For schoolchildren, salmon are providing lessons about water and the environment. But some scientists worry that what students are being taught may have unintentionally counterproductive results.
Springing up like mushrooms after a fall rain, salmon-rearing aquariums have replaced cups of beans and sunflowers as the centerpiece of elementary-level biology lessons around Puget Sound.
These mini-hatcheries offer children first-hand knowledge of the life cycle of the five species of Pacific salmon, and dramatize the importance of water and a clean environment.
Nevertheless, some biologists and educators remain remain wary of salmon-in-the-classroom projects. They worry that the schools' hatchery fish could damage wild salmon runs through competition for limited resources or through genetic changes. And at a time when hatcheries are increasingly controversial, they are concerned about what they perceive as a pro-hatchery curriculum.
"The whole process carries two messages," says a leading critic, University of Washington fisheries professor Ray Hilborn. "One is that hatcheries are the solution to the problem. The other is that the wild fish are gone."
Neither message is correct, according to Hilborn, who says wild fish still account for two-thirds of the salmon caught by fishermen in Puget Sound.
Hilborn's concerns are shared by a number of fisheries experts, including King County stream ecologist Bob Fuerstenberg, who says: "We have to take the kids out to the streams, too, and say, `This is where fish come from - not from glass boxes.' "
Others are enthusiastic about new salmon studies, which have brought refrigerated aquariums to as many as 200 schools in King County and 500 schools statewide.
"We're not promoting hatcheries here at all," says Anthony Matlock, a public education specialist with Seattle's Drainage and Wastewater Utility, the largest local sponsor of classroom aquarium projects. "We want kids to know they have to keep the lakes and streams clean so that if the salmon return they will have a place to return to."
To promote its clean-water message, the agency has spent the past three years installing an aquarium in every elementary school in Seattle and sponsoring visits by fourth-graders to the UW fish hatchery, the Seattle Aquarium and the Springbrook Trout Farm in Renton.
A similar state Department of Fisheries program distributes 40 to 50 aquariums annually to schools around the state.
Matlock views salmon as an "indicator species" that measures the health of Puget Sound's streams in much the same way that the spotted owl is regarded as an indicator of the health of old-growth forests.
If naturally spawning salmon are flourishing, a stream is in good shape. If the stream is devoid of fish, it may have serious problems caused by dams, culverts, silt, pollution or a lack of pools or shade trees.
"The reason I like this is the fish are used to learn about water quality," says Bill Hershberger, the UW fisheries professor who manages the university hatchery.
Visiting a hatchery to learn about fish, he says, is as natural as visiting a zoo to see an elephant or visiting a farm to find out where milk comes from.
A growing number of teachers supplement the hatchery-based program with visits to local streams and with projects to clean up watersheds so that one day they will be able to support new runs of naturally spawning salmon. It may be decades before that day comes for many streams, says Bob Boye, a former Shoreline School District elementary teacher who is widely known as the father of the salmon-in-the-classroom movement.
"Our program has never been one of saying, `How many salmon will come back?' It's strictly a way of having kids see what it takes to raise salmon. That's clean water," Boye explains.
Since Boye's students first started rearing salmon at Hillwood Elementary School 13 years ago, advocates of classroom hatcheries have become more cautious about how many eggs they hatch and where they release the young fish. Skeptics, in turn, acknowledge that aquariums can be a useful learning tool.
Tom Murdoch, whose Adopt-A-Stream Foundation promotes grassroots efforts to restore streams, suggests the following guidelines for schools that raise salmon:
-- Only a small number of eggs should be hatched, perhaps one per student.
-- Fish shouldn't be released into a waterway in which wild salmon are present.
-- Students must be taught that hatching, rearing and releasing salmon is the easy job. "Now the challenge ahead of them is making sure that the water they release them to is suitable for the fish to come back to three or four years from now."