Bycatch

Fishing methods that produce bycatch

There are a variety of fishing methods being used in Canada and around the world. The level of bycatch depends on the type of method, where it is used, and how much care is taken.

Trawling

Trawling. / ©: WWF-Canada
Trawling.
© WWF-Canada
Bycatch Levels
High level of bycatch, especially in non-target fish species; bottom trawling can cause significant damage to corals & sponges.

How Are Fish And Shellfish Caught?
Large, cone-shaped net towed across the seabed.

Gillnetting

Gillnetting. / ©: WWF-Canada
Gillnetting.
© WWF-Canada
Bycatch Levels
High levels of bycatch, especially sea turtles and large marine mammals.

How Are Fish And Shellfish Caught?
Translucent curtain of netting anchored at each end to the seafloor.

Longlining

Pelagic Longline. / ©: WWF-Canada
Pelagic Longline.
© WWF-Canada
Bycatch Levels
High level of bycatch, especially albatrosses, sea turtles and sharks.

How Are Fish And Shellfish Caught?
Heavy fishing line containing baited hooks in succession.

Dredging

Dredging. / ©: WWF-Canada
Dredging.
© WWF-Canada
Bycatch Levels
High level of bycatch, especially sponges, flatfish, and non-target shellfish.

How Are Fish And Shellfish Caught?
The digging up of seabeds to harvest scallops, clams, oysters, and mussels.

Purse Seines

Purse Seines. / ©: WWF-Canada
Purse Seines.
© WWF-Canada
Bycatch Levels
Moderate bycatch associated with schools of fish, especially dolphins.

How Are Fish And Shellfish Caught?
Nets used to encircle schools of fish at or near the surface.

Weirs

Weirs. / ©: WWF-Canada
Weirs.
© WWF-Canada
Bycatch Levels
Moderate bycatch, but porpoise common among herring weirs.

How Are Fish And Shellfish Caught?
"V" shaped fence-like structures that channel fish into a pen dug in a riverbed.

Pots or Traps

Lobster Traps. / ©: WWF-Canada
Lobster Traps.
© WWF-Canada
Bycatch Levels
Moderate bycatch, fishermen release unwanted live species upon inspection of traps.

How Are Fish And Shellfish Caught?
Baited cages used to attract and catch lobster, crab, and shrimp.

Fish Traps

Fish Traps. / ©: WWF-Canada
Fish Traps.
© WWF-Canada
Bycatch Levels
Minimal selective bycatch.

How Are Fish And Shellfish Caught?
Similar to weirs; netting or wire used to catch upstream migrating fish.

Jigging

Jigging. / ©: WWF-Canada
Jigging.
© WWF-Canada
Bycatch Levels
Minimal bycatch.

How Are Fish And Shellfish Caught?
Baited hook attached to a line that is continually moved up and down.

Harpooning

Harpooning. / ©: WWF-Canada
Harpooning.
© WWF-Canada
Bycatch Levels
Bycatch not a concern.

How Are Fish And Shellfish Caught?
Spear-like weapon that is attached to a long line with a buoy at the end. The harpoon is either thrown or shot by mounted guns, and is aimed at individual fish.

Hook-and-Line

Bycatch Levels
Very low level of bycatch, live species released when caught.

How Are Fish And Shellfish Caught?
Fishermen equipped with a single pole and baited line.

Trolling

Trolling. / ©: WWF-Canada
Trolling.
© WWF-Canada
Bycatch Levels
Minimal bycatch, as unwanted fish can be released from hooks easily.

How Are Fish And Shellfish Caught?
Baited lines that are pulled behind a boat at various depths.

Tongs

Tongs. / ©: WWF-Canada
Tongs.
© WWF-Canada
Bycatch Levels
Minimal level of bycatch.

How Are Fish And Shellfish Caught?
Pair of rakes attached to long, scissor-like handles. Used to harvest oysters.

Diving

Diving. / ©: WWF-Canada
Diving.
© WWF-Canada
Bycatch Levels
No bycatch.

How Are Fish And Shellfish Caught?
Hand picking of species like lobster, sponge, urchin, and sea cucumber.

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