How the Gulf Oil Spill May Harm Dolphins

Like sea turtles and birds, dolphins and other marine mammals are extremely vulnerable to the effects of oil. There are 35,000 to 45,000 bottlenose dolphins in the Gulf of Mexico, one of the largest populations of dolphins off the coast of the U.S.

Bottlenose dolphin mother and calf

Unlike fish, dolphins need to come to the surface frequently to breathe. When they surface, they may come in contact with the oil slick that now covers thousands of square miles of the Gulf of Mexico.

Dolphins are smooth-skinned, hairless mammals with extremely sensitive skin—even more sensitive than human skin. Oil can cause chemical burns or skin irritation.

Dolphins may inhale oil and oil vapor. This may lead to damage of the airways, lung ailments, mucous membrane damage, or even death.

Oil may damage a dolphin’s eyes, which can cause ulcers, conjunctivitis, and blindness, making it difficult for them to find food, and sometimes causing starvation.

Ingesting oil can cause ulcers or internal bleeding.

Oil can impair a dolphin’s immune system and may cause secondary fungal or bacterial infections.

Oil may move up through the food chain as dolphins eat contaminated prey. Dolphins feed on fish and squid and spend much of their time in waters close to shore.

Dolphin calves may be poisoned as they can absorb oil through their mothers’ milk

Dolphins may experience stress and behavioral changes due to oil exposure.

Marine mammals are our closest relatives in the ocean—it’s heartbreaking that we have fouled their habitats and are potentially poisoning large numbers of these beautiful and intelligent animals. You can help by donating to The Institute for Marine Mammal Studies, Gulfpost, MS

Most of this information in this post is from Effects of Maritime Oil Spills on Wildlife, on the Australian government website


How the Gulf Oil Spill Threatens Birds

The BP oil spill in the Gulf of Mexico, caused by an explosion and fire that destroyed a drilling rig about 50 miles offshore, has cost 11 oil workers’ lives. The oil spill also endangers the livelihood of the area fishermen/women, potentially harms tourism and local businesses, and is another blow to an already beleaguered area.

In addition, the oil spill is a potential environmental tragedy that may have devastating effects on the area’s wildlife. Birds will be among the first to experience the effects of the spill. In separate posts, we will also cover sea turtles, dolphins, bluefin tuna, and other animals, including amphibians, that may be potentially harmed by the spill.

Why is oil so terrible for birds?

According the International Bird Rescue and Research Center (IBRRC), even a dime-sized glob of oil can kill a bird. A bird is kept waterproof, not by the natural oils in its feathers, which serve more as a conditioner, but by the position of the birds’ feathers. When a bird preens, it carefully aligns each feather—made up of a shaft, veins, and tiny barbs—that connect the veins in a tightly woven unit. This keeps water out and provides the bird with buoyancy and insulation.

A bird can’t preen with oil on its feathers, which mat and separate, exposing birds to hypothermia (too cold) or hyperthermia (too warm). The bird will instinctively try to preen, and will ingest oil, which causes severe damage to its internal organs. Because they are frantically trying to rid their feathers of oil, they are not hunting as much and so suffer from starvation, anemia, and so on.

According to IBRRC, washing an already stressed bird could cause its death.  It is more important to give these birds needed nutrition, hydration, and medical treatment first. Once stable, the oiled birds go through a series of tub washes alternating between one percent solution dishwashing liquid in water, and clean water. After being washed, they are put in cages with warm air dryers, then gradually acclimated to being released in the wild.

According to the National Audubon Society website, these birds may be affected by the spill:

Brown Pelicans
The state bird of Louisiana, Brown Pelicans nest colonially on barrier islands and feed on fish in nearshore waters. They have just begun their breeding season, and many pairs are already incubating eggs. Brown Pelicans were removed from the U.S. endangered species list only late last year, but they remain vulnerable to storms, habitat loss and other pressures. Their reproductive rate is relatively low, and a disruption to their breeding cycle this year could have serious effects on the population.

Least terns and other beach-nesting terns and gulls
These birds nest and roost in groups on barrier islands and beaches. Some species have begun nesting or building pair bonds in preparation for nesting. They feed on fish and other marine life. Because they roost and nest directly on the sand and plunge-dive into the water to catch fish, they are extremely vulnerable both to oil on the surface of the water and oil washing ashore.

Reddish Egrets are large, strictly coastal egrets known for wild dance-like behavior as they hunt for prey in the surf. Their numbers have dwindled due to habitat loss and disturbance, and because they are specialized residents of coastal environments, they have nowhere else to go if their feeding and nesting grounds are fouled by oil.

Large wading such as herons and egrets and other species feed in marshes and along the coast, and they nest in large colonies called rookeries. They are vulnerable if oil comes ashore in areas where they nest and feed. The central Gulf Coast region hosts continentally significant populations of many of these birds.

Other birds affected include migratory shorebirds (plovers, sandpipers), migratory songbirds (warblers, orioles, buntings, flycatchers, swallows, and others), and ocean-dwelling birds, including the Magnificent Frigatebird.

The National Audubon Society suggests ways you can help the birds.