Ocean Dead Zones

Have you ever heard of an ocean dead zone?  It is basically exactly what is sounds like.  In a dead zone in the ocean, there is no form of life.  Why is that?  Well, what happens for a dead zone in the ocean to form, according to the site http://oceanservice.noaa.gov/facts/deadzone.html , is that there is pollution that makes its way into the ocean in the form of runoff, and this causes the growth of a lot of algae.  This algae then will sink to the bottom and begin to decompose.  This however, poses a threat.  When the algae decomposes, it will consume a lot of oxygen.  With this decrease in oxygen level, the marine life In the area can't survive.  So, animals die or move locations due to this pollution problem.  According to the site http://www.onearth.org/earthwire/devil-deep-blue-sea , The Gulf of Mexico has 5,000 miles of beach front water that is completely uninhabitable for marine life due to the pollution around that area.  It is one of the largest dead zones in the world actually.  So, imagine with all of the pollution that occurs in the world, just how many dead zones could there be? Well, it is estimated that there are around 400 of these dead zones throughout the world, but that is only on areas that have been studied.  There are a lot of areas unstudied, so the estimate is more around 1000 dead zones.  The dead zones are usually located along the shores around the world.  Why is this?  Primarily runoff pollution.  This pollution is filled with nitrogen from fertilizers.  There are dead zones that are inland as well, but they are usually in the ocean off shore and near the coast.  When you think about it, that's not very healthy for the water to be polluted like that, especially when people go and use the ocean for recreational purposes.  That can be very dangerous to one's health.  As you might expect, this isn't just something that can be looked over like it is no big deal.  These dead zones have a huge impact on the ecosystems around it as well as the economy.  According to the site http://www.seaweb.org/resources/briefings/dead_zone.php for example, it is said that the fisheries and shipment canals in the Gulf are being affected by these dead zones.  Not only that, but the fish that are being caught in these fisheries are believed to possibly be affected by the pollution as well.  Not only fish, but other organisms that are in hatcheries, like shrimp.  On an ecosystem level of thinking, the dead zones put a loop in the migration and spawning of fish. The food sources of fish are nonexistent as well, so that is causing problems for the fish too.  I hope that this article was helpful in providing information about what a dead zone is.  The pollution that is going into these waters is putting a great disruption in the ecosystems in the waters as well as off shore and in the economy.  Something needs to be done to reduce the effects that this pollution is causing.