44 



during fishing operations --and while the ves- 

 sel is anchored on fishing grounds. The sta- 

 bilizers help considerably to dampen the roll 

 of the vessel. One major shrimp boatyard in- 

 cludes stabilizers as standard equipment in 

 all new construction (fig. 1). Normally, the 

 stabilizers are suspended from blocks 

 mountedabout two-thirds out on the outrigger 

 booms; occasionally, the stabilizers are sus- 

 pended from the extremities of the booms (fig. 

 2). This technique is used in the deepwater 

 (down to200 fathoms) royal-red shrimp fish- 

 ery, in which a single trawl is fished from a 

 separate gallows frame. 



Fig. 2 - Stabilizers suspended from the outriggere' extremities of 

 shrimp vessel fishing a single trawl in deep water. 



(Photo: J. B. Rivers) 



Another recent development is the use of 

 tag lines on trawl doors. The tag line, long 

 enough to reach the deck, is permanently tied 

 to the upper part of the doors. A pole is used 

 to recover line. Formerly, a crew member 

 had to catwalk out to the end of the outriggers 

 and tie a line to the door's chain for subse- 

 quent hauling aboard. This practice was al- 

 ways dangerous , and expecially so during 

 heavy seas. 



Main trawl winches have increased in size 

 and ruggednessto allow for greater versatil- 

 ity in faster setting and haulback of gear and 



greater cable capacity for fishing in deeper 

 waters. Also, they provide for use of larger 

 diameter cable, which reduces breakage, lasts 

 longer, and improves safety. 



The following graphs and table provide in- 

 formation about the shrimp vessels 'over 5 

 gross tons that operated in the Gulf during 

 1963 and 1964. They are compiled from pub- 

 lished (Lyles, 1965)and unpublished!]. S. sta- 

 tistical data. A 10 percent, random sample 

 of the vessel list was used in computing the 

 data. Similar statistics on vessel character- 

 istics are not readily available for the years 

 before 1963. 



The characteristics of the Gulf tieet are 

 fairly similar for the 2 years (table); however, 

 the average number of crew members per ves - 

 sel for 1964 on the double-rigged vessels de- 

 creased 0.14. This decrease implies that 5 

 percent, or 100 vessels of this fleet of over 

 2,000, employs one m.an less. Similarly, but 

 to lesser degree, the single -rig trawl data also 

 show reduction in manpower. Increase of 

 single-rig vessels in 1964 over 1963 (table) 

 may indicate conversion of smaller double 

 riggers to single rigs, or entry of vessels from 

 other activities into the shrimp fishery. 



Many new vessels, 65 to 75 feet long, are 

 shrimping in international waters off the 

 northeast coast of South America, and else- 

 where. The migration tothese grounds is in- 

 dicated in figure 3, which shows fewer ves- 

 sels in the higher gross -ton category. It also 

 shows that most double -rigged vessels are in 

 the 30- to 49-gross ton class, which coincides 

 with the 50- to 59 -foot length groups shown 

 in figure 4. The gross ton-length relation, 

 however, is not well defined for the smallest 

 and largest vessels (figs. 3 and 4). Figure 5 

 shows the relative size of the nets (footrope 

 measurement) used by double- and single-rig 

 vessels. Footrope measurement of the two 

 nets used by the double riggers have been 

 combined. The lower graph indicates a de- 

 crease in size of nets on double -rig vessels 

 for 1964 in the 84- to 90-foot range, and a 

 slight increase in the nets with groundropes 



Average Measurements and Characteristics of Shrimp Trawlers Operating in the Gulf of Mexico During 



1963 and 1964 





1963 



1964 



Total 

 Vessels 



Gross 

 Tonnage 



LOA 



Men in 

 Crew 



Size of 



Neti/ 



Total 

 Vessels 



Gross 

 Tonnage 



LOA 



Men in 

 Crew 



Size of 

 Net 



Main Engine 

 Power?/ 



Double Rig 

 Single Rig 



No. 

 2,051 

 646 



Tons 

 37.2 

 17.4 



Feet 

 53.6 

 45.3 



No. 

 2.85 

 2.12 



Feet 

 43.5 

 57.0 



No. 



2,059 



723 



Tons 

 39.3 

 18.4 



Feet 

 55.2 



45.4 



No. 

 2.71 

 2.06 



Feet 

 44.5 

 55.5 



Horsepower 

 197 

 145 



l/Net size measurement is length of leadline. 

 2/HP data not available for 1963. 



