Characterizing movement patterns of lobster Homarus americanus within lobster fishing areas 33 and 34

This project aimed to characterize lobster migration in the context of two of the most financially significant fishing regions in Canada, Lobster Fishing Areas 33 and 34. The main objective was to elucidate the trends observed by local harvesters suggesting that lobster in these areas move to deeper, offshore waters in the winter, and migrate to shallower inshore waters in the summer. Quantification of this was done through a large-scale mark-recapture tagging project partnered with the Brazil Rock 33/34 Lobster Association and Southwest Lobster Science Society. Tagging was done both in and out of commercial lobster fishing season and using streamer tags. Recapture information was primarily provided by the local harvesters, during the fishing season, around Nova Scotia. Between both datasets, over 26,000 lobster were tagged and released from 2021 to 2024, with over 1,400 reported recaptures. Movement was quantified through metrics and changes in intensity, depth preference, and direction. Intensity of movement was compared between legal and undersized lobster, and between male and female lobster. It was found that female and larger lobster had significantly higher rates of movement in comparison to undersized or male lobster. Changes in depth was quantified through seasonal comparisons, between release and recapture seasons. A GLM was used to predict expected recapture depths, and, in turn, predict target depths of lobster for a given season. Direction of movement was standardized with respect to nearest bearing to shore, and then modelled to predict inshore versus offshore movement for a given time of year. These general findings indicated a trend that lobster moved into deeper, or offshore water in the winter. These findings align with the proposed ideas from the harvesters, and generally agree with other findings on American lobster in different geographic regions.