Virginia Institute of Marine Science
Bulletin of the European Association of Fish Pathologists
The epizootics in eastern oysters, Crassostrea virginica, of haplosporidiosis or “MSX” disease caused by Haplosporidium nelsoni, and perkinsosis or “dermo” disease caused by Perkinsus marinus, were two of the most significant marine disease events of the last century. Haplosporidium nelsoni, a protozoan parasite
native to Asian populations of the Pacific oyster Crassostrea gigas, emerged in Delaware Bay in 1957 and Chesapeake Bay in 1959 (Andrews,1962; Haskin et al., 1966), and in the decades that followed caused major mortality events
from the Mid-Atlantic region of the USA to Atlantic Canada. Perkinsus marinus is a native pathogen, also a protozoan, that had always been present in southern US (and Mexican) Atlantic and Gulf waters as far north as theChesapeake Bay region; it dramatically intensified in its activity and impacts in the mid-1980s,
however, causing reduction and loss of oyster populations from the Chesapeake Bay regionnorth to the New England region of the USA as it expanded its range rapidly northward (Burreson and Andrews, 1988; Ford, 1996). (...)
Carnegie, Ryan, The importance of long-term data collection to understand the historical and evolutionary ecology of marine diseases: the eastern oyster disease system in the USA, as a case study (2021). Bulletin of the European Association of Fish Pathologists, 41(5), 211-214.