FAO/FIIT Fishing Gear Type Fact-Sheet Otter twin trawls [OTT] updated : 10-mai-2001 ISSCFG Classification : > Category : Trawl nets > Type : Otter twin trawls Profile General Description: This special rigging system for this particular gear was developed to increase the horizontal fishing area of the trawl and comprises two identical trawls ("twin") fixed together. The horizontal opening is provided by a single pair ofotter boards, which are attached to the trawl close to the wings. Their inner wings are attached to asledge towed simultaneously with the otter boards from a commoncrow foot. An other option used on modern vessels in the northern shrimp fishery is to tow the gear with three warps. Specific Handling Equipment: Trawl winches installed on deck control the trawling wires and store them when not in use. In addition to the standard two-bobbins winch (or to two single-bobbin winches), a third winch with one bobbin can be necessary according to the rigging of the twin trawls (which can be either two or three warps arriving to the trawler). Fishing Vessels using this gear: Trawler Fishing Operations: In twin trawling one vessel tows two to four trawls. In shrimp trawl and nephrops trawl fisheries it is common to tow twin trawls over the stern. With a special rigging there is also a possibility for towing three trawls using to warps. In tropicalshrimp trawling with outriggers twin trawls are towed on each side (which makes a total of four trawls towed at the same time). Features Target Species: They are generally used for catchingshrimp or bottom species. Areas: all The Gear and its Environment: Deployment Area: All shrimp trawling areas. Impact on Aquatic Species: Unwanted bycatch of fish is one of the main negative impacts. Use ofbycatch reduction devices (BRD) can mitigate the problem.