Gulf spill taints 'Mediterranean of the Americas'
The gigantic Gulf of Mexico oil spill is the latest blow to a unique marine environment already fragile after decades of human encroachment and natural upheavals — at a time of year when some of its most vulnerable species are nurturing their young.
A watery expanse of 600,000 square miles, the Gulf features marshes and coral reefs, commercial and recreational fisheries and hundreds of wildlife species, including imperiled birds, whales and sea turtles. Many are in harm's way, as the oil unleashed when an offshore rig exploded two weeks ago threatens their food supply and the marshlands where they spawn or build nests.
The spill "could not have come at a worse time," said Carole Allen, Gulf director of the non-profit Sea Turtle Restoration Project.
It's too early to know how extensively the waters and wetlands could be damaged or how badly any particular species — even those listed as endangered — could suffer, scientists say. Although 30 dead sea turtles had turned up on Mississppi beaches in recent days, necropsies completed on five showed no evidence that oil killed them.
Still, biologists who study the region's birds and fish are worried.
"You hear that noise?" Mark LaSalle, director of the Pascagoula River Audubon Center near Biloxi, asked recently while strolling on the beach wearing the bird-watcher's trademark gear, a button down khaki shirt with binoculars slung around his neck. His voice was practically drowned out by the whistling and chirping of several thousand endangered seabirds known as least terns, nesting on the beach. The Gulfport area has one of the country's largest nesting colonies.
"Look at those gray dots," LaSalle said, pointing down about a mile-long stretch of sand. "There's probably 1,000 birds right there.
"If the oil comes onto the beach, it'll hit the eggs and they'll be gone," he said. "And if the fish disappear, they'll starve."
Up to 5,000 bottlenose dolphins may be calving in the path of the slick, said Moby Solangi, director of the Institute for Marine Mammal Studies in Gulfport.
"During calving season, these animals move from deeper to shallow waters to give protection to their young," Solangi said. "These animals are going to go in and out of the spill just for curiosity."
Larry Schweiger, president and CEO of the National Wildlife Federation, said Monday there was a large number of dead jellyfish along the coast of an island at the mouth of the Mississippi River.
"You occasionally see dead jellyfish anytime you have high winds, but this was far beyond the normal," Schweiger said.
Young shrimp, popular with diners and a key part of the marine food chain, are preparing to migrate from estuaries to open waters "in the midst of the oil being pushed into onshore areas," said Chris Dorsett, director of Ocean Conservancy's fish conservation and management in Austin, Texas.
The Gulf, bordered by the United States, Mexico and Cuba, also supports endangered birds such as the snowy plover, as well as the formerly listed brown pelican.
The area between Louisiana and Florida is "some of the most biologically varied marine habitat in the country," said Bill Hawkins, director of the Gulf Coast Research Laboratory in Ocean Springs, one of many scientific outposts along the coast where staffers are anxiously monitoring waters in the advancing oil plume.
Warm temperatures extend breeding seasons for fish and other marine creatures, while coastal waters, marshy bottomlands and nutrient-rich estuaries yield abundant vegetation, providing spawning grounds and food for an incredibly complex food web.
The endangered Kemp's ridley sea turtle nests only along Gulf beaches in Texas and Mexico.
"And their entire population is in the Gulf of Mexico right now," and the turtles are nesting for the next several months, said Duke University biologist Larry Crowder.
"If things go really bad for the Kemp's ridley, they could be gone."
Despite its ecological richness, the Gulf was suffering from years of degradation even before the spill.
The nutrients that feed estuaries have been increasing due to agricultural runoff that drains into the Mississippi River, causing a roughly 8,000-square-mile "dead zone" that forms annually off the Louisiana and Texas coasts. It has so little oxygen that few if any aquatic animals can survive there.
Fishing pressures, too, have caused decreased stock, while the Gulf coastline is losing wetlands at a rate of about 25 square miles a year due to erosion from storms and construction of flood-control levees that prevent the Mississippi River from depositing sediments that could rebuild them.
The region has lost more than a million acres of wetlands in the past century, and the National Oceanic and Atmospheric Administration predicts parts of the Louisiana coastline could migrate inland as much as 33 miles by 2040. Wetlands are crucial spawning and feeding grounds for marine creatures.
Yet the Gulf, dubbed the "Mediterranean of the Americas," supports a dizzying variety of ecosystems and wildlife, and is the only place in the Western Atlantic where bluefin tuna spawn.
Five species of imperiled sea turtles live in Gulf waters, along with seven endangered or threatened whale species. There are sharks, dolphins and all manner of seafood the world consumes daily, from tuna to oysters, shrimp and crabs. The fisheries here are some of the world's most productive.
Simply put, the entire Gulf of Mexico ecosystem is an ecological smorgasbord of marine life.
"If you go to any of the oceans' shorelines, I don't think you'd find that much diversity and habitat, maybe from Maine to Florida," said Nancy Rabalais, a biological oceanographer and executive director of the Louisiana Universities Marine Consortium. "It's just an incredible body of water."
Flesher reported from New Orleans. Associated Press Writer Jason Dearen contributed to this report from San Francisco