Hatcheries have been a part of the freshwater fisheries
scene for well over a century.
Initially seen as an unalloyed good that could reduce the
impacts of overfishing and other adverse effects of an expanding population,
hatchery fish have recently been subject to significant criticism. It
has been argued that they degrade the fitness of wild-spawned fish, and that
hatchery fish compete with wild fish for limited food and other resources.
The State of Montana
stopped stocking trout in its rivers forty years ago, after studies
indicated that eliminating hatchery fish will significantly increase a stream’s
productivity.
On the other side of the Atlantic, the Scottish
Fisheries Research Service, an agency of the Scottish Executive, warns that
“Stocking is only one of the tools available to fishery
managers to restore or increase fishing opportunities. The decision as to whether or not to stock
should not be taken in isolation, but as part of a broader plan for the
management of the fishery as a whole.
Such a plan should consider all the possible options. These include altering the level and
distribution of fishing…
“Stocking can do harm as well as good, and ill-considered
stocking exercises can have a deleterious effect on the wild resource…”
On the East Coast, hatcheries haven’t had too much of an
impact on angling; their only significant and continuous use occurs in the Gulf
of Mexico. Texas
has what is, by far, the largest hatchery operation, which releases red drum
and spotted seatrout
“to ensure that harvest levels are sustained and stocks are
replenished…[and] to counterbalance the effects of habitat degradation, natural
catastrophes and fishing pressure on the species.”
A
paper written by an employee of the Texas Parks and Wildlife Department,
about six years after the state’s red drum stocking program began, argued that
the stocking effort was successful, noting that
“the number of fish harvested in bays that have been stocked has
nearly doubled over historic mean harvest rates in those systems.”
However, it is important to note that “success” was gauged
solely by an increase in angler harvest, not by more permanent values, such as
an increase in the overall red drum spawning stock. In addition, there was no mention at all in
the paper about any possible environmental downside caused by, for example, an
adverse impact on the genetic makeup of the wild stock or stocked fingerlings
competing with wild fish for food resources or nursery habitat.
Seen in that light, one comment in the paper can be read as
a warning.
“The effectiveness of marine fisheries stock enhancement
programs cannot be evaluated on an a priori basis. To measure the impact, fish must be
stocked. Once they have been stocked successfully, the system will be forever changed. [emphasis added]”
That being the case, it might make sense to move forward
very slowly when considering the release of hatchery fish into salt water
environments.
The likelihood that marine fisheries managers may become
more open to hatchery “enhancement” of coastal fish stocks is suggested in the
National Marine Fisheries Service’s National Saltwater Recreational Fisheries
Policy, which was released earlier this year. Once section of that policy, which was heavily influenced by various
angling industry organizations, notes that
“Examples of strategies that NMFS supports
include…[d]evelopment and application of aquaculture tools and technologies
that support recreational fisheries.”
The phrase “aquaculture tools and technologies” sounds like
a bureaucratic euphemism for “hatcheries,” and the fact that the same industry
groups supporting this policy are the
organizations trying to weaken the conservation and stock rebuilding provisions
of current federal fisheries law provides plenty of reason for
concern.
It’s not hard to envision such folks, already advocates for
irresponsible fishery management, using the alleged success of the
Texas hatchery program as a basis for arguing that it’s fine to overharvest
wild marine fish stocks, so long as there is enough hatchery production “to
assure that harvest levels are sustained.”
Freshwater fisheries management was led astray by just such
Pied Pipers many decades ago, and is only now trying to undo some of the damage
and restore healthy populations of native fish.
Even so, such an approach may already be moving forward in
Mississippi, where the
Mississippi Press-News reported that
“Marine biologists are trying to learn whether they can
increase populations of [spotted seatrout and red snapper,] two of the Gulf of Mexico’s most popular sport and food
fish—and
perhaps further relax quotas on one of them—by raising and releasing
small fry. [emphasis added]
Not everyone is sold on the idea. The Press-News quoted Alec D. MacCall, a senior scientist at NMFS’ fisheries ecology
division based in Santa Cruz, California, who observed that
“The real fundamental problem is fisheries reform. If a hatchery effectively stops management
reform for the natural stock, I’d be hesitant to call anything successful.”
