74 Memoir Sears Foundation for Marine Research 



no statistics as to actual amounts of shark scrap for comparison with scrap from other fishes. 

 Small amounts of shark refuse also find their way into commercial fertilizers, but here 

 again definite statistics are lacking. Efforts have even been made in the Maritime Provinces 

 of Canada (p. 462), as well as in the United States and possibly elsewhere, to develop this 

 industry. But so far as we know all such attempts have been short-lived, because of irregu- 

 larity in the supply of sharks. 



Sharks are not as highly esteemed for food as are various bony fishes that support the 

 great fisheries, partly because the available supply is only a fraction as great; hence, the 

 landings of sharks are correspondingly smaller, especially in northern seas, and they are 

 correspondingly less in value. Thus, the reported catch of sharks (4,417,700 pounds) was 

 less than one-half of one per cent of the total catch of all kinds of fish (1,458,687,600 

 pounds) along the Atlantic and Gulf coasts of the United States in 1942, and about one 

 per cent (10,171,900 pounds out of a total of 1,346,559,600 pounds of fish of all kinds) 

 on the Pacific Coast of the United States. In warmer regions the shark catch may rank 

 relatively higher, the catch of bony fishes being much smaller than it is in the northern seas, 

 e.g., the Chilean catch mentioned above (p. 73). But previous experience suggests that 

 fisheries for large sharks, if intensive and on a large scale, are likely to be short-lived, seem- 

 ingly through exhaustion of the local supply. 



Recently commercial shark fishing in the western Atlantic has been carried on most 

 actively off the southern part of the North Carolina coast (Morehead City), along eastern 

 and southeastern Florida (Mayport, Salerno, Cortez and Key West) and off the Bahamas. 

 The yield consists chiefly of Tiger Sharks (Galeocerdo), Sand Sharks (Carcharias), vari- 

 ous species of Carcharhinus, Nurse Sharks {Ginglymostoma) , Hammerheads, and Lemon 

 Sharks (Negaprion) ; on the whole, the first two rank foremost in commercial importance, 

 both in quantity and in value. Anchored gill nets with a stretched mesh of about 20 inches, 

 and anchored set lines (best of chain) with snoods of wire rope every six to eight feet, both 

 set at depths of 3 to 20 fathoms, are the types of gear chiefly used. The catches of Green- 

 land Sharks that are made in the waters off Iceland and Greenland are mostly by long lines, 

 or by hand lines. Basking Sharks have usually been harpooned because of their large size, 

 and this applies equally to the Whale Sharks that have been fished from time to time in 

 the Bay of Bengal and in the waters around India. 



Habitat and Range. Sharks are marine for the most part, but a few members of the 

 genus Carcharhinus run far upstream into brackish or even into fresh water in large rivers 

 such as the Ganges, the Tigris and the Zambezi. We have received two specimens of Car- 

 charhinus leucas, a well known west tropical Atlantic species, that had been taken in Lake 

 Yzabal, Guatemala (p. 341), and one landlocked species is known in Lake Nicaragua 

 (p. 381). Many are oceanic and roam the high seas,"" while others dwell on the ocean 

 bottom or close to it. In warm latitudes they are often seen following ships for days 



2ia. A shark tagged off Ventura, southern California, was recaptured on the west coast of Vancouver Island, it 

 having migrated about a thousand miles; see Ripley (Calif. Fish Game, [2] 52, 1946: loi). 



