Annual and Seasonal Size-frequency Changes of Trap-caught Lobsters (Homarus americanus) in the Bay of Fundy

Abstract

Size and sex of 'trap-caught lobsters (Homarus americanus) were recorded on commercial and chartered boats from selected areas in the Bay of Fundy during 1979-88. Size-frequency distributions varied considerably between geographic areas, over fishing seasons and between years. A higher proportion of large, mature lobsters was caught in the upper reaches of the Bay of Fundy and Passamaquoddy Bay. In contrast, areas off Chance Harbour showed evidence of high recruitment and lobster landings were characterized by a large proportion of smaller lobsters close to the legal minimum size (81 mm carapace length). Some of the factors contributing to changes in size-sex of lobster catches were identified as: (1) seasonal deep-shallow migrations of mature lobsters during summer and autumn (June-November); (2) molting of prerecruits to recruits during summer; and (3) fishing mortality removing legal size lobsters during the fishing season. Egg hatching and egg extrusion in ovigerous females occurred 1-2 weeks earlier in the upper reaches of the Bay of Fundy (Alma), compared to the lower reaches (Chance Harbour).