Louisana Dolphins Are Very Sick

Dolphins captured in Louisiana as part of a health study related to the BP oil spill were "very sick," according to federal scientists.

Thirty-two dolphins caught in August in Louisiana's heavily oiled Barataria Bay were found to suffer from a range of symptoms including anemia, low body weight, hormone deficiencies, liver disease, and lung problems.

Those symptoms are typical of mammals exposed to oil in laboratory experiments, scientists said.

"The dolphins we sampled from Barataria Bay are not in good health. Some are very sick," said Lori Schwacke, who led the dolphin study for the National Oceanic and Atmospheric Administration. "We are concerned that many of the Barataria bay dolphins are in such poor health they may not survive."

Scientists recorded abnormally low levels of cortisol and other hormones produced by the adrenal gland. Those hormones work together to control immune function, metabolism, and the body's response to stress.

"These low levels of hormones suggest adrenal deficiency," Schwacke said, explaining that adrenal issues are also associated with low blood sugar, low blood pressure and heart conditions. "These health concerns have not been observed in other parts of the south Atlantic and Gulf coasts."

Since February 2010, the number of dead dolphins washing ashore in the Gulf has been much higher than normal, scientists said. A total of 693 dolphins have washed up in the last two years.

The "unusual mortality event" continues in Alabama, Mississippi and Louisiana, though the number of dead animals found along the Florida Panhandle has returned to normal.

While Schwacke said it was too soon to confirm a connection to the oil spill, she noted that the health issues in the Barataria Bay population are similar to problems seen in mink that were exposed to fuel oil during laboratory tests. The testing was conducted as part of the ongoing Natural Resources Damage Assessment, which will form the heart of the government's legal case against BP.

The NOAA testing involved 32 dolphins out of a total population of about 1,000 living in Barataria Bay. The area was selected because it was one of the most heavily oiled areas on the Gulf Coast.

So far, 180 dolphins have washed up dead in Barataria, or about 18 percent of the population there, including some of those that had been caught and tested by NOAA.

Teri Rowles, the NOAA veterinarian in charge of investigating dolphin strandings, said the agency was trying to gain similar information about the health of dolphins in Alabama and Mississippi but had not yet studied live animals. Many of the tests conducted in Louisiana required live animals.

"Most of the animals that come in dead are more decomposed. Only 73 of the 693 have been live or freshly dead where we could get a good body condition," Rowles said.

Rowles said NOAA had ruled out biotoxins, such as algae blooms related to red tide, and a measles-like virus common in dolphins, as being responsible for the ongoing die off.

Based on the findings in Barataria Bay, the agency has advised scientists in the Gulf States to be on the lookout for similar symptoms.