Monday, August 2, 2010

Crashing ocean productivity: what's it mean?

Climate change appears to be messing with the fundamental dynamics of ocean productivity.

The oceans are humanity's great dump. Our plastic bottles, pesticides, industrial chemicals and so much more end up polluting the oceans. Just look at any storm drain in the Islands that's marked with a fish and a warning that anything dumped on the street flows to the sea.

Increasingly, climate change is also polluting the oceans. There have been plenty of reports of increased ocean temperatures, rising sea levels, threats to heat-intolerant coral reefs, the acidification of the oceans.

But a new threat is in many ways even darker. Phytoplankton, the tiny forms of plantlife that are base of the marine food web, have declined 40 percent in the past 60 years, according to a new study.

Here are a couple of reports on the Nature article that prompted the concern. NatureNews. Reuters.

It is still not clear what the most important causes of this decline are—it could be secondary to warming and acidification, which in turn are linked to increased carbon dioxide in the atmosphere. It could be something entirely different.

And it isn't entirely clear what the impacts might be, although one impact of reduced productivity is poorer fisheries. Fisheries are being hammered from many directions. Rising temperatures, overfishing, acidification and the rest are just some of them.

The conservative Heartland Institute sought to downplay the research with a series of off-point studies. Those studies argue that increased carbon dioxide ought to increase phytoplankton growth, and therefore there's no problem.

That's a little like arguing that driving at 100 miles an hour is better for the environment than 50 because it gets you there faster. The faster part is true, but it's irrelevant to the environment part.

The key issue here is that, as Heartland correctly says, this is just one study. Other researchers will follow up and determine whether its conclusions are valid.

If so, it ain't good.

© Jan TenBruggencate 2010

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