Figure 7. — Worker obtaining a temperature record with a 

 bathythermograph before a longline set. 



Field Research in the Gulf of Mexico 



In August 1 966 participants at a Government- 

 industry meeting in Pascagoula discussed the 

 alarming decline in menhadencatches, especi- 

 ally on the east coast of the United States and 

 means of maintaining a healthy industry in 

 spite of the decline. Our Base was asked for 

 advice on (1) use of alternate resources and 

 (2) new advances in harvesting for greater 

 industry economy. Stress during the meeting 

 was placed on immediate relief to the fishery 

 and use of present industry equipment. 



Over the years, experiences aboard the 

 exploratory fishing vessel Or egon in the Gulf 

 and Caribbean had shown the existence in 

 ccastal areas of large stocks of anchovies and 

 other small schooling fishes that could be 

 attracted to lights at night. As a stop-gap 

 measure we decided to study night-light at- 

 traction and purse seining to take anchovies 

 for fish meal. 



Sea trials with a 13,500-watt above-surface 

 light bank and a 125-foot small-mesh purse 

 began in September, with the George M. 

 Bowers , in the coastal waters of the north 

 central Gulf of Mexico. 



Trials continued throughout the fiscal year, 

 with emphasis on dark-of-the-moon periods. 

 Several other attractors were acquired and 

 used during the period, including 1,000-watt 

 mercury vapor lamps and 12-volt direct cur- 

 rent lamps used singly, alternately, and in 

 combination. We found generally that the more 



light used, the more fish were attracted, 

 but the lights varied in their abilities to 

 "harden" the attracted fish into balls of mill- 

 ing fish. 



The small-mesh purse seine, later 

 lengthened to 250 feet, was very effective in 

 capturing the assembled schools, especially 

 with a single -boat pursing operation. In most 

 instances, the entire assembled congregation 

 would be captured. 



The study will continue through September 

 1967 to provide full -year coverage. Results to 

 date, however, do not show commercial prom- 

 ise, owing to relatively low numbers of fish 

 assembled (less than 1,000 pounds per set). 

 Anchovies of three species dominate most 

 catches, with small thread herring, scaled 

 sardines (razor bellies), harvestfish, bumpers, 

 and cutlass fish also appearing often in the 

 catches. On occasion, large predators would 

 appear in the catches or slash through the 

 milling school before capture. These predators 

 include several species of jacks, Spanish 

 mackerel, and leather jackets. If time permits, 

 the fishery potential for predators in the 

 "shadow area" just beyond the lighted zone 

 will receive additional attention. 



Along with the aforementioned commercial 

 harvest attempts, we had a small-scale project 

 aimed at a basic understanding of the whys 

 and wherefores of schoolfish behavior as re- 

 lated to light attraction. Behavior studies of a 

 preliminary nature were carried out at sea 

 and in the laboratory. 



