It will take years, maybe even decades, before we know the full impact of the Deepwater Horizon oil spill, but we will begin to get a sense of just how far-reaching its effects are as the first round of wintering migratory birds makes their way through the Gulf Coast this fall. Coming from as far away as the Arctic, Canada and Greenland, one billion birds, comprising hundreds of species, will pass through the Gulf of Mexico this year, seeking a place to rest and find nourishment before continuing their flight to warmer winter habitats, many in the Southern Hemisphere.
But the fertile wetlands, which usually sustain these vulnerable bird populations on their epic trek, are not what they once were. As the ocean was inundated with oil during the Deepwater Horizon spill, the coastline and its habitats were also deeply affected. And though some reports claim as much as 75 percent of the oil has disappeared, the truth is that much of that oil has come to rest on the sea floor as a result of the use of dispersants, where it is being ingested by microbes and bacteria. Because these creatures are a part of the food chain -- and because the effects of dispersants are bioaccumulative -- it is likely that those birds that manage to find food in the Gulf will likely be ingesting oil and dispersant. Oil-induced food scarcity and contamination have led biologists to predict mass starvation in migratory bird populations, a catastrophic shift that may last for decades.
While 7,396 birds have been collected from the oil spill--5,362 of them dead as of August 30, 2010--as many as 90 percent of the birds injured or killed as a result of the oil spill we will never find, rendering the total number of oil-spill related avian casualties unknown.
Contamination and food scarcity are not the only obstacles facing the millions of migratory birds that pass through “one of the most important migratory bird corridors on Earth.” There are additional concerns that oil could kill off the root systems of marshland plants, transforming the habitats into open water and destroying other resources that migratory birds rely on for sustenance mid-flight. Finally, the residual oil in the ocean and wetlands impedes swimming, diving, flight, and migration and will plague chicks hatching in the Gulf this winter, leaving a new generation of birds stranded and paralyzed in an environment which has already been stressed by human induced impacts for decades.
In an effort to overcome the catastrophic effects of the oil spill, the U.S. Fish and Wildlife Service has dedicated $20 million to creating new wetlands out of southern farmland in hopes that, if alternative habitats are made available to migratory birds, they will flock to the non-toxic environments, which will provide resting and nesting grounds, and hopefully, food sources as well. While the Fish and Wildlife Service is cautiously optimistic about the benefits of turning farmland into wetlands for migratory bird populations, its senior officials still recognize that successfully redirecting the natural migratory cycles of ”literally hundreds of millions of birds” is a long shot.
It has been over four months since the explosion of the Deepwater Horizon but the impacts of the largest human-made marine oil spill will be with us for years perhaps decades. Migratory birds are just one of many species that are our canary in the coal mine; populations that may ride out the wave of this catastrophe or that may crash in the short-term and take decades to recover. All we can do is get out our binoculars and appreciate an ancient migration that has depended on the Gulf of Mexico as a critical habitat, one of the most important migratory bird corridors on Earth; sustaining millions and millions of birds for thousands of years. The skies might not be blackened by billions of birds as they were less than a hundred years ago, but these migratory birds are still an important link, connecting land to sea. They bridge vast habitats, reminding us that we live on a liquid planet, a home that we must not take for granted and where we have to value all life as a gift to cherish and protect.
First Photo: Birds fly over an oiled boom in Louisiana. © Carrie Vonderhaar, Ocean Futures Society
Second Photo: One of thousands of casualties from the Deepwater horizon oil spill in the Gulf. © Carrie Vonderhaar, Ocean Futures Society
Third Photo: A Great Egret catches lunch. © Carrie Vonderhaar, Ocean Futures Society
Fourth Photo: A Roseate Spoonbill feeds in a marsh. © Carrie Vonderhaar, Ocean Futures Society.