Louisiana dolphins sick from BP oil spill
Dolphins living in the Gulf of Mexico near Louisiana are in poor and sometimes grave health following the 2010 BP oil disaster. Thats based on a study released last week conducted by researchers from various governmental and private groups.
The study looked at 32 dolphins in Barataria Bay off the coast of the southeast tip of Louisiana. Of those, 29 were examined by ultrasound and lab tests. According to the study published in the journal Environmental Science and Technology, nearly half of the dolphins were in bad shape with almost 20% considered in grave condition. During a conference call last week, Cynthia Smith, one of the lead authors, said one of the problems identified in the marine mammals was lung disease and dysfunction.
In fact, one of the dolphins we examined was actually recovered dead about five months later and we were able to confirm that animal did have severe bacterial pneumonia.
The lung problems were measured by ultrasound which also allowed researchers to examine pregnant females. Smith said about half of the dolphins studied during the 2011 research were pregnant.
that one of the pregnancies had failed. We did detect a dead fetus which we based that diagnosis on the lack of a fetal heartbeat, the lack of fetal movement and ultrasound evidence of organ and tissue destruction. Other pregnant females were found to be in poor overall health, so we also considered that their pregnancies were at risk.
The authors concede the results also coincide with what scientists call an unusual mortality event that began before the Deepwater Horizon blowout. However, the bottlenose dolphins in Barataria Bay were compared to the same species in Sarasota Bay where oil from the spill wasnt a problem. Lori Schwacke, lead author for the study headed up by the National Oceanic and Atmospheric Administration, said another clue that dolphins living in areas where oil impacted the ecosystem the greatest was a lack of two hormones cortisol and aldosterone which affect an animals response to stress.
So, keep in mind that to conduct these assessments, we had to encircle the dolphins with a net and then the dolphins would usually hit into the net trying to escape and then at that point wed have a team of human handlers jump into the water and restrain the animals. So, you can imagine that in a wild animal, this would prompt an acute stress response and if the animal is healthy, it should increase its production of cortisol which would then prompt the other responses that I mentioned such as the rapid heart rate and increased blood sugar.
But that didnt happen in the Barataria Bay dolphins. In a response to the study sent by BP, it claims that NOAA still has not provided BP with any data demonstrating that the alleged poor health of any dolphins was caused by oil exposure. The statement goes on to say, the symptoms that NOAA has observed in this study have been seen in other dolphin mortality events that have been related to contaminants and conditions found in the northern Gulf. The BP statement specifically names pesticides as a possible cause of some of the health effects. But Schwake, the lead author of the study, said those chemicals were measured.
We also compared the concentrations we measured in Barataria Bay dolphins with those previously reported in dolphins from around the Southeast coast and we found that the levels in Barataria Bay dolphins were some of the lowest. So, we feel like its highly unlikely that the toxic effects that we observed in Barataria Bay dolphins were associated with exposure to other environmental contaminants.
She added that incorrect adrenaline hormone levels were shown to have a toxic effect on minks that were exposed to oil in a separate study.
But I should point out that the adrenaline sufficiency has been reported as a toxic effect in experimental studies of mink that were exposed to oil. So, we feel like this is pretty compelling evidence that the observed adrenal issues in Barataria Bay Dolphins could be linked with their exposure to DWH oil.
The results of the study could be used to help figure out where to allocate BP settlement money. Cathy Harrelson is with the Gulf Restoration Network in the Tampa Bay area. She said during an interview this week that impacts from the oil disaster will continue to come up.
BP, of course would like it to be otherwise. They would like to, certainly, get this thing settled and done and pay what they have to pay and get out from under this. But, the reality is even in the legal side, this really illustrates why we need to have a re-opener clause in that settlement meaning that discovery of these devastating effects years down the road would enable agencies and communities to go in and reopen the settlement talks.
The study was funded by BP, but Harrelson warns people not to let that fool them.
Its not like out of the goodness of their corporate heart, they decided, oh, were going to donate to this study. I think that is untrue. What they said there yes, it was their money that paid for it because they were forced if you were remember a fairly large amount they were forced to give to the government pretty early on.
The mortality event identified during the study shows more than 1,000 dolphin strandings in Barataria Bay. BPs statement concludes there isnt evidence to support claims that the deaths are related to the oil spill. Researchers on the study agreed that other environmental factors cannot be ruled out.comments powered by Disqus