(1) HOW IS THE MACONDO OIL SPILL DIFFERENT FROM OTHER SPILLS?
The BP Deepwater Horizon oil (Macondo) spill is now the largest in history, exceeding the 1979 Ixtoc leak in Mexico. It is the deepest leak, a mile down into the Gulf of Mexico (the Ixtoc was 160 feet). Unlike an isolated event like a tanker spill, it is a continuous leak without a defined end point. It is an eruption of crude oil and methane gas (40% of total) at high pressure emanating from two miles under the ocean floor. Much of the gas and oil is trapped in layers under water. It is actually a twin disaster: an oil slick subject to winds and surface currents, and a toxic soup of chemicals under the water steered by deep ocean currents.
(2) WHAT IS THE BIG PICTURE OF THE OIL SPILL?
This oil spill is not only an ecological disaster, but an economic and cultural catastrophe. The environmental and economic impacts are nearly unimaginable and will last for decades. The oil spill affects the food chain from deep water to surface currents to shoreline habitats and onto land. The devastating effect on fishing, recreational activities, tourism, and culture will expand in size and dimension. The Gulf of Mexico has been irreparably harmed and an unabated flow of oil threatens the world’s oceans. This oil spill is a grievous wound on our planet.
(3) WHAT ARE SOME OF THE BODILY THREATS TO WILDLIFE AND PEOPLE?
There is a triple threat from this disaster that includes oil, methane gas, and chemical dispersants. Oil affects animals and people in a similar manner; by direct contact, ingestion, and inhalation. Crude oil contains carcinogens like benzene, and aromatic polycyclic hydrocarbons that cause respiratory and nervous system damage. Toxic substances (found in oil) like mercury, lead, and arsenic build up in the food chain and stay in the environment for years.
Methane gas is an unappreciated pollutant. Most of the gas from the Macondo spill stays in underwater plumes along with components of oil. Microbes use up oxygen when they ingest methane, and this oxygen is needed for further breakdown of oil. When oxygen in the water is depleted it creates dead zones. There is already a large dead zone around the mouth of the Mississippi River caused by agricultural run-off. Dead zones will spread to a large area in the Gulf of Mexico.
Chemical dispersants have been used in massive amounts on surface oil and (for the first time) mixed with gas and oil on the ocean floor. Dispersants keep oil out of sight but they keep toxins hidden in the environment. These chemicals are harmful to fish, crustaceans, and mollusks. They can be lethal to deep sea plankton and worms. A study in Israel showed dispersants were harmful to coral reefs, killing organisms and retarding growth.
Corexit, a dispersant used by BP, has ingredients like butoxyethanol which acts like an anesthetic agent and causes nervous system disease, blood, and kidney disease in people and animals. Propylene glycol, another component, has skin and respiratory effects. Dispersants are volatile and enter the air, posing a risk to clean-up workers. An earlier, more toxic version of Corexit was used in the Exxon Valdez oil spill.
(4) WHAT IS THE EFFECT OF OIL ON COASTAL MARSHES?
Coastal marshes and estuaries are vital to the ecosystem and serve as the most important nursery for marine life. They act as a barrier to storms and prevent inland pollutants from entering the ocean. Coastal marshes and estuaries are nutrient-rich feeding grounds for birds and animals. Louisiana has one-third of the coastal wetlands in the lower 48 U.S. states. The inter-tidal zone of marshes situated on the shoreline is the most productive. Oil kills these marshes, and it is almost impossible to remove.
(5) WHAT IS THE EFFECT OF THE SPILL ON FISH?
Coastal marshes are nurseries for many fish, so their fate is intertwined. Fish eggs and larvae are found on the surface of water and are susceptible to oil and its byproducts. Adult fish can swim away from dead zones but fish like grouper and snapper venture close to shore to spawn. Previous oil spills have seen a 40% reduction in species of prey fish that lasts several years.
Menhaden is a top commercial fish in the U.S., used for everything from fish oil to animal food. Menhaden spend the first few months of their lives nibbling marsh grass. If you lose the marsh, you lose the menhaden. The Atlantic blue-fin tuna is a critically-endangered fish that uses the northern Gulf for spawning in April and May. The endangered smalltooth sawfish and the Gulf sturgeon are both threatened by the oil disaster.
Fish and organisms living at or near the sea floor are in the cross-hairs of this oil disaster; this includes soft-bottom fish such as Atlantic croaker, sand seatrout, Atlantic bumper, and sea robin. The hard-to-detect oil/dispersant mix is likely to rain down and wreak havoc on the unique deep water coral reef of Viosca Knoll, close to the BP oil leak.
Sharks are impacted by the Gulf oil spill. A major spawning ground for several shark species resides in a seagrass area south of the Chandeleur Islands, close to the Deepwater Horizon spill. The largest fish in the world, the whale shark, which lives on plankton, congregates in this area and has been spotted swimming in oil-contaminated water.
(6) WHAT DOES OIL DO TO SEAFOOD LIKE OYSTERS, SHRIMP, AND CRAB?
Oysters, shrimp, and crab and their larvae are decimated by oil in coastal marshes and estuaries. Oysters are filter feeders and can’t get out of the way of oil. All of these animals feed on plankton which is smothered and killed by oil. Lousiana produces 50% of shrimp, 40% of oysters, and 35% of crabs in the U.S. Lousiana’s 2 billion dollar oyster industry has come to a standstill.
(7) WHAT IS THE EFFECT OF OIL ON SEA TURTLES?
In a word, devastating. Five of seven species of sea turtles are found in the Gulf of Mexico. These animals come to the surface to breathe where they can suffocate in oil. They are affected by fumes, contaminated prey items (e.g. jellyfish), and soiled beaches. Loggerhead, green, hawksbill, and leatherback turtles breed elsewhere, but the endangered Kemp’s Ridley breeds only in the Gulf.
