Dead Zones
Human Dependence Project
Issues and Effects
One of the main issues of dead zones is lack of oxygen causing many organisms to die. This effect can destroy food chains and even food webs! Another problem is that algae can get so dense that it can block sunlight causing underwater plants to lack in photosynthesis, also destroying food chains starting with the blue crab.
http://leftrightandcentered.com/2012/08/06/its-just-summer-heat-nothing-to-see-here-move-along/
In America
http://www.lumcon.edu/bayousideclassroom/hypoxiabad.asp
http://soilsci.wordpress.com/2010/09/23/massive-fish-kills-in-louisianas-bayou/
http://wamu.org/news/12/05/17/dead_zones_reversible_virginia_biologist_says
Who does it affect?
Phytoplankton, the World Dictionary definition is, tiny plant found in plankton: very small free-floating plants, e.g. one-celled algae, and are also found in plankton. While feeding on the nutrients in the water the plankton devour the oxygen. When the plankton has consumed enough oxygen they begin to die and decompose as they settle to the ocean floor. But, as they travel downward the plankton kill everything in their path. In fact, plankton destroys marine animals and birds as well. What’s even scarier, once settled at the bottom of the ocean everything that cannot swim, or crawl away expires. Including shrimp, lobster, clams, and scallops, all other crustaceans will utterly die, all fish that get trapped within these enormous dead zones die…all living creatures that cannot get oxygen suffocate and die. What if a school of fish cannot find its way out of the dead zone and they become trapped for any length of time? Take a deep breath, if you will. Now imagine swimming out of an 8,000 square mile dead zone, located at the mouth of the Mississippi River, said to be the second largest dead zone in the world.
http://deadzonesinoceans.weebly.com/who-is-affected.html
Near us!?
The Gulf of Mexico is experiencing the same problems as all the other dead zones, such as the Mississippi river. The algae builds up and the fish can not breath causing them to suffocate and die!
http://serc.carleton.edu/microbelife/topics/deadzone/index.html
Can it affect us?
How does it happen?
The cause of such “hypoxic” (lacking oxygen) conditions is usually eutrophication, an increase in chemical nutrients in the water, leading to excessive blooms of algae that deplete underwater oxygen levels. Nitrogen and phosphorous from agricultural runoff are the primary culprits, but sewage, vehicular and industrial emissions and even natural factors also play a role in the development of dead zones.
Solutions!
- Improvements in the treatment of sewage to try and stop it finding its way into the water.
- Re-establishment of wetlands, grasslands and forests to help produce a more balanced eco-system on land that would absorb more nitrogen.
http://www.environmentabout.com/1524/into-the-dead-zones-causes-and-solutions