Tl'RNKR ET AL.: TILEFISH IN MIDDLE A TLANTK WHTHKRN NEW ENGLAND 



In (eviscerated wt) = -5.18 + 3.21 In (FL). 



Overall, whole weights were 7% greater than evis- 

 cerated weights. However, this percentage increased 

 from about 5% for 40-54 cm FL females to 14% for 

 90-94 cm females, while it increased only from 5 7c for 

 males of 50-54 cm FL to 8% for males of 90 cm FL 

 or more. 



Size Structure 



Randomly collected length measurements from 

 longline, recreational, and foreign trawl fisheries 

 showed differences in sizes of tilefish exploited. All 

 three fisheries had similar modal sizes, but the 

 majority of the foreign trawl catch was smaller than 

 the modal size, while the majority of the longline and 

 recreational catches exceeded the modal size (Fig. 8). 

 Size structure was available for the longline and rec- 

 reational landings in 1977 and for all three fisheries 

 in 1978. Because sample sizes were often small, no 

 weighting was used in preparing length-frequency 

 histograms and all fishing areas were combined. In 

 1977 the longline and recreational fisheries had one 

 mode at 61-65 cm FL, and similar size distributions 

 (65-70% of the fish between 56 and 75 cm FL, Fig. 8). 

 In 1978 there was a mode for all three fisheries at 51- 



55 cm FL. Foreign trawl catches were most distinct; 

 the majority of the catch was below the modal size 

 (51% from 26 to 50 cm FL), and only 17% was in the 

 56-75 cm FL interval. The longline and recreational 

 catches were similar in that most of the catch 

 exceeded the modal size, but the longline land- 

 ings had a second mode (61-70 cm FL) while the rec- 

 reational catch did not. Fifty-three percent of the 

 longline catch was in the 56-75 cm FL interval, and 

 37%; of the recreational catch was in that size range. 



Size structure in the longline fishery became trun- 

 cated between 1974 and 1980. In some years, the size 

 structure differed between the two fishing areas (Fig. 

 5). The earliest length-frequency histogram (1974) 

 for the Hudson Canyon area showed what Grimes et 

 al. (1980) considered to be a relatively unexploited 

 population, and the first histogram for the Southern 

 New England fishing area (1976) showed smaller 

 modal sizes than the 1974 data for the Hudson 

 Canyon. In 1 97 4, 7 1 % of the tilefish from the Hudson 

 Canyon area were >70 cm FL. In 1976, 43% of the 

 fish from the Hudson Canyon area and 46% from the 

 Southern New England area were >70 craFL. These 

 percentages declined in 1978 to 36 and 30%, respec- 

 tively, and in 1980 to 16 and 21%, respectively. 



Size at complete recruitment to the longline fishery 

 (occurring just above the modal size in the length- 



FlGURE 8. — Length frequencies of tilefish caught during 

 1977 and 1978 in all fishing areas by recreational and long- 

 line fishermen and foreign fishing vessel trawls, n = 

 sample size. 



1977 



1978 



FOREIGN TRAWL 

 50 i 



40 



30 1 



20 



10 



n 280 



i "" . """>-' r™ i 



LONGL 

 n 429 



n 3267 



RECREATIONAL 



n 126 





-P- 



n 193 



20 40 60 80 100 

 Length (cm) 



20 40 60 80 100 

 Length (cm) 



759 



