As images of lifeless black-slicked birds and limp sea turtles begin to flood the media, it is becoming apparent just how catastrophic the Deepwater Horizon oil spill is becoming. (Oil “spill,” which would imply a contained amount, seems a rather gaping misnomer–it’s more of a gushing leak, direct from the source.) No one can predict how long it will continue and just how devastating this disaster might prove to be.
One thing is clear: The fragile ecosystems of the Gulf of Mexico are at great risk. Adding to the tragedy is that this is an incredibly vital area–and an incredibly vital time of year–for countless numbers of species that come for refuge to this specific stretch of the country to breed, nest, spawn, feed, and rest during migration. Peak migration and breeding times are late-April through mid-May. It really could not be worse timing.
As noted in The New York Times, “even the frantic preparations to protect the most vulnerable coastlines likely will not prevent devastating harm to key species as the Gulf of Mexico oil spill hits shore at the worst possible time for migration and breeding.” The U.S. Fish and Wildlife Service said the oil spill could affect up to 20 national wildlife refuges, and four covering more than 70,000 acres are in immediate concern.
Which animals are most threatened by this nightmare of an environmental disaster? Here is a round-up of some of those most in peril.
1. Nesting and Migrating Shore Birds
Shorebirds such as plovers, sandpipers and oystercatchers are nesting or preparing to nest on beaches and barrier islands in Louisiana. Those that build their nests on the ground and feed on invertebrates are vulnerable to oil coming ashore.
Many shore birds are also making their spring migration through the area, and habitually stop along the Gulf Coast to rest and feed. Shorebirds currently coming from wintering grounds in South America to breeding grounds in boreal forests and arctic tundra congregate in large numbers on beaches and barrier islands during the last week of April and first week of May–as chance would have it, the two weeks of the entire year that migration peaks. Experts are very concerned for a number of different bird groups and species based on the uncanny timing and the possible scope of the impact.
2. Migrating Songbirds
We may not associate songbirds with the gulf shore, but migratory songbirds–warblers, orioles, buntings, flycatchers, swallows, hummingbirds and others–fly across the Gulf from the Yucatan Peninsula in Mexico and rest and feed in the spill area. The non-stop journey across 500 miles of open water tests their endurance to its limits, and they rely on clear skies and healthy habitats on both sides of the Gulf in order to survive their journey.
The next two weeks mark the height of their migration as they travel north from Central and South America to breed in North America. Aside from needing healthy habitats for rest and food, the smoke from controlled burns to mitigate the oil spill could affect the migration.
3. Brown Pelicans
The brown pelican has not had an easy time of it. The gracefully gangling birds were only removed from the endangered species list last year, and there is a major population, around 34, 000 of them, currently nesting in the Gulf at the Breton National Wildlife Refuge–they are facing serious threat.
Diving birds are very susceptible to oil spills because they come into direct contact with the oil. A bird’s feathers overlap to trap air and provide the bird with warmth and buoyancy. Birds that come in contact with an oil slick may get oil on their feathers and lose their ability to stay waterproof, they may ingest oil while trying to clean their feathers or when they try to eat contaminated food, and they may suffer long-term reproductive effects.
Brown pelicans were once the victims of hunters seeking feathers for millinery–which led to the birth of the National Wildlife Refuge System more than 100 years ago when President Theodore Roosevelt created the first refuge at Pelican Island in Florida. In 1970, brown pelicans were officially declared an endangered species when their population was decimated by the use of DDT.
4. Sea Turtles
Of the seven remaining species of sea turtles known today, five of those species are in the Gulf. The oil spill area is one of the only foraging grounds for the most endangered species of the bunch, the Kemp’s ridley turtle, which is in its peak nesting season. One of its two primary migration routes runs south of Mississippi. Loggerhead turtles, also endangered, feed in the warm waters in the Gulf between May and October.
The seven species that can be found today have been around for 120 million years (longer than the dinosaurs)–and many of these species live up to 80 years.
5/6. Whales and Dolphins
A total of 21 whale and dolphin species that routinely inhabit the northern Gulf are protected under the Marine Mammal Protection Act, and two whale species may be in the area of the spill: Bryde’s whales and endangered sperm whales, according to the National Oceanic and Atmospheric Administration. The greatest threat is if whales get oil in the filtering structure in their mouths, which could lead to starvation and death, notes the The New York Times.
As well, when marine mammals come to the surface to breathe they may inhale hydrocarbon vapors that can result in lung injuries; oil that comes in contact with the animals’ sensitive mucous membranes and eyes may produce irritations. Young cetaceans may be injured due to ingestion of oil from contaminated teats when nursing; and there may be long-term chronic effects as a result of migration through oil-contaminated waters.
Manatees are beginning to spread out along their full range of summer habitat in the Gulf, making them vulnerable to contaminated waters. According to the EPA publication, Wildlife And Oil Spills, manatees may be affected by inhaling volatile hydrocarbons while they are breathing on the surface, and it is very likely that exposure to petroleum would irritate sensitive mucous membranes and eyes. As with most animals, the young are the most at risk. Nursing pups may be injured due to ingestion of oil from contaminated teats. There may be long-term chronic effects as a result of migration through oil-contaminated waters, and there is a substantial possibility of consuming contaminated plant material and other incidental organisms. Manatees may not be severely affected by the oil spill through direct contact, but they are sensitive to habitat disturbances and injury, such as collisions with boats and barges and propeller strikes, that may occur during response actions.
8/9/10. Fish, Shellfish and Crabs
According to The New York Times, the delta estuary is also the breeding ground for a lot of fish, shellfish and crabs, says LuAnn White, director of Tulane University’s Center for Applied Environmental Public Health. “All of those are at risk for being damaged,” she said. “That estuary area is responsible for the breeding for about 40 percent of the aquatic life that’s in the Gulf, [so] you could be affected not only the wildlife that lives in that area, but the whole Gulf.”
Fish may be affected by spilled oil in different ways. They may come into direct contact and contaminate their gills; the water column may contain toxic and volatile components of oil that may be absorbed by their eggs, larvae, and juvenile stages; and they may eat contaminated food. Fish that are exposed to oil may suffer from changes in heart and respiratory rate, enlarged livers, reduced growth, fin erosion, a variety of biochemical and cellular changes, and reproductive and behavioral responses.
If chemicals such as dispersants are used to respond to a spill, there may be an increased potential for tainting of fish and shellfish by increasing the concentration of oil in the water column. This can affect humans in areas that have commercial and recreational fisheries.
Coastal marshes are key to the life cycle and development of Louisiana shrimp and blue crab; both staples of the local seafood industry. Inshore shrimp season will open in mid-May, while brown shrimp are in their post-larval and juvenile development stages. The coastal waters around the very tip of Louisiana’s boot-shaped coast are home to some of the most productive oyster farms in the country. Oils and hydrocarbons are toxic to oysters. Unfortunately, hydrocarbons can persist in coastal sediments for months or even years. The New York Times notes that Louisiana oyster farmers, many of whom barely scrape by with high fuel costs and global competition, could have trouble weathering the oil spill if their harvests are affected.
11. Gulf Sturgeon
Gulf sturgeon are gathering in coastal areas preparing to migrate upstream to spawn–oil reaching their congregation areas could be disastrous for the fish. At the turn of the 1900s, sturgeons in North American waters were heavily fished for their flesh and caviar. The gulf sturgeon was fished off Florida from 1887-1985 with a peak harvest at the turn of the 20th century
The gulf sturgeon was listed as a threatened species in 1991 under the protection of the Endangered Species Act of 1973, making it illegal to catch or kill this species. It is also covered under Appendix II of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1998. Species included under Appendix II are those that may become threatened with extinction if their trade is unregulated.
In addition to commercial and recreational fishing, habitat destruction has also been responsible for the decline of the gulf sturgeon. Dams have prevented access to sturgeon migration routes into the headwaters of rivers where they spawn. Dredging and decrease of groundwater flows as well as recent droughts may have also contributed to the decline of suitable gulf sturgeon habitat; and agricultural and industrial contaminants cause reproductive failure, reduced survival of the young, and/or physiological alterations in the species.
photo: Noel Burkhead
12. North Atlantic Bluefin Tuna
Unfortunately for the North Atlantic bluefin tuna, their meat is regarded as exceedingly delicious and overfishing throughout their range has driven their numbers to extremely low levels. Critically endangered (according to the IUCN Red List), their stocks have already fallen about 90 percent since the 1970s. The tuna return between mid-April mid-June from vast distances to spawn in an area very close to the spill, where the water is warm and full of nutrients flowing from the Mississippi River.
What can you do? Take action, sign a petition: Prevent Another Oil Spill: Rethink Offshore Drilling