sea lions at Astoria, OR; credit: L.Topinka |
Scientists say the collapse of the Southern California sardine fishery and a large area of warm ocean water, nicknamed "the Blob", has driven more sea lions than the habitual males north in search of food. They found it in the Columbia. This year biologists counted 2400 male sea lions at Astoria near the river's mouth, 1,000 more than last year. A smelt boom kept them fed through February and they lingered for the spring Chinook run. One investigation by a NOAA fisheries biologists suggests that sea lions eat as many as 25% of the salmon migrating up the Columbia to the Bonnneville barrier. Other scientists say they eat one in 25 salmon. Either way the evidence is circumstantial and there are plenty of reasons for declining salmon numbers beside hungry sea lions. Salmon must swim through polluted water in brownfields. Invasive fish species like bass and walleye feed on juvenile salmon and human predation is intense; native tribes have a recognized stake in salmon harvesting for human consumption.
There lies the rub. The US government spends $500 million a year to increase salmon spawning. Fishermen--commercial, sport and native-- are complaining constantly about the competition from sea lions. Conservationists say more killing is not the answer. It is much harder and more costly to restore a riverine system than kill a few sea lions or comorants. So far native tribes have resorted to only hazing offending sea lions, but they want more authority to kill "problem" sea lions say spokespersons standing amid the roar of the biggest salmon killer of all: Bonneville Dam. Fundamentally, this is a philosophical debate: either wildlife as sentient beings have a moral right to existence or they are only a resource to be exploited by man.