Union/Tahuya Summer Chum Restoration

A Cooperative Project Between HCSEG & WDFW Hatchery Staff

HCSEG & WDFW began a new Summer Chum restoration project in Hood Canal. Hood Canal Summer Chum are ESA listed and many recovery efforts are underway.

The goal of the program is to increase the numbers of returning Summer Chum in the Union River to a safe level for transplanting eggs to the Tahuya River (determined to be extinct, WDFW).  The Union River has a relatively stable stock of Summer Chum, and it is one watershed south of the Tahuya River, which makes it a good donor stock.

The Union River adult fish trap is run by volunteers 24 hours a day, during a 3-month period.  Below  is a graph of 2000-2005 Summer Chum results at the Union River.

The first year our Union Summer Chum supplementation project started, we counted a total of 743 salmon returning for the seasons total.  Due to extremely good ocean conditions, an anomaly of an incredible 11,916 Summer Chum returned in 2003.  This year also had a world record return of Pink Salmon returning globally. Coincidentally, this was the return year of the initial brood stock of Union River Chum that were supplemented back in 2000. 

Volunteer Zac Palmer release a female Chinook the trap

We have had a cyclical decline in numbers since this initial return.  However, the numbers though seemingly low have been average to high to what has been estimated.  As return trends go, we expect a cyclical rise and fall in populations based on the returning numbers and factors that sustain or inhibit their existence.
 
An adult fish trap was installed in the Union River to count all adult Summer Chum and to enable us to collect 51 pairs of fish for spawning, throughout the entire run.  All of these Summer Chum eggs collected are now being used entirely for supplementation efforts of the Tahuya River.  Collecting fish throughout the run is one of the ways we try to preserve genetic diversity. 

Since the trap was visible from the road, volunteers manned the trap 24 hrs a day from August 15th until October 15th, the three months it was in the river. 

Before the fish are spawned, they are killed and length & weight data are taken from them.   Pictured right a female Summer Chum is laid on the measuring board for length data.

The fish we collect for spawning are kept in PVC tubes in-stream until they are ripe (ready to spawn). 

The fish are factorially spawned so that each female's eggs are fertilized by at least 2 or 3 different males.  This is another way we preserve genetic diversity.  The eggs and milt (sperm) are mixed in separate containers and water is added to activate the sperm. 

 George Adams Hatchery staff, Ed Joper & Brett Hatchel weigh a Summer Chum before it is spawned.
 
After the fish are spawned, we take many different samples from them including: ovarian/kidney/spleen for detecting viruses, scales samples for age, heart/liver/body/eye tissue for GSI data, pieces of gill plate for DNA analysis, GSI-Genetic Stock Identification

Half of the Summer Chum eggs are raised at the hatchery until they are ready to feed, and the other half are raised at a remote site in the Union River Watershed in WSI's (Wild Salmon Incubators).  The eggs become eyed (an eye is visible) in about a month.  Then they hatch and become alevin.
 

Eggs being taken from a Summer Chum female.
 
Pictured bottom right Union Summer Chum eggs are hatching into alevin (Nov. 2000).  Once they have buttoned-up (absorbed their yolk sac), they will become fry and begin to seek food.  We will feed the fry for about a month and release them when they are 1 gram per fish.

We are now seeing the returns of those initial supplemented stocks on the Union River and will likely see returns to the Tahuya system by fall of 2007.