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Dead zones form where excess nutrients, such as fertilizers
and sewage, are carried into the ocean by rivers. These nutrients, carried into the Gulf of Mexico by the Mississippi
river, feed microscopic algae creating large algae blooms. The algae are then decomposed by bacteria, which deplete
the oxygen levels in the water. Fish flee from the low oxygen areas but bottom dwelling animals that can't escape
suffocate or experience severe stress. Large amounts of dead crabs have washed ashore from dead zone areas.
Jellyfish and microbes seem to be the only animals that are able to survive in these "hypoxic" or low oxygen
circumstances. The pollution resulting from the 2010 BP Deepwater Horizon oil spill disaster in the Gulf is an
additional burden on an already severely compromised ecosystem. |
