Thursday, May 08, 2008

The Salmon and the Sea Lion

It’s always gratifying to engage an expert in debate about subjects of interest to me and discover that what I think I know is not all that far removed from scientific reality. Such was the case on the afternoon of this Sunday past when I cornered my neighbor, who just happens to be a fish biologist, and solicited his educated opinion on the long-term prospects for Pacific Northwest salmon. Hint: Don’t look for cheap salmon anytime soon.

As it turns out, sea lions play a less important role in the decline of salmon runs than do dams and deteriorating ocean conditions. In fact, salmon (and other commercial fish species) face numerous threats, almost all of which relate to human activity. Global warming, air and water pollution, and overfishing are major contributors to the sharp decline of nearly all marine species.

Sea lions infiltrating inland waterways are a fairly recent phenomenon. But the fact that sea lions are dining at Chez Bonneville Dam rather than at Sea Lion Caves Dive ‘n’ Thrive is of little consequence to salmon’s long-term survival. Sea lions have always dined on salmon, among other fish species.

That so many sea lions have found it necessary to learn a new behavior in order to keep themselves fed brings to mind the famous (infamous?) Willie Horton quote: When asked why he robbed banks, Willie answered, “Because that’s where the money is.” It’s highly probable that sea lions are feasting at Bonneville Dam because they’re not finding sufficient sustenance in their normal ocean habitat.

The human impact on oceans is huge, and it’s taking a toll on all life forms on the planet—not just those that live in marine environments. If only humans would change their behaviors in ways that lessen their impacts on Gaia’s ecosystems, fewer other species would find it necessary to change theirs.