BUREAU OF FISHERIES 85 



understaiicling of the causes of rapid declines in the apparent 

 abundance of certain year chisses contrasted with the gradual de- 

 clines in others. The situation urgently calls for tagging experi- 

 ments to determine the commercial drain on the yearling mackerel. 

 Such determination of the strain on the stock would not only render 

 a prediction more certain but would also yield important evidence 

 as to whether beneficial effects would attend a restriction of fishing 

 on these younger mackerel. 



When investigations of the shore fisheries of the Middle Atlantic 

 States were begun in 1927, statistics of the yield presented the gloomy 

 picture of declining yields of several important food and game 

 fishes amounting in comparison with 1921 to 72 percent for blue- 

 fish, 21 percent for croakers, 37 percent for scup, and 36 percent for 

 squetcague. Studies have been pursued to discover the causes of 

 these observed declines and to formulate recommendations for the 

 restoration and preservation of the resource. Most recent canvasses 

 show a substantial recovery from the low yield of squeteague of 

 1926, particularly in New Jersey. Investigations have shown that 

 this recovery was brought about by the appearance of large num- 

 bers of fish of the 1926 and 1927 year classes. The yield of butter- 

 fish has recovered to near record levels during the course of the 

 investigations. In view of the fact that a complete natural recovery 

 has occurred and that there is no prospect of a material increase 

 in the fishing intensity of the future, regulation or restriction of this 

 fishery is not recommended. 



The yield of scup has likewise recovered naturally to very high 

 levels. The development of a year-round trawl fishery during the 

 past three years has increased the strain on this stock, however, and 

 particular attention is being paid to a study of this fishery which is 

 prosecuted off the Virginia capes during the winter seasons. 



During the past spring a preliminary report on the life history 

 of the most important commercial species of shrimp in the South 

 Atlantic and Gulf areas was approved for publication by the Bureau. 

 Field investigations in cooperation with the States of Georgia, 

 Louisiana, and Texas have been conducted throughout the year and 

 recently operations on the Atlantic coast have been extended from 

 Georgia waters to include the shrimping areas of South Carolina 

 and Florida. A study of the life history and migrations of the 

 commercial shrimp has revealed the surprising and significant facts 

 that this species spawns principally in the open ocean and Gulf, 

 grows rapidly in the inshore waters of bays and estuaries, migrates 

 seaward again where the life cycle is completed within a year by 

 spawning and subsequent death. Hence, conservation measures must 

 be applied promptly as soon as depletion is indicated in order to 

 avoid serious consequences. 



Ichthyological studies in the South Atlantic and Gulf areas have 

 been concerned with an examination of the fish fauna of the Gulf 

 coast, which have resulted in extensive revision in the taxonomy of 

 such species as the various flounders, gobies, and others, and a study 

 of the fishery resources in streams and lakes in the State of Missis- 

 sippi. This latter survey, conducted in cooperation with the State 

 authorities, is an effort of the newly formed fish and game commission 

 to^ assess the fishery possibilities of the State as a basis for more 

 effective conservation laws. 



