According to NOAA, bottlenose dolphins are showing signs of severe ill health in Barataria Bay, Louisiana.
Preliminary results show that many of the 32 dolphins sampled in a NOAA health assessment in summer, 2011, are underweight, anemic, have low blood sugar and/or some symptoms of liver and lung disease. Nearly half also have abnormally low levels of the hormones that help with stress response, metabolism and immune function.
Barataria Bay suffered heavy and prolonged exposure to oil from the Deepwater Horizon oil spill in spring and summer 2010.
Even before the oil spill, this region was included in an area for which a marine mammal Unusual Mortality Event was declared, beginning in February 2010 and continuing today.
Some of the study dolphins are in such poor health that researchers fear for their survival. One of these dolphins, last observed in late 2011, was found dead in January 2012.
This news is especially troubling because 27 dolphins from Sarasota Bay, FL, are not showing similar symptoms. They were sampled during 2010 and 2011 health assessments. The same methods were used in Sarasota and in Barataria Bay, LA.
NOAA is sharing the preliminary results from the comparative study of dolphins in Barataria and Sarasota Bays so that stranding responders and veterinarians can better care for live-stranded dolphins and look for similar health conditions.
An informal Questions and Answers pdf provided by NOAA is available as a download.
In other news:
Investigation of Dolphin Strandings in the Northern Gulf Continues
Since February 2010, more than 675 dolphins have stranded in the northern Gulf of Mexico (Franklin County, Florida, to the Louisiana/Texas border). This is a much higher mortality rate than the usual average of 74 dolphins per year, and it is what prompted NOAA to declare an Unusual Mortality Event, and investigate the cause of death for as many of the dolphins as possible.
Follow these links to:
read the NOAA information release on March 23, 2012 which is only briefly summarized here; you can get on the email list here too.
see a Photo Gallery supplied by NOAA with pictures of dolphins, health assessments, and a data graph from the northern Gulf of Mexico;
read more Questions and Answers provided by NOAA about Barataria Bay and Northern Gulf of Mexico dolphins.