Top Story: June 21, 2010

Wildlife in the Spill

800px-Phytoplankton_-_the_foundation_of_the_oceanic_food_chain

It’s been almost two months since oil started leaking into the Gulf of Mexico, and it may take years to realize how the oil will effect the wildlife in the area. Aside from the visibly oiled animals, like birds, what’s happening to other life forms in the area?

Scientific American considered the effects on endangered sperm whales in the area in a recent podcast.

The NOAA ship Pisces discovered a dead sperm whale on June 15—a possible victim of the ongoing oil spill in the Gulf of Mexico…

…It is known that such sperm whales feed on deepwater squid that may be impacted by plumes of dispersed oil. The endangered whales have also been spotted surfacing into the slick. How the millions of liters of oil will impact sperm whales and other cetaceans is an ongoing, unintentional science experiment.

Meanwhile, The New York Times is following researchers tracing the movement of manatees along the Florida coast. About 100 manatees (out of a total population of 5,000) migrate each summer to Mobile Bay, Alabama which means they could be swimming right into the oil.

As oil spreads into the bay, these travelers are now in danger of having their migratory routes and habitats contaminated, putting at risk a group that Dr. Carmichael believes may represent the scouts for the larger population. “So much is unknown,” she said. Manatees eat 10 percent of their body weight in sea vegetation per day. If oil clings to the sea grass, the animals could eat it, get the oil on their bodies and pass it to others by contact. After a 1983 oil spill in the Persian Gulf, between 38 and 60 dugongs, a species that is similar to manatees, died from exposure.

LiveScience focuses on those sea grasses in its recent story, “Small Creatures Will Be Oil Spill's Biggest Victims”. The article includes an interview John Caruso, an ecology and evolutionary biology professor at Tulane University:

In particular, the cord and Spartina grasses that grow on the coast of Louisiana are crucial to the ecosystem and especially sensitive to the oil leak, Caruso said. These grasses form the foundation of the local food chain, and their root systems lessen the erosion of the small islands that protect inland Louisiana from hurricanes, Caruso said.

The other small creatures they include are phytoplankton and zooplankton:

During the spring and early summer, plankton and other organisms at the base of the food chain reproduce in the shallow water on the Gulf of Mexico. The newborn critters that result are particularly vulnerable to the oil, Caruso said.

New Scientist poses the possibility that phytoplankton are already being affected:

In fact, it's possible – but difficult to prove at this point – that the dispersants and oil are already killing phytoplankton, which could account for low oxygen levels recorded in near-surface waters.

One thing is for certain, the oil will affect life for a long, long time. Again, from LiveScience:

As for vertebrates like birds and sharks, the major consequences of the oil leak will occur later, said Caruso. Even though birds coated in oil will die, or face difficulty after cleaning, the degradation of the food chain will cause larger problems for these animals over a longer span of time, Caruso said.

(Watch Academy researchers’ thoughts on the Gulf of Mexico wildlife and the oil spill here.)

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