Thursday, February 28, 2008

It's a capitalist ocean, and the big fish win

...until we come along and start catching them.

New insights from an uninhabited and pristine island in the Pacific Ocean show predatory fish are the mega-capitalists of the oceanic economy. Around Kingman Reef, the top predators like sharks manage to consume almost everything else. Around nearby islands, fishing has removed the big predatory fish and the ocean is dominated by small plankton-eating fish.

Predatory fish are not a nuisance in the ocean, they're necessary. Without predatory fish, our oceanic economy breaks down in surprising ways. Corals become more vulnerable to death by rising temperatures and previous studies have shown that overfishing that removes large predatory fish and can lead to nutrient accumulation and the resulting low oxygen dead zones, and related water quality problems.

This new insight may increase political support for protecting large predatory fish, or at least earn some new tax breaks for sharks.


Anonymous said...

You're right.

You might enjoy watching some of
the hundreds of fish videos @

There are some really BIG fish on these videos.

Anonymous said...

Reportedly, Italian fishermen landed many more sharks just after WWII, when fishing in the Mediterranean resumed after a few years of interruption. I learned this from the book by Martin Braun. He used differential equations to model the predator-prey relationship; removing fishermen benefited predators the most.

Mark Powell said...

Thanks for the example Carl, it's a fortuitous (and unfortunate) experiment during wartime, but if we're smart we get our lessons where they're availble. I don't think we'll use this approach agian as a fishery management tool, but other means to the same end might be possible.