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NW Fishletter #374, October 2, 2017
 Eulachon Recovery Plan Identifies Top Threats and Priority Actions
NOAA Fisheries has finalized a recovery strategy for the southern distinct population segment (DPS) of eulachon, an anadromous smelt in the northeast Pacific Ocean that spawn in freshwater rivers from northern California to southern British Columbia.
Although this DPS has four subpopulations--Klamath River, Columbia River, Fraser River and B.C. coastal rivers south of the Nass River--most of eulachon population are spawners from the lower Columbia River and its tributaries.
The September 2017 Recovery Plan for Southern Distinct Population Segment of Eulachon identifies climate change effects on ocean conditions as the most serious threat to eulachon throughout their range.
The recovery plan says the principal threat to eulachon is likely the changes in ocean conditions--in temperature, precipitation, wind patterns and sea level heights--induced by both human activities and natural climatic variability.
"Climate change is the one phenomenon that correlates with the recent species-wide declines in abundance," the plan says.
The southern eulachon is a small fish with an average weight of 1.4 ounces and average length of 8 inches; they were listed as threatened under the Endangered Species Act in 2010.
The recovery plan considers eulachon bycatch in ocean fisheries as a high level threat to Columbia River and British Columbia populations.
Dams and water diversions, predation and water quality are moderate threats in the Columbia and Klamath rivers. Dredging and shoreline construction are also moderate threats to the Columbia River eulachon population.
Cowlitz River eulachon harvest circa 1920. Credit: Cowlitz County Historical Museum
The Columbia River population consists of the Cowlitz, Gray, Kalama, Lewis and Sandy rivers, although eulachon were known to migrate farther upstream beyond Bonneville Dam as far as the Hood River and possibly the Klickitat River.
The recovery plan emphasizes that when it comes to eulachon there are more unknowns than knowns. A case in point is abundance data.
Because no historical abundance estimates exist for this species, the recovery plan considers historical landings data to be a minimum measure of abundance.
To sustain abundance and reach recovery, the total run size has to be substantially higher than the estimated range of adult eulachon harvested each year, the plan says.
Historical catches have ranged between 12 million and 128 million fish per year. Commercial, recreational and tribal/First Nations fisheries have historically harvested eulachon all along the West Coast of the U.S. and Canada.
Because of the paucity of information on eulachon, the recovery strategy sets numerous research priorities to improve fish managers' understanding of eulachon population abundance and demographics, and the linkages between threats, marine and freshwater environments and the species.
Most actions to deal with threats, including the top threat of climate changes in the ocean and in freshwater, involve research and other analytical products.
Regarding bycatch, the plan says NOAA Fisheries will continue to reduce the sizable ocean bycatch, or incidental harvest, of eulachon. It recommends the fleetwide adoption of rigid-grate bycatch reduction devices and light-emitting diode lights.
The recovery strategy describes the operation of the Federal Columbia River Power System as having altered the hydrological cycle in such a way that freshwater inputs to the estuary--plume environment are diminished during April-July. This period coincides with the eulachon freshwater-ocean transition period and is thus likely to adversely effect marine survival of eulachon larvae and juveniles.
NOAA Fisheries intends to reduce the ecological impacts of dams by continuing its collaboration with the entities that manage and operate them, the plan says.
In the Klamath River Basin, the plan calls for a research and monitoring plan to assess the effects of post-dam removal. Four Klamath Basin dams owned by PacifiCorp are slated for demolition and await federal funding.
The cost of implementing recovery actions in the U.S. over the first five fiscal years is $12.2 million. A rough estimate for the total cost of recovery in the U.S. jurisdiction is $21.4 million over 25 years or $32.0 million over 100 years. -Laura Berg
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