(Florida Today) -- Federal scientists hope Indian River Lagoon dolphins are immune to a
measles-like virus already suspected to have killed hundreds of
bottlenose dolphins from New York to Virginia.
some biologists worry that morbillivirus, the same pathogen that
hammered the bottlenose dolphin population from New Jersey to central
Florida in the late 1980s, might follow a similar pattern, spreading to
the lagoon region. The virus' re-emergence here could inflict yet
another blow to lagoon dolphins already under assault from some other
mysterious, fatal ailment.
Studies show some lagoon dolphin have antibodies to morbillivirus, but it's unknown whether that's enough to make them immune.
no different than any other virus. Over time, if you're not exposed to
the virus again in lower doses, your immunity wanes," said Greg Bossart,
a marine mammal pathologist at the Georgia Aquarium, who led a major
federal study of lagoon dolphins' health. "While they have antibodies
against the disease, it doesn't mean they're protected."
Tuesday, NOAA officials said they suspect morbillivirus has killed or
stranded more than 300 bottlenose dolphins from New York to Virginia in
the past few months.
July and August, more than nine times the historical average of
bottlenose dolphins died or stranded in the mid-Atlantic region,
including New York, New Jersey, Delaware, Maryland and Virginia.
mid-Atlantic deaths prompted NOAA Fisheries this month to declare an
"Unusual Mortality Event," triggering a formal federal investigation by
The agency made a similar designation in July for the Indian River Lagoon region.
At least 66 bottlenose dolphins have died or stranded in the lagoon this year, about three times the average.
"It may be totally unrelated, or indeed it could be related," Bossart said of the two unusual dieoffs.
are concerned that the 600-plus dolphins that live almost exclusively
in the lagoon could get exposed to morbillivirus carried here by
dolphins migrating from the mid-Atlantic.
"That population is a migratory population, so we are expecting to
see those dolphins in another month or two to come to Florida," said
Megan Stolen, a research scientist with Hubbs-SeaWorld Research
Institute. "But there's no evidence that those dolphins mix with the
But during the
1987-88 morbillivirus outbreak, some dead dolphins washed up in lagoon
inlets and along local beaches, according to a 2009 research paper
Bossart co-authored. Testing of archived samples showed the virus had
infected lagoon dolphins at least five years earlier, according to the
dolphins may serve as an early-warning system for morbillivirus, the
paper concluded, emphasizing the need for ongoing surveillance of live
and stranded dolphins.
telltale symptoms for morbillivirus - skin and oral lesions - have not
been seen in the dead dolphins from the lagoon, Stolen said.
more worried about bottlenose dolphins offshore Brevard getting
infected. "Then, we have a die-off on both sides of the barrier island,
which is kind of frightening," Stolen said.
April, NOAA formally declared the manatees dying in the lagoon an
unusual die-off. More than 111 manatees have perished from an unknown
Biologists also are investigating the death of 250 to 300 brown pelicans this year.
with the dolphin deaths in the Brevard County region, all age groups of
dolphins have been involved in the mid-Atlantic deaths, and all but a
few of the dolphins found have died.
Virginia has the largest increase over the long-term average dolphin deaths.
1987 and 1988, biologists confirmed more than 740 bottlenose dolphins
died of morbillivirus infections along the mid-Atlantic coast, from New
Jersey to Florida.