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Fishing Methods I got 99 problems, but a fish ain’t one!

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Presentation on theme: "Fishing Methods I got 99 problems, but a fish ain’t one!"— Presentation transcript:

1 Fishing Methods I got 99 problems, but a fish ain’t one!

2 Over-Fishing Between 1950 and 1994, commercial fishermen increased their catch by 400% to keep up with the growing demand for seafood. Since 1989, the oceans have been over-fished (fish are caught faster than they can reproduce).

3 Bycatch Unintended organisms caught by fishermen Unintended organisms caught by fishermen

4 Dredging Fishermen drag a heavy frame with an attached mesh bag—called a dredge— along the seafloor to catch bottom- dwelling shellfish. Fishermen drag a heavy frame with an attached mesh bag—called a dredge— along the seafloor to catch bottom- dwelling shellfish. Most dredgers catch scallops, clams, oysters and other shellfish that live on the seafloor or burrow into mud or sand. Most dredgers catch scallops, clams, oysters and other shellfish that live on the seafloor or burrow into mud or sand. Environmental Impact Dredges cause significant habitat damage when dragged along gravel and rocky bottoms. Dredges cause significant habitat damage when dragged along gravel and rocky bottoms. Dredges also smooth out sandy and muddy bottom habitats, removing or smothering a variety of animal and plant life. Dredges also smooth out sandy and muddy bottom habitats, removing or smothering a variety of animal and plant life. Fish, sponges and other marine life unintentionally caught as bycatch are unlikely to survive under the weight of the heavy bag. Fish, sponges and other marine life unintentionally caught as bycatch are unlikely to survive under the weight of the heavy bag.

5 Gillnetting A gillnet is a curtain of netting that hangs in the water at various depths, suspended by a system of floats and weights, or anchors. A gillnet is a curtain of netting that hangs in the water at various depths, suspended by a system of floats and weights, or anchors. The mesh spaces are large enough for a fish's head to pass through, but not its body. The mesh spaces are large enough for a fish's head to pass through, but not its body. The size of a gillnet's mesh determines the type of fish it will catch The size of a gillnet's mesh determines the type of fish it will catch Environmental Impact Gillnets entangle large numbers of marine mammals and sea turtles in addition to other marine life, resulting in a significant amount of bycatch Gillnets entangle large numbers of marine mammals and sea turtles in addition to other marine life, resulting in a significant amount of bycatch Habitat damage can occur when gillnets anchored to the seafloor are hauled in and become tangled on structures such as coral and rocky bottoms. Habitat damage can occur when gillnets anchored to the seafloor are hauled in and become tangled on structures such as coral and rocky bottoms.

6 Harpooning When a harpooner spots a fish, he or she thrusts or shoots a long aluminum or wooden harpoon into the animal and hauls it aboard. When a harpooner spots a fish, he or she thrusts or shoots a long aluminum or wooden harpoon into the animal and hauls it aboard. Harpooners catch large predators such as bluefin tuna and swordfish. Harpooners catch large predators such as bluefin tuna and swordfish. Environmental Impact Bycatch of unwanted marine life is not a concern because harpoon fishermen visually identify the species and size of the targeted fish before killing it Bycatch of unwanted marine life is not a concern because harpoon fishermen visually identify the species and size of the targeted fish before killing it

7 Hook-and-Lining Hook-and-line fishermen use a pole (rod) and fishing line with one to several hooks. Hook-and-line fishermen use a pole (rod) and fishing line with one to several hooks. The catch is hauled in manually or with a mechanized reel. The catch is hauled in manually or with a mechanized reel. Environmental Impact Hook and lining is an environmentally responsible fishing method Hook and lining is an environmentally responsible fishing method Fishermen can quickly release unwanted catch from their hooks since lines are reeled in soon after a fish takes the bait. Fishermen can quickly release unwanted catch from their hooks since lines are reeled in soon after a fish takes the bait.

8 Longlining Longliners attract fish with a central fishing line that ranges from one to more than 50 miles (80 km) long. This central line is strung with smaller lines of baited hooks, which dangle at spaced intervals. Longliners attract fish with a central fishing line that ranges from one to more than 50 miles (80 km) long. This central line is strung with smaller lines of baited hooks, which dangle at spaced intervals. Environmental Impact Longlining can accidentally kill sea turtles and seabirds Longlining can accidentally kill sea turtles and seabirds The baited hooks of longlines attract a variety of open ocean swimmers, such as endangered sea turtles, sharks and other fish, resulting in wasteful bycatch The baited hooks of longlines attract a variety of open ocean swimmers, such as endangered sea turtles, sharks and other fish, resulting in wasteful bycatch As the line is deployed into the water, seabirds dive for the bait and are ensnared on the hooks and drown. As the line is deployed into the water, seabirds dive for the bait and are ensnared on the hooks and drown.

9 Purse Seining A purse seine is a large wall of netting that encircles a school of fish A purse seine is a large wall of netting that encircles a school of fish Fishermen pull the bottom of the netting closed (like a drawstring purse), herding the fish into the center Fishermen pull the bottom of the netting closed (like a drawstring purse), herding the fish into the center Purse seines are primarily used for schooling fish Purse seines are primarily used for schooling fish Environmental Impact The net encircles the school of fish, but also catches bycatch like dolphins, sharks, sea turtles, and juvenile fish The net encircles the school of fish, but also catches bycatch like dolphins, sharks, sea turtles, and juvenile fish

10 Traps and Pots Traps and pots are submerged wire or wood cages that attract fish and hold them alive until fishermen return to haul in the gear Traps and pots are submerged wire or wood cages that attract fish and hold them alive until fishermen return to haul in the gear Traps and pots catch bottom-dwellers like lobsters, crabs, and shrimp Traps and pots catch bottom-dwellers like lobsters, crabs, and shrimp Environmental Impact Baited traps may attract juveniles or unintended species. However, these animals can either escape through specially designed vents or be released alive once the trap is hauled aboard. Baited traps may attract juveniles or unintended species. However, these animals can either escape through specially designed vents or be released alive once the trap is hauled aboard. Traps may damage seafloor habitats when large ocean swells and tides bounce the gear around. Hauling in a row of traps may also drag the cages along the seafloor, causing damage. Traps may damage seafloor habitats when large ocean swells and tides bounce the gear around. Hauling in a row of traps may also drag the cages along the seafloor, causing damage. Marine mammals can become entangled in the lines connecting the traps to the buoys. Marine mammals can become entangled in the lines connecting the traps to the buoys.

11 Trawling/Dragging Trawlers tow a cone-shaped net behind a boat Trawlers tow a cone-shaped net behind a boat Trawling at different depths catches different animals Trawling at different depths catches different animals Environmental Impact Trawl nets catch everything in their path and can damage the seafloor Trawl nets catch everything in their path and can damage the seafloor Trawlers often accidentally catch endangered sea turtles, juvenile fish and other unwanted species, resulting in a significant amount of bycatch Trawlers often accidentally catch endangered sea turtles, juvenile fish and other unwanted species, resulting in a significant amount of bycatch Dragging nets along the seafloor can damage or destroy fish habitat Dragging nets along the seafloor can damage or destroy fish habitat

12 Conclusion Question Which fishing method do you think yields the most bycatch? Which fishing method do you think yields the most bycatch?

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