July 1966 



COMMERCIAL FISHERIES REVIEW 



Table 5 - Species Composition of Industrial Fish Samples from Trawl Fishery 

 in Percent of Weight by Month during Sample Year, March 1964 through February 19651/ 



Species 



Jan. 



Feb. 



Mar. 



Apr. 



June 



July 



Aug. 



Sept. 



Oct. 



Nov. 



Dec. 



Croaker 



20 

 11 

 19 

 10 



9 

 <1 

 <1 

 11 



2 



2 

 <1 



1 

 12 



1 



8 

 5 

 



<:i 



<l 



<1 



<1 



6 



<1 



9 



1 



17 



42 



10 



30 



28 



15 



7 



3 



<1 



2 



1 



2 



<1 



<i 



£1 



9 



2 



5 



7 



43 



21 







<1 







<1 



20 















3 







47 



22 



6 



7 



<1 



<1 



2 



<1 



<1 



2 



<1 



<1 



7 



5 



43 

 21 



1 



5 

 <1 

 <1 



8 

 <1 

 •«1 

 <1 

 <1 

 <1 



9 

 11 



39 



30 



2 



3 







1 



<1 



<1 



<1 



<1 



<:i 



<■! 

 12 

 11 



47 



11 



4 



4 



1 



<1 



3 



1 



2 



1 



4 



<1 



11 



10 



25 



13 



1 



23 



<1 



7 



6 



1 



2 



2 



2 



<1 



10 



7 



24 



15 



21 



24 



1 



<1 



<1 



<1 



1 



2 



<.l 



<1 



7 



3 



18 

 1 



31 

 7 



25 



<1 

 4 



<1 

 2 

 2 

 4 

 

 3 

 1 



Spot 





Butterfish 



Sand perch 



Pinfish 



Longspine porgy 



rlogfish 



Puffer 



Clear-nose ray 



FUefish 



Rock sea bass 



All other fish 



Invertebrates 





10 



4 



8 



2 



10 



11 



6 



6 



9 



9 



7 



1_/Samples imavailable in May. 



England (Edwards and Lux 1958; Edwards 1958), Gulf of Mexico (Haskell 1961), and Califor- 

 nia (Best 1959), about 75 percent or more of the catch was provided by three or four species. 

 Similarly in North Carolina in 1962 and 1964, four species supplied 73 and 68 percent, re- 

 spectively, of the catch by weight. 



In most studies of industrial fish fisheries, information concerning the number of indi- 

 vidual fish sampled is not considered. Snow (1950) sampled the catch of one boat according 

 to number of individuals, but Best (1959) counted and measured individual fish to determine 

 length composition of the catch by species. In the North Carolina study individual fish were 

 counted to establish species composition of the catch in percentage of number of individuals 

 and to provide an estimate of size of individual fish. In each year of study four species are 

 shown to account for 75 and 73 percent of the catch by number of individuals. 



The New England fishery (Edwards and Lux 1958) is based upon nonedible fish or edible 

 fish used on occasion. The Gulf of Mexico fishery is based principally upon croaker and spot, 

 but in that area those species are not considered desirable as food fish (Haskell 1961). In 

 California the fishery is based upon two nonedible species and one species of limited use as 

 food (Best 1959). In the North Carolina fishery in 1962, three edible species constituted 67.5 

 percent of the catch by weight and a total of 17 edible species accounted for 79.7 percent. In 

 1964, four edible species contributed 68 percent of the catch by weight and a total of 19 edible 

 species contributed 78.6 percent. The catch depends on those edible species to a slightly 

 greater extent on the basis of number of individuals than on weight. 



Thus the North Carolina industrial fish fishery differs from those previously reported 

 in that marketable fish form the source of supply. However, it must be noted that all trash 

 fish are caught merely incidental to regular fishing operations. Whether trash fish is proc- 

 essed into marketable byproducts or shoveled overboard, the trash fish are dead or dying. 

 Further, individuals of all edible species are indicated to be young-of -the -year, and among 

 such, natural mortality could be expected to be high. 



The small size of fish comprising the bulk of the catch as shown in the last column of 

 tables 1 and 4 indicates strongly young-of -the -year individuals. In general the fish of 1964 

 are slightly smaller than those of 1962. 



Economic factors can influence the make-up of trash fish according to species and size. 

 For example, if small gray sea trout (weakfish) as marketable food fish have temporarily 

 glutted the market, the next catch of small trout would be routed to a dehydrating plant and 

 processed into meal. This action "increases" the amount of an edible species in the trash 

 fish and also tends to increase the average individual size of the species. 



In monthly contributions to the industrial fish catch those species contributing most to 

 the total catch by weight apparently contribute consistently throughout the year. Some im- 



