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Special Report: The BP Gulf Oil Disaster

Marine Life
Toxic Brew
Millions of gallons of oil and dispersants have been pumped and dumped into the Gulf of Mexico, essentially creating what amounts to a science experiment. Carl Safina, a prominent ecologist and marine conservationist, explores the repercussions for sea life, and its uncertain future.

 

Compared with a similar stretch of American coast or area of open ocean, the Gulf of Mexico has an unusually rich concentration of wildlife. Certain species that roam the open Atlantic stream into the Gulf to breed; some breed there exclusively. Many others winter on the Gulf’s shores or in its warm waters. Year-round residents, such as shrimp and oysters, support wildlife up the food chain, forming the base of the region’s vibrant seafood industry. The Gulf is of hemispheric importance to fisheries—its bounty has made the United States the world’s third-largest seafood producer, and it generates about 20 percent of our commercial seafood. I’ve visited the region several times since the oil eruption began, seeing the effects firsthand, speaking to fishermen and others affected by the disaster.

At present, the most accurate assessment of marine wildlife is: No one really knows anything. At this writing, we don’t even know the problem’s dimensions. Millions and millions of gallons of crude remain in the waters, and dispersants have irretrievably dissolved oil into the sea, where it can’t evaporate or weather as it would in the heat and sunlight of the surface. Nor can it be seen or quantified. Furthermore, the main deployed defenses, booms and dispersants, work at cross-purposes. Booms along the coast have many gaps, and they are not designed to work in open water. As bird protection they’re pointless, because birds fly, and the whole idea behind booms—that oil floats—is defeated by dissolving the oil into the water with dispersants, creating a toxic brew.

In that water, of course, lives an extraordinary range of wildlife. While laboratory tests show dispersants, oil, and a mixture of the two kill fish, fish larvae, and shrimp, sedentary creatures are perhaps most at risk from these substances. Oysters and coral reefs—and the people and other wildlife that depend on them—are essentially defenseless. Crude has reportedly come up on fishing nets and crab traps in places where little or none has been visible on the surface. Everyone understands that the troubled wildlife we observe is a small fraction of what is being affected. How big is the problem? How long till recovery? The dose makes the poison. The entire system and its wildlife can—and do—withstand natural oil seeps and chronic oil spills from boat engine exhaust, fuel leaks, bilge pumping, and road runoff. It’s a matter of how much oil will enter the Gulf (unknown), where it will go and in what concentrations (unknown), and for how long (unknown).

The Gulf’s species, of course, recover at greatly varying rates. Shrimp, fishes, corals, crabs, molluscs, cetaceans, and turtles have quite different rates of maturation, reproduction, and potential population growth. Some can withstand more stress and some bounce back better. Others may feel the consequences for decades. Oil from the Exxon Valdez killed more than a third of the killer whales in Alaska’s Prince William Sound. Their numbers have never recovered. The effects of temperate and sub-Arctic spills have lasted decades. In the Gulf the heat will likely speed weathering and evaporation of surface oil, raising the possibility that recovery will occur sooner than it has in some other oil incidents. It all remains to be seen.

 

Animals that breathe at the surface, like dolphins, whales, and sea turtles, are especially vulnerable to oil in the water. Whale sharks, the world’s largest fish, often use a mode of feeding that almost seems designed to skim floating oil from the surface. Many of these fish have been concentrated not far from the blowout and the main surface slick, and if they get into the gummy, sticky crude, it’s likely to clog their gills. During an aerial survey in June, Hurricane Creekkeeper John Wathen and author David Helvarg photographed a sperm whale and dolphins swimming through long floating streaks and dark, discolored slicks of oil, and another pod of dolphins in distress, with several dead and dying members.

