Tuesday, January 13, 2009

Fishing makes fish grow smaller?

If you catch them, they will change. Now we can put numbers to the problem, and the news is bad.

Animals change fast in response to fishing, hunting and other human uses. "Harvest selection" can cause rapid and potentially harmful changes in exploited fish and other animals.

Killing large, healthy individuals of an exploited species can

have profound conservation and economic implications. Specifically, the widespread potential for transitively rapid and large effects on size- or life history-mediated ecological dynamics might imperil populations, industries, and ecosystems.
Translated into English, it says catching the biggest fish can produce a population of runts. And it says so in fairly alarming terms, unusual for staid scientists.

Should we care? Yes. Can we do something? Yes. We can reconfigure our use of fish so that we're not giving a big survival advantage to the runts. So we don't end up like the fisherman in this satirical picture above.


Fish Whisperer said...

I personally find the small fish of a species tastier. As habit I put the big ones back. Just always made sense to me.

Tracy Rouleau said...

I'm in full agreement with you Mark! Got to get back to the BOFF campaign - how bout using "Big is beautiful" as the tagline??

Here in DC we are eagerly anticipating Tuesday's events.
The Happiest of New Years to you and all the BOFFs!

Anonymous said...

I never thought about that but it makes total sense - survival of the fittest...

DNLee said...

Yeah, I heard a talk about this topic, might be the same paper, at a conference this summer - The Behavioral Ecology conference at Cornell. The sesssion was on individual differences in behavior. The talk was about fish in the Alaska area and how individual differences in behavior (boldness) lead some fish to eat more, grow faster and ger caught. The shy, slow growing fellows survive better. But it's shifting the whole growth curve of the population. neat, huh?

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