PRODUCTION AND DISTRIBUTION OF COD EGGS IN 

 MASSACHUSETTS BAY IN 1924 AND 1925 



By CHARLES J. FISH 

 Formerly Associate Aquatic Biologist, United States Bureau of Fisheries 



Page 



Introduction 253 



Pelagic eggs and larvae 253 



Previous evidence of coastal drift in 



the Gulf of Maine 255 



Program and methods 259 



Spawning areas examined 259 



Spawning season 259 



Cod and haddock eggs 259 



Itinerary 260 



Equipment and methods 263 



Summary of observations 266 



General conditions 266 



Absence of fry 266 



Definite drift of eggs 266 



Local production in Massachusetts 



Bay 267 



Page 



Summary of observations — Continued. 

 Extent of the spawning season on the 



Plymouth grounds 267 



Drift as indicated by the eggs 270 



Drift-bottle experiments 277 



Current movements in Febru- 

 ary 278 



Rate of drift in February, 1925. 280 



Drift-bottle results in May 280 



Rate of drift in May 282 



Ipswich Bay 283 



Drift-bottle records 284 



General discussion 286 



Summary 290 



Size of cod eggs 291 



Bibliography 292 



INTRODUCTION 



PELAGIC EGGS AND LARV/E 



With very few exceptions all marine animals, and in fact almost all plants of the 

 sea as well, spend a large part of their lives in the surface waters. Some forms remain 

 pelagic a very short time, while others drift about for months. The fate of even the 

 invertebrate communities inhabiting our coastal waters lies solely in the success or 

 failure of their pelagic young to maintain themselves in the plankton. There must be 

 ample food available, and the winds and tides must remain favorable at least until 

 they reach the stage when benthonic life begins. 



In regions where a definite drift flows constantly in one direction the communities 

 would soon become exhausted were there not a constant supply of individuals from 

 other sources. The fact that some groups of benthonic animals are not found in 

 certain regions does not imply necessarily that conditions there are unfavorable for 

 their growth. It is likely that currents would carry the young away before they could 

 attach and the neighboring communities are not situated in such a way that they can 

 serve as sources of supply. 



