US Navy


Marine Species Monitoring

Characterizing the distribution of ESA-listed salmonids in Washington and Alaska

Introduction & Objectives

This project supports Pacific salmonid studies in the offshore waters of the existing Northwest Training Range Complex (NWTRC), offshore Naval Undersea Warfare Center Keyport Range Complex (together known as the Northwest Training and Testing (NWTT) Study Area), and the Gulf of Alaska Temporary Maritime Activities Area (GOA TMAA). The goal of this study is to use acoustic tagging technology to provide critical information on spatial and temporal distribution of salmonids to inform salmon management, U.S. Navy training activities, and Southern Resident Killer Whale (SRKW) conservation. 


Technical Approach

In May 2019, 107 acoustic receiver stations were deployed in a grid pattern along the coast of Washington State.  These will be retrieved, data downloaded, and redeployed until the end of the project. 

Salmonids including bull trout, Chinook salmon, and Coho salmon will be the target species for this project.  Data collected from caught fish will include measurements, fin clips for genetic analysis, and healthy fish of appropriate size will be tagged with either an acoustic pinger tag or a pop-up satellite tag. 

Analysis will include the use of oceanographic models to determine spatially explicit environmental conditions within the ocean, as well as the development of a specific analysis with Brad Hanson (NOAA Northwest Fisheries Science Center) to examine the degree to which tagged salmonids and piscivorous killer whales overlap through space and time.


Progress & Results

In April of 2019, researchers tagged six bull trout in the Hoh River and 11 in Kalaloch Creek. From May to August 2019, researchers tagged 142 Chinook salmon and 35 Coho salmon along the coast of Washington State. They collected fin clips to perform genetic stock identification of the Chinook salmon and Coho salmon. Receivers were retrieved, data was downloaded, and stationary receivers were redeployed in September 2019. 

Using the retrieved data, the number of unique individuals detected at each stationary receiver location was plotted for Chinook salmon, coho salmon, bull trout and green sturgeon (tagged by other researchers). The mean residence time for each receiver was calculated and then interpolated through space. Further analysis examining the distribution of salmon will be completed once the complete detection history of each fish is obtained.

Please refer to the report to view figures of the number of unique individuals detected at each receiver location, as well as the mean residence time for each species.

Publications: None