PISHES OF THE GULF OF MAINE 117 



5,000 fish, assuming an average of 2J/£ pounds). They have also been reported in 

 abundance near Cape Ann, off the Isles of' Shoals, near Boothbay Harbor, and at 

 Herring Cove near Eastport, Me. 



Summary. — The evidence at hand suggests that shad, like herring, spend 

 the first winter near the mouth of the river in which they are hatched; that for 

 two or three years, as immatures, they roam our coast in summer, wintering some- 

 where offshore; and that finally, as mature breeding fish, they come inshore in spring, 

 run up rivers from April to June to breed, return promptly thereafter to the sea to 

 pass the late summer and autumn, fattening near the surface not far from land, 

 and, like herring, they winter offshore in deep water. 



Food. — The shad, like other herrings, is primarily a plankton feeder. We 

 have found shad taken in the Gulf of Maine in summer packed full of copepods 

 (chiefly Calanus), and the stomach contents of fish from the Nova Scotian coast 

 of the Bay of Fundy examined by Willey (1923, p. 11) consisted chiefly of the 

 copepod genera Acartia and Temora with other smaller ones, Mysid shrimps, and 

 the larval stages of barnacles. Shad are also known to feed as greedily on the 

 pelagic euphausiid shrimps as herring do, on fish eggs, and even on bottom-dwelling 

 amphipods, showing that at times they forage near the ground. They are not 

 known to eat fish. 



Breeding habits. 2 * — It is now T sufficiently established that on their spawning 

 migration shad return year after year to the same general region, sound, or estuary; 

 and in the Gulf of Maine, where so few rivers can now serve as spawning grounds, 

 this necessarily means to the same stream, the date when the sexually mature shad 

 enter fresh water being governed by the temperature of the streams — that is, when 

 the river water has warmed to 50° to 55°. Consequently the shad "run" cor- 

 respondingly later in the year passing from south to north along the coast. Thus 

 the run commences in Georgia in January; in March in the waters tributary to 

 Pamlico and Albemarle Sounds; in April in the Potomac; and in May and June in 

 northern streams generally from the Delaware to Canada. In the Kennebec, 

 according to Atkins (1887), the first shad appear late in April, with the main run 

 in May and June; the first ripe females are caught the last week in May and they 

 begin to spawn about June 1, most of them doing so during that month, a few 

 in July, and possibly an occasional fish as late as August. Probably these dates 

 applied equally to the Merrimac in the good old days when shad were plentiful there, 

 but the season begins somewhat later in the St. John, as might be expected, with 

 the fish running from mid-May until the end of June. 



The fish select sandy or pebbly shallows for spawning ground. On the average, 

 females produce about 30,000 eggs, though in. the case of very large fish as many 

 as 156,000 have been estimated. After spawning the spent and very emaciated 

 fish at once begin their return journey to the sea. In the Kennebec they are first 

 seen on their way down about June 20 and constantly thereafter throughout July; 

 in the St. John spent fish are running down in July and August. According to 



" Accounts of the breeding habits of the shad have been given by Ryder, Report U. S. Commissioner of Fish and Fisheries, 

 1885 (1887); by Prince (1907); and in the Manual of Fish Culture, 1900. 



