YELLOWTAIL FLOUNDER OFF NEW ENGLAND 



233 



species; the high cost of fishing them will ease the 

 pressure in time to save a spawning nucleus. The 

 greatest catch from the yellowtail stocks may be 

 obtained by fishing them when available without 

 restriction other than the inevitable economic ones, 

 which are necessarily greater in a higlily fluctuat- 

 ing fishery. 



Such erratic catches as characterize the yellow- 

 tail fishery cause serious economic consequences 

 among short-range vessels of the kind prevalent 

 in the southern New England fishery. If the 

 fluctuations in yellowtail catch cannot be 

 smoothed out, the earnings of the fishermen would 

 be better maintained by turning to other species — 

 some of which replaced the yellowtail when it de- 

 clined. Finding uses and markets for these 

 species should be helpful. 



Not much is known about the yellowtail and 

 the factors influencing the size of the stocks. One 

 of the most troublesome features of our study has 

 been the lack of knowledge of the yellowtail pop- 

 ulations not being taken by the fishery. The study 

 of these apparently numerous populations and 

 subpopulations which do not fully intermingle 

 can be accomplished only by thorough sampling 

 of the commercial landings and of the fish in other 

 areas of the sea by a research vessel. Such a study 

 should also include proper consideration of the 

 relation of the yellowtail to its environment and 

 to other species in the area — vertebrate and in- 

 vertebrate, competing and noncompeting, preda- 

 tor and prey. Other aspects of its life history 

 need to be investigated. We know little of its food 

 habits or fecundity, the requirements and habits 

 of the larvae and juveniles, or of other factors 

 which may limit the size of the stock. 



Adequate answers to these questions will re- 

 quire considerable effort; however, a satisfactory 

 guardianship of the stocks can probably be main- 

 tained with a limited study to determine trends 

 in total catch, abundance, and size composition of 

 the fishery, supplemented by a watchfulness for 

 evidence of any significant waste of young fish 

 either through discard at sea or reduction to fish 

 meal. Such a study will not lead to a full under- 

 standing of the causes of fluctuations in the fish- 

 ery, but it can be maintained at a cost commen- 

 surate with the value of the fishery and will pro- 

 vide invaluable data for any future, more elab- 

 orate investigation that may become desirable. 



SUMMARY 



An intensive study of the yellowtail flounder 

 (Limanda ferruginea) was undertaken in 1942 

 and continued through 1947, with additional data 

 on landings and catch per unit of effort collected 

 through 1951. 



Following the decline in the populations of the 

 winter flounder — mainstay of the otter-trawler 

 fleet in southern New England — in the mid- 

 thirties, the abundant yellowtail proved a suitable 

 substitute. The total United States landings of 

 this flounder rose from 23 million pounds in 1938 

 to 70 million in 1942, then declined to about 30 

 million pounds annually from 1944 through 1949. 

 Price changes were not the cause of the declining 

 catch. 



Between 1942 and 1949, a total of 2,597 yellow- 

 tail was tagged and released at 14 points along 

 the New England coast, covering all the major 

 United States fishing grounds. Through Decem- 

 ber 1952, a total of 377 tags, or 14.5 percent, had 

 been recovered. The recoveries indicated that the 

 yellowtail occur in relatively localized populations 

 and that they make short, seasonal migrations. 

 The majority of the recaptures were within 50 

 miles of the release points and the most distant 

 recapture was only 170 miles from the release 

 point. Almost all the fish were recaptured in 

 depths between 15 and 35 fathoms. 



The mingling of the tagged yellowtail and the 

 fishing concentrations indicated the existence of 

 five more or less distinct stocks : 



1. A complex southern New England stock be- 

 tween Nantucket Shoals and Long Island, part of 

 which may have begun to move to Georges Bank 

 in the summer of 1947. 



2. Georges Bank stock on the shoal parts of 

 the Bank. 



3. Cape Cod stock from east of Cape Cod north 

 to the vicinity of Cape Ann. 



4. A northern Gulf of Maine stock along the 

 coast of Maine. 



5. One or more Nova Scotian stocks which are 

 fished incidentally by United States boats seeking 

 other species. 



The bulk of yellowtail production in the United 

 States has come from the southern New England 

 stock, hence any fluctuations in its numbers are a 

 cause for concern. Because of the great impor- 

 tance of the southern New England stock to 



