Over-Fishing
Web link http://www.youtube.com/watch?v=F6nwZUkBeas
Fish are renewable because they can renew their numbers quickly. If fish are over exploited it can seriously deplete world fish stocks. This happens as fish cannot recover their numbers by breeding, like before.
The main reason for overfishing are directly to do with improved technology and the rising world population. Improved technology has resulted in countries becoming too efficient fishing. A rising population has put a strain on food supplies.
Example of the Scale of Over-Fishing Some fishing boats can employ 100 people on board. They can catch and hold enough fish on board to provide meals for over 14 million people. They are so huge that they could possibly over-fish a given area of the seas. Such large trawlers make up only about 2% of the world’s fishing boats but catch nearly 60% of the world’s fish catch. Do you think this makes sense??
Improved Technology Fishing vessels are now bigger and better than they ever have been. These “super-trawlers” can carry large amount of fish for months due to improved refrigeration. Echo-sounds, sonar, motorised winches to pull in the nets, and monofilament nets stretching 40km long allow fisher men catch more fish and also kill other marine life.
Case Study- The Irish Sea’s Cod Stock. Over-fishing has resulted in the cod depleting in the Irish Sea. Reasons for this are to do with 1. Improved Technology 2. Cod have a high commercial value. 3. Large number of fishing vessels from outside Ireland fish illegally in Irish waters. 4. The shallow waters of the Irish sea are rich in plankton, and huge numbers of cob are attracted to this rich feeding round. 5. Cod move slow during spawning season. Case Study- The Irish Sea’s Cod Stock.
The depletion of cod stocks is threatening to the species existence in the Irish sea. This has resulted in the government taking significant actions.
“Full Nets - Empty Seas” Quotas on the amount of fish a vessel can catch are targeted at preventing over-fishing. In rich countries boats and fishermen have become so efficient at catching fish and too wasteful in their use which worsens the problem. This has occurred mainly due to improved technology.
1. Areas of the Irish sea being closed to fishing. 2. The quota of fish allowed to be caught being reduced. 3. Surveys being carried out every year to monitor the stock. 4. Fishery protection vessels being introduced to prevent poaching. 5. Holes in nets getting bigger to allow smaller fish get out.
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