State Fish and Wildlife held a public meeting on the state of Lake Washington’s sockeye salmon on May 26 at the Issaquah Hatchery, and one sport fishing group came up with a proposed plan they think would enhance sockeye runs to the huge urban watershed.
The Muskies, Inc. local chapter group says a way to increase sockeye returns is by using a biological control method.
The group proposed introduction of tiger muskies for three years at a cost of about $10,000 per year, which was offered as an “option” to greatly reduce the number of predatory northern pike-minnows.
Only 22,166 adult sockeye returned to Lake Washington last year, the lowest since 1972.
In 2006, the lake hosted a 13-day sport fishery when 458,005 sockeye returned. At least 350,000 are needed for spawning escapement before any type of fishery is allowed. Other times when a fishery occurred was 2000, 2002 and 2004.
In a release by Muskies, Inc. they reported that Jack Tipping, a retired state Fish and Wildlife biologist found that the 1995 introduction of tiger muskies to Merwin Reservoir in southwest Washington reduced the number of northern pike-minnows by around 80-percent, and subsequently the kokanee, landlocked sockeye salmon, sport fishery skyrocketed.
Adding credence to this idea, is a recently completed thesis by Niccolo Piacentini, “Exploring the Impact of Introducing Tiger Muskies to the Lake Washington Ecosystem Using Ecopath”.
Excerpts from his report:
1: “The ecopath models have made it apparent that a controlled introduction of Tiger Muskies in the Lake Washington ecosystem could potentially have an extremely beneficial impact on the juvenile sockeye population ”
2: “The mortality due to predation of juvenile sockeye would be cut down by over 40-percent, nearly doubling the survival rate.
Niccolo added: “Another interesting point that his study makes is that the other fish populations, especially the cutthroat trout, would not suffer from the introduction of tiger muskies because their rates of biological production are higher than that of the northern pike minnows; they may actually even benefit from such an introduction.”
“Some level of funding is available to help with this kind of project, via our Grant Program geared toward research”, added Perry Peterson, V.P. Internal Affairs, Muskies, Inc., who has more than 50 chapters across the United States.
Tiger Muskies are a sterile hybrid and were first introduced into Washington in 1988 as a biological control of northern pike-minnows. They are currently planted into seven Washington lakes by the state Fish and Wildlife for fish control purposes.
The topic of the meeting was construction on a permanent hatchery facility on the Cedar River that was set to begin this spring or summer, and be finished and operational by September 2011.
A temporary hatchery that has been in place since 1991 has the capacity to produce 17 million fry, and has only done so once during that period. The permanent hatchery could produce 34 million fry.
“Scientists that we have spoken to believe the new hatchery should be built,” Frank Urabeck, a longtime sportfishing advocate and Cedar River Council member said in a recent Seattle Times story.
“Lately we haven’t even been near that (17 million fry) level of capacity,” Urabeck said. “By adaptively managing the new permanent hatchery with less than full capacity releases of fry initially, (it) should give us some idea of what the actual yield is in terms of adult returns,” Urabeck said.
Urabeck also mentioned that one way to avoid overwhelming the food source in the south end of the lake would be to transport some of the fish and spread them out over the entire lake.
(Photos taken by Seattle Times staff photographers)