The oceans are in trouble due to serious overfishing, destructive fishing methods, and a lack of global ocean management. By making better choices about the seafood we eat, we can alleviate some of the pressure placed on ocean life and ensure our enjoyment of many species in the future.
The Issues
1. Overfishing
Fish are being caught faster than they can reproduce, increasing the number of fish that are overexploited or depleted to 25% of the world's fish stock. According to recent studies, fish stocks are permanently affected by overfishing due to the harmful genetic alterations caused by gradually reducing the numbers of large fish. The global fishing fleet is operating at 2.5 times the sustainable level, causing fisherman to move on to new species when one is no longer plentiful, causing serious damage to ocean ecosystems.
2. Illegal Fishing
It is estimated that 1/4 of the world's catch is unreported or unregulated. Some fisherman ignore the management plans and "these violations include taking undersize fish, fishing in closed areas, during seasonal closures, using illegal gear or taking more fish than is allocated."
3. Habitat Damage
The future of fishing depends on the health of the habitats in which these fish live. Many ecosystems are fished so often, they never have time to recover. The type of fishing method used is important, some are more harmful than others.
Fishing Methods:
Gillnetting:
This method of fishing employs nets selected specifically for a particular size and species of fish. They can be set at any point in the water column. They are particularly useful in the snaring of any ground or pelagic fish species, including cod, salmon, swordfish, halibut, and tuna. These type of nets pose a serious threat to other marine wildlife such as sea turtles, sea otters, porpoises, dolphins, whales, and seabirds who find themselves caught and die because they are unable to surface for air.
Trawling:
Dragging mobile nets from the backs of boats at various depths, the trawling method succeeds in catch large numbers of target fish, as well as many other bycatch species. These nets can be as large as 40 feet tall and 200 feet wide. The environmental impact trawling has is immense. The sediments stirred up by bottom trawling affects the local environment and reintroduces pollutants like DDT and PCB trapped in soil on the ocean floor. Trawling also damages slow growing coral. Most trawling in completely unregulated.
Purse Seining:
A boat drags a net around in a circle and the bottom singes up like a drawstring purse, catching entire schools of fish at once. These method often ensnares dolphins as bycatch, especially tuna (dolphin's food source).
Poll Fishing:
The most environmentally friendly method, pole fishing has a very low rate of bycatch.
Trolling:
A method employing one or more long fish lines, baited and dragged through the water. Salmon, mackerel, marlin, bluefish and kingfish are common species caught using this type of fishing. It is an environmentally friendly way of fishing because bycatch can be identified and released quickly.
Traps and Pots:
These submerged cages rest on the sea floor and attract target fish with bait. They cause minimal damage to the ocean environment because the simply rest on the bottom and rarely catch unintended species. Lobster, crab, shrimp, Pacific Cod, and sablefish are caught in these.
Longlining:
A long central fishing line (between 1 and 50 miles long) from which other smaller lines baited with hooks dangle is dragged through the water. Although less destructive to bottom habitats, they are notorious for catching unintended bycatch such as seabirds and sea turtles. It is estimated that 100,000 albatross are killed each year using this method and 19 out of the 21 species are threatened.
Source List:
http://en.wikipedia.org/wiki/Omega-3_fatty_acid
http://www.sciencedaily.com/releases/2006/01/060112040047.htm
