Oil spill could wipe out Gulf's sperm whales

Washington, May 22 (ANI): Experts say that the death of even three sperm whales could entirely deplete their population in the Gulf.

If the Gulf of Mexico oil spill kills just three sperm whales, it could seriously endanger the long-term survival of the Gulf's native whale population, according to the scientists.

Sperm whales are considered endangered under the U.S. Endangered Species Act, but the Gulf of Mexico population is considered especially vulnerable due to its relatively small size.

A 2009 stock assessment report by the National Oceanic and Atmospheric Administration (NOAA) estimated that the potential biological removal, or PBR, level for the Gulf of Mexico sperm whale population is three.

That means if in addition to natural deaths, three sperm whales a year are killed or removed by human causes, it could wipe out their population permanently.

Even the loss of a handful of whales could be disastrous because sperm whales - especially females - take a long time to mature sexually, and don't give birth to more than two or three calves in their whole lifetime.

"As soon as we get to the level of three deaths caused by human interaction-and this would include the oil spill-that would jeopardize that particular sperm whale population."

The sperm whale can be affected in 3 ways - by taking in toxins when they come up to surface to breathe, by inhaling poisonous fumes that can knock them unconscious and cause them to drown, and the last - the oil can taint the toothed whales' prey-fish and squid-affecting the whales' diets and hurting their chances of raising healthy calves.

Previous studies have shown that at least some of the Gulf of Mexico sperm whales are known to hang around where the Deepwater Horizon oil rig was located before it exploded on April 20, triggering the spill.

"Between 2000 and 2005, about 300 [sperm] whales were seen on a consistent basis right in that area," National Geographic News quoted Texas Tech's Godard-Codding as saying.

"That would be the most likely way we would detect dead sperm whales." (ANI)