The Key to Preventing Dolphin Strandings May be in Their Blood

Scientists did not always know how dolphins came to be stranded, but a new study shows that clues about survival rates after release may be found in the marine mammal's blood.

Published in Marine Mammal Science, the study looked at the blood work of common dolphins and compared it to their survival rates after release - a relatively easy and simple method of determining which dolphins are tough enough to survive on their own.

"The establishment of these blood values provides a window into the overall health of the dolphin and, for responders onsite, collecting blood in the field is relatively easy to do," the paper's lead author Sarah Sharp, of Tufts University, said in a statement. "Now we have a way to predict which stranded dolphins have a better chance of survival after release and this can help triage care."

Cape Cod, Mass., is a popular spot for dolphins to get stranded on land. Over the study's 10-year period, common dolphins represented about one-third of the 1,300 cetaceans stranded in this area.

Sharp and her colleagues examined 26 common dolphins that were stranded alive on the beaches of Cape Cod, between January 2010 and June 2012. They found significant hematological differences between survivors and non-survivors.

Dolphins that didn't survive the stranding or a three week post-release period had anemia and lower levels of red blood cells. Anemia in dolphins can be caused by chronic disease, poor nutrition, blood loss, pregnancy or liver disease.

Compared to survivors, failed dolphins also had an increased concentration of acid in their blood, were dehydrated and had leaner body mass relative to their length.

These findings could be contributed to pre-existing illnesses, stranding-induced conditions such as capture myopathy - a condition in which the animal gets so stressed out from being stranded on land that it develops a metabolic muscle disease - or both.

"Our team is already utilizing this new information in our stranding response protocols," said Katie Moore, IFAW's Animal Rescue Program Director.