Saturday, September 13, 2008

Dolphins deaths raise concerns!

If a dolphin die-off in the northern lagoon moves south, the marine mammals' population in Martin, St. Lucie and Indian River counties could be at risk, says a researcher at Harbor Branch Oceanographic Institute.

"Indian River dolphins are excellent sentinels of ecosystem health and, beyond that, human health," said Dr. Gregory Bossart, marine mammal veterinarian and pathologist at the Fort Pierce research center. "They're the canaries in the coal mine. We need to address the problems they have not just for their sake but out of concern for the health of the ecosystem and even our own health.

"We need to find out what's going on before it comes around and bites us in the rear end."
Since May 1, 47 dolphins have died in a stretch of the Indian River Lagoon from the southern end of the Mosquito Lagoon near Titusville south to Palm Bay, said Megan Stolen, research biologist at Hubbs-SeaWorld Research Institute in Orlando, who has been designated as the on-site information coordinator for what has been deemed an "unusual mortality event" by federal officials.
That designation means scientists throughout the country have been tasked with investigating the die-off and trying to determine a cause.

So far, Stolen said, "we don't have a smoking gun."

Stolen said the area of the die-off "doesn't appear to be spreading; there's no indication at this point that it's moving south." But both she and Bossart noted that the distinct groups of dolphins in the lagoon interact.

"So there's the possibility that whatever is killing dolphins in the northern part of the lagoon could affect dolphins (in Indian River, St. Lucie and Martin counties)," Bossart said. "And with the health problems our dolphins have already, this could push them over the edge."

Bossart began studying the lagoon's dolphins after a die-off claimed 27 in 2001.

"Our research over the past few years has shown some very disturbing health problems already among dolphins in the lagoon," Bossart said, "such as levels of mercury 21 times what we permit in the fish we eat."

Even if the cause of the die-off is determined, Stolen said, "there's not much we can do right away. We can't move in and save the sick dolphins. But we can learn from this; and if the cause is something we're putting in the water, we can stop future deaths by doing the right thing."


Megan Stolen, research biologist at the Hubbs-SeaWorld Research Institute in Orlando, said possible causes of the dolphin die-off include:

•Biotoxins, "toxins with biological origins, such as algae blooms, as opposed to those with manmade origins, such as oil spills."

•Man-made contaminants such as pesticide runoff and mercury.

•Infectious diseases such as viruses and bacteria. "One possibility we have discarded," Stolen said, "is direct human contact such as boat strikes and entanglements in fishing nets."


•If you see a dolphin that's dead or in distress, immediately call the Florida Fish and Wildlife Conservation Commission hot line: (888) 404-3922.

•Signs that a dolphin is in distress include: a newborn by itself for a long period of time and animals that aren't moving or are having trouble breathing, especially in shallow water.

•Time is of the essence: The sooner researchers can examine an animal, alive or dead, the better their chances of determining the cause of the die-off.


Number of dolphins killed since May 1: 47

Number of males:a 24

Number of females: 11

Number in which sex could not be determined: 12

Number of newborns: 15

Number of dolphins killed in 2001 event near Cocoa Beach: 27

Hubbs-SeaWorld Research Institute

Quick "Facts about Dolphins"