This is Scientific American's 60 Second Science.

I'm Christopher Intagata.

Every spring, the Mississippi River dumps tens of thousands of tons of nutrient runoff into the Gulf of Mexico.

Add temperature, current, and wind to that pollution,

and you have the Western Hemisphere's largest stretch

of oxygen-poor waters, a so-called dead zone.

That dead zone hits the Gulf's famed and financially

important brown shrimp fisheries. And it does two things. First, the low oxygen

slows down the shrimp's growth. The other thing that happens is what I like to call the burning building effect. The shrimp

try to avoid the burning building effect. Martin Smith, an environmental economist at Duke University.

The shrimp try to avoid the low oxygen so they swim out of these areas of depleted oxygen and as a result they end up

kind of aggregating on the edges they kind of line up when they get

outside the deoxygenated waters and that's why I call it the burning

building effect if you're in a burning building you're running to get out of the

fire you don't keep running when you get outside you stop and you take a

breath fishermen flock to where those shrimp take a breath and shrimp get caught earlier in the season.

So combine these two effects, slower growth and earlier catches,

and the result is a hall of more small shrimp and fewer large and

jumbo shrimp meaning the price on big shrimp temporarily goes up.

Supply and demand right? Smith and his team studied that link between the

dead zone and a spike in large shrimp prices using 20 years of shrimp pricing data.

Their analysis is in the proceedings of the National Academy of Sciences.

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