14 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Distribution off Atlantic coast of the United States and 

 in eastern Gulf of Mexico 



The northern limit of the range of the sandbar 

 shark is easily established. There are no reliable 

 records of its capture from the Gulf of Maine 

 (Bigelow and Schroeder, 1953), but south of 

 Cape Cod it has been taken frequently but irregu- 

 larly at Woods Hole, Mass. Numerous records 

 of the species along the Atlantic coast of the 

 United States are summarized by Bigelow and 

 Schroeder (1948). Sandbar sharks may be said 

 to be common in summer along the Atlantic coast 

 of the Ignited States from Long Island to the tip 

 of Florida and in winter along the waters of the 

 Continental Shelf off the Carolinas southward to 

 the southern tip of Florida, in water of moderate 

 depths in the Florida Straits and along the west 

 coast of Florida northward to Tarpon Springs 

 or the Middle Grounds (the rough bottom area 

 south of Cape San Bias, Fla.). This area is the 

 principal known range, but the species has also 

 been taken in small numbers from the northern 

 and western Gulf of Mexico, the western borders 

 of the Bahama Bank, the northern coast of Cuba, 

 and the Caribbean coast of Nicaragua and north- 

 ern Costa Rica (fig. 4). , i" 



The hypothesis is advanced hejie that the sand- 

 / bar sharks of the eastern and southern sides of 

 the Gulf Stream in the Straits of Florida are 

 casual visitors to those areas and that the stock 

 of the northern and western parts of the Gulf of 

 Mexico is a breeding stock which is not self- 

 sustaining, but is recruited in part from migra- 

 tory adults moving to the northern and western 

 parts of the Gulf by mistake or through error in 

 orientation and navigation during the regular 

 winter migration of the principal stock. 



The sandbar shark has been taken from the 

 shallows along beaches out to a depth of about 

 135 fathoms. The young have been taken most 

 often in shallow waters to depths of about 5 to 

 25 fathoms in summer, but in winter they move 

 offshore to warmer water and depths as great as 

 75 fathoms off the Carolina coast. 



The sandbar shark is known only from the 

 shallower part of the Continental Shelf in the 

 warmer months in the extreme northern part of 

 its range. Probably the adults are more common 

 off beaches tlian in major bays or inlets. Hilde- 

 brand and Schroeder (1928) found the species 



rather rare in Chesapeake Bay although more 

 common than any other shark except the spiny 

 dogfish. Radcliffe (1916) states that the species 

 appears to be rare in the Beaufort, North Caro- 

 lina, region. However, it was regarded as com- 

 mon in bays on the ocean side of Long Island 

 from mid-June to mid-September, by Nichols and 

 Breder (1927). 



The apparent scarcity of adult E. milberti 

 noted by Hildebrand and Schroeder and by Rad- 

 cliffe is easily explained. It is possible that E. 

 milberti enters the mouths of bays to give birth 

 to young more frequently than records suggest. 

 Female Carch/irhinus Jeucas and Negaprion hrevi- 

 rostris move inshore and stop feeding for a short 

 period at the time of the birth of their young, 

 and immediately after the young are born the 

 females move into comparatively deeper water. 

 This may be a common habit among carchar- 

 hinids and certainly a very useful one to provide 

 for survival of the species. The Long Island 

 records are to a large extent based on harpooned 

 specimens, and adult females should probably not 

 be expected to be easily available to capture on 

 baited hooks in areas where the young are born. 



The best fishing depth for adult E. mWberti 

 from the Carolinas south to Miami was found by 

 the commercial shark fishermen to be 15 to 30 

 fathoms. On this stretch of coast it was rarely 

 if ever taken beyond 50 fathoms on bottom set- 

 lines and made up less than 5 percent of the catch 

 on floatlines set beyond the 100-fathom curve. 



Southward from Miami, mUberti was rare 

 among the keys, in Hawk Channel, or along the 

 shallower portions of the reefs south of the 

 Florida Keys. In the winter, a few appeared in 

 catches made in the Northwest Ship Channel but, 

 in general, these waters were left to other species. 

 The sandbar sharks, however, were the common- 

 est sharks on the bottom beyond the fringing reef 

 out to depths of 50 fathoms and made up sub- 

 stantial portions of catches out to 100 fathoms. 

 They were appreciably more numerous in catches 

 off the lower keys where currents were not so 

 strong. Northward from the keys along the west 

 Florida coast as far as Tampa, E. milberti was 

 found to be most abundant in depths of less than 

 30 fathoms. 



Shark-fishing vessels operated out of Salerno, 

 Fla., almost every day that weather permitted 



