Before I go into this post….
I was searching for a support photo for this post, and the NOAA (National Oceanic & Atmospheric Association) is generous in allowing photo use with credit, so I typed in the familiar address of NOAA.gov.. but.. ‘”hello? anyone there?” Nope, they are on shutdown. Glad I’m resourceful…. I found it ‘elsewhere’….
A friend recently asked me, “What are dead zones”?
Dead zones are found near coastlines, in both large lakes and oceans where the oxygen levels are very low (hypoxic), and aquatic life suffers or doesn’t survive at all.
Global Environmental Outlook Yearbook reported 146 dead zone areas in the world in 2003, and a recount in 2008 revealed 405. One of the most infamous is an 8,543 Sq mile area where the Mississippi dumps into the Gulf of Mexico. Others appear in Chesapeake Bay, on the coastline from California to Washington, and in Kattegat (strait) at the mouth of the Baltic Sea, to name a few.
One of the causes linked with dead zones is a rise in chemical nutrients from fertilizers called “eutrophication”. Basically, erosion of all the chemicals used in farming run into local rivers, then flow to larger rivers, to eventually flow into the ocean. Another cause is all the human and animal shit we like to make disappear in the waterways. Other links are soil erosion, animal wastes, and sewage.
There are many effects dead zones have on the aquatic life of the water. Nitrogen and Phosphorous cause algae to grow rapidly, block sunlight from penetrating the water and alter the food chain. Another problem is that it affects reproductive organs of fish, causing low reproductive rates.
There is some dim hope for the reduction of dead zones in our waters. During the collapse of the USSR around 1991 – 2001, the dead zone in the Black Sea almost disappeared completely. Environmentalists claimed it was because the cost of fertilizer was too high for the local area to afford it, so it wasn’t used. As prices became lower, and more farmers were able to buy again, the dead zone returned.
How do we stop these dead zones from forming? Aside from the obvious, stop over-fertilizing… Two other possible cures would be to restore wetlands in the coastline areas to act as a filter for the contaminants, and another method would be to add Aluminum Sulfite to zone to reduce the Phosphates.
© Ilex Farrell ~ Midwestern Plant Girl