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article imageNew report on Gulf ecosystem gives mixed review

By Lynn Herrmann     Apr 18, 2011 in Environment
Washington - A new study on the Gulf of Mexico's coastal wetlands and wildlife a year after BP's Deepwater Horizon debacle suggests some wildlife species are recovering while others are in an imperiled state, with recoveries dependent on decisive action.
The National Wildlife Federation (NWF) has released a new report almost a year to the date of the BP explosion in the Gulf that claimed the lives of 11 workers and released more than 200 million gallons of oil and vast quantities of hydrocarbon gas into its waters.
The report, The Long Road to Recovery: Wetlands and Wildlife One Year Into the Gulf Oil Disaster (pdf), provides a look at the current status of the Gulf’s coastal wetlands and five wildlife species (or groups of species) dependent upon a healthy Gulf.
The report notes that 22 years after the Exxon Valdez oil spill in Alaska’s Prince William Sound, the area’s killer whales, sea otters, mussels and clams are still considered to be “recovering.” The local Pacific Herring population, a commercially harvested product before the spill, has show little sign of recovery.
The NWF report points out the long-term detrimental effects of other oil spills, noting
In fact, other oil spill disasters have taken years to reveal their full effects and often recovery is still not complete after decades. Impacts of the Gulf oil spill will likewise be unfolding for years, if not decades, and take even longer to understand.
Coastal wetlands along the Gulf after the spill received a “poor” status, according to the report. The oil spill contaminated some 3,000 miles of beaches and wetlands along the Gulf coast. The contamination, along with cleanup efforts can damage and kill vegetation, creating an accelerated rate of erosion, thus converting land to open water.
Thanks to the Mississippi River and other coastal rivers, Louisiana is called the Sportsman’s Paradise and is home to a rich variety of fish and wildlife. The report points out, however, that
The Gulf oil disaster hit an ecosystem that was already struggling with eroding wetlands starved of sediments and freshwater by human alterations to the Mississippi River delta.
During the 20th century alone, Louisiana’s coastal wetlands were destroyed by almost a third. The average rate of coastal wetland loss between 1990 and 2000 was the equivalent of a football field every 38 minutes.
Losses of these coastal wetlands continues into the 21st century, with 118 square miles disappearing from the combined hits of Hurricanes Rita and Katrina alone. Louisiana’s cumulative loss of coastal wetlands is now some 2,300 square miles, the report states, and
The huge net loss has been caused primarily by levees and channelization of the river for flood control, shipping, dredging of extensive canals for oil and gas development, and land subsidence which is often triggered by withdrawal of gas.
Large-scale restoration efforts are critical to the survival of remaining coastal wetlands, or Louisiana could face the loss of another 1,000 square miles of them by 2050. If that occurs, the total lost area of coastal wetlands would be larger than the state of Rhode Island.
Bottlenose dolphins in the Gulf received a “good” status in the report, although it noted at least 145 dolphin strandings, almost half of them babies, from January through early April 2011 are about five times the normal rate, and
The number of reported strandings throughout the oil spill is only a fraction of total deaths. As few as 1 in every 50 dead marine mammals in the northern Gulf of Mexico are ever found.
While snowmelt was documented in the Mobile Bay watershed last January and could be a factor in recent dead dolphin findings, the stranded and stillborn dolphin calves were conceived just before or during the oil spill. The report calls for a thorough investigation of possible toxic impacts to the dolphins, as oil exposure can reduce their fitness level, exposing them to disease and cold water stunning.
Although the status of the Gulf’s bottlenose dolphin population, estimated at around 44,000, is good, the health of this species could be weakened by pollutants such as PCBs, biotoxins (red tide), cold water stunning and reduced food availability due to negative impacts on prey species.
The report comes at a time when scientists have just confirmed some of the dead dolphins appearing along the Gulf coast have BP oil on them. It also comes at a time when the Obama administration is attempting to stifle findings on research of the dead dolphins, citing a federal investigation into the spill for its stance.
Western Atlantic bluefin tuna populations have crashed, down 82 percent from the 1970’s, resulting in their “poor” status in the report. The primary cause for this decline is commercial overfishing.
