Climate Fact: Parasite Populations
From the time of its discovery in the 1940′s until about 1990, a single-celled marine parasite (Perkinsus marinus), which can cause massive die-offs of the commercially important Eastern Oyster (Crassostrea virginica), was rarely spotted north of the Chesapeake Bay. Since 1992, however, outbreaks have been occurring as far as 310 miles north of the bay. The winter water temperature off of the East Coast is an important predictor of the parasite’s success. If winter water temperature falls below 37.4 degrees Fahrenheit, the parasite does not reproduce as readily and its numbers become limited. Since the 1960′s, this temperature has been increasing, and the parasite’s range has expanded to the north.
Season: Winter
Sources: Cook, T et al. “The Relationship Between Increasing Sea-surface Temperature and the Northward Spread of Perkinsus marinus (Dermo) Disease Epizootics in Oysters.” Estuarine Coastal and Shelf Science 46 (1998): 587-597 and Blander, K.M. “Global fish production and climate change.” Proceedings of the National Academy of Sciences 104 (2007): 19709-19714.
