Marine 



Advice 



Extending Knowledge to the Coastal Community 



Bayou Technology Makes Good in Tar Heel Waters 



Fishermen in North Carolina's 

 commercial shrimping industry are finding 

 that a little borrowed technology and a 

 willingness to experiment can be a 

 lucrative combination. 



Trials of a new "skimmer" trawl rig 

 during the summer and fall provided 

 encouraging results — increased catch, 

 particularly in autumn's white shrimp or 

 "greentail" fishery, and reduced bycatch. 



The skimmer, which is pushed 

 alongside the boat rather than towed 

 behind it, promised many advantages over 

 the conventional otter trawl. 



The idea to try the rig, first used by 

 Louisiana shrimpers in the Gulf of Mexico, 

 originated within the Carteret County 

 Waterman's Association. President Clinton 

 Willis says an article about the skimmer in 

 National Fisherman caught the eye of 

 association members two years ago. 



The group then approached Sea 

 Grant advisory agent Bob Hines about the 

 possibility of adapting the skimmer for use 

 in North Carolina's estuaries. 



In the spring of 1990, Hines and a 

 few companions took a trip to Louisiana to 

 test the waters. While there, they consulted 

 with netmaker Layne "Ike" Pelas. It looked 

 like the net would work in Tar Heel waters 

 and potentially reduce bycatch mortality. 

 With these advantages in mind, Sea Grant 

 was able to obtain a grant from the 

 National Marine Fisheries Service to test 

 the net. 



Experiments with the skimmer gear 

 and Pelas' net began in North Carolina in 

 June 1991 aboard the Frankie and Al 

 owned and operated by Paul Biermann of 

 Beaufort. Willis' boat, the Captain Will, 

 was used as the control for the experi- 

 ment. He pulled two 35-foot otter trawls 

 with sleds. 



Hines says initial results were 

 disappointing — the skimmer caught less 



brown shrimp than its conventional 

 counterparts. 



But unusual circumstances may have 

 impaired the results. Problems with the 

 gear during initial testing decreased 

 efficiency. It took several days to learn 

 how to operate the gear properly. And a 

 drought in July caused brown shrimp to 

 enter deep channels, prohibiting effective 

 shrimping with the skimmer. 



By the time nets and gear were 

 properly tuned at the end of July, the 

 available brown shrimp were being caught 

 in deeper water (15-16 feet) in the channel 

 and the skimmer couldn't reach bottom. 

 The skimmer works best in water no 

 deeper than 8 to 10 feet. 



But when white shrimp began to 

 show up in North River in August, the 

 skimmer gear proved its worth, outfishing 

 conventional trawls by as much as 5 to 1. 

 News spread fast; within a week, five 

 other Carteret County shrimpers rigged 

 skimmers of their own to fish the estuary. 



Jim Murray, Sea Grant's Marine 

 Advisory Service director, heard reports of 

 at least one fishennen catching 8,000 

 pounds of white shrimp in a matter of 

 weeks. At $1.75 a pound, that translates to 

 S14,000 at the market, he says. 



Hines and Murray offer one theory in 

 regard to the skimmer's superiority on 

 white shrimp. This species has a tendency 

 to swim higher in the water column; they 

 swim above or jump out of conventional 

 shrimp nets, says Hines. But since the top 

 of the skimmer net extends above the 

 surface of the water, it is able to contain 

 the feisty greentails. 



The skimmer has many other 

 advantages over conventional trawls: 



• The tailbag fishes near the stern of 

 the boat, which allows for frequent 

 haulbacks and no loss of fishing time 

 because the mouth of the net is still 

 fishing. 



• Because it's not dragging the heavy 

 otter doors, the skimmer can travel faster. 

 Willis says it reduces nearly a third of the 

 strain on the vessel. 



• Shorter tow time keeps bycatch in 

 better condition. Also, preliminary data 

 show the amount of bycatch is reduced 

 with skimmer use. 



• The bycatch is returned overboard 

 behind the mouth of the net so the same 

 bycatch is not caught repeatedly. Also, the 

 more frequent haulbacks mean there's less 

 catch to cull, reducing the time bycatch is 

 on the culling table. 



Disadvantages include: 



• The gear is heavy and cumbersome 

 to set and pick up. 



• The gear cannot reach bottom in 

 water deeper than the rigid frames will 

 allow. 



• The skimmer doesn't fish well over 

 irregular bottoms, such as along steep 

 channel edges. 



• Seaweed tends to clog the net, 

 requiring special attention during fishing. 



North Carolina fishermen are already 

 working on their own adaptations of the 

 skimmer to improve efficiency. They are 

 talking about constructing lightweight 

 frames of aluminum for easier handling, 

 using polywebbing to alleviate seaweed 

 clogs and making other structural changes 

 to improve maneuverability. 



"My guess is that by next year there 

 will be a lot of perfection," says Murray. 

 Once the bugs are worked out, Murray 

 thinks the skimmer will be competitive in 

 the brown shrimp fishery also. 



As for Willis, he'll trade in his "control 

 vessel" status next season and build 

 skimmer rigs of his own. 



"If they can catch as good or better, 

 I'd be a fool not to put 'em on," he says. 



— Carta B. Burgess 



16 JANUARY/FEBRUARY 1992 



