466 Memoir Sears Foundation for Marine Research 



and early in December. It is certain that at least some of the Dogfish that summer as far 

 north as Newfoundland journey southward in autumn past the Gulf of Maine, for one 

 tagged near St. John on July 14, 1942, was recaptured on the 23rd of the following No- 

 vember, off Thatcher's Island, Cape Ann, Massachusetts, having travelled a distance of at 

 least 1,000 miles during the interval of 132 days or at an average of about 7.6 miles per 

 dayj actually, it probably travelled much farther and faster, for it is not likely to have 

 followed a straight line. An equally interesting case is that of another fish tagged near St. 

 Johns, Newfoundland, in April 1942 which was recaptured in September of the following 

 year at the mouth of the Bay of Chaleur, within the Gulf of St. Lawrence;" it is evident 

 that Dogfish that summer off one part of the coast during one year may do so off some 

 other coast many miles distant during another. Additional information in these respects is 

 much to be desired. 



Wintering Grounds. It now seems certain that the Spiny Dogfish winter chiefly on 

 bottom in deeper water offshore, from the ofiing of New York southward, for while none 

 are reported from Georges Bank in February (though a few in January, however), con- 

 siderable numbers have been trawled on the outer part of the shelf off New York in late 

 November and in January and likewise in depths of 16 to 70 fathoms*' between the 

 offings of Delaware Bay, of northern Virginia and of Cape Hatteras in February. The 

 fact that Spiny Dogfish have been washed ashore in some numbers on the southwest 

 coast of Newfoundland in mid-January (p. 465) also opens the very interesting possi- 

 bility that some of those that summer in that general region may survive the winter in the 

 trough of the Gulf of St. Lawrence in temperatures (4°-5° C; or 39°-4i° F.) consider- 

 ably colder than those that prevail on the southern wintering grounds. 



Numerical Abundance. During its periods of abundance this is by far the most nu- 

 merous local shark; in fact, it is the only one that even remotely rivals the commercially 

 important food fishes in abundance. It has been described repeatedly as "in great abund- 

 ance," in "schools of thousands," or as being caught as fast as fishermen can haul them 

 in. Unfortunately the statistics of commercial landings do not afford any Information 

 in this respect about the Dogfish in American waters. But the foregoing is no over- 

 statement, judging from such records as the following: 690 caught on a 700 hook line at 

 Cape Breton; a Dogfish on nearly every one of 1,500 hooks in the Gulf of Maine; three 

 wagon loads from a single lift of two pound-nets on Long Island; 1,800 pounds in one 

 day in pound nets in North Carolina} more than two tons preserved for use in biological 

 laboratories in a three- weeks' period; or an average trawl catch of 6,000 to 8,000 per trip 

 on Georges Bank during the peak of abundance in 1913. At the time of the 1904-1905 

 peak of abundance it was estimated, from reports of fishermen's catches, that at least 

 27,000,000 were taken yearly off the coast of Massachusetts alone." There is, in short, no 



47. For these and other tagging records, see Templeman (Res. Bull. Dep. Nat. Resources Newfoundland, 15, 1944: 

 67, fig. 18). 



48. For details, see Bigelow and Schroeder (Bull. U.S. Bur. Fish., ^S, 1936: 323). 



49. Rep. Comm. Fish. Game Mass. (1906), 1907: 20. 



