How We Fish in the US Tuna Swordfish Cod Halibut Salmon Scallops Oysters Fishing Methods Long Line Fishing Purse Seining Trawler and Dredges Driftnetgillnetting Traps and pots Bycatch ID: 637292
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Slide1
Fishing Techniques
January 11, 2013Slide2
How We Fish in the US:Slide3
TunaSlide4
SwordfishSlide5
CodSlide6
HalibutSlide7
SalmonSlide8
ScallopsSlide9
OystersSlide10
Fishing Methods
Long Line Fishing
Purse Seining
Trawler and Dredges
Drift-net/gillnetting
Traps and potsSlide11
Bycatch
Any unintended species caught through fishing.Slide12
Longlining
Employs a single fish line that can extend for 50 miles!
This central line is strung with smaller lines of baited hooks
Can be set near the surface
Catch pelagic fish like tuna and swordfish
Can be laid on the sea floor
Catch
deepdwelling
fish like cod and halibutSlide13
LongliningSlide14
Dangers of Longlining
They hook and kill large numbers of endangered sea turtles, dolphins, and sea birds each year.Slide15
Purse Seine Fishing
Establishes a large wall of netting to encircle schools of fish.
Used to catch schooling fish, such as sardines or species that gather to spawn, such as squid.
Danger:
Bycatch
(such as when tuna seines are intentionally set on schools of dolphins)Slide16
Purse Seine Fishing
http://www.youtube.com/watch?v=
jyeqNOAFkwI
Slide17
Trawlers and Dredges
Nets are towed at various depths to catch fish or shellfish.
Trawl nets, which can be as large as a football field, are either dragged:
along the sea floor or
midway between the floor and the surfaceSlide18
Trawlers Slide19
Dangers of Trawlers
They ruin the seafloor by scraping the bottom.
Bottom trawling can result in high levels of
bycatch
.
Refer back to shrimp farming and the mangrove forests.Slide20
Driftnet/Gillnetting
Uses curtains of netting that are suspended by a system of floats and weights.
They can be anchored to the seafloor or allowed to float at the surface.
Used to catch sardines, salmon, and cod.Slide21
Drift Net FishingSlide22
Traps and Pots
Are submerged wire or wood cages that attract fish with bait and hold them alive until fisherman return to haul the catch.
More sustainable:
Less
bycatch
Less sea floor impact