strange behaviors

Cool doings from the natural and human worlds

  • Richard Conniff writes about behavior, in humans and other animals, on two, four, six, and eight legs, plus the occasional slither.

  • Categories

  • Wall of the Dead

  • Advertisements

Inconvenient Truths (The Oiliest Catch–Conclusion)

Posted by Richard Conniff on December 7, 2012

But there is one final outcome that might be even more disturbing than the messy political fighting and procrastination over menhaden: it could turn out that Omega Protein is not the ultimate cause of the problem. That would no doubt annoy some conservationists for whom the company has served as a convenient target. But much worse, it might mean the menhaden fishery is broken beyond easy repair.

Scientists say they simply can’t promise that making Omega catch fewer fish will lead to recovery of the population. In theory, it ought to work: a mature menhaden female can produce 500,000 eggs annually, enabling even a heavily fished population to bounce back when the environmental circumstances are right.

But the failure of the population to rebound for 23 years straight suggests that something else is going on now, said University of Maryland biologist Edward D. Houde, a member of the Lenfest Forage Fish Task Force. One hypothesis is that it’s a periodic shift in weather patterns offshore, where the menhaden spawn. In the past, a “Bermuda high” in March seemed to sweep more young fish into the Chesapeake, promising a good year for menhaden. Or an “Ohio Valley low” kept them out at sea. But that pattern seems to have broken down over the past two decades.

The larger problem of climate change may also mean that more menhaden are bypassing the Chesapeake, said Houde, and moving into estuaries farther north, where “the habitat isn’t big enough to produce what used to be produced.” Finally, there is the dismally polluted state of the Chesapeake itself—to which, ironically, the menhaden may now contribute, by being served up as feed on Maryland’s many poultry farms and then returned to the water in the form of nitrogen runoff.

These are big, intractable problems. Even so, said Houde, reducing the catch now is about the only short-term fix available, and it’s the right thing to do. Such reductions in the past have brought about recovery for species such as striped bass, mackerel, blue crabs, and summer flounder—as well as for the commercial fishermen who depend on them. This time, moreover, it’s not just about a single species.

In Reedville, people naturally focus on the painful economic consequences if the menhaden fishery faces a reduction. But it raises the larger question: What will happen if the base of the entire Atlantic coastal food chain disappears?



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s