| FAO/FIIT Fishing Gear Type Fact-Sheet |
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Midwater pair trawls [PTM] | updated : 10-mai-2001 |
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Profile |
General Description: A midwater pair trawl has roughly
similar design as other midwater trawls. Midwater pair
trawls might, however, be designed to have a more
rectangular opening than ordinary midwater otter trawls. Midwater
pair trawls might be rigged with two
towingwarps from each vessel or
alternatively with one towing warp from each vessel and a
bridle arrangement. One of the advantages of pair trawling
is the possibility to tow the trawl very close to the
surface. Herding effect on fish by the two vessels may
increase the capture efficiency in shallow waters and at the surface. |
Specific Handling Equipment: The net handling system is the same
as on a single trawler and consists ofnet
drums,trawl
winches,sweep
winches,gilsons, etc. |
Fishing Vessels using this gear: A pair trawler may be a very small
undecked boat with an outboard engine, or any vessel up to
60 meters decked trawlers. It is a possibility for
lower powered vessels to use larger trawls. The pair
trawlers should have similar size and power (for having the
same towing power on both sides of the trawls). |
Fishing Operations: A midwater pair trawl is towed
simultaneously by two boats, thus ensuring the horizontal
opening of the net. Setting and hauling of the trawl take
place alternating between each vessel hauling the net. An
important operational parameter is to maintain correct and
steady distance between the two towing
vessels.Radar measurements is
commonly used for this purpose and for smaller boats a
connecting line between the vessels will do the job. |
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Features |
Target Species: Pelagic and demersal species |
The Gear and its Environment:
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![](../assets/images/invidot.gif) | Deployment Area: Midwater pair trawling is carried out
mainly at sea in all depth
fromcoastal to offshore
areas, but also in lakes. |
![](../assets/images/invidot.gif) | Impact on the Environment: No impact on bottom habitat and
bottom structure. |
![](../assets/images/invidot.gif) | Impact on Aquatic Species: In most cases it is a single
species fishery, bycatch rates of other species are
low. Incidental catch ofdolphins and marine mammals may
occur in some areas. |
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