THE EFFECT OF COOKING AND FREEZING ON THE CARAPACE LENGTH OF THE AMERICAN LOBSTER, HOMARUS AMERICANUS

In the southern Gulf of St. Lawrence, American lobsters (Homarus americanus) seized as evidence in cases of suspected infraction to the minimum legal size regulation are stored frozen. This study tested whether freezing or cooking and freezing measurably affected the carapace length of live lobsters. Tests were performed on 30 soft- and 30 hard-shell animals to reflect the carapace condition of lobsters caught during Spring (hard shell) and Summer/Fall (soft- and hard-shell) fisheries. Cooking and/or freezing had a measurable impact on the carapace length and the changes observed were related to the carapace condition. Except for freezing of soft-shell lobsters, all treatments produced a statistically detectable reduction in carapace length. However, the average carapace length reduction ranged from 0.1 to 0.5 mm, the highest decrease being for hard-shell lobsters after cooking, freezing then thawing (repeated ANOVA, P < 0.0001). Of the 60 animals studied, none had carapace length reductions over 0.7 mm, while four had carapace length increases. Although a carapace length reduction could be detected statistically, the impact on regulation enforcement should be minimal.