20 



trawl, is a commercially productive catch 

 rate. This catch average also adds consider- 

 able support to the success the system exper- 

 ienced during the Bowers cruise off the Ala- 

 bama and Mississippi coasts: an efficiency 

 of 109% for the daytime electric trawl. The 

 catch weight averages were 17.7 Ibs./hr. for 

 the daytime electric trawl--and 16.3 Ibs./hr. 

 for the night non-electric trawl. 



Cruises 66 and 67 of the Bowers show the 

 electrical shrimp trawl to be very effective 

 on the Alabama, Mississippi, and Texas coast- 

 al shrimiping areas. 



5}: :?fi i^fi >[< >lc 



ATTRACTION OF ANCHOVIES 

 TO LIGHT STUDIED 



The Bowers conducted light attraction 

 studies on anchovies in Mississippi Sound 

 (Cruise 68) during the October "dark-of-the 

 moon" phase --October 10-15. The objective 

 was to experiment with a variety of light 

 sources to determine attraction rates and be- 

 havior control of Gulf anchovies ( Anchoa sp.). 



Four experimental lighting arrays were 

 used: a 90 -lamp bank of incandescent lights 

 capable of 13,500-watt output; a 2-lamp bank 

 of mercury vapor lights with 2,000-watt out- 

 put; a 3 -lamp, 3, 000 -watt bank of incandes- 

 cent lights; and single 6 VDC seal -beam 

 lamps. Variable intensity controls were used 

 on each unit. Experimental fishing and sam- 

 pling gear included a 215 -foot fine meshpurse 

 seine, gill nets, and dip nets. 



Throughout the study period, strong winds, 

 choppy seas, and heavy turbidity greatly re- 

 stricted operations, observations, and the ef- 

 fectiveness of light attractors. But general- 

 ized observations indicated that the mercury 

 vapor lights were most effective in attracting 

 both anchovies and clupeids to the vessel. By 

 switching to the 90 -lamp bank of incandescent 

 lights, circular milling behavior was quickly 

 established --and then the "school" could be 

 held through successive dimming down to one 

 low intensity lamp. Weather conditions per- 

 mitted only one purse seine set that yielded 

 about 200 pounds of anchovies, and 10 pounds 

 of thread herring ( Opisthonema oglinum ), 

 scaled sardines ( Harengula pensacolae ), and 

 small numbers of harvestfish (Peprilus paru), 

 bumpers ( Chloroscombrus chrysurus ); and 

 cutlassfish ( Trichiurus lepturus ). 



Six-bulb banks of red incandescent lights 

 attracted primarily squids and eels. No 

 measurable results were obtained with a five - 

 bulb bank of blue lights. 



To obtain menhaden samples, gill -net sets 

 were naade in the Sound in cooperation with 

 BCF's Beaufort Biological Labor atory. 



Note: For more information, contact: Base Director, Explora- 

 tory Fishing and Gear Research Base HQ, Pascagoula, Miss. 

 39S67. _ 



K> Ol- 



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N 



North Atlantic Fisheries Explorations 

 and Gear Development 



"DELAWARE" SEEKS INDUSTRIAL FISH 

 ON GEORGES BANK 



The exploratory fishing vessel M/V Dela- 

 ware returned from the Georges Bank area 

 to Gloucester, Mass., on October 10 after 

 completing the second in a planned series of 

 exploratory cruises for industrial fish spe- 

 cies (Cruise 66-8, Sept. 29-Oct. 10, 1966). 

 Thirty -three tows were made with a Dutch 

 herring trawl specifically to evaluate herring 

 ( Clupea harengus ) distribution, relative abun- 

 dance, and availability to this type of gear. 

 The major part of the survey was conducted 

 on the northern half of Georges Bank, from 

 Cultivator Shoal to the Northern Edge, at 

 depths of 16 to 52 fathoms (see cruise chart). 

 Also, electronic fish sounding and ranging 

 transects were made both in the fishing areas 

 and while steaming to and from Gloucester. 



Commercial concentrations of herring were 

 found in the northeastern section of the Winter 

 Fishing Ground. A fleet of 35 to 40 foreign 

 vessels, mostly Soviet factory-stern trawlers, 

 was actively fishing here; estimated catches 

 of 10,000 to 35,000 pounds were observed. 



The main objectives of this cruise were: 

 (1) to investigate the seasonal distribution and 

 relative abundance of industrial fish (primari- 

 ly herring) in the area of Georges Bank and 

 adjacent parts of the Gulf of Maine, (2) deter- 

 mine the availability of these species to a 

 Dutch herring trawl, and (3) to obtain biologi- 

 cal and environmental data relative to col- 

 lected species. 



A Dutch herring trawl was used. Two types 

 of kites (fiberglass and plywood) and varying 



