Age validation, size-at-age, size-at-maturity, and age-at-maturity in snow crab (Chionoecetes opilio) from different thermal regimes in Newfoundland

Abstract

Calcein dye was used to determine the deposition rate of growth bands on snow crab gastric mill ossicles, although this was unsuccessful due to dye leaching. Annual deposition of growth bands was, however, corroborated based on age estimates from size-frequency histograms. There is limited understanding of the effects of temperature on snow crab growth and sexual maturation. Band counts revealed no significant difference in size-at-age, size-at-maturity, and age-at-maturity between crabs inhabiting “colder” and “warmer” waters around Newfoundland, but a significant difference in size-at-age and size-at-maturity between males (larger) and females (smaller) was found. Some of my findings were consistent and others inconsistent, with the literature, which may have been partly due to a warming trend preceding this study and/or crab movements. Future studies should attempt to relate snow crab growth and maturation to the temperature they experience throughout their lifetime, which should assist fisheries management in a rapidly changing climate.