Risk Factors for the Development of Shell Disease in Impounded Populations of the American Lobster, Homarus americanus

Abstract

Abstract A logistic regression model building approach was used to evaluate the association between the development of impoundment shell disease in an American lobster (Homarus americanus) storage facility, and prestorage physiological parameters (hemolymph total protein concentration, molt stage, sex, and shell hardness) and environmental factors (surface sludge accumulation). A total of 540 disease-free, winter-harvested lobsters from southwest Nova Scotia were tested prior to storage and then examined for signs of shell disease at 30, 60, 90, and 120 days of storage. Total protein concentration was the strongest predictor of shell disease, with the odds of developing shell disease ranging from 4.3–26.7 times higher for lobsters with low total protein concentration versus lobsters with high protein concentration, depending on the time point examined. Lobsters in the intermolt stage and removal of sludge from the surface of the lobster also emerged as important risk factors for shell disease development....