Question

1. Define the different types of capture fishing and culture fishing methods briefly. How has the production increased in them?

Answer 1

FISH CAPTURING
Beach and Boat Seines
Seines are long nets, with long ropes on each end, which herd fish when dragged or towed. They’re hauled over sandy or muddy bottom habitat, and the cloud of sediment helps herd the fish into the net.

Bottom Trawls
Bottom trawls are cone-shaped nets that are pulled along the seafloor by one or two boats to catch cod, halibut, lobster, rockfish, shrimp and other bottom-dwellers.

Dredges
Dredges are metal-framed baskets that are dragged across the seafloor to collect clams, cockles, mussels, oysters, scallops and sea cucumbers.

Gillnets
Gillnets walls of stationary or drifting netting that are almost invisible to fish, so species like cod, perch, salmon, sardines and trout swim right into them.

Harpoons
Harpoons are poles that have a steel point with one or more barbs at the end and usually a retrieving line.

FISH CULTURING
Bottom Culture
Bottom culture involves growing mussels, oysters, scallops and clams on the seabed and harvesting them by hand, rakes or dredging. Seaweed may also be grown by bottom culture.

Flowthrough Raceways
Flowthrough raceways allow farmers to divert water from a waterway, like a stream or well, so it flows continuously through channels containing fish. These long and linear containment structures can be indoor or outdoor and are usually above ground in a terraced configuration. Treating wastewater can greatly minimize environmental impacts, which can include contamination of waterways and spreading disease to wild fish. U.S. farmers raise rainbow trout in raceways.

Net Pens
Marine and freshwater net pens are enclosed on the bottom and sides by wooden, mesh or net screens, and submersible net pens are fully enclosed by mesh or net screens.

Off-bottom culture
Off bottom culture involves growing shellfish like mussels, oysters and scallops in suspended or off-bottom systems. In bag culture, juvenile shellfish, or “spat,” are cultivated in mesh bags that are attached to trestles placed in the intertidal zone.

Recirculating tanks
Recirculating tanks have continuous water flow, and the wastewater is pumped through treatment systems that clean the water before returning it to the tank. These systems can be indoor or outdoor, and they’re usually above ground.