2 U. S. BUREAU OF FISHERIES 



of the Atlantic, Gulf, and Pacific coasts and of the stocks of game and 

 commercial fishes in the interior waters. Principles of fish manage- 

 ment developed by scientific research have been applied with conspicu- 

 ous success to these fisheries. The application of similar management 

 practices to the great marine fisheries is relatively a virgin field, but 

 one in which encouraging progress is being made. 



As a basis for effective fish husbandry, direct and continuing obser- 

 vations of the fisheries themselves are essential. In addition, funda- 

 mental ]3roblems of fishery conservation are often solved only with 

 the aid of highly teclmical laboratory research. Both types of studies 

 are necessarily carried on over long periods of time, and progress 

 re])orted in any particular year must be interpreted in relation to the 

 whole program of investigation? of which it forms a part. Neverthe- 

 less outstanding trends and developments in the commercial fisheries 

 during the year 1937, as well as important achievements in the bio- 

 logical investigations conducted by the Division of Scientific Inquiry, 

 may well be summarized at this time. 



Commercial Fisheries. — In the North Atlantic area notable develop- 

 ments occurred in both the mackerel and haddock fisheries. The 

 spectacular decline of the mackerel catch to a level which was only 

 about one-third of the previous year's yield was an event of economic 

 and biological consequence, resulting in a sharp increase in price per 

 pound, but in a greatly reduced total return. This decline, of unfore- 

 seen magnitude, is believed to be the result of oceanographic condi- 

 tions at present not understood, which prevented the mackerel from 

 congregating in the usual fishing areas. The year continued the 

 downward trend in haddock landings begun in 1931. Of even greater 

 significance is the fact that it was the first year of simultaneous decline 

 in abundance (as measured in terms of catch per trawler ])er day) on 

 the Georges and Nova Scotian banks. Declining abundance on 

 Georges Bank drove the greater part of the otter trawl fleet to the 

 distant Nova Scotian banks in 1934, giving the former area an oppor- 

 tunity for moderate recovery. By 1936, however, the catch ])er day 

 on the Nova Scotian banks began to decline and a return to Georges 

 Bank followed, again increasing the strain on the inshore banks. As 

 a result of these shifts, both major haddock areas are now in a state of 

 declining abundance. The developments in these two fisheries empha- 

 size the need for continuation and extension of the biological studies 

 that have been prosecuted by the Division in this area. It is the pur- 

 pose of these studies to provide knowledge of the limits of safe exploi- 

 tation by the haddock fishery and to establish a sound basis for 

 prediction of fluctuations in mackerel abundance. 



A program of studies designed to direct the rehabilitation of the 

 seriously depleted shad fishery was initiated during the year in the 

 Middle and South Atlantic area. Headquarters for the fishery in- 

 vestigations of this entire section have been transferred from Massa- 

 chusetts to a more centralized location at College Park, Md,, and a 

 field laboratory has been established at Charleston, S. C. A survey 

 of Long Island fisheries by the Bureau staff in cooperation with the 

 New York Conservation Department has been launched to provide 

 information on the relative intensity of the commercial and the grow- 

 ing sports fisheries of this region. A flounder tagging program car- 

 ried out by the Bureau in cooperation .with the State of Rhode Island 

 has already demonstrated that the catch by sportsmen in many cases 



