CCM.ERCIAL FISHERIES HKVJLKvV 



Vol. 13, No. l^. 



by a red snapper fishing boat was made available for examination through the Warren 

 Fish Company of Pensacola. 'The specimen is provisionally identified as Parathunnus 

 atlanticus , frequently referred to as Altantic blackfin tuna. 



The information gathered by the Oregon on the tunas of the G-ulf , other than the 

 little tuna, is fragmentary and largely negative. Besides the little tuna, two or 

 more species are present in the north Gulf outward from the continental shelf in sum- 

 mer, but they evidently appear at the surface rarely and for brief intervals. The 

 behavior of those seen was erratic and an attempt to approach some unidentified school 

 of fish, presumably tuna, was not successful. The facts suggest that liiese fish 

 normally remain below the layer of warm surface water at depths as great or greater 

 than 40 fathoms. For example, on September 23, I95O, fish resembling yellowfin tuna 

 appeared briefly at the surface, jumping and racing about within a few yards of the 

 stem of the Oregon , just as a shrimp trawl was being pulled over the side from a 

 depth of 258 fathoms. These fish which had apparently followed the trawl to the 

 surface, sounded and disappeared before lines could be put overboard. Efforts to 

 catch the tuna were rewarded only by sharks. 



f^^' 



RED SNAPPER 



The red snapper fishery of the Gulf is an old one and the fishing grounds are 

 relatively well known. The industry at present does not need explorations of new 



grounds, but would profit by any new develop- 

 ments in methods or equipment that would give 

 more productivity per unit of effort. With 

 this in view, gear is being prepared to com- 

 pare trap fishing for rei snapper with hand- 

 line fishing. Since time lost in the location 

 of the best fishing spots is a considerable 

 factor in the reduction of productivity per 

 unit of effort, the use of Loran-receiving 

 equipment is being studied to learn vdiether 

 it can effect important savings in time. 

 Loran-receiving equipment is capable of 

 obtaining navigational lines of positions in 

 the earth's surface by the reception of radio 

 signals from Loran transmitting stations lo- 

 cated on shore, Unfortimately, only a small 

 part of the east Gulf of Mexico is covered 

 at the present time by Loran transmitting 

 stations, (Figure 3) 



FIGURE 3 - RED SNAPPER TAKEN FROM 

 SHRIMP TRAWL FISHED BY THE OREGON. 



LARGE SNAPPERS, SUCH AS THIS ONE, ARE 

 RARELY TAKEN IN SHRIMP TRAWL NETS. 



SHARK 



The small shark fishery operating in inshore waters in the Gulf has been aban- 

 doned following the decline in the market price of vitamin A in 1949 and 1950. Large 

 sharks were found to be abundant in the areas visited by the Oregon . At times sharks 

 are responsible for serious losses to fishermen by their attacks on catches in nets 

 and gear. Large sharks in offshore waters also present a serious problem in the 

 use of long lines or nets for pelagic fish. The i..ost abundant surface shark noted 

 by the Oregon in the blue water near the continental shelf was the silky shark (Eu- 

 lamia floridanus ) which reaches a length of ten feet. Young silky sharks and smooth 

 hounds ( Mustelus canis) were found to be troublesome in the north and northwest Gulf 

 on offshore snapper fishing grounds. 



