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Title: Steelhead Spawning Surveys Near Locke Island, Hanford Reach of the Columbia River

In 1997, the National Marine Fisheries Service (NMFS) listed upper Columbia River steelhead trout (Oncorhynchus znykiss) as endangered. This action affected management of land-use activities along and within the Hanford Reach of the Columbia River, which flows through the U.S. Department of Energy (DOE) Hanford Site. Steelhead covered in this listing include all naturally spawned populations of steel-head and their progeny in streams in the Columbia River Basin upstream from the Yakima River to the United States/Canada border. The NMFS has identified a general listing of activities that could potentially result in harm to steelhead (62 FR 43937, August 18, 1997). One of these concerns includes land-use changes resulting in mass wasting or surface erosion. Landslide activity along the White Bluffs on the east ,side of Locke Island has redirected river flow into the island where substantial erosion has occurred. This erosion has exposed important anthropological and archaeological resources that were previously buried on the island. The DOE is working with affected tribes and other agencies to develop a plan for addressing the erosion of Locke Island. As part of this effort, the U.S. Army Corps of Engineers has prepared an assessment of potential alternatives to stabilize the erosion, includingmore » a no-action alternative. Steelhead historically spawned in the vicinity of Locke Island, but recent information on the occurrence of steelhead spawning or availability of spawning habitat was lacking. Therefore, the purpose of this study was to determine if steelhead spawned in the vicinity of Locke Island erosion and to evaluate the composition of substrate in the affected area. Surveys to document the occurrence of steelheads redds were conducted in Spring 1999. The surveys were conducted from the air as well as with the use of an underwater video camera. Neither aerial nor underwater surveys documented steelhead spawning within the survey area. Habitat surveys were conducted in July 1999. The survey area was divided into an area adjacent to the erosion zone and an area immediately upstream of this zone. The majority of the survey area was composed of gravel and medium cobble (particle sizes 0.6 to 15.2 cm). Aquatic vegetation (milfoil) was found in the upstream section, indicating lower water velocities not conducive to steelhead spawning. Based on the available substrate within the entire survey area, we estimate 81% of survey site could be used by adult steelhead for spawning.« less
Authors:
;
Publication Date:
OSTI Identifier:
13843
Report Number(s):
PNNL-13055
R&D Project: 12674; TRN: AH200135%%548
DOE Contract Number:
AC06-76RL01830
Resource Type:
Technical Report
Resource Relation:
Other Information: PBD: 19 Oct 1999
Research Org:
Pacific Northwest National Lab., Richland, WA (US)
Sponsoring Org:
US Department of Energy (US)
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; COLUMBIA RIVER; COLUMBIA RIVER BASIN; FISHERIES; HABITAT; ISLANDS; LAND USE; PLANTS; RIVERS; TROUT; US CORPS OF ENGINEERS