Hood Canal Steelhead Supplementation Project

 

Collaborators: National Oceanographic and Atmospheric Administration (lead agency), Washington Department of Fish and Wildlife, US Fish and Wildlife Service, Skokomish Tribal Nation, Long Live the Kings, and Hood Canal Salmon Enhancement Group

 

The Hood Canal Steelhead Supplementation Project is a 16-year study designed to rebuild steelhead populations in Hood Canal while testing the effects of hatchery supplementation on natural populations. 

 

 

Steelhead smolt are collected by seine net in the Dewatto

 

 

There is a great need to better understand how conservation hatchery programs impact natural populations.  Large-scale experiments using both treatment and control populations are necessary to answer this question.  This is the first year of a long-term study that will fulfill this objective.  It is an expansion of the Hamma Hamma River Steelhead Supplementation Project and will include three new supplementation streams (Duckabush River, Dewatto River, and Skokomish River) and three control streams (Dosewallips River, Tahuya River, and Big Beef Creek).     

                                                           

 

O. mykiss parr collected from seining   

 

 

The study includes pre-supplementation, supplementation, and post-supplementation phases.  For eight years, beginning in spring 2007, eyed Steelhead (Onchoryncus mykiss) eggs will be collected from naturally constructed redds in the Duckabush, Dewatto, and Skokomish Rivers.  The fish will be reared in hatcheries until they are released as either smolts or adults.  All fish will be released to spawn naturally.  During all phases, the study will monitor adult and smolt abundance, genetic composition, life-history patterns, and early marine migration and survival.

This project is a large collaborative effort to conduct work on seven Hood Canal streams.  The primary focus of

the HCSEG is to carry on work on the Dewatto and Tahuya Rivers and assist on the other streams.

                                                       

 

O. mykiss parr are fin clipped for gentetic analysis        

                                                 

Adult and smolt abundance monitoring

Adult steelhead abundance will be monitored using redd surveys from February to June.  Different stream characteristics require a combination of foot, aerial, and raft surveys.  Smolt abundance will be monitored with screw traps, as well as the weir and trap on Big Beef Creek, from late March through early June.

 

Genetic monitoring

A key goal of this study is to determine if genetic changes take place as a result of supplementation.  Genetic samples will be collected from eggs, summer parr, smolts, and resident rainbow trout, and scale samples will be collected for age determination.  Analysis of treatment and control populations will determine if genetic diversity is affected by supplementation.  

 

O. mykiss smolt are measured and wieghed as part of the anaysis and

determination of gentic make-up                              

 

                                                                                                                 

                                          O. Mykiss prepared for surgery to implant acoustic transmitter 

 

Life-history monitoring    

Oncorhynchus mykiss exist as resident rainbow trout and anadromous steelhead.  The project will monitor the proportion of resident trout versus anadromous steelhead and the genetic characteristics of the two forms.  By analyzing chemical ratios in otolith cores, it can be determined whether a juvenile fish is the offspring of a resident or anadromous mother.  This allows the paring of life-history patterns with genetic makeup.                                      

 

Otoliths and genetic samples are collected during summer parr sampling, which began in 2006.  During the summer sampling, fish over a certain size are assumed to be resident fish, and genetic samples are collected.  Supplemented and control populations will be sampled for the duration of the study to determine if changes in the proportion of resident and anadromous fish occur as a result of hatchery supplementation. 

 

 

Transmitter is implanted in O. Mykiss smolt   

                                                                                                                          

 

Early marine migration and survival monitoring

Using acoustic telemetry technology, steelhead early marine migration and survival will continue to be investigated.  Acoustic transmitters are surgically implanted in a sample of steelhead smolts captured in smolt traps.  The unique signals from these transmitters are detected by 

receivers located at river mouths, at  nearshore sites in Hood Canal, and in

transects in northern Hood Canal and the Straits.  The information gathered from the individual receivers is assembled to show migration patterns, survival rates, and the length of time that steelhead spend in the marine environment before moving to the ocean.  

 

 

The Hood Canal Steelhead Supplementation Project will address many critical questions relating to hatchery impacts and steelhead populations in general.  As the numbers of salmon and steelhead restoration efforts increase, it is important to have a more complete knowledge of the impacts and effectiveness of conservation strategies.