COLTON: TEMPERATURE TRENDS AND GROUNDFISH DISTRIBUTION 



Cape Cod (lat 40°30'N, long 70°00'W) marks 

 the southern and western limits of its normal 

 range, although plaice are occasionally taken 

 west to Block Island. Tagging experiments in 

 the Grand Banks area (Pitt, 1969) suggest that 

 there are a number of relatively sedentary pop- 

 ulations of plaice and that the limited migrations 

 that do occur are associated with spawning and 

 feeding patterns. Research ship and commer- 

 cial catch statistics indicate that this is also true 

 of the Gulf of Maine populations. 



HADDOCK 

 (MELANOGRAMMUS AEGLEFINUS) 



The haddock is a boreal species inhabiting 

 both sides of the North Atlantic whose distribu- 

 tion, for the most part, is confined to waters 

 shoaler than 200 m. On the American coast the 

 westerly limit of its normal occurrence is the 

 Nantucket Shoals area (long 70°00'W) although 

 in winter haddock are sometimes taken in the 

 area between Nantucket Shoals and New Jersey. 

 Young-of-the-year haddock are found in the area 

 between Nantucket Shoals and Hudson Canyon 

 during the summer and fall. Indications are 

 that the majority of these young fish are con- 

 centrated at mid-depths (Colton, 1965) and 

 caught while the trawl is being set out and re- 

 trieved, Young-of-the-year haddock are not 

 included in the catch statistics presented in this 

 paper. Tag returns and the distribution of com- 

 mercial fishing effort indicate that in compar- 

 ison with the cod, the haddock is a relatively 

 stationary fish, and except for short-term shifts 

 in depth distribution they do not follow any reg- 

 ular migratory routes (Needier, 1930; Schroe- 

 der, 1942; Schuck, 1952) . 



YELLOWTAIL FLOUNDER 

 {LIMANDA FERRUGINEA) 



The yellowtail flounder is a shallowwater spe- 

 cies which occurs along the Atlantic coast of 

 North America from Labrador to New Jersey. 

 The bulk of the catch is taken in water shoaler 

 than 100 m. The yellowtail flounder is one of 

 the few species which is common both to the 

 east and west of Cape Cod at all seasons of the 



year. The tagging studies of Royce, Buller, and 

 Premetz (1955) and Lux (1963) show that, in 

 general, the populations of New England yellow- 

 tail are to be found in relatively localized groups 

 which may make short seasonal migrations and 

 only a limited amount of mixing takes place be- 

 tween groups. 



BUTTER FISH (PEPRILUS TRIACANTHUS) 



The butterfish ranges in the northwestern At- 

 lantic from the outer coast of Nova Scotia and 

 Cape Breton to northern Florida. There is a 

 separate population in the Gulf of Mexico (Cald- 

 well, 1961). This temperate-region species is 

 only a warm season migrant to coastal waters 

 off" New England and the Maritime Provinces. 

 In general, butterfish appear off southern New 

 England at the end of April, but it is not until 

 July that they are plentiful in the inner parts 

 of the Gulf of Maine and on Georges Bank. 

 Butterfish disappear from the coast by the end 

 of December at the latest, 



COLLECTION AND REDUCTION 

 OF DATA 



The data were collected during the period 

 1950-1968 by personnel at the Bureau of Com- 

 mercial Fisheries (now the National Marine 

 Fisheries Service) Biological Laboratory, Woods 

 Hole, Mass., on surveys designed to determine 

 the distribution and relative abundance of 

 groundfish in the Gulf of Maine and adjacent 

 waters. The fishing gear used during these 

 surveys was similar to that being used by the 

 commercial haddock fleet at the time. A li/^ 

 Iceland trawl was used prior to 1951, and a No. 

 36 redfish trawl has been used since that time. 

 A description of these trawl nets is given by 

 Knake (1956), The cod end and top belly of 

 both type nets were lined with fine mesh netting 

 to retain smaller fish. Three vessels were used 

 in these surveys; the side trawlers Albatross III 

 and Delaware and the stern trawler Albatross 

 IV. On all cruises the trawl was towed for 

 30 min at each station at a vessel speed of ap- 

 proximately 3.5 knots. Various sampling pat- 

 terns employing both random and grid station 



641 



