8.000 



- 







67 



6,000 



- 









4.000 



c 



68 f 



Y 



1199.437X - " 6 



r =.861 





2,000 



■70* 71 









h 











«-75 











■*-76 









SPRING SURVEY CATCH PER TOW - AGE l ( NUM6ERS OF FISH I 



Figure 7. — Power curve relationship between Atlantic mackerel 

 year-class size at age 1 from cohort analysis and spring survey 

 catch per tow at age 1. The 1968 point was not used in calculating 

 the curve. 



where Z = instantaneous total mortality = F + M. Catch 

 (in weight) options for 1978 were calculated for a range of 

 F values by applying mean weights at age to the catch at 

 age in numbers (C,) determined using the catch equa- 

 tion: 



C = W. i_i (i _ e 

 ' Z, 



'•') 



(3) 



and summing over all ages. Resultant stock sizes at age 

 in 1979 were determined using Equation (2). 



RESULTS 



Catch 



Table 6 contains a summary of annual Atlantic mack- 

 erel catches by the United States, Canada, and other 

 countries during 1961-77. International catches in- 

 creased from 13,700 t in 1961 to 431,600 t in 1972 and 

 then declined to 243,000 t in 1976. United States 

 commercial catches varied from 900 to 4,400 t during this 

 period and averaged 2,300 t/yr. Estimated U.S. recrea- 

 tional catches increased from 6,800 t in 1961 to a high of 

 33,300 t in 1969 and then declined to 5,000 t in 1976; the 

 yearly average for the period was about 15,000 t. Cana- 

 dian catches ranged between 5,500 and 21,200 t and 

 averaged 12,600 t. 



A total allowable catch (TAC) of 105,000 t was 

 allocated by ICNAF for the international commercial 

 fishery in 1977. The provisional reported catch for 

 January-March was 52,114 t (Table 7). Because of the 

 considerable reduction in TAC from 1976 (310,000 t) and 

 the high demand for Atlantic mackerel by the distant- 

 water fleets, it was assumed that all countries, except 

 Canada, the United States, and "Others," would harvest 

 their full catch allocations during the remainder of 1977. 

 Based on past performance, the Canadian catch was con- 



©67 









" 





Y = 954. 587 X 278 





- 





r = .834 





- 



74 



68 



•.« 



66 



73 









• ^0 



^ 7 .°.71 







Al2 



I 5 



1 



1 l 



1 1 



2,000 - 



5 1,000 



4 8 12 16 20 24 



SPRING SURVEY CATCH PER TOW - AGE 2 ( NUMBERS OF FISH) 



Figure 8.— Power curve relationship between Atlantic mackerel 

 year-class size at age 2 from cohort analysis and spring survey catch 

 per tow at age 2. The 1967 point was not used in calculating the 

 curve. 



Table 6. — Atlantic mackerel catch (metric tons) from ICNAF Sub- 

 areas 3, J, and 5 and Statistical Area li during 1961- 





United States 



Canada 



Other 

 countries 





Year 



Commercial 



Recreational 



Total 



1961 



1.361 



6,828 



5,459 



11 



13,659 



1962 



938 



8.698 



6,801 



175 



16,612 



1963 



1,320 



8,348 



6,363 



1,299 



17,330 



1964 



1,644 



8,486 



10,786 



801 



21,717 



1965 



1,998 



'8,583 



11,185 



2,945 



24,711 



1966 



2,724 



10,172 



11,577 



7,951 



32,424 



1967 



3,891 



13,527 



11,181 



19,047 



47,646 



1968 



3,929 



29,130 



11,134 



65,747 



109,940 



1969 



4,364 



33,303 



13,257 



114,189 



165,113 



1970 



4,049 



'32,078 



15,690 



210,864 



262,681 



1971 



2,406 



30,642 



14,735 



355,892 



403,675 



1972 



2,006 



21,882 



16,254 



391,464 



431,606 



1973 



1,336 



9,944 



21,247 



396,723 



429,250 



1974 



1,042 



'7,640 



16,701 



321,837 



347,220 



1975 



1,974 



6,503 



13,544 



271,719 



293,740 



-1976 



2,345 



'4,947 



15,744 



219,997 



243,033 



1977 



3,000 



5,000 



20,000 



64,000 



92,000 



! From angler survey; 



-Provisional. 



'Estimated. 



remaining years estimated (see text) . 



Table 7. — Estimated Atlantic mackerel catches (metric Ions) in 1*177 

 by country from ICNAF Subareas 3, 4, and 5 and Statistical Area (». 





Reported through 



Estimated 







Country' 



March 



remainder 



Total 



Allocation 



Bulgaria 



3,110 



890 



4,000 



4.000 



Canada 



— 



20,000 



20,000 



30.000 



Cuba 



683 



1,317 



2,000 



2.000 



F.R.G. 



— 



1,100 



1,100 



1.100 



G.D.R. 



7,981 



4,419 



12.400 



12,400 



Italy 



50 



250 



300 



300 



Poland 



17.167 



3,033 



20,200 



20,200 



Romania 



— 



1,100 



1.100 



1,100 



Spain 



10 



— 



10 



— 



U.S.S.R. 



22,586 



214 



22.800 



22.800 



U.S.A. Icoram.) 



.527 



2,473 



3.000 



6.000 



U.S.A. (reel 



— 



5,000 



5,000 



— 



Others 





90 



39,886 



Mil 

 92.000 



5,100 



Total 



52.114 



105.000 



