Chinook rearing

LLTK's first hatchery program began at Wishkah in 1986 as a recovery effort in response to severely depressed returns of adult chinook salmon. The first chinook eggs used for broodstock were taken from fish in the tidal reach of the river, which begins about 12 miles downstream from the hatchery. Since the program's first year, broodstock has come either from fish returning directly to the hatchery or from fish ready to spawn downstream from the hatchery, or both. In 2002, for example, water levels were so low in the lower reaches of the river that returning adults were unable to get upstream, and water levels in traditional spawning grounds were too low for successful spawning. LLTK staff captured 80 fish near the mouth of the river, spawning 61 at the hatchery and releasing 19 back into the river.

After the eggs are hatched, we keep the young salmon in incubators until they have consumed their egg sacs. The resulting salmon fry are then moved to outdoor tanks for as little as three days, while they acclimate to eating solid food. The juvenile fish are then released into an earthen pond surrounded by native plants and connected directly to the river. They migrate out at a time of their own choosing over a two-month period (a "volitional release"), rather than being forced out all at one time.

Whether LLTK's efforts are leading to recovery of Wishkah River chinook is unknown, although the program appears to be preventing a further decline: adult returns have remained steady even though habitat conditions have not improved since the program began in 1986. In 2003, the Hatchery Scientific Review Group recommended that LLTK mark or tag hatchery-released chinook in order to distinguish between them and naturally spawning fish, allowing us to better evaluate the status of both.

Coho rearing

LLTK's Wishkah coho salmon program began in 1988 in response to declining adult returns and the desire to rebuild a popular fishery in Grays Harbor, located at the mouth of the Chehalis River near downtown Aberdeen (the Wishkah is a tributary of the Chehalis). The first eggs used for broodstock came from adults returning to spawn in the Wishkah River.

Every year since then, broodstock has been taken mostly from hatchery-origin returning adults. Some wild fish are also used in order to increase the genetic diversity and genetic fitness of that year's broodstock. Each of the 300,000 coho released annually is marked by clipping its vestigial adipose fin, ensuring that both Wishkah staff and fishermen can differentiate between hatchery and natural-origin coho adults.

After being incubated to the fry stage, juvenile coho are reared in an earthen pond until they are approximately 18 months old. They are then moved to net pens at the mouth of the Chehalis River, where fresh water mixes with salt water, and are fed and allowed to acclimate to salt water for about three weeks before being released. Even though this release occurs some 30 miles away from where they were reared, many return to the river at or near the hatchery, where they spawn naturally or are captured as broodstock. Some actually return to the collection channel at the outflow of the rearing pond where they were raised, a powerful demonstration of salmon's remarkable homing ability.

In its 2003 review of Wishkah, the Hatchery Scientific Review Group recommended releasing half of the 18-month-old coho from net pens, as all currently are, and the other half at the hatchery. This would allow evaluation of whether the net-pen release strategy increases adult survival compared to an in-river release strategy, as is currently assumed. Other recommendations included evaluating the contribution of the Wishkah coho program to the Grays Harbor fishery, which is also supported by programs at other hatcheries in the Chehalis River Basin.

Rearing and refuge habitat

Only two of the Wishkah facility's constructed ponds are used specifically to rear hatchery fish. Seven others were built to provide refuge and rearing habitat for wild coho and other species of fish and wildlife. These off-channel ponds, connected to the river, are maturing and are used regularly by young coho, which often spend more than a year in fresh water before migrating to the ocean. The ponds are particularly valuable during times of drought and flooding. And in the Wishkah Valley, heavily logged and dense with roads, large amounts of gill-clogging sediment can be flushed into the river by even moderate rainfall.

We have similar off-channel habitat-development projects elsewhere in the area, including the East Fork of the Wishkah and the Wynoochee Rivers. These sites—Simpson Pond, the Okie Thompson Project, the Carter Pit Site, and Darrin's Pond—have been developed and maintained with various partners, including the U.S. Fish and Wildlife Service, the Washington Department of Fish and Wildlife, the Chehalis Basin Fisheries Task Force, the Grays Harbor Chapter of Trout Unlimited, and private landowners.

These LLTK ponds regularly host a variety of fish and wildlife, including coho, chinook, and chum salmon as well as cutthroat trout, lamprey, peamouth, and newts.

Monitoring and evaluation

At our Wishkah facility, LLTK set out to develop replicable, low-tech natural rearing and off-channel habitat projects. Mounting anecdotal evidence points to their success. The next step is scientific monitoring and evaluation.

The same natural qualities that make the hatchery's off-channel projects and constructed ponds desirable habitat for salmon also make them difficult to evaluate and monitor. The channels and ponds are integrated with the Wishkah River. Their biological complexity makes them naturally productive, but also makes it difficult to quantify fish production as a measure of their success.

LLTK has hired University of Idaho graduate Dr. David Smith to assess Wishkah's monitoring needs and to write a protocol for LLTK staff to quantify production. Among other benefits, the new monitoring project will help LLTK better evaluate the contribution the hatchery is making to the popular coho sportfishery in Grays Harbor. We expect the first results of the monitoring in 2004. Dr. Smith is affiliated with the Aquaculture Research Institute in Moscow, Idaho.