98 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



out is far more effective because more rapid; but 

 because so little is known as to journeys any indi- 

 vidual school actually makes as season follows 

 season, whether of fat herring or of spawners. 

 Perhaps the most interesting question of all, and 

 one as yet unsolved, is how and why the spawning 

 fish seek their spawning grounds year after year, 

 when their sex organs mature. 



Spawning grounds and season. — It appears that 

 the most productive spawning ground for our 

 Gulf formerly was and still is at the mouth of the 

 Bay of Fundy, particularly on the shoals south- 

 west of Grand Manan. The Trinity Ledges off 

 western Nova Scotia are another important 

 ground; and herring are reported as spawning 

 commonly, though irregularly, in Machias Bay; 

 about Jonesport; at Mount Desert; in French- 

 mans Bay; among the islands at the mouth of 

 Penobscot Bay (Swans, Isle au Haut, and Matin- 

 icus); in Casco Bay; also about Wood Island a 

 few miles south of Cape Elizabeth, which has long 

 been known as the resort of breeding schools. 

 Herring have also been found spawning off the 

 beaches along the western shore of the Gulf, 

 Ipswich Bay, for example; about Cape Ann; in 

 Massachusetts Bay; about Provincetown; along 

 outer Cape Cod ; in the Woods Hole region ; near No 

 Mans Land; and about Block Island which is the 

 southern breeding limit. But whatever spawning 

 does take place either southward from the vicinity 

 of Cape Elizabeth on the one hand, or in the inner 

 parts of the Bay of Fundy on the other, is trifling 

 as compared with the production along the 

 eastern coast of Maine and in the Grand Manan 

 region. 



Spawning takes place both along shore in our 

 Gulf and on the various shoals and ledges that lie 

 for 5 to 25 miles off the coast, a habit betrayed by 

 the eggs that are found sticking to the anchor 

 ropes of fishing vessels. But we find no definite 

 record of herring spawning on Browns or Georges 

 Banks, nor are young fry known there, a fact that 

 was commented upon by Storer long ago. 



Spawning season. — Both spring - spawning 

 schools and summer-fall spawning schools of 

 herring were reported formerly, in the Bay of 

 Fundy, the spring spawners visiting the south 

 (Nova Scotia) side of the bay from Bier Island 

 at the mouth in as far as Digby Gut, also the 

 Parrsboro region on the New Brunswick shore 

 near the head of the bay, spawning during April 



and May. But they seem never to have been 

 very numerous, and it is not known whether any 

 spawn now in the bay before summer. Spring- 

 spawning as well as autumn-spawning herring 

 have also been reported to us by fishermen along 

 the west coast of Nova Scotia, though we have 

 not been able to verify this. Other than this, 

 spring spawners are neither recorded nor rumored 

 anywhere in the Gulf of Maine. 



Around Grand Manan and in Machias Bay 

 nearby, the heaviest runs of summer-autumn 

 spawners usually come in July, August, and Sep- 

 tember, the spawning season continuing until late 

 in the fall in some years, 65 but not commencing 

 until early August, and ending by early Oc- 

 tober in others. 66 Passing westward we find the 

 breeding period progressively later and shorter; 

 mid-August for example until October around 

 Petit Manan and near Mount Desert, while 

 the few herring that spawn farther south do so 

 chiefly during October in Ipswich 67 and Massa- 

 chusetts Bays; in late October and early Novem- 

 ber in the vicinity of Woods Hole. 



So many observations have been taken in the 

 Gulf from the vessels of the Bureau of Fisheries, 

 and in the Bay of Fundy by the Biological Board 

 of Canada, that it is possible to establish the 

 temperatures rather closely at which herring 

 spawn in our waters. Around Grand Manan and 

 in the northern part of the Gulf generally, prac- 

 tically all spawning is carried out in water of about 

 46-52° F. But such herring as spawn in the 

 southern part of Massachusetts Bay and along 

 the shores of Cape Cod, where autumnal cooling 

 of the surface waters is not so rapid as it is farther 

 north, may do so in slightly warmer water, say 

 up to 53° or 55°. The Gulf of Maine herring 

 spawn in rather low salinities (such characterize 

 the coastal zone as a whole as compared with the 

 North and Norwegian Seas), the most saline water 

 in which it is known to spawn within our limits 

 being not saltier than 33 per mille, the freshest 

 probably about 31.9 per mille. They never spawn 

 in brackish water within the limits of the Gulf, 

 although known to do so at the mouths of certain 

 European rivers in water that is nearly fresh. 



Destruction by natural causes. — The herring is a 

 very "tender" fish, prone to wholesale destruction 



" So described by Moore, Rept. U. S. Comm. Fish. (1896), 1898, p. 408. 



69 Dr. Huntsman informs us that this was the case in 1917. 



«' Allen, Mem. Boston Soc. Nat. Hist., vol. 8, No. 2, 1916, p. 201. 



