While the bad news keeps flowing — along with the oil — from the Deepwater Horizon Oil Spill, a glimmer of good news surfaced last week.
A team of scientists studying the Mississippi River Delta determined that the natural and physical characteristics of the delta may reduce (but not prevent) oil contamination within the Delta.
When oil slicks impact or reach deltas and coastlines, they can be more dangerous than in the open ocean. This is partially because the vegetation and composition of the shoreline makes clean up efforts vastly more difficult, but also because there is a much greater diversity of life in the near-shore bottom sediments of any river, lake or ocean.
Did you know? The littoral zone is the shallow, near-shore environment of a river, lake or ocean bottom where many plants and animals are found. Many small microscopic organisms, insects and plants live here and provide food and micro-habitats and protection from predators for eggs and small animals.
When the littoral zone is inundated with oil or pollution, it can affect the entire food chain by killing the organisms that feed higher level species like fish and can also eliminate an entire generation of offspring. It is no wonder that fishermen who depend on the gulf for their livelihood are concerned about how long the oil spill clean up will take.
With so much at stake, the discovery that the Mississippi River Delta has natural and man-made characteristics that may help protect it and the biodiversity within it from the worst impacts of the oil spill, is a welcome announcement.
The natural characteristic that is helping the River Delta wash away the oil slicks is the high flow volume from the river to the gulf. Due to a strong rainy season this spring, the gushing water levels from the Mississippi River are creating a hydraulic barrier to prevent the oil from moving upriver.
The man-made characteristics that are helping the Mississippi River consist of concrete river diversion structures, or gates, that have been built to control flooding along the river, and can also be used to increase the flow of water to areas that need it. Furthermore, in worst case scenarios where the oil does move up-river, these concrete structures will prevent it from damaging upstream habitats.
These characteristics will not fully protect the Mississippi River from the oil slick so there is still need to prevent oil from reaching sensitive areas and to clean up the oil that is already there. For more information on how this is being done, check out the article from earlier this month.
National Science Foundation. http://www.sciencedaily.com/releases/2010/06/100617120720.htm
Canadian Centre for Marine Biodiversity. http://www.marinebiodiversity.ca
National Geographic. http://channel.nationalgeographic.com/episode/gulf-oil-spill-5488/Overview
Article first published on June 26, 2010.