[env-trinity] Redding.com editorial: Close Coleman hatchery to save fish?
tstokely at att.net
Tue Jun 4 17:09:06 PDT 2013
I missed this one from a month ago.
May 2, 2013 3:29 PM | 2 Comments
Close Coleman hatchery to save fish?
The Public Policy Institute of California came out with a deep look recently at the likely costs and benefits of the many possible approaches to improving the ecological health of Sacramento-San Joaquin Delta and its fisheries. Here's an especially provocative one with major local effects, from an assessment of costs.
Action #14: Manage hatcheries to separate hatchery fish from wild populations (considered, $$)
Hatcheries were established to mitigate the negative effects of dams on migratory salmon and steelhead trout, because dams cut off access to their natural upstream spawning grounds. However, recent evidence points to unintended harm from hatcheries to the wild populations of these species (Williams 2006; Lindley et al. 2009; Carlson and Satterthwaite 2011). Populations of winter-run and spring-run Chinook salmon--both listed under federal and state Endangered Species Acts--are partially supported by hatchery production, but substantial recovery has not occurred. The main remaining run is fall-run Chinook, which now consists almost entirely of fish of hatchery origin or progeny of hatchery fish. The result is a more genetically uniform (and presumably more behaviorally uniform) population throughout the Central Valley. These fish are poorly adapted for surviving periods of adverse conditions in the ocean, resulting in yo-yo population dynamics. Salmon numbers were so low in 2008 and 2009 that the fishery was closed, whereas in 2012, the numbers were the highest in decades.
Recent proposals have suggested that the effectiveness of hatchery operations in California can be improved by managing hatcheries that support commercial and residential fisheries in ways that isolate them from wild populations (Hanak et al. 2011). In the extreme, hatcheries supporting the fisheries would be closed, and regulated rivers would be managed better to support wild salmon, perhaps even by removing some dams (#28). Such a strategy could result in the closure of the commercial and recreational fisheries for Central Valley salmon and steelhead for many years, until wild populations recovered. According to Michael's (2010) estimate of losses from the complete closure of California's salmon fisheries in 2008 and 2009 (#10), the complete closure of the fishery would have annual losses on the order of $35 million in revenues and $18 million in value added (relative to 2005 baseline conditions).
An alternative would be to continue some fishery-oriented hatcheries but in a more segregated manner. Hatcheries run entirely to support fisheries would presumably be located near the ocean and operated to minimize the straying of hatchery fish and their interbreeding with wild fish. For example, all fish would be marked so that strays could be removed from upstream areas and fisheries could concentrate on marked fish. Most rivers would be reserved for wild salmon, to re-initiate the processes of natural selection. As a compromise, the hatcheries on the American and Mokelumne Rivers, which are closer to the ocean than more upstream hatcheries, could be managed for fisheries, in part by trucking juveniles around the estuary (#7) and making sure that only marked fish in the river are harvested or used for hatchery purposes. Relocation and/or closure of the Coleman, Feather River, and Merced Hatcheries as production facilities would be necessary because of their distance from the ocean and proximity to remaining natural spawning areas.Alternatively, they could be operated as conservation hatcheries (#10). Such a strategy could maintain the commercial and recreational fishery (albeit perhaps at reduced levels). Cost would include relocating equipment and staff -- perhaps 50 percent to 75 percent of the costs of building a new facility, or $100 million to $150 million (#10) -- or $5 million to $8 million in annualized terms per facility.
-------------- next part --------------
An HTML attachment was scrubbed...
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 9457 bytes
Desc: not available
Url : http://www2.dcn.org/pipermail/env-trinity/attachments/20130604/6bb3b2ad/blogs_bross-0001.jpg
More information about the env-trinity