In an average summer, 6000 square miles of Gulf Coast sea floor has too little dissolved oxygen to support marine life. This "Dead Zone" is caused by runoff of fertilizer nutrients from agriculture in the fertile Mississippi River Valley. The presence of these nutrients allow algae and other organisms to grow, and when they decay and fall to the bottom, they take out the dissolved oxygen in the seawater that marine life depends on. The 2009 Dead Zone was only 3000 square miles in area, but extended closer to the surface than ever before.
Wednesday, April 21, 2010
Too Little Oxygen: The Dead Zone
In an average summer, 6000 square miles of Gulf Coast sea floor has too little dissolved oxygen to support marine life. This "Dead Zone" is caused by runoff of fertilizer nutrients from agriculture in the fertile Mississippi River Valley. The presence of these nutrients allow algae and other organisms to grow, and when they decay and fall to the bottom, they take out the dissolved oxygen in the seawater that marine life depends on. The 2009 Dead Zone was only 3000 square miles in area, but extended closer to the surface than ever before.
Subscribe to:
Post Comments (Atom)
Dead zones are often caused by the decay of algae during algal blooms. An example of this is present off the coast of La Jolla, San Diego in California.
ReplyDelete