Hood Canal Juvenile Salmonid Production Evaluation in 2013: Duckabush River
 
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Hood Canal Juvenile Salmonid Production Evaluation in 2013: Duckabush River

Category: Fish/Shellfish Research and Management

Date Published: May 2014

Number of Pages: 45

EXECUTIVE SUMMARY:

Juvenile salmonid monitoring on the Duckabush River, located in central Hood Canal, Washington, began in 2007. This work has been a collaborative project between the Washington Department of Fish and Wildlife (WDFW), Long Live the Kings (LLTK), and the Northwest Fisheries Science Centerfs (NWFSC) Manchester Research Station. This study measures the juvenile abundance and outmigration timing of Chinook salmon, chum salmon, pink salmon (even years only), coho salmon, and steelhead. We derive independent estimates for summer and fall chum salmon stocks in these watersheds via molecular genetic analysis. For those species with adult abundance surveys (chum, Chinook and pink salmon), we also estimate egg to migrant survival.

In 2013, a floating eight-foot screw trap was located at river mile 0.3 (0.48 rkm) and operated by WDFW from January 10 to July 2. The abundance of juvenile summer chum salmon was over six times larger than fall chum (Table 1). Egg-to-migrant survival was higher for summer than fall chum salmon. The peak of the summer chum outmigration occurred 4 weeks earlier than the peak of the fall chum outmigration. Chum salmon were by far the most abundant salmonid species emigrating from the Duckabush River in 2013 (Table 1).

TABLE 1.Abundance, coefficient of variation (CV), egg-to-migrant survival, average fork length and median out-migration date for juvenile salmonids of natural origin leaving the Duckabush River, 2013.

Abundance
Species Estimate CV Survival Median migration date Average fork length
Summer chum 285,468 5.1% 5.0% 9-Mar -
Fall chum 42,213 14.6% 1.2% 7-Apr -
Chinook 5,221 6.2% 52.2% 2-Apr 38.8 (±6.1)
Coho 6,732 22.1% - 6-May 91.9 (±12.3)
Steelhead 1,908 15.3% - 3-May 171.8 (±22.7)