Leatherback, green, loggerhead, hawksbill, and Kemp’s ridley turtles—five of the world’s seven sea turtles—range into the Gulf of Mexico. The Kemp’s ridley is the world’s most endangered sea turtle. In the 1980s its numbers were so low that several experts feared it was doomed to extinction. Exhaustive conservation efforts brought it back from the brink and put the species on firmer footing. The number of nesting females, which lay eggs on only a few Gulf of Mexico beaches, rose from fewer than 300 in 1985 to approximately 5,500 in 2009. Breeding adults, juveniles, and hatchlings are highly vulnerable to oil slicks. In July turtle conservationists exhumed eggs from hundreds of nests around the Gulf and incubated them. They then released the hatchlings on Florida’s east coast (which, at this writing, remains free of oil). I’m sure similar relocation plans for oyster reefs, coral reefs, seabirds, and cetaceans would be under discussion, too, were that possible. But sea turtles, because they come ashore to nest and require no parental care, are perhaps the only wildlife that lend themselves to mass evacuation. Yet such a plan would not save existing turtles transiting the Gulf. Nor—because they are thought to home to the beaches from which they first enter the sea—would such displaced hatchlings return as adults to breed on their native Gulf shores.

The Atlantic bluefin tuna, already beleaguered from decades of overfishing, spawns only in the Mediterranean and in and near the Gulf of Mexico. Although individuals from the two populations mix throughout the North Atlantic, they never interbreed. The spawning area for the western Atlantic bluefin tuna significantly overlaps the spreading oil, which makes the entire western breeding population quite vulnerable during the egg, larval, and breeding stages of their long lives (they can survive 30 years and exceed half a ton). Adults are high-performance athletes, and any oil fouling their gills would likely put them in jeopardy. As yet the extent of oil-related adult mortality is not known, nor is mortality to eggs and larvae. Adults might have been repelled by the oil and remained in safer waters, but the spill began at the peak of spawning in April, thus devastating already-laid eggs and larvae. I spoke to several sportfishermen who had gone offshore for yellowfin tuna, wahoo, and mahi-mahi in areas that were still open. They reported dismal fishing when it should have been excellent, as if the fish had moved away. What’s more, they saw unusual concentrations of sharks, dolphins, and other animals near shore, as if they, too, were avoiding plumes of oil.

The deep sea contains a galaxy of planktonic animals—everything from jellies to billions of small fishes called lanternfishes (myctophids)—that live in a layer of life. Twice a day this is the scene of the greatest animal migration on earth, when life moves from the darkness of deep daytime waters to the darkness of shallow nighttime waters, and back again. This zone is like a flying carpet that extends throughout an astonishingly large portion of the world’s oceans. On a moving ship, it is extraordinary to watch it slowly rise and dive over the course of the day, even while covering hundreds of miles. Those who defend the use of dispersants contend that by dissolving the oil, microbes can more easily feed on it. But before that happens, these billowing toxic clouds will roll through this zone of life in the Gulf, and it’s unlikely the damage they cause will ever be adequately assessed.

 

The bottom line is that this oil spill is a very bad thing that cannot be reversed. How it will play out remains a great unknown. It was caused by reckless operators and scandalously lax government oversight. A federal appeals court determined that the U.S. government was unprepared for a major marine oil spill, calling the environmental analysis of the risks “irrational” months before the blowout. In the ensuing months we’ve learned about a stunning lack of preparedness and an inability to respond effectively. But the blowout is only the most acute threat to the people and wildlife who rely on the Gulf’s seashore and seafood. The same fossil fuels are causing temperatures to rise, melting Arctic ecosystems, and killing coral reefs. On top of that, they’re acidifying the world ocean so rapidly that it is already affecting the growth of shellfish and corals.

The good news? A great many birds with no trace of oil can still be seen, especially away from the Louisiana coastline, but on the shore as well. There are plenty of adult brown pelicans in Alabama that retain their white heads, and many unstained egrets are visible in bays and marshes that remain free of heavy oiling. At Pensacola Beach, where oil has arrived ashore mostly in the form of weathered tar-balls, most birds looked clean to me on the early July day I wrote this. One can only hope that out in open water some semblance of refuge remains, and that many fish and marine mammals are avoiding rather than succumbing to the copious amounts of oil leaked into the Gulf.

Carl Safina is president and cofounder of the nonprofit Blue Ocean Institute and the author of five books, including Song for the Blue Ocean, a New York Times Notable Book of the Year. His new book, The View from Lazy Point: A Natural Year in an Unnatural World, will be available in January.

 

Read other stories from this special report:
Birds: Black Bayou
Energy: Windfall
Blog: Dispatches From the Field

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Slideshow: Deep in Oil
A look at the Deepwater Horizon oil spill and the species it has threatened.