Nature Resources in the World

1. Nature Resources in the World Fisheries

2. Introduction • Important natural / living resources • Renewable natural resources • Important components of the ecosystem

3. Lower course of rivers & lakes Continental shelf Distribution of fish Freshwater fish Marine fish

4. The global distribution of fish Areas producing about 50% of commercial fish harvest Upwelling areas - the main fishing zones Average daily plankton production mg of carbon per m2 >500 250-500 100-250 <100 Distribution of fish

5. 99% of the fish stock concentrated within 200 nautical miles off the coast which are plankton rich

6. Small fish Large fish Plankton Reason accounting for the distribution of fish The main reason: • Fish feed on plankton (including unicellular plants). • They associate with the plankton.

7. Unicellular plants need: Carbon dioxide Sunlight Nutrients Condition in these areas: Shallow water - light can reach most part. Close to continent - receive loads which are rich in nutrient. Reasons accounting for the distribution of plankton

8. Cold…! Good! Another important factor - Temperature • Most of the ocean is cold. • Advantages of low temperature: •  solubility of oxygen in water • metabolic rates  need less energy  need less food.

9. Present situation of the world's fisheries • People get an average of 20% of the animal protein in their food from fish and shellfish. • Contribute 30 - 90% of animal protein in Asian coastal and Island countries. • 87% comes from the ocean and 13% from fresh water.

10. Fisheries • Concentration of particular aquatic species suitable for commercial harvesting in a given area of the ocean. However, only a few groups harvested extensively (40 out of 200000 known species – half annual harvest which is near to its maximum sustainable yield) - cods, herrings, jacks, redfishes, mackerels and tunas. Why? Tradition and taste

11. Operating costs in what aspects? • More than 90% of the fish obtained by small and large motorized fishing boats to hunt and gather over a large area. • 30 - 40 % of the operating costs spent on fuel. --> higher price of many favourite types of fish and shellfish.

12. Is the fish resources renewable? • The highest rate at which a potentially renewable resources can be used without reducing its available supply. • 1950 - 1970, the weight of fish catch grew annually by 7% and increased more than threefold. The rate of growth has slowed down and the marine catch may soon reach the estimated sustainable yield. • Although the total fish catch has grown, the world-wide per capita fish catch has declined.

13. Many human activities causes impact to fish: Over-fishing Illegal fishing practices Water pollution The human impacts to fish

14. World population  Demand on fish  Over-fishing Over-fishing Rate of removal of fish > rate of production of fish

15. Fishermen try to catch more fish by using net with smaller holes. Immature fish are also captured. Less fish can spawn. Foreign exchange for third world countries Over-fishing

16. Fish Bombing (use of explosives) Fish Poisoning (use of toxic substances) Illegal fishing practices Destructive fishing methods

17. Not only kills the target fish, but also nearby small fish and even plankton. The related food chains & marine ecosystem are destroyed. drift net fishing, dynