Assisting injured animals may seem like a great idea; however, in disasters what seems helpful can be harmful and even dangerous. Picking up an animal that has been exposed to crude oil is a bad idea for several reasons. First, oil is a hazardous material that can cause damage if it comes into direct contact with human skin. Second, injured wildlife can be very defensive, which could result in bodily harm to a person who handles an animal, as well as further stress and injury to the struggling animal.
You are urged not to attempt to help a distressed animal yourself, and not to transport injured wildlife to a veterinarian, rehabilitator, or zoo. Tri-State Bird Rescue and Research has been contracted to handle oiled wildlife, and a hotline has been established for sightings of distressed animals.
Wildlife in the Gulf
The Gulf of Mexico is home to a vast number of bird species. This includes seabirds (such as terns, gulls, and pelicans), shorebirds (such as plovers and sandlerlings), wading birds associated with marshes and estuaries (such as egrets and herons), and many migratory species that live on land but cross the Gulf each spring and fall.
According to NOAA, 21 different species of marine mammals inhabit the Northern Gulf of Mexico, including the endangered sperm whale, several types of beaked whales, as well as bottlenose and striped dolphins and manatees. There are five species of sea turtles in the Gulf of Mexico, most commonly the loggerhead, green turtle and the Kemp’s Ridley – all considered either endangered or threatened under the Endangered Species Act. Large numbers of juvenile sea turtles live in the sea grass and offshore hard bottoms of the Florida shelf.The Gulf also supports some of the most productive fisheries in the world.
Oil Spills and Wildlife
Six large oil spills have occurred in the Gulf of Mexico during recent times, providing important insight on how best to manage such catastrophes to minimize harmful effects to wildlife. Many federal, state, and local agencies, as well as volunteers, are working together to minimize the damage to wildlife from oil that began leaking when the Deepwater Horizon drilling platform collapsed off the Louisiana coast in late April.
The vulnerability of various species of wildlife to an offshore oil spill changes over time as the duration and quantity of the spill increases. Species that spend time at the surface of the water will be impacted most during the early stages of the spill. Once the oil begins to wash ashore, species that use the shoreline are affected. Finally, influence on deeper-dwelling, or benthic, species begins once the oil particles leave the surface and become mixed throughout the water column.
Mammals are susceptible to harm from oil spills through a variety of means. Though mammals in the Gulf are hairless, and therefore not likely to lose insulation when oil coats their fur, they can experience irritation and increased likelihood of infection when exposed to oil. Also, the whales, manatees, and dolphins found in the Gulf of Mexico must come to the surface to breathe, which increases their risk of inhaling volatile compounds. Baleen whales, such as Byrde’s whales, may face difficulties filtering food through their baleen if they forage in areas with oil.
Birds are primarily affected by oil ingestion, and an increased risk of hypothermia, because oil reduces the ability of bird feathers to provide insulation. Rate of heat loss is much higher in the water than in air, so oiled plumage is particularly problematic. Oil is most commonly ingested while preening their contaminated feathers or while feeding on contaminated prey.
Sea turtle adults are probably most susceptible to oil spills through inhalation when they surface to breathe, or through ingestion of soiled plant materials. Eggs and hatchlings are susceptible through absorption. Three of the five species of sea turtles occurring in the Gulf of Mexico are endangered (Kemp’s Ridley, Leatherback, and Green), whereas the other two are threatened (Loggerhead, Hawksbill). Nesting season for these species begins in the spring, which means that eggs and hatchlings are likely to experience high risk of exposure to this spill.
(Information courtesy Holly Ober, UF/IFAS Wildlife Extension Specialist, Quincy, Fla., 516.398.4430.)