between October 1949 and October 1952 when the av- 

 erage annual catch was 20.1 million pounds, repre- 

 senting 84 percent of the legal population. If predic- 

 tions had been based on 1953-55 sampling, when an- 

 nual catch averaged 22.2 million pounds, representing 

 86 percent of the legal population, then the predicted 

 catch would have been: 1958, 20.8 million pounds; 

 1959, 22.8 million pounds; 1960, 23.7 million pounds; 

 and 1961, 24.1 million pounds, or a total of 91.4 million 

 pounds for the 4-yr period, with an error of 2.9 million 

 pounds or 3.2 percent. 



With the present minimum size, the anticipated 

 range of lobster carapace sizes recruited by moulting 

 from sublegal stocks is 81 mm (3''/ik in.) to 91 mm 

 (3"'/;i2 in.). The weight increase from 81 to 91 mm has 

 averaged 43 percent. 



An increase from 81 mm (3-Vi(i in.) to 83 mm (3'/4 in.) 

 would reduce the catch an estimated 9 percent in 

 number of lobsters during the first year. During the 

 second year the new sublegal lobsters, between 81 and 

 83 mm, would be expected to increase an average 14 

 percent in carapace length, 93 mm (3^'/32 in.), and an 

 average 47 percent in weight to 1.37 pounds, while the 

 next '/i6 in. minimum size increase would remove 

 from the legal stock those lobsters less than 3Vi6 in. in 

 carapace length, representing 19 percent of the catch 

 remaining between 3Viii in. and the maximum size of 5 

 in. carapace. In the meantime. 3Vib in. lobsters, rep- 

 resenting 9 percent of the catch, during the preceding 

 year have moulted and increased to an average 

 carapace length of 3% in. (92 mm) and an average 

 weight of 1.34 pounds or 47 percent increase. 



Since annual mortality appears to average approxi- 

 mately 7.5 percent per ^/i6 in. (3.2 mm) carapace be- 

 tween the minimum legal size and the maximum 

 carapace length of lobsters recruited by moult from the 

 sublegal population, the loss of these animals by can- 

 nibalism, predation, permanent entrapment, or other 

 mortality causes associated with trap fishing must be 

 subtracted from the anticipated benefit in total yield 

 from increases in the minimum legal size. With the 

 types of traps used in the fishery incidental mortalities 

 will occur, at perhaps varying levels of magnitude, no 

 matter what minimum legal size may be devised. The 

 only means of eliminating trap-associated mortalities is 

 to develop alternative methods of capturing lob- 

 sters. 



To express number of lobsters as weight, the con- 

 versions in Table 17 have been used. 



Annual sea temperature during the 3-yr period 

 1969-1971 has remained virtually the same: 8.9°, 8.9°, 

 8.7°C; yet, lobster catch has declined 8.4 percent and 

 3.4 percent on a year-to-year basis and 11.4 percent 

 cumulatively (Table 18). 



During the 1957-1963 period of near-optimum sea 

 temperature, the catch of lobsters annually averaged 

 10.2 thousand metric tons and mean annual tempera- 

 ture was 8.6°C. During the equally near-optimum 

 temperature years 1969-1971, when the average was 



Table 17. — Average length-weight of lobsters. 



Length 



Weight 



8.8°C the annual lobster catch averaged only 8.4 

 thousand metric tons, a decline of 17.7 percent. Be- 

 tween the two periods, average gross fishing effort in- 

 creased 54 percent, from 700,000 to 1,080,000 units per 

 year. 



The relationship among temperature, effort, and 

 landings suggests that overfishing (effort) has had an 

 annual value of nearly 6 percent in reducing catch. 



Maine lobster abundance declined after 1957. Since 

 the rate of decline has increased during the last 15 

 yr, it is likely, in view of the demonstrated overfishing 

 of the resource and anticipated less favorable sea 

 temperature conditions until the decade between the 

 mid-1970's and the mid-1980's (H. Willett, pers. 

 commun.), that decline during the 1973-1976 period 

 may average about 12 percent with an annual average 

 catch of 7,400 metric tons (Table 19). 



F. Labor Force Characteristics. 



The Maine Department of Sea and Shore Fisheries 

 reports the trends in lobster licenses issued (Table 20) 

 and the age distribution of those licensed (Table 21). 

 However, to get some idea of the socioeconomic 

 characteristics of the labor force, the University of 

 Maine was given a contract by the NMFS to study this 

 matter. The study concentrated on three typical com- 

 munities rather than encompassing the entire Maine 

 lobster fishery. These communities are: Phippsburg, 

 Beals, and Corea (see Fig. 16). The selection was 

 made in consultation with the Maine Department of 

 Sea and Shore Fisheries and the National Marine 

 Fisheries Service. The existence of some contrasts in 

 the structure of the local economy and the relative 

 importance of the lobster fishery in their economy 

 weighed heavily in the selection process. Corea rep- 

 resents a highly specialized, isolated economy where 



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