The industry folks who would use hatchery production to
justify overfishing would, of course, disagree.
Earlier this year, two biologists, Gregory T. Ruggerone and
Brendan M. Connors, published a paper entitled “Productivity
and life history of sockeye salmon in relation to competition with pink and
sockeye salmon in the North Pacific Ocean.“ It described the sort of problems that
hatchery fish might cause when large numbers of them are introduced into a
marine ecosystem.
Ruggerone and Connors began by investigating why sockeye
salmon runs were declining sharply over a wide area that extended from southern
Alaska down the entire coast of British Columbia and into the rivers of
Washington. Anything that could affect
sockeye salmon over such a broad geographic area, and spanned fish returning to
so many river systems, had to be taking place out at sea.
Eventually, they found a strong correlation between declines
in sockeye salmon and increases in the numbers of pink salmon. More specifically, they found that the
growth, age at maturity and survival of sockeye salmon were adversely impacted
when the sockeye had to compete for food with large numbers of pink salmon during
the sockeyes’ second year in the sea.
That becomes relevant to the hatchery debate because, in
recent years, hatcheries
in both Alaska and Russia have been ramping up salmon production, and pink
salmon have comprised a large part of the approximately 5 billion salmon
that are released into the ecosystem every year. To minimize the impact on sockeye salmon, the
paper’s authors recommend that hatchery production be capped.
Not surprisingly, the
folks who run the hatcheries don’t accept the researchers’ finding and
recommendations.
Some challenge the science, arguing that there is no link
between the seeming correlation and actual causation.
Others take a more fatalistic view, suggesting that the harm
was inevitable. Along with challenging
the science, Steve Reifenstuhl, the general manager of Northern Southeast
Regional Aquaculture reportedly responded to the paper by saying
“Do you think that we can control Russia? Russian [sic] and Japan would quickly move to
fill that void if there were a cap.”
What Reifenstuhl left unsaid was exactly what he meant by “void”
and why he believed that both Japan and Russia wouldn’t maximize hatchery
production regardless of anything that Canada and the United States might do.
Others emphasized economics. Trent Dodson, production and operations
manager for the Kodiak Regional Aquaculture Association, said that
“when we had a low wild pink salmon return and a better than
average hatchery return, we were able to help bridge that gap and provide a
[sic] economic benefit for common property fishermen that wouldn’t have been
there otherwise.”
Thus, hatchery supporters
repeat a common theme whether they are dealing with the recreational red drum
fishery in Texas, the mixed red snapper fishery in Mississippi or the
commercial salmon fishery in Alaska:
Hatcheries let people kill more fish.
They also seem joined by another
common theme: None of them appear to be
giving serious consideration to the damage that hatchery fish may do out in the
ocean, when they compete with wild-spawned fish of their own or perhaps of
other species.
Given Ruggerone and Connors’ work,
fisheries managers shouldn’t be so unconcerned about the effects of releasing
hatchery fish into our marine waters.
As the Texas Parks and
Wildlife biologist has already told us,
“Once they have been stocked successfully, the system will be
forever changed.”
" Coastal Fisheries should continue to address the question whether hatchery stockings provide a cost-effective increase in population abundance in coastal waters. Substantial resources have been allocated to augmenting populations of red drum and spotted seatrout with hatchery stockings. While the survival of hatchery-reared fish has been documented, the research hypothesis that hatchery stockings increase abundance has not been conclusively proven." pg. 17
ReplyDeleteTo my knowledge, the above questions of cost effectiveness and program efficacy have not been adequately addressed by Texas Parks and Wildlife Dept.
re: http://www.tpwd.state.tx.us/publications/nonpwdpubs/media/afs_fisheries_divisions_science_review_report.pdf
Thanks for the link. It was an interesting read. And more evidence that the argument in favor of hatcheries may be overstated.
DeleteThe "evidence" from TPWD seems to be motivated more for good PR than for scientific validation of so called "stock enhancement".
DeleteI suppose that producing PR is a lot easier than producing good science--and has a greater political benefit, at least in the short term. And it would be awfully embarrassing, after all the time and money was spent, to do the science only to discover that the "enhancement" was largely imaginary.
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