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.


MIUMIU said...

Nice to meet you, empathize with your blog.
I linked to please.

Bpaul said...

According to the reports used to determine whether or not to kill off some of the Sea Lions, the year humans took 43% of the salmon that would have passed over the dam, the sea lions took 4%. This was by far the largest percentage of the cap the sea lions took in any one season -- the percentage mostly is inflated due to the unusually runs that year. I believe those stats were for 2007, but might have been 2006, don't have it in front of me.

So, although I'm not totally against culling a few California Sea Lions (NOT the endangered Stellars -- which the vigilante community seems to like to shoot -- bigger targets I guess) -- it's by NO MEANS going to save the salmon. It's basically a political band-aid, with a side benefit of letting a few more salmon over the dam to try and find a place to breed in the degraded spawning areas (which, by far, are the biggest problem -- over and above human catches I'd dare say).

Not that I have an opinion or anything hehe.


Phil said...

Hey, Bp, now they're saying that the sea lions weren't shot, that something else killed them. Could be they died from feasting on all those heavy metals-laden, toxin-saturated sturgeon, don't you think? If you're a sport fisherman, I hope you're not catching and eating that stuff.

Oregonian37 said...

Did I see a report today that they are now saying that the sea lions died from the heat? Dang it I've read so much news today I can't remember where I saw that! I'll try and find it and put it up.

Phil said...

Hi, OR37,

Necropsies showed that the sea lions died of heat prostration. The question most in need of an answer is who lowered the cage doors to trap the animals inside. I don't think we've heard the last of this.