We concluded from the sections under catch 

 and effort that the effective effort is related 

 to the number of trap-hauls in association with 

 the number of set-over-days rather than simply 

 the number of traps. 



To supplement the above concept, we com- 

 piled the average number of traps per boat 

 with the minimum and maximum range of 

 traps for all boats for a sample-day. This in- 

 formation was taken from the survey of the 

 commercial fishery and was compiled by month 

 and year (Table 10). 



We considered all of this information in 

 relation to two specific proposals: (1) a limit 

 of 400 traps per boat and (2) a minimum limit 

 of 200 traps to a maximum limit of 600 traps 

 per boat. In both proposals, no limitation on 

 the total number of fishermen was considered. 



In the case of the 400 trap limit, we should 

 understand that it is possible for a crew of 

 two men with a hydraulic hauler, fishing 8 to 

 10 traps in a string, to haul 400 traps in a day. 

 If these men fished 800 traps before the pro- 

 posed limitation, then possibly the regulation 

 would reduce the number of set-over-days with 

 the trap limitation but not the number of trap- 

 hauls for each fishing day because quite pos- 

 sibly these men would haul these same traps 

 each fishing day, provided they receive a profit 

 from this undertaking. We have already demon- 



strated that the catch does not increase arith- 

 metically with more set-over-days; therefore, 

 fewer set-over-days for hauling the same traps 

 might not reduce the catch in numbers per 

 trap-haul during the months of peak shedding. 

 The minimum-maximum proposal would re- 

 sult in a similar situation for the catch and 

 effort. The compilation of average number of 

 traps per boat with the range of number of 

 traps from all boats brought out another im- 

 portant fact for consideration, that in all likeli- 

 hood the proposal would not reduce the number 

 of traps by more than a small percentage, if 

 at all, compared to the present level. This 

 could come about by an increase in the number 

 of traps to 200 or more by so called "punt" 

 fishermen, while only a small percentage of 

 the "full-time" fishermen would reduce their 

 number of traps to 600. 



Use of Population Parameters to 

 Estimate Mean Length of Catch 



Beverton and Holt (1957) devised an equa- 

 tion for estimating the mean length of the catch 

 by using certain population parameters. We 

 substituted the values from the study on lobsters 

 into the following equation: 



Table 10. — Mean number of traps per boat by month and year, 1967 through 1970. 





1967 



1968 



1969 



1970 





Number o 



f traps 





Number o 



f traps 





Number c 



f traps 





Number c 



f traps 











standard 







standard 







standard 







standard 





range 



mean 



e r r " r 



range 



mean 



error 



range 



mean 



error 



range 



mean 



error 



Jan. 



31-500 



200 



± 1 



10-300 



210 



± 85 



80-325 



201 



±12 



- 



- 



- 



Feb. 



50-21(0 



155 



±28 



210-600 



315 



±128 



111-200 



150 



- 





- 



- 



Mar. 



90-300 



168 



±56 



250-350 



302 



± 2 



200-200 



200 



- 



- 



- 



- 



Apr. 



50-350 



237 



±73 



35-500 



155 



± 31 



80-280 



175 



±18 



150-100 



291 



±20 



May 



72-500 



292 



±38 



15-100 



212 



t 25 



75-600 



258 



±10 



10-500 



175 



±39 



June 



125-525 



261 



±10 



18-500 



187 



± 35 



60-500 



233 



±15 



50-1100 



391 



±165 



July 



85-500 



292 



±22 



30-1200 



191 



i 58 



30-550 



197 



±10 



30-600 



169 



±23 



Aug. 



30-61(0 



271 



±70 



10-800 



217 



± 17 



8-900 



187 



±37 



25-600 



275 



±25 



Sept. 



25-800 



252 



±62 



12-150 



192 



± 28 



10-600 



212 



±51 



30-660 



250 



±21 



Oct. 



10-300 



172 



±13 



22-800 



238 



± 56 



10-650 



220 



±21 



10-500 



216 



±21 



Nov. 



50-500 



215 



±30 



85-700 



321 



± 17 



61-100 



218 



±31 



30-600 



210 



±18 



Dec. 



30-1000 



280 



±75 



_ 



_ 



_ 



35-500 



186 



±25 



70-100 



222 



±36 



Totals 



25-1000 



215 



±11 



15-1200 



219 



±16 



8-900 



211 



±13 



25-1100 



252 



±12 



49 



