most of the remaining months of 1970 as com- 

 pared to the situation in 1969 and 1968. 



This combination of factors could also ex- 

 plain the slightly higher value of catch in 

 numbers per THSOD in 1970 than in 1969, 

 although the total catch in pounds is slightly 

 higher in 1969 than in 1970 as reported in 

 "Maine Landings." I concluded that while catch 

 in numbers per THSOD is a much better indi- 

 cator of stock density than any other known 



ratio, it must be carefully analyzed each year. 

 Such a continued treatise will be valuable 

 in future years. 



Relationship Between Catch per 

 Unit of Effort and Effort 



Gulland (1968) discussed the usefulness and 

 expected type of curve between the relation- 

 ship of catch per unit of effort plotted against 



Table 8. — The compilation of the catch in numbers per trap-haul and the number of set-over-days by 

 month and year, 1968 through 1970. The ratios are enclosed by parentheses. 



1968 



Month 



Number 



of set 



-over-days : 









1 



2 



3 



4 



5 





Number 



of: 











trap- 

 hauls 





-obs- 

 ters 



trap- lobs- 

 hauls ters 



trap- lobs- 

 hauls ters 



trap- lobs- 

 hauls ters 



trap- lobs- 

 hauls ters 



Jan. 



40 



.175 0) 



7 



150 49 

 (.3267) 



125 51 

 (.4080) 



( -" ) 



( " ) 



Feb. 







" ) 





( - ) 



( " ) 



( " ) 



150 15 

 (.1000) 



Mar. 



520 



.4500) 



234 



( " ) 



( " ) 



( " ) 



( " ) 



Apr. 



1145 



.2978) 



341 



295 134 

 (.4542) 



100 10 

 (.1000) 



250 78 

 (.3120) 



35 6 

 (.1714) 



May 



330 



.6848) 



226 



2315 1094 

 (.4726) 



585 394 

 (.6735) 



240 106 

 (.4417) 



120 52 

 (.4333) 



June 



262 



.2709) 



71 



617 309 

 (.5008) 



700 257 

 (.3671) 



80 117 

 (1.4625) 



532 321 

 (.6033) 



July 



796 



.2249) 



179 



2495 996 

 (.3872) 



1280 392 

 (.3062) 



( -- ) 



120 23 

 (.1917) 



Aug. 



4524 



.4772) 



2159 



1155 386 

 (.3342) 



653 363 

 (.5559) 



668 334 

 (.5000) 



( " ) 



Sept. 



2722 



.5760) 



1568 



1943 1212 

 (.6238) 



64 30 

 (.4687) 



( " ) 



( " ) 



Oct. 



1735 



.7032) 



1220 



1520 867 

 (.5704) 



970 984 

 (1.0144) 



164 189 

 (1.1524) 



( " ) 



Nov. 



100 



.8200) 



82 



1212 834 

 (.6881) 



705 536 

 (.7603) 



30 28 

 (.9333) 



( - ) 



Dec. 











_ _ 

















- ) 





( "- ) 



( " ) 



( "- ) 



( " ) 



Totals 



12,174 



.5000) 



3,087 



11,702 5,881 

 (.5026) 



5,182 3,017 

 (.5822) 



1,432 852 

 (.5950) 



957 417 

 (.4357) 



38 



