SAVANNAH, Ga., Nov. 24 (UPI) -- Georgia researchers say the state's recent drought is the indirect cause of the decline in the area's blue crab population.
The Skidaway Institute of Oceanography team, in a study published in the November-December issue of the American Scientist, said many of the crabs caught during the drought seemed to be suffering from a parasitic infection. The infection was determined to be Hermatodinium perezi.
Though crabs infected with Hermatodinium were not unknown to the Georgia coast, the team wanted to know why the parasite overwhelmed the local blue crab population so suddenly.
The team found that the drought affected the delicate balance of salt water and fresh water that exists in brackish coastal estuaries where blue crabs spend most of their lives. During a drought, less fresh water comes down the state's rivers to mix with salt water that tides bring in from the Atlantic Ocean.
This raises the salt content in coastal estuaries. And it is in water with this higher percentage of salt that Hermatodinium thrives and spreads from crab to crab.