The eastern population of the Atlantic bluefin tuna breeds in just two locations of the northern Gulf of Mexico. The BP spill occurred during the April-May breeding season, at a time when eggs and young tuna are highly vulnerable to contaminants such as oil. The report suggests juvenile bluefin numbers may have been reduced by 20 percent in 2010 and for a species in peril, these reduced reproductive rates can be significant. The report states that
Atlantic bluefin tuna have little chance of recovery as long as commercial over-fishing continues. Breeding areas in the Gulf should be restored to healthy productive conditions.
Several species of Gulf shrimp, including brown, white and pink shrimp, are dependent upon habitats offered by shallow wetlands and coast lands. Despite a continued overall decline of Gulf Coast wetlands and their large historic loss leading to extensive habitat destruction that was formerly used by shrimp, Gulf shrimp received a “good” rating in the report. It notes, however, an understanding must be reached on oil toxicity for larval and adult shrimp, and the continued degradation of coastal wetlands remains a long-term threat to Gulf shrimp.
Far below their historic numbers, sea turtles received a “poor” rating. Pressure on endangered sea turtles’ survival rates remains high due to marine debris, long-line fishing equipment, trawling nets, loss of coastal nesting habitat, robbing of eggs, and oil spills.
Sea turtle strandings (dead or impaired) along the Gulf for the May through September 2010 period exceeded all previous record highs over 22 years of stranding data, with the report noting that
In May and June 2010 when oil spilled nonstop, sea turtle strandings were 8 times higher than the 22 year average.
It will never be known how many sea turtles were never found due to the negative impact of the oil spill, but of 609 known dead, 481 were Kemp’s ridley sea turtles. They lead the list as most endangered sea turtle species in the world, and the Gulf of Mexico is their only nesting area.
Sargassum provides foraging habitat and protection for young sea turtles out in the open waters and is critical to sea turtle survival. Oil-soaked sargassum, caused by the spill, likely led to sea mortalities far greater than what has been revealed in the strandings.
Because of their extremely low populations, sea turtles are vulnerable to impacts that then lead to further number losses. In addition to the problems associated with commercial fishing, marine debris and oil spills, endangered sea turtles must deal with other factors linked to global climate change.
Stronger hurricanes cause increased destruction of nesting beaches. Global warming, causing increased water temperatures, leads to altered sex ratios and reproductive success while ocean acidification reduces sea animals’ abilities to create shells. Coastal development, including light installations that disorient hatchlings, is another pressure that sea turtles must contend with.
An oiled pelican along the Gulf coast.
An oiled pelican along the Gulf coast.
Despite being an endangered species in 1970, brown pelican populations overcame early 20th century obstacles, including their killings for feathers and food and widespread use of DDT, which caused egg-shell thinning. They were completely absent along Louisiana’s coastal area by then.
DDT’s ban in 1972 began the brown pelican recovery process, and with their Texas/Louisiana populations rebounding to around 12,000 pairs, were removed from the endangered species list in 2009, just months before the Deepwater Horizon incident.
The oil spill’s effects on brown pelicans’ prey fish are still being studied, but the NWF report gave the Louisiana state bird a “good” rating. This comes despite the fact that over 700 brown pelicans were gathered in the oil spill area, of which two-thirds were dead.
Of the total number of brown pelicans collected, more than 40 percent were oiled while the oiling estimation of another 15 percent was not recorded. The oil disaster also impacted island mangrove thickets the birds use for nesting.
The report calls for decisive action, with Congress enacting legislation dedicated to the Gulf’s restoration and levying fines against BP for the oil spill as related to the Clean Water Act.
Research of the Gulf oil spill must continue and be long-term to properly measure its impact and help reveal the extent of damage caused.
State and federal agencies should develop and apply a comprehensive Gulf Coast restoration program, including a halt of ongoing wetland loss, that would return the Gulf to its status of providing social, economic and environmental benefits.
The report also recommends that Congress and the Obama administration begin the task of reforming oil and gas leasing practices that will lead to improved wildlife and environmental safeguards.
Lastly, BP needs to begin making immediate payments for restoration efforts required by the Oil Pollution Act so that they can be most effective.
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