Sargassum is a type of seaweed that floats offshore in the Gulf of Mexico. It is a biological oasis that harbors myriad creatures including larval fish and shrimp. Baby sea turtles like to ride the sargassum mats and are carried in the same currents that accumulate oil and floating debris.
(8) HOW’S ABOUT OUR FELLOW MAMMALS, WHALES AND DOLPHINS?
Cetaceans are in trouble. 28 species of marine mammals have been recorded in the Gulf of Mexico. Near shore animals are more directly threatened than offshore animals. These animals face danger from oil including coating, blindness, hypothermia, disrupted communication, and contaminated food. Among endangered whales (e.g. sei, fin, blue, humpback, and Atlantic right), the Gulf sperm whale is most at risk. Near shore dolphins; bottlenose, spotted, and Risso’s, are already suffering injury and death.
(9) WHAT IS THE EFFECT OF THE OIL SPILL ON BIRDS?
For a birder, the Gulf oil spill is beyond heartbreaking. Everyone is sickened by pictures of pelicans and other birds covered with oil. Birds are affected by direct contact with oil (swimming, diving), ingesting (by preening and eating contaminated prey) and sometimes fumes. Oil on birds causes problems with buoyancy and temperature regulation. Ingestion of oil produces kidney and liver damage and metabolic disturbances. Oil destroys birds’ habitat for foraging and breeding.
George Fenwick, president of American Bird Conservancy (ABC), says, “The oil spill spells disaster for bird in the Gulf region and beyond – the impacts could last for decades.” The ABC website shows the oil spill in relationship to over a dozen Important Bird Areas (IBA’s) and National Wildlife Refuges (NWR’s) in the region. Already impacted are Delta NWR, Gulf Coast Least Tern Colony, Gulf Islands National Seashore, Bon Secour NWR, and Breton NWR (Chandeleur Islands). The system of NWR’s down the east coast Texas (to Laguna Atacosa) and the west coast of Florida (to Dry Tortugas) are considered at risk.
Birds adapted to coastal marsh habitat are directly threatened by oil. These include herons, egrets, spoonbills, rails, and sparrows (e.g. seaside). Wintering shorebirds and waterfowl use these same marshes and near shore waters. Birds that require clean beaches or rocky shores for breeding or foraging include plovers (snowy, Wilson’s, and piping), skimmers, and American oystercatcher. Birds that dive into the water for food include the brown pelican, terns, and wintering gannets. Scavenging birds (gulls and crows), fish-eating raptors (bald eagle and osprey), and diving birds (cormorants, ducks, grebes, and loons) are likely to die in significant numbers.
(10) WHAT WILL HAPPEN TO BIRDS DURING MIGRATION?
That remains to be seen, but it can’t be good. Greg Butcher (National Audubon Society) says, “A lot of birds that were safe in their spring migration won’t be in their autumn passage.” Shorebirds that breed in the Arctic begin arriving on the Gulf coast in July. Some 500 million birds use the Mississippi Flyway during migration, and the oil mess is smack in the middle of this flyway on the Gulf coast.
Countless birds use barrier islands and coastal marshes as stopover and refueling points during migration. Passerine (perching) birds will suffer negative impacts of air (smoke), lack of fresh water, and loss of critical coastal habitat where they congregate, especially in inclement weather. A USDA plan to flood farmlands along the migration route may lure some birds, but most species will instinctively return to their coastal haunts.
(11) WHAT IS THE SURVIVAL RATE OF OILED BIRDS?
Poor, although this varies by site and species. Survival of oiled pelicans is low compared to unaffected birds. Some (e.g. German biologist Silvia Gaus) argue that since only 1 in 100 oiled birds is likely to survive, it is more humane to “kill, not clean” and concentrate on habitat protection. The International Bird Rescue Research Center (IBRRC) reports about 10% of oiled birds in the Gulf makes it to a rehab center, where mortality is high during captivity or following release.
Here in the Florida Keys, hundreds of miles away from the oil spill, it makes more sense to rehabilitate oiled or injured birds (Florida Keys Audubon Society will support those efforts). We should do everything we can to save our “special birds,” so more effort should go into cleaning a reddish egret or pelagic (ocean-going) bird than say, a cormorant. People should understand that cleaning oiled birds is just a beginning; the real challenge is protecting and restoring habitat.
(12) WHAT CAN I DO TO HELP?
Educate yourself about this crisis. You need to read and study, and not just listen to the evening news. Begin observing the natural world around you. You can report impacted wildlife in Florida to (866) 557-1401 and oiled shoreline to (877)-2-SAVE-Fl. Cornell Ornithology Lab has a website for observations and comments (www.ebird.org).
Contribute to nonprofit environmental groups and/or become a member. You can make sure your neighborhood is clean and free of debris (especially if you live on the water). You can volunteer and receive training for clean-up operations. You can register at www.volunteerflorida.org (Florida) or at www.volunteermonroe.info (Monroe County).
You can contact your congressman (Senator Bill Nelson is very outspoken on this issue). You can reduce your own oil consumption. You can support a rational national energy policy. You can tell folks how you feel. You can get angry, and try and funnel that energy into something useful.
Sources: Center for Biological Diversity, National Resources Defense Council, Environmental Defense Fund (Doug Radar), Cornell Lab of Ornithology (Ken Rosenberg), World Wildlife Fund, Ocean Conservancy (Philippe Cousteau), American Bird Conservancy, Audubon, the Miami Herald, and on-line media including Time, Newsweek, and CNN.

Mark Whiteside
Vice-president/Special Projects
Florida Keys Audubon Society