100 



80 



X 60 ■ 



40 



20 



MEDifiN : % 102. ae- 



pMEiN = $ 116.79 



-<00 -300 -200 -100 lOO 200 JOO 400 500 600 



TO TO TO TO TO TO TO TO TO TO TO 



-300 -200 -100 100 200 300 «00 500 600 700 



WEEKLY LABOR INCOME (dollars) 



Figure 14. — Estimated labor weekly income for a sample of Ameri- 

 can lobster boats, 1967. (A 15 percent return on capital invested in 

 boat and pots was subtracted from the total income — after 

 expenses — to obtain weekly labor income.) 



lobstermen worked for negative or no wages at all. 

 That is. the additional laboring made a negative con- 

 tribution after adjustment for capital investment. This 

 is clearly a risky industry. 



(5) Determinants of the Distribution of Re- 

 turns. — Why do hourly and weekly returns to boat and 

 lobsterman vary so greatly, as shown in Figures 12-14? 

 To explain this variation, we related "returns"" per 

 week to the following variables: 



(1) Crew size 



(2) Boat size (length) 



(3) Boat age 



(4) Horsepower 



(5) Number of traps fished 



(6) Trips per week 



(7) Average price received per pound 

 of lobsters 



(8) Years lobstering 



(9) Average depth fished in 



(10) Distance to grounds (summer). 



Obviously, there are other factors which may explain 

 the variation in returns. Managerial ability is not easily 

 quantifiable, but the so-called "good captain"' 

 hypothesis is well recognized in the literature on cost 

 and earnings in fishing. Table 16 shows the statistical 

 results. Of all the variables specified above, only boat, 

 age, number of traps fished, and trips per week were 



statistically significant at the 5 percent level. Finally. 

 Figure 15 shows the actual and computed distribution 

 of average weekly earnings. Notice that we underpre- 

 dicted the very low income group (()-$100) and over- 

 predicted the middle income group ($l()()-$20()) while 

 doing fairly well with the upper income group 

 ($200-$300). The large unexplained variation in earn- 

 ings may be due to many factors such as firms not 

 incurring actual cost by doing work themselves. This is 

 reflected in our poor ability to explain costs (Table 14). 

 Therefore, it must be concluded that much of the varia- 

 tion in lobstermen"s earnings are explained by "unex- 

 plained" variation in costs of production as well as the 

 "good captain'" hypothesis. 



E. Supply Relationships. 



Although the demand for all lobsters was considered 

 above, for management purposes we want to focus on 

 one component of the total supply: the inshore Maine 

 American lobster stock. The number of traps fished in 

 this fishery expanded from approximately 222,000 in 

 1940 to 1.2 million in 1971, or an annual rate of growth 

 of 5.6 percent. This largely resulted from the rising 

 demand pressures discussed above. Dow showed the 

 strong relation between the catch per trap of lobsters 

 and two important factors: (1) the total number of 

 traps fished and (2) seawater temperature.' This was 

 also demonstrated in Section III. That is, catch per 

 trap falls as the total number of traps fished increases. 

 However, within certain ranges, catch per trap is in- 

 creased by increases in seawater temperature which 

 causes lobsters to be more active in foraging and to 

 grow more rapidly. Therefore, the supply of inshore 

 Maine lobster is largely governed by the population 

 dynamics indicated in Section HI. The estimated max- 

 imum sustainable yield from the fishery was estimated 

 to be about 22, 108,000 pounds (live weight) that can be 

 taken with approximately 642,000 traps (see Table 12). 

 Presently, there are 1.2 million traps (1971) in the 

 fishery catching less than 18,000,000 pounds. As indi- 

 cated above, the Maine inshore fishery is considerably 

 overcapitalized on all accounts. Therefore, it is safe to 

 conclude that further increases in the demand for lob- 

 sters in general will result in decreases in supply from the 

 Maine American lobster fishery. 



If additional lobster supply is desired, then the most 

 likely source is existing populations. Several studies to 

 evaluate what effects minimum legal size increases 

 would have on the fishery have been conducted in 

 Maine (Baird and Harriman. 1951; Baird. 1953: Dow, 

 Goggins, Harriman, and Hurst*) based on size- 



'Dow. R., D. Harriman, G. Pontecorvo. and J. Storer. 1961. The 

 Maine lobster fishery. Unpublished manuscript submitted to the 

 U.S. Fish and Wildlife Service, Washington, DC. (May be ob- 

 tained from Sea and Shore Fisheries, Maine.) 



"Dow. R. L., P. L. Goggins, D. M. Harriman, and J. W. Hurst, 

 Jr. 1962. The lobster resource of Maine. Unpubl. ms., Dept. of Sea 

 and Shore Fisheries, Maine. 



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