Shock and despair turned to bewilderment this summer as aquatic biologists and fishermen up and down the West Coast tried to understand what is happening to our beleaguered ecosystem.
Earlier this summer, scientists became alarmed when they couldn’t find much of the marine life normally present on the coast, including birds, fish, and marine mammals. On the North Coast, naturalists and fishermen waited in vain for the spring salmon run to start. And wildlife watchers in the Sacramento Delta discovered that many fish counts, particularly salmon, weren’t nearly as high as expected, particularly in light of efforts to revive those populations.
Worse, the spring winds that normally generate the marine upwelling of nutrients upon which plankton feed did not appear, an alarming event which could devastate the entire marine food chain. Scientists noticed declines in common murres, Brandt’s cormorants, and Cassin’s auklets. Biologists also found unusually small numbers of juvenile salmon and rockfish.
The winds came back in mid-July, bringing the long-overdue upwelling months later than usual, leaving biologists puzzled. Perhaps most ominous, even though the upwelling has come back, the plankton still are not recovering, and scientists aren’t sure why.
“There hasn’t been a lot of response,” says Bill Peterson, an oceanographer at the National Marine Fisheries Service, based in the Hatfield Marine Science Center in Newport, Oregon. “There’s been plenty of time for recovery, but it hasn’t happened yet. The upwelling is really strong, but the plankton just aren’t there. It might be that the upwelling is too strong, and it’s pushing the nutrients away from shore, so wildlife doesn’t have a chance to grow, but we just don’t know yet.”
For some species, the nutrients didn’t come at the right time in marine life cycles, so populations might not recover this season. “The damage has already been done, and a lot of animals are dead and gone,” Peterson says. ” About the best we can hope for is that it will stay cold into the winter, which might be a good sign for next year.”
Freshwater ecologists, too, are seeing huge declines in fish and other wildlife in the Sacramento Delta. “We’re noticing big declines in smelt, bass, and others, and zooplankton have plummeted to record low levels,” says Tina Swanson, senior scientist with the Bay Institute in Novato.
Salmon stocks are much lower than expected. “Since salmon fishing was curtailed three years ago in the wake of the Klamath die-off, and we had a good count three years ago [of young salmon who are now maturing], there should have been huge numbers, maybe even too much for the rivers to support,” she says. “Instead, there are far fewer than we expected, which suggests that maybe something is going on in the oceans.” She hastens to point out that so far, research has not proven the link.
“I would say that [trouble in the Pacific marine system] is likely to have an effect on the salmon,” says Peterson. “Right now, it doesn’t look good. It’s possible the salmon went to cooler places, but that’s not likely.” And in a recurring theme, “We just don’t know yet.”
CALFED, a research organization composed of state and federal scientists, is studying the decline. It should be releasing its data over the next few years, says Swanson, but, “They’ve done an appallingly bad job of monitoring and explaining their results,” she adds.
Lack of public awareness—and the activist outrage it would engender—has handicapped efforts to restore wildlife in the Delta and all along the coast, says Swanson. “The level of interest has declined& People wonder why they should care about the Delta smelt. That kind of thinking nearly did in the bay during the last drought. That’s when I like to remind people that the Delta provides water to two-thirds of the people in California.”
Scientists looking for explanations offer a number of culprits: global climate change, toxic contamination, invasive species, and in the case of the Delta, water exports from Northern California to Southern California. Swanson speaks for many when she says that while she believes further research is needed before anyone can give a definitive answer, “It’s probably a combination of those factors.”
MAKING CONTACT
www.bay.org
