Period 3: Even though recruitment is oc- 

 (September- curring, the monthly catch-per- 

 December) unit-of-effort values decrease 

 along with the ocean tempera- 

 tures. The values for this period 

 are higher than those for pe- 

 riods 1 and 2, indicating perhaps 

 that our premise of increased 

 vulnerability after shedding is 

 correct. 



Our next step in analyzing the catch-in- 

 numbers-per-trap-haul-set-over-day was to 

 compare these values with another measure of 

 effort (boat-days) in order to determine if this 

 relationship demonstrates any condition not 

 revealed by temperature (Fig. 11). There is 

 an amazing similarity between the two types 

 of relationships. This led us to believe that 

 our original hypotheses concerning periods 

 of the year and the related assumptions are 

 greatly strengthened. Therefore, in the face 

 of this evidence we concluded that the rela- 

 tionship of catch-in-numbers-per-trap-haul-set- 

 over-day with boat-days is the more impor- 



tant consideration after the ocean water tem- 

 perature warms above a certain level. 



These same types of relationships appeared 

 to hold true for 1969 (Fig. 12). However, as 

 usually happens with hypothetical concepts, 

 something somewhat different obviously oc- 

 curred in 1970 (Fig. 13). 



By way of explanation for the omission of 

 data from January through March 1970, the 

 sampling in that year began in April because 

 of the demonstrated reduction in the catch 

 and effort categories for January through March 

 from 1967 through 1969 (Table 4). The reasons 

 for the reduction might be an evolving shrimp 

 fishery which usually concentrates its effort 

 between January and March of each year and 

 the ease by which lobster boats and fishermen 

 are converted to fishing for shrimp. This situa- 

 tion, in addition to a tremendous backlog of 

 data from sampling the lobster catch in other 

 months, led us to the decision to discontinue 

 the lobster survey during this period of the year. 



Returning to the months that we sampled 

 in 1970, there is an abrupt increase in the 

 catch in numbers per trap-haul-set-over-day in 



> 

 < 



1968 



> 



O 



3 

 < 



x 



.3- 



(PERIOD 3) 



Oct 

 ( t ) 



5 

 z 



x 

 o 

 I- 

 < 

 o 



>- 



< 



2 

 ■5. 



(period i) 



/ 



Jo 



(period 2) 



3b 



40 



SUMMARY EFFORT IN BOAT-DAYS(ac U oi) 



50 



Figure 11. — The relationship between catch in numbers per trap-haul-set- 

 over-day and boat-days by month for 1968. 



35 



