Endangered Oceans

West Africa’s coastal dead zone continues to expand. Rising water temperatures, along with the runoff of chemical fertilizers, create large areas of water with low-level oxygen making the area inhospitable to marine life. As fish leave these areas in search of oxygen they are moving into areas with greater fisheries activity where oxygen is more abundant.

There are about 400 of these “hypoxic” regions throughout the world, many caused by human activities. The most notorious dead zone is in the Gulf of Mexico at the mouth of the Mississippi River where oxygen-depleting algae is growing unchecked. Another dead zone was discovered in 2007 off the coast of Texas, where the Brazos river empties into the Gulf.

Three major dead zones are known to have been caused by climate change: one off the coast of Chile and Peru, one off the east coast of Africa, and another off of Africa's west coast. A new dead zone was reported off the US west coast in 2002. It occurs seasonally and is believed to be part of a continuum of South America's dead zone.

The hypoxic zone off West Africa covers virtually all the equatorial waters in the Atlantic Ocean and is roughly the size of the continental United States. The zone is growing every year further reducing the available habitat for fish. Fish that are already experiencing a decline in population due pressures from fisheries are escaping into smaller areas making it appear to fisheries that the population is experiencing a growth spurt when actually they are just being concentrated in a smaller area. This is going to lead to a probable crash in fish harvest.

The only way this die-off of population can be prevented is to stop the practice of polluting our oceans while reversing the trend of climate change. It doesn’t seem either of these possibilities is going to take place. We may very well soon see the end of ocean fish sales.