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Snow Crab and Lobster Thermal Habitat Changes in the Southern Gulf of St. Lawrence


Modelled snow crab habitat index (in red). The blue curve is the 1987-2010 observed habitat index.

Snow crab and lobster, two of the most economically important species in Eastern Canada, both inhabit the Gulf of St. Lawrence but have distinctly different temperature preferences—snow crab inhabit cold water (-1℃ to 5℃) and lobster inhabit warmer water (-1℃ to 26℃). Changes in the bottom temperature of the region brought on by climate change are expected to have an impact on the habitats and life cycles of both species. This project aimed to investigate how bottom temperatures in the southern Gulf of St. Lawrence changed in the past, to aid in predicting the suitable range for snow crab and lobster habitat in the future and to contribute to appropriate fisheries management approaches in a changing climate.

Results: Researchers mapped past and current thermal habitats for commercial snow crab and lobster, and used models to estimate future habitat for these two species. Results suggested that the availability of preferred snow crab habitat in the southern Gulf of St. Lawrence will continue to shrink throughout the period of study (until 2069). Lobster habitat will continue to expand during this period with the exception of some areas where the temperature will exceed the preferred temperature range of lobsters.

Results of this study will be included in a technical report and scientific publications that detail snow crab habitat, describe projected changes in the habitats of lobster and snow crab, and examine the potential impact on the standing stock of both commercially important species.

Program Name

Aquatic Climate Change Adaptation Services Program (ACCASP)


Atlantic: Gulf of St. Lawrence, St. Lawrence Estuary

Principal Investigator(s)

Joël Chassé
Fisheries and Oceans Canada

Mikio Moriyasu
Fisheries and Oceans Canada

Michel Comeau
Fisheries and Oceans Canada

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