Thursday, October 11, 2012

Salmon Spawner Requirement Needed to Control Harvest

October 10,2012
Wild Salmon Escapement Allocation:
There are major unresolved issues associated with the effort to re-allocate harvest share and management on the Columbia River. Since most wild salmon and steelhead in the lower Columbia River are threatened with extinction and protected by the Endangered Species Act, the health of all wild populations of salmon and steelhead and recovery of threatened populations should be included in any harvest management changes.  The effect of harvest, especially non-selective harvest that takes wild salmonids, is to subtract spawners from their natal watersheds and this can have negative demographic and ecological consequences.  All harvest has an impact, even harvest that targets hatchery fish, for there is always an associated kill of wild salmonids that are caught and released.  The only way to effectively manage harvest to protect and recover wild salmon and steelhead in the lower Columbia River is to regulate harvest to set tributary and specific escapement targets, and then regulate harvest to meet those targets.  There must be sufficient monitoring to ensure the escapement targets are met.

Knudsen (2000) confirms the importance of having conservation escapement requirement: “Both productivity and biodiversity depend on sufficient escapement of spawners to fully utilize the available freshwater habitat, fertilize the systems with carcasses, and optimize genetic diversity.” 

Even though there are currently interim spawner goals recommended (HSRG 2000; NMFS 2002) they have not been adopted as formal requirements.  The important question is this: Does harvest support recovery of ESA-listed salmon and steelhead and protect all wild populations utilizing the lower Columbia River for reproduction?  That is a key question to ask of any harvest allocation plan.

There are other issues that must also be addressed along with a spawner allocation.  They include releasing hatchery fish in the spawning areas used by wild salmon and steelhead; stray hatchery fish that breed with wild salmonids and compete with them for available habitat and food resources in the tributaries, the main stem Columbia and in the estuary, and the impact of stray hatchery fish on streams near hatchery release sites in the lower Columbia River.  Each of these issues can seriously compromise the effectiveness of recovery actions for wild salmonids in lower Columbia River tributaries. 

It is important to not only resolve allocation of fish among user groups, but in doing so, to make sure that wild salmon and steelhead recovery is a benefit of any harvest allocation agreement. 

Harvest reallocation problems have been around for over 100 years.  It is not something new. The history of harvest reallocation in Oregon and Washington indicates that the expected benefits from salmon and steelhead spawner escapement have not been accomplished.  Beginning in the 1930s through the 1950s there were several citizen initiative petitions aimed at protecting salmon from excessive harvest.  The states of Oregon and Washington, in response to citizen promoted measures, eliminated fixed harvest gear like traps and fishwheels.  In 1948 the Fish Commission of Oregon evaluated this change to determine whether what they called the “dire” depletion of salmon in the Columbia River had been addressed by increasing salmon spawner numbers.  Their conclusion was that the fisheries that continued to operate legally in the river simply consumed more fish and the spawning escapement did not increase (Johnson et al 1948). 

Commercial netting in Oregon bays was brought to an end by citizen action in order to rebuild depleted salmon and steelhead populations (Cleaver 1951). What happened is that some species (coho salmon) continued to be over harvested in other fisheries.  These two examples have one thing in common; that is, the state fish management agencies did not establish a spawner requirement and the fisheries could not be adequately controlled.

Harvest management involves two primary activities: setting the allowable harvest and allocating the allowable harvest among the different sport and commercial fisheries. The former is a technical task, the latter is a political task. Too often the technical and the political tasks are so intertwined that their separate roles become confused.  To avoid that confusion the two activities should be clearly separated
(separate oversight and supervision paths) within the organization structure of the management agencies (Lichatowich and Bakke 2012).

The questions in this harvest allocation agreement are whether the agreement includes a spawner escapement requirement sufficient to aid in recovery and reduce the impact of hatchery fish on the spawning grounds. If the answer to either of those questions is “no”, then the allocation agreement will be insufficient to meet Governor Kitzhaber’s dual goals of increasing the economic benefits of the fisheries while aiding in the restoration of threatened and endangered wild fish populations.

Reducing Impact of Hatchery Salmon:
Governor Kitzhaber has expressed concern about the number of hatchery fish in rivers.  Naturally spawning hatchery fish can and do interbreed with wild salmon in rivers reducing the reproductive success of wild salmon (Araki et al 2009; Christie et al. 2011; Chilcote et al. 2010), most of which are threatened with extinction.  In addition, naturally spawning hatchery fish produce juveniles that compete with wild salmon for habitat and food, limit nutrient enrichment of streams from salmon carcasses, and reduce the productive capacity of rivers (Kostow et al. 2006).  

In order to control the impact of naturally spawning hatchery fish in Columbia River tributaries two actions are needed: 1) remove production releases from the tributaries and move them to off-channel net pens in the Columbia River; 2) control stray hatchery fish entering tributaries to help reduce spawning with wild salmonids and creating competition for habitat and food.  These two actions will assist in recovery of ESA-listed salmonids in the tributaries.  The species that are now released into the tributaries and causing problems are hatchery winter and summer steelhead, coho salmon and spring chinook.  By moving production releases of coho and spring chinook to off-channel net pens and applying measures to control strays in streams near those net pens, wild coho and spring chinook in the tributaries could benefit.  It is important to avoid transferring the upstream impacts to downstream locations. Monitoring and evaluation is necessary to prove exactly what benefits are achieved in the tributaries. 

In addition, releases of hatchery salmon at net pens or in tributaries have an impact on wild salmon and steelhead in the mainstem Columbia, the estuary and near-shore ocean waters.  These impacts include competition for food and habitat, predation and predator attraction.  These issues will not be resolved by moving production hatchery fish to net pens. 

Impacts of hatchery steelhead on wild steelhead in tributaries will have to be addressed at the tributary level, for these fish are not a target species for the commercial fishery and should not be moved to off-channel net pens.  However, converting the fishery to selective gear for hatchery fish and live release of wild fish would contribute to improved spawner escapement in the tributaries and increase nutrient enrichment. 

Recommended Hatchery Salmon to be Relocated:
Sandy River spring chinook and coho salmon
Molalla River spring chinook salmon
North Santiam spring chinook
Clackamas River spring chinook and coho salmon

Bill Bakke, Conservation Science Director, Native Fish Society

Araki, Hitoshi, Becky Cooper, and Michael S. Blouin. 2009. Carry-over effects of captive breeding reduces reproductive fitness of wild-born descendants in the wild.  Biological Letters 5: (5) 621-624.

Chilcote, Mark M.W., K.W. Goodson, and M.R. Falcy. 2010. Reduced recruitment performance in natural populations of anadromous salmonids associated with hatchery-reared fish. Can. J. Fish. Aquat. Sci. 68: 511-522.

Christie, Mark R., Melanie L. Marine, Rod A. French, and Michael S. Blouin. 2011. Genetic adaptation to captivity can occur in a single generation. Proceedings of the National Academy of Sciences of North America (PNAS)

Cleaver, F.C. 1951. Fisheries statistics of Oregon. Oregon Fish Commission. Contribution No. 16.

Hatchery Science Review Group (HSRG). 2000. Findings of the Columbia River System-wide Report. HSRG Report Appendix E. 

Johnson, D.R., W.M. Chapman, and R.W. Schoning. 1948. The effects on salmon populations of the partial elimination of fixed fishing gear on the Columbia River in 1935. Fish Commission of Oregon.

Knudsen, et al. 2000. Sustainable fisheries management: Pacific salmon. Eds. E. Erich Knudsen, Cleveland R. Steward, Donald D. McDonald, Jack E. Williams, and Dudley W. Reiser.  Lewis Publishers. Ann Arbor Press.

Kostow, Kathryn E. and Shijie Zhou. 2006. The effect of an introduced summer steelhead hatchery  stock on the productivity of a wild winter steelhead population. Transactions of the American Fisheries Society 135:825-841.

Lichatowich and Bakke. 2012. The way forward to protect and recovery wild fish. The Osprey. Issue No. 73.

National Marine Fisheries Service. April 4, 2002. Interim abundance targets for interior Columbia Basin salmon and steelhead listed under the Endangered Species Act (ESA). Bob Lohn letter to Frank L. Cassidy, Jr, Chairman, Northwest Power Planning Council.

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