Spanning 40 percent of the Sunshine State's east coast, the Indian River Lagoon is home to diverse aquatic life ranging from manatees and bottlenose dolphins to a variety of fish and algae species. Recently however, scientists and researchers alike have been stumped as the area's manatee, bottlenose dolphin and pelican populations have plummeted. In the last year, death tolls have risen dramatically for what appears to be no apparent medical reason. However, some researchers believe that the series of events were an indirect result of the unforgettably and uncharacteristically chilly Florida winter of 2009/2010.
In the beginning of January 2010, Florida experienced multiple morning freezes, with the coldest on Jan. 8th when temperatures dipped down to 21 degrees. Then in February, the cold remained as morning frost stayed prominent in the area and morning temperatures huddled around the 30s. These frigid temperatures for Florida were caused by an event known as sudden stratospheric warming that began around Jan. 1st, according to AccuWeather Senior Meteorologist Frank Strait.
"When that occurs, it often results in a major discharge of very cold air from the Arctic and in January 2010, the weather patterns for this were favorable for this extremely cold air to push into the eastern part of the U.S.," said Strait. March warmed up a bit that year, but on average had temperatures still about five degrees below normal.
Despite the sheer shock of the chilly temperatures for the typically warm beach-going state, this unusual winter would become a catapult for a series of ecological events that would affect Florida's wildlife today.
One year after the cold winter of 2010, a green algae superbloom occurred in the Indian River Lagoon, killing 47,000 acres of seagrass, or 60 percent of all the seagrass, according to the Florida Fish and Wildlife Conservation Committee, or the FWC. Blooms are a naturally occurring phenomena in which organisms bloom and take over the water, like a weed would in a garden, Dr. Alina Corcoran, a research scientist with the FWC tells AccuWeather.com. This superbloom killed off most of the lagoon's seagrass by blocking the availability of sunlight that the seagrass on the bottom of a lagoon needs for photosynthesis to survive. The cause of the superbloom is still unknown, but a multitude of factors seem to have played a large role, including the 2010 severe Florida winter.
"I think the weather was a pretty significant factor," said Dr. Corcoran. After the winter of 2010, parts of Florida experienced droughts which increased the salinity of the lagoon water and allowed yet another type of bloom to occur and prosper, a brown tide.
A brown tide, similar to a red tide, turns the lagoon water into a murky, brown color and produces mucus that affects the clam and oyster populations. This inhibited the re-growth of the seagrass previously lost. Both superblooms coupled together have changed the dynamics of the lagoon for both its wildlife and commercial users.
The lagoon's marine animals, specifically the manatees feed on seagrass as their main source of food. The extreme loss of seagrass forced these mammals to find an alternative food source and mortality rates seem to indicate that that may have been a harder feat than expected. This year alone there has already been a 64 percent increase in the deaths of the lagoon's manatees and an almost 83 percent increase in deaths from unknown causes. According to the FWC's spokesperson Kevin Baxter, multiple tests are being done for common diseases, illnesses and bacteria, but so far all tests on the deceased manatees have been negative.
"The manatees outwardly looked in good health and seemed to die more suddenly, sort of shocked, said Baxter. So far no specific causes have been found, but the investigation is still ongoing."
While the lagoon's manatee population takes a steep dive, the bottlenose dolphin and pelican populations are seeing a similar problem. According to Baxter, most of the pelican deaths occurred mid-February to mid-April of this year, but no cause of death could be determined with their species either. So the question remains, what is killing the lagoon's wildlife and how can it be stopped?
Perhaps the cold Florida winter of 2010 caused a series of chain reactions that are just now devastating the lagoon's wildlife populations. The FWC, along with other concerned organizations have begun to make steps for finding a solution, but the Indian River Lagoon community can only sit back and wait, hoping that they find one soon or that the brown tide recedes.