Trawl - Cetacean Bycatch Resource Center

Trawl nets are dragged behind a boat, either along the seafloor or through the water. The cone-shaped net is held open with a beam or by heavy doors on either side of the mouth of the net. Pelagic or midwater trawls are pulled through the water column, though these nets may sometimes reach the bottom when full.

Trawl fishing involves three basic steps. First the net shoots into the water from the boat. Then it is towed until the net is full. Finally, the net must be hauled back onboard, concentrating the catch in the very end of the net, known as the "cod end" or the "bag."

Bottom trawls or draggers tow their nets across the seafloor. Historically trawlers have avoided rocky reefs, corals, and other structures on the seafloor to prevent tangling the nets. However, the recent development of rockhopper trawls with large wheels designed to roll over seafloor obstructions has allowed trawlers to fish in larger areas than ever before. Rows of rubber tires send the net bouncing along the seafloor in areas that were previously inaccessible.

Both midwater and bottom trawls sometimes catch cetaceans. Animals caught as bycatch may be discarded after the catch is hauled onto the boat, but often do not survive.

Kinds of trawl gear

Bottom trawl - trawl net is dragged along the seafloor
Beam trawl - a beam holds open the net
Dragger - trawl net is dragged along the seafloor
Midwater trawl - trawl net is towed through the water, above the bottom
Outrigger trawl - larger nets are towed and held open by outriggers extending from each side of the boat
Otter trawl - net is held open by heavy doors known as "otter boards"
Pair trawl - larger net is towed and held open between two boats
Pelagic trawl - trawl net is towed through the water, above the bottom
Rockhopper trawl - the net bounces along the seafloor with large wheels

Examples of targeted fish

cod, flatfish, flounder, haddock, halibut, herring, mackerel, pacific whiting, pilchard, pollock, rockfish, sablefish (black cod), sardine, sea bass, sea bream, shrimp, sole, sprat

[ Sources ]




		Fishing Gear: Gillnet \| Longline \| Purse Seine \| Trawl \| Sources Trawl Trawl nets are dragged behind a boat, either along the seafloor or through the water. The cone-shaped net is held open with a beam or by heavy doors on either side of the mouth of the net. Pelagic or midwater trawls are pulled through the water column, though these nets may sometimes reach the bottom when full. Trawl fishing involves three basic steps. First the net shoots into the water from the boat. Then it is towed until the net is full. Finally, the net must be hauled back onboard, concentrating the catch in the very end of the net, known as the "cod end" or the "bag." Bottom trawls or draggers tow their nets across the seafloor. Historically trawlers have avoided rocky reefs, corals, and other structures on the seafloor to prevent tangling the nets. However, the recent development of rockhopper trawls with large wheels designed to roll over seafloor obstructions has allowed trawlers to fish in larger areas than ever before. Rows of rubber tires send the net bouncing along the seafloor in areas that were previously inaccessible. Both midwater and bottom trawls sometimes catch cetaceans. Animals caught as bycatch may be discarded after the catch is hauled onto the boat, but often do not survive. Kinds of trawl gear Bottom trawl - trawl net is dragged along the seafloor Beam trawl - a beam holds open the net Dragger - trawl net is dragged along the seafloor Midwater trawl - trawl net is towed through the water, above the bottom Outrigger trawl - larger nets are towed and held open by outriggers extending from each side of the boat Otter trawl - net is held open by heavy doors known as "otter boards" Pair trawl - larger net is towed and held open between two boats Pelagic trawl - trawl net is towed through the water, above the bottom Rockhopper trawl - the net bounces along the seafloor with large wheels Examples of targeted fish cod, flatfish, flounder, haddock, halibut, herring, mackerel, pacific whiting, pilchard, pollock, rockfish, sablefish (black cod), sardine, sea bass, sea bream, shrimp, sole, sprat [ Sources ]

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