Pathogens of marine bivalves in Maine (USA): A historical perspective

摘要

Shellfish aquaculture (in particular oyster cultivation) has the potential to play a significant role in refreshing the coastal economy in the state of Maine (USA). Although ocean warming and acidification are often listed as the primary manifestations of climate change in the marine environment, the issue of expanding geographic ranges of parasites and pathogens is an equally serious threat to shellfish populations. Protozoan parasites of the genera Bonamia, Haplosporidium, and Perkinsus, the bacterial pathogen responsible for Roseovarius oyster disease, and the disease condition is known as disseminated neoplasia are currently recognized as some of the significant threats to natural and farmed bivalve populations. We have analyzed the peer-reviewed literature for reports of these pathogens/conditions in Maine. Most reports focus on oysters from the Damariscotta River Estuary and are the result of directed studies into the biology of a particular pathogen rather than the result of intensive monitoring programs. The sampling effort could be interpreted in several ways including; the pathogens/conditions not impacting the annual harvest to any great extent due to limited distribution of the causative agent, the oysters developing a tolerance to the diseases, or just a lack of resources directed at studying this topic. With the shellfish aquaculture industry expected to grow in the next several decades, we recommend that a rigorous and sustained survey of parasitic diseases and believe that such an effort is fundamental to the success, resilience, and well-being of Maine's shellfish aquaculture industry.