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Health of the Oceans - Transience Divine
October 20th, 2012
11:41 am


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Health of the Oceans
*pokes head out of semester*

So much to tell! I just finished a week of presentations (or preps for presentations), and the world feels much lighter. So, here's one fun piece.

There's a curious mix of opinion on the future of the oceans. Quite a few ecologist are convinced that they're doomed-- imminent collapse of core species will turn them into pools of algae and jellyfish. But estimates vary, and the they're really tough to do: we don't have much ocean data, and all our information starts long after we impacted fish populations. The best efforts usually settle for a "under-exploited", "fully-exploited", "over-exploited" distinction (like Oceana's Too Few Fish report-- 77% of stocks "cannot withstand increased fishing activity."). I recently learned about the Ocean Health Index, which takes a much more comprehensive view, but in all the situation doesn't look so bad.

These evaluations are subject to a scientific "shifting baselines" problem, since we don't expect as much of an already degraded ocean. But we have data back to 1950, before most region's peaks of global fishing. Where are we relative to that historical level?

Fish Productivity Index

A simple average suggests that we're on a dangerous downhill trend. We're currently at 25-50% of the observed level-- which means that we're only bringing in 25-50% of the fish we could be. We don't know if that peak was ever really sustainable-- it could have been a one-time collection dozens of years of building up. But taking a 7-year average around each fish stock should account for both most of the observed variability in fish populations and drop the artificially high peaks to more sustainable levels.

With demand increasing, ocean acidification and warming, and more human impact everywhere, the situation looks like it can only get worse. How do we convince ourselves to lay off the ocean, if for no other reason than for our own benefit of more fish for later?

(2 comments | Leave a comment)

[User Picture]
Date:October 20th, 2012 05:52 pm (UTC)
Long term, by having fewer people.
[User Picture]
Date:October 21st, 2012 03:24 pm (UTC)
Definitely, but people I think people are going to take a long time to thin out. In the meantime, there's a lot we can do. For example, the Gulf of Mexico could be fixed with some fertilizer regulation and one New Jersey full of wetlands. West Africa is so depleted because of European trawlers, and the EU just needs to clamp down on them or support those countries In management.
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