Fishing and Aquaculture Notes

Transcription

1 Fishing and Aquaculture Notes If you're overfishing at the top of the food chain, and acidifying the ocean at the bottom, you're creating a squeeze that could conceivably collapse the whole system. - Carl Safina 1

2 Pole Fishing Pole fishing, where a line is attached to a baited hook, which can catch and pull in the fish. Pole fishing has the lowest rate of bycatch; species of fish that are unwanted and accidentally caught. Pole fishing in the Maldives. Photo by Greenpeace. 2

3 Longline fishing a commercial fishing technique where baited hooks are attached to a single, long fishing line that trails behind a ship. 3

4 Compared to pole fishing, longline fishing has a much higher rate of bycatch. Sea birds,sea turtles, sharks, and other fish are also accidentally caught. 4

5 Trawling The fastest and most efficient way to catch fish is by trawling, where a large net is dragged behind a ship. If the net actually drags along the bottom, it is called bottom trawling. 5

6 Trawling has the highest rates of bycatch, since any species big enough to be caught in the net will be trapped. 6

7 Bottom-trawling is damaging to any habitat at the bottom of the sea floor, such as coral reefs. 7

8 The large commercial trawlers were incredibly successful in Newfoundland, harvesting over 800,000 tons of cod in In following years, harvests began to decrease. Canada evicted the fishing fleets of other countries from its waters, but harvests continued to decline. In 1988, fisheries managers called for a 50% reduction in allowable catch. Officials only reduced it by 10%. 8

9 Maximum sustainable yield: maximum fish that can be harvested without diminishing the population for future years. Overexploited fisheries:harvest at unsustainable levels. Over time, these can become depleted fisheries with stocks so low that fishing cannot be supported. 9

10 Cod Moratorium In 1992, a complete stoppage, or moratorium, to cod fishing off Newfoundland and Labrador in Canada was announced. The moratorium was devastating to the coastal towns, whose economies were dependent on the fisheries. Fishermen were so angry, they tried to forcibly interrupt the press conference of Fisheries Minister John Crosbie, as he announced the moratorium. 10

11 Fishing Regulations Up to the 1960s, the only regulations on fishing were territorial waters; exclusive fishing zones that reached 12 miles off each coastline. 11

12 Exclusive economic zones: extended 200 miles from each nation s coastline. 12

13 Annual catch limits in US, have been established and enforced by the National Oceanic and Atmospheric Administration (NOAA) since These catch limits are lower than the maximum sustainable yield, meaning the stocks are able to recover each year. 13

14 Marine reserves: no living organisms can be legally harvested, established to protect areas high in biodiversity. Fully protected. 14

15 Aquaponics: Waste-water from fish farming is circulated through plants, which absorb the waste as nutrients and clean the water. 15

16 Consumer Labels Any fish labeled as farmed was raised in a mariculture or aquaponics facility. Wild caught fish is just that it was caught from a body of water. 16

17 MSC Certification is a label attached to any seafood that follows sustainable fishing practices, as established the Marine Stewardship Council. 17