COD EGGS IN MASSACHUSETTS BAY, 1924-1925 



289 



During the early part of the spawning season at Plymouth, and again near the 

 end of the season, the eggs drift for 14 to 17 days. However, in the coldest months 

 (February, in 1925) the drift may range from 24 to 30 days. Taking 4 miles per day 

 as the average rate at which eggs are carried out of the bay, in December they might 

 travel 56 to 68 miles before hatching; in February they would travel 104 to 120 miles, 

 and it must be remembered that after leaving the egg young cod drift from two to two 

 and one-half months before seeking the bottom. It is quite probable, therefore, 

 that each year fry produced in Massachusetts Bay and the inshore waters north of 

 Cape Ann may be distributed over almost all of the offshore banks. In fact, it is 

 conceivable that some circle the gulf and are carried in on the east side by the same 

 drift that carries the eggs out on the west. Nantucket Shoals, Georges Banks, and 

 the grounds in the Gulf of Maine may all benefit by this dispersal, but to what extent 

 is a question. 



It is possible that the presence of the young cod that each year enter the shore 

 waters about Woods Hole in company with large numbers of pollock may be explain- 

 able on this basis. Pollock, as far as is known, do not spawn south of the cape, but 

 the extensive breeding grounds on Stellwagen Banks lie in the path of the southerly 

 set, and the eggs could easily be carried south to Vineyard Sound. It is also possible 

 that of the small cod, 3 to 4 inches in length, found in abundance on Georges Bank, in 

 August, 1926, some originated in the inshore waters. Until this work has been 

 extended to cover the outer waters, these suggestions must remain mere possibilities. 



We can speak with more confidence about conditions in the inshore waters. 

 There is reason to believe that the cod stock of the coastal belt of the Gulf of Maine 

 is not self-supporting, so that were it not for constant immigration from the outer 

 waters the supply would be exhausted. It is possible that the same drift that carries 

 the eggs out of Massachusetts Bay may carry young fish in from the offshore banks. 

 The large numbers of young cod, 12 to 14 inches in length, found at certain places 

 along the coast of Maine suggest this. 



How important Massachusetts Bay is as a production center has not yet been 

 determined. Its value as a nursery is no greater than that of any other equal sector 

 of the coastal belt, but as a source of supply for offshore banks it may prove of signifi- 

 cance. To estimate this, it will be necessary to trace the courses of the eggs from the 

 bay, determining where they hatch, the food and enemies of the fry, and their fate. 

 Although it has not been possible, on these 13 cruises, to find solutions to all of the 

 problems involved in a determination of the value of Massachusetts Bay as a produc- 

 tion center, it is hoped that it will form the beginning of a much more extended investi- 

 gation of (1) the outer banks and (2) the fate of the eggs that pass beyond the confines 

 of the bay. 



In discussing the cod Professor Baird long ago stated that deep-sea fisheries 

 depleted in any particular locality will not be restored; no fish will come from sur- 

 rounding localities to take the vacant place (Prince, 1909). The second statement 

 has been borne out to some extent by recent cod-tagging experiments, which indicate 

 that in places schools of cod are confined to certain definite areas and do not migrate 

 up and down the coast in a haphazard manner. However, whether or not the depleted 

 areas would be restored will depend not necessarily on immigration by adults, but 

 upon the ultimate goal of the millions of tiny eggs and fry that drift out of such areas 



