O'BRIEN AND MAYO: CPUE OF YELLOWTAIL FLOUNDER 



annual and seasonal interactions. A three-way 

 linear model, incorporating annual and seasonal 

 components, is employed to compute relative 

 fishing power coefficients over the entire 20-yr 

 period and estimate annual standardized CPUE 

 indices. 



DISTRIBUTION OF CATCH AND 

 EFFORT 



Commercial exploitation of yellowtail flounder 

 began in the late 1930's following the decline of 

 the winter flounder fishery (Royce et al. 1959). 

 Nominal catches^ for the three grounds combined 

 rapidly increased to 31,500 metric tons (t) in 1942 

 but subsequently declined to 5,500 t in 1954. 

 Landings by U.S. vessels gradually increased to a 

 record high of 36,900 t in 1963, but declined again 

 to 10,500 t in 1978 (Fig. 2). Distant water fleet 

 (DWF) catches were also substantial during this 



2Nominal catch defined as live weight equivalent of landings, 

 excluding discards. 



period, peaking at 20,700 t in 1969. Overall 

 catches from the three fishing grounds have re- 

 cently increased to 30,800 t in 1983, although 

 1984 landings declined to 15,500 t (Clark et al. 

 1984). The decline in catch during the 1940's was 

 not due to overfishing (Royce et al. 1959) but may 

 have been related to a warming trend in the re- 

 gion which affected recruitment (Sissenwine 

 1974). The more recent decline between 1969 and 

 1978, however, has been attributed to increased 

 fishing effort by both domestic and distant water 

 fleets (Brown et al. 1980). 



In the early 1940's the size of vessels fishing for 

 yellowtail flounder varied from 5 to 75 GRT. The 

 predominant vessels on Southern New England 

 and Cape Cod grounds ranged from 26 to 50 GRT; 

 on Georges Bank, the dominant vessels were in 

 the 51-75 GRT range. By the mid-1960's larger 

 vessels had begun to enter the fishery, increasing 

 the maximum size to 215 GRT. During this period 

 the size range of the dominant vessels on South- 

 ern New England grounds and on Georges Bank 

 had increased to 51-72 and 73-104 GRT, respec- 



55 n 



O 



CO 



O 

 O 



o 



I 



O) 



c 



C 

 <0 



50- 



45 



'cJj 

 S 40 



30- 



Total 



DWF 



nVja-yy 



1940 



1945 



1950 



1955 



1960 1965 



Year 



Figure 2. — Yellowtail flounder landings (metric tons) by United States and distant water fleet (DWF) vessels 

 from the combined Georges Bank, Southern New England, and Cape Cod grounds, 1940-84. 



93 



