XXXVI REPORT OF THE COMMISSIONER OF FISHERIES 



oceanography of the same region marks the culmination of several 

 years of investigation and provides data more complete than those 

 for any similar area of American waters. This very important 

 study of oceanography, or the physical environment of fish in the 

 sea, is being extended to the offshore regions of the various banks, 

 To aid in conducting the work, a suitable vessel has been acquired 

 from the Navy Department. Further study of the general ocean 

 drift and local currents by means of drift bottles, and direct observa- 

 tions on temperatures, salinities, and other physical characteristics 

 of the ocean circulation, together with the contained microscopic 

 life, will be continued and correlated with the fluctuating yield of the 

 fisheries. 



The mackerel investigations initiated last year have been con- 

 tinued. Progress has been made in determining the ages of the fish 

 composing the various runs, and the study of migrations, by means 

 of tagging experiments, has been extended. An attempt is being 

 made to foretell seasons of great abundance or scarcity of mackerel 

 by studying their habits and the relative numbers of fish of various 

 age classes that make up the catch. The results of these biological 

 investigations are being correlated with the statistics of the fishery, 

 and on this account the formulation of conclusions must be delayed 

 pending the accumulation of several years' data. 



Observations on the fish and fisheries of Chesapeake Bay have been 

 made by the bureau from time to time for many 3'ears. Our knowl- 

 edge of this region has been materially increased by a recent intensive 

 survey, the assembling of all previous records, and the compilation 

 of an extensive report, which not only gives descriptions and an au- 

 thoritative account of the systematic relationships of all the fishes 

 known to occur in the bay, but includes a great amount of informa- 

 tion on the natural history of the more important species. An analy- 

 sis of the statistics of the fisheries covering a long period, together 

 with a detailed study of the seasonal abundance of a great many spe- 

 cies and considerations of economic bearing, makes the report of par- 

 ticular value. 



In the South Atlantic States the staple food fish is the mullet, 

 which yields approximately 40,000,000 pounds of products annually. 

 The fishery is conducted in shallow sounds and inshore water areas 

 from North Carolina to Texas, but is most highly developed in 

 Florida and North Carolina. The fishery has been declining in pro- 

 ductivity for a number of years in several localities because of waste- 

 ful and destructive fishing and for other reasons, and an investiga- 

 tion begun during the last fiscal year was continued. The prelimi- 

 nary work has shown that the mullet of North Carolina and Florida 

 belong to distinct races. It is shown further that various other racial 

 units exist, so that the problems of conservation are of a local nature 

 and remedial measures must be devised to fit the needs of each sepa- 

 rate locality. Depletion in this fishery apparently has occurred more 

 rapidly in North Carolina than elsewhere, and particular attention 

 is being given to the fishery in that region. 



Many fish were tagged and liberated and their migration routes 

 traced. In this way it was shown that the stock native to the North 

 Carolina coast, while taking part in a regular annual migration from 

 the sounds to the sea, does not migrate to South Carolina or waters 



