The BP Gulf oil spill is clearly a disaster for wildlife, but it's probably even worse than it seems. The federal government is not getting an honest assessment of the wildlife toll, and the disaster's effects will be unfolding for many years into the future.
Like crude oil, scientific comparisons can be slippery, as Environmental Defense Fund scientist Stacy Small wrote in yesterday’s Miami Herald. Frequent media comparisons of the official bird death toll to-date from the BP oil disaster to that of the Exxon Valdez tragedy give the false impression that the Gulf disaster is clearly less of a catastrophe for birds.
The official Gulf bird death toll available to the public is likely a gross underestimate. Oil is still gushing from the well at high volumes, so we don’t have anything near a final tally to compare to Valdez or other oil disasters. Wildlife population monitoring and public reporting of damages has lagged. The daily oiled from Unified Area Command represent just a fraction of the harmed wildlife dying in the wild. Incredibly, BP and the Interior Department are reportedly asking researchers to sign data confidentiality agreements that restrict their publication rights and independent biologists monitoring the situation have been denied access to oil impact areas by BP and the Coast Guard.
The Gulf oil disaster presents unique challenges to counting wildlife casualties. The Deepwater Horizon explosion occurred 48 miles offshore in a dynamic environment of winds, currents, and migratory pathways, and oil has reached over 500 miles of Gulf Coast shoreline. Because the oil from this disaster is dispersing over such a large surface and underwater area, birds can be exposed to oil not only along remote portions of coast, but miles from shore and even underwater when they dive for fish. Birds that encounter oil in the Gulf during their migratory journey may be exposed in one location and die elsewhere, never to be counted.
Still, widespread, systematic surveys and transparent reporting of oil-exposed animals in the wild are urgently needed to fully assess the damage of the Gulf disaster. A simple count of captured and collected animals does not adequately reflect real wildlife impacts. What’s worse, just as nesting birds are raising chicks along the coast, millions of migratory birds -- ducks and geese, shorebirds, songbirds, and raptors -- will soon start their southward migration and may be exposed to crude oil and chemical dispersants when they reach the Gulf. Several shorebird species have already arrived in Louisiana within the last few days (American Birding Association).
The full damages to coastal and wetland habitats and the birds that depend on them, including marsh birds, shorebirds, pelicans, raptors, songbirds, and wading birds, are still unknown. But oil kills wetland vegetation and persists in mudflats over time, so it may take years of monitoring before we know the real magnitude of this disaster. Also, little is even known about the long-term toxicity of the oil-dispersant mix, since little research has been done in this area.
To assess the real damage to fish and wildlife will require in-depth, long-term and widespread surveys that systematically monitor how widely oil from the Deepwater Horizon is being transported inland and throughout the Gulf region, how long it persists, and the long-term impacts to animal populations and the entire food web. In the meantime, we should not rely solely on the official wildlife collection tally as a metric of the ecosystem damages from the BP oil disaster.