Characteristics of the American Lobster Fishery of Grand Manan, New Brunswick, Canada

Changes in catch and effort trends and size frequencies of the fishery for American lobster Homarus americanus from the island of Grand Manan were examined. Fishermen from southern communities of Grand Manan have traditionally caught small lobsters (about 81–100 mm in carapace length, CL) from shallow waters (≤73 m deep). Since 1974, North Head fishermen have caught mostly large lobsters (>100 mm CL) in deep waters (74–200 m). Total seasonal lobster yields were stable at around 326 tonnes and provided a mean 2.7 tonnes per fishing license during 1948–1987. However, North Head fishermen increased their catch to 23.6% of the Grand Manan total landings by 1986. There were almost twice as many active fishermen and landings in November–December than in April–June, and there was little fishing activity in the cold winter months (January–March). However, some North Head fishermen continued to trap large lobsters in deep waters in winter. Although the median size (88 mm CL) and sex ratio (1:1) of recruited lobsters caught off southern Grand Manan did not change substantially during the last decade, there was a reduction in median size (from 134 to 118 mm CL) and mean weight (from 2.2 to 1.6 kg) and an increase in the proportion of females (from 52 to >70%) among lobsters caught off North Head. The continued high exploitation of new recruits and the increased removal of large lobsters probably contributed to the decline in size of lobsters caught off North Head between 1978 and 1987. Despite socioeconomic resistance to changes in management regulations, an increase in recruit size is recommended as an effective management option to increase both yield and eggs per recruit.