Discussion 



In the three most recent years, gross fishing 

 effort in the Maine lobster fishery has, perhaps 

 temporarily, stabilized at approximately 1.25 

 million traps, a 67% increase over the 0.75 million 

 level of the preceding 12-yr period. 



Annual loss of traps has varied markedly since 

 the mid-1940's. In major late summer-fall storm 

 years, fishermen have reported losses of up to 100% 

 in many fishing areas; at other times less than 10% 

 in other areas. An average annual loss of 20 to 25% 

 has been estimated from interviews v^ith fisher- 

 men and counts made by departmental scientific 

 and enforcement personnel of traps stranded in- 

 tertidally by storms. This estimate would indicate 

 that about 200,000 traps have been lost annually 

 during the past decade from storms, accidents, or 

 vandalism, with each trap containing an average 

 of 3.1 lobsters (Dow 1961). Storm-lost traps are the 

 most consistently damaged and when they are 

 washed ashore, they usually contain dead lobsters. 



Cannibalism occurs principally from July to 

 early November, coincident with the greatest 

 concentration of traps, fishermen, and catch. 

 Within this period, 70 to 75% of the annual catch is 

 made, which for the last 30 yr has averaged 9,000 

 metric tons, consisting of approximately 18 

 million lobsters. Previous studies (Dow 1961, 1966) 

 also demonstrated a 2V2-fold increase in the total 

 number of lobsters entering traps of the summer- 

 fall fishery in comparison with the winter and 

 spring fisheries. 



During the 2-yr period of this investigation, in 

 which only 12% of the traps used were sufficiently 

 damaged by lobster chelipeds to permit escape, the 

 annual Maine lobster catch was 7,670 metric tons, 

 consisting of 14.2 million lobsters caught in 1.25 

 million traps. Between July and November when 

 the peak of cannibalism occurs, 77% of the annual 

 catch was made and consisted of 10.9 million lob- 

 sters. 



Conclusions 



1. Unbaited, unbuoyed traps continue to catch 

 lobsters for an indefinite time, with most of the 

 catch being made between June and September. 



2. Cannibalism occurs during the summer and 

 fall coincident with moult. 



3. Approximately one-third or more of all lob- 

 sters in or entering unbuoyed traps will be lost to 

 the fishery from cannibalism or retention. 



Literature Cited 



Dow, R. L. 



1961. Some factors influencing Maine lobster landings. 



Commer. Fish. Rev. 23(9): 1-11. 

 1966. Limitations on measurement of effort-yield in the 

 Maine lobster fishery. Fishing News Int. 5(8):32-36. 



William W. Sheldon 

 Robert L. Dow 



Maine Department of Marine Resources 

 State House 

 Augusta, ME OJ^SSO. 



451 



