The rock crab (Cancer Irroratus Say) populations in lobster fishing areas of the Bay of Fundy

Observers sampled the rock crabs, Cancer irroratus, found in five lobster fishing areas during the summer of 1979 to obtain information on distribution, abundance, Sex ratio, and average size of these crustaceans in the Bay of Fundy. Rock crabs were more abundant on the Nova Scotia shore of the Bay, near Digby Gut (0.99 crabs per trap) and near Minas Channel (1.19 crabs per trap) than in Chignecto Bay (0.13 crabs per trap). Males outnumbered females in all areas, by ratios varying from 1.6:1 to 35.5:1. The average size of males in- creased steadily from a mean carapace width of 81.6 mm in Chignecto Bay to 109.4 mm in the waters off Chance Harbour, New Brunswick. The average size of females ranged from 72.0 mm to 92.0 mm, but did not follow a definite distribution pattern. Analysis of the populations in Chignecto Bay and from Delap's Cove, near Digby Gut, revealed that size may be correlated with water temperature. Of 110 crabs dissected, 31% of the 65 crabs from Chignecto Bay and 9% of the 45 crabs from Delap's Cove were parasitized by a nematomorph worm which has been tentatively identified as a member of the genus Nectonema. Further research is needed to determine the effect of this parasite and of other factors on the rock crab population in the Bay of Fundy.