Researchers studying the Gulf of Mexico 'dead zone' have confirmed what fishermen have probably known for a long time - that trawling for shrimp around its edges yield larger catches. Shrimp and fish move to a narrow band surrounding the edges of the dead zone, where the low oxygen levels aren't lethal, making them more vulnerable to getting caught in shrimp trawls.

The problem is that these fish are then thrown back over the side. Discarded fish, known as bycatch, usually die.A Gulf without a dead zone means fewer fish wind up in shrimpers' nets. Less bycatch means more fish available for commercial or recreational harvesting.

This study demonstrates yet another unintended consequence the dead zone is causing to both commercial fisheries and the environment. This project led by NOAA Fisheries is funded by the National Centers for Coastal Ocean Science.

Last summer a researcher we fund discovered that chroniclow oxygen levels cause female croakerto become male, increasing the possibility that they could face a population crash.