More Animals Are Dying, but the Causes Have Not Yet Been Determined

As of Aug. 16, more than 7,000 birds, sea turtles and dolphins have been found dead or debilitated in the gulf since the oil spill began. A majority of the dead were not visibly oiled, and officials have yet to determine why they died. But they have confirmed that many more animals are dying than during the same time period in previous years. Related article »

Sea Turtles Found alive Found dead Total found Visibly oiled 444 17 461 Not visibly oiled 63 510 573 Officials have found more than twice the number of stranded sea turtles than normally found this time of year. A majority have been a species called Kemp’s ridley, one of four that are endangered in the gulf, and among the smallest and rarest of sea turtles. Most of the dead are not visibly oiled. Some suspect that shrimpers are causing the increased deaths by not using devices that prevent turtles from getting trapped in nets and drowning. Dolphins Found alive Found dead Total found Visibly oiled 1 5 6 Not visibly oiled 4 67 71 More dolphins have been found dead or debilitated since the start of the spill than are usually found at this time of year. In previous spills, dolphins have been observed swimming in oiled waters. Like whales and sea turtles, dolphins surface to breathe air, and scientists think that the dolphins may be inhaling toxic chemicals from the oil. A majority of those found have been bottlenose dolphins, the best-known species and one commonly seen in zoos. Birds Found alive Found dead Total found Visibly oiled 1,924 1,886 3,810 Not visibly oiled 0 2,333 2,333 Most of the birds recovered have been brown pelicans, the state bird of Louisiana, which was recently removed from the endangered species list. Biologists say the birds dive into oil because the slick makes water look calmer. While pelicans are large, and thus easier to find, many smaller birds harmed by oil may never be found. The hardest-hit species in Mississippi, Alabama and Florida has been the northern gannet, which spends most of its life over open water.

Data in tables are as of Aug. 16. There were an additional 14 dead birds that have been found for which it has not yet been determined if they were oiled. Numbers include all injured or dead fish and wildlife collected by officials from the U.S. Fish and Wildlife Service or NOAA in the area impacted by the oil spill. Not all of deaths or injuries were necessarily caused by the Deepwater Horizon incident, and some of those found dead may have been oiled after death. The higher than expected numbers of animals found may be caused in part by the increased number of workers evaluating the spill area.