Re: NANFA-- releasing captive fish into the wild

Shireen Gonzaga (
Mon, 13 Dec 1999 18:48:01 -0500

Thanks for your responses, Jay, they are useful starting
points for further research.

While surfin' for more on this issue, I came across a very
interesting article titled
The Future of Captive Breeding Programs for Endangered Fish Species
by Kristen Staiger, Claremont McKenna College, published in
Advanced Topics in Environmental Biology.

The paper can be found at

Not knowing much about the background of this controvertial
issue, I'd be curious to hear the reactions of folks on the list to this

Here are a few thought-provoking quotes:

The scientific community is slowly realizing that hatchery success
deteriorates after only a few years of use (Hilborn, 1992). Examples of
both hatchery-reared coho in Oregon and chinook in British Columbia
demonstrate significant trends in declining survival rates (Hilborn, 1992).
Therefore, the use of artificial propagation to supplement fish
populations has become a highly debated enhancement practice.


Furthermore, skeptics of artificial propagation have identified ecological
and genetic problems that cultured stocks can pose to the native ones which
are themselves already being threatened. Some studies have identified threats
such as competition for food, predation of artificial fish on wild fish, genetic
dilution of wild stocks, and an increased fishing pressure on wild stocks as
potential causes for termination of hatcheries (Hilborn, 1992), while others
have looked to examining the variations in techniques and identifying
possible alternative solutions.


Reducing hatchery practices to a precise science does not answer the
ethical issues involved with its use. The use of artificial propagation has
implications beyond the mere survival and evolution of a fish run.
Through supplementation, we risk portraying the notions that through
technology, we can counter our mistakes, or that fish originate from
hatcheries (Hilborn, 1992). The failures of hatcheries are overwhelming,
yet we continue to perpetrate their use.


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