Excluder devices

A grid of metal bars or mesh placed usually within the neck of a trawl that has an opening for escape at either the top or bottom. Large animals that strike the bar exit through the opening, while the smaller target species pass through the bars and are captured in the net. Examples of excluder devices in trawls are the Nordmore grid, the Turtle Excluder Device (TED), and the Sea Lion Excluder Device (SLED). A sea turtle excluder chain mat is used in the Northwest Atlantic scallop dredge fishery. A new modification to pound nets may reduce sea turtle bycatch by replacing the upper two-thirds of the leader netting with vertical ropes spaced wide enough apart to let sea turtles swim through without becoming entangled (DeAlteris et al., 2005).

Field Study

Study Type: 

wild

Location: 

Lake Opinicon, Canada

Target catch: 

Bluegill and other bony fish

Effect on bycatch species: 

The exclusion device with bars across the net significantly reduced turtle catch rates. All turtles were able to escape through the escape chimney.

Effect on target catch: 

Fish catch rates were not impacted by either excluder device. The majority (88%) of fish were retained when the escape chimney was used.

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 644

Study Type: 

wild

Location: 

Massachusettes Bay

Target catch: 

Silver hake

Effect on bycatch species: 

Over 88% of spiny dogfish were excluded by the grate regardless of color or gear configuration.

Effect on target catch: 

Within typical commercial quantities

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 560

Study Type: 

wild

Location: 

Northern Australia

Target catch: 

Prawns

Effect on bycatch species: 

Upward facing TED's reduced sea turtle bycatch by 99%

Effect on target catch: 

Reduced the proportion of soft and damaged prawns by 35.8% and reduced catches of tiger prawns by 6.3%

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 357

Study Type: 

wild

Location: 

Northern Australia

Target catch: 

Prawns

Effect on bycatch species: 

JT 2 design reduced finfish bycatch by 5%

Effect on target catch: 

Caught 5.2% more tiger prawns and 6.9% more endeavour prawns than standard net

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 356

Study Type: 

wild

Location: 

Northern Australia

Target catch: 

Prawns

Effect on bycatch species: 

JT 2 design did not prevent capture of large sharks and rays

Effect on target catch: 

Caught 5.2% more tiger prawns and 6.9% more endeavour prawns than standard net

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 355

Study Type: 

wild

Location: 

Northern Australia

Target catch: 

Prawns

Effect on bycatch species: 

JT 1 design did not prevent capture of large sharks and rays

Effect on target catch: 

Caught 6.6% more tiger prawns and 10.5% more endeavour prawns than standard net

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

Field Study 354

Study Type: 

wild

Location: 

Northern Australia

Target catch: 

Prawns

Effect on bycatch species: 

JT 2 design did not prevent capture of sea turtles

Effect on target catch: 

Caught 5.2% more tiger prawns and 6.9% more endeavour prawns than standard net

Article: 

Bycatch species: 

Reduction technique: 

Fishing Gear: 

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