish. Aquat. Sci. 50, 2043 (1993).
3. R. S. Waples, Fisheries 24, 12 (February 1999).
4. Alsea Valley Alliance v. Evans, 161 F. Supp. 2d 1154 (D. Or.
2001).
5. R. Lent, Fed. Regist. 67, 6215 (2002)
6. R. S. Waples, Mar. Fish. Rev. 53, 11 (3: 1991).
7. S. Einum, I. A. Fleming, Nordic J. Freshw. Res. 75, 56 (2001).
8. J. Lichatowich, Salmon Without Rivers (Island Press,
Washington, DC, 1999).
9. P. McGinnity et al., Proc. R. Soc. London Ser. B 270, 2443
(2003).
10. NMFS, 2003, http://www.nwfsc.noaa.gov/trt/brt/backintro.pdf
11. R. Reisenbichler, G. Brown, in "Assessing Extinctions Risk for
West Coast Salmon," A. D. MacCall, T. C. Wainwright, Eds. (NOAA
Tech. Memo, NMFS-NWFSC-556, U.S. Department of Commerce,
Washington, DC, 2003), pp. 147-154.
12. A. J. F. Gibson, J. Bryan, P. G. Amiro, Can. Data Rep. Fish.
Aquat. Sci. (no. 1123), 2003.
13. IUCN, 2002,
http://www.iucn.org/themes/ssc/pubs/policy/exsituen.htm.
14. F. Allendorf, R. S. Waples, in Conservation Genetics: Case
Histories from Nature, J. C. Avise, J. L. Hamrick, Eds. (Chapman &
Hall, New York, 1996), pp. 238-280.
15. We thank R. S. Waples for explaining aspects of the problem
and C. A. Ottensmeyer for assistance.