Two protozoan pathogens, Haplosporidium nelsoni (MSX) and Perkinsus marinus(Dermo) are known to be present in Great Bay oysters. With funds provided by the New Hampshire Estuaries Project (NHEP), the Marine Fisheries Division of New Hampshire Fish and Game Department, (NHF&G) continues to assess the presence and intensity of both disease conditions in oysters from the major beds, some open for harvest, within the Great Bay estuarine system. Histological examination of Great Bay oysters has also revealed other endoparasites.
New Hampshire Estuaries Project
Nelson, John I., "Testing of Great Bay Oysters for Two Protozoan Pathogens" (2006). PREP Reports & Publications. 173.