Marine Dead Zones - Fertilizer's Effect On Marine Life

Our oceans nowadays are polluted with a myriad of harmful chemicals, as well as the crude oil from the oil spills. These pollutants are killing marine creatures as well as destroying their habitat. One kind of pollutant that I find surprising is fertilizer and biowaste from agricultural run off. These substances, which mainly consists of nitrogen and phosphorous, can actually boost algae growth. However, even though algae provides shelter and is a source of food for many marine creatures, they can also drastically harm marine ecosystems. This happens when large amounts of overgrown algae dies and decomposes. This takes up a lot of oxygen from the waters and suffocates or asphyxiates marine life. This process is called eutrophication.

Areas affected by eutrophication are called dead zones and at least 405 of such areas have been located. In first world nations, the main culprit for eutrophication is human sewage while in third world nations, where agriculture is prevalent, agricultural run off is the main culprit.

Dead zones, fortunately, are not permanent. They can be reversed by reducing the amount of waste entering the oceans. One example is in the Soviet Union in the 1980's. The Black Sea at that time contained the world's largest dead zone. However, when the Soviet Union collapsed, the farmers there could not obtain synthetic fertilizers and as a result, by 1996, the dead zone in the Black Sea is almost non-existent.

Click here to learn more about ways we can reduce marine dead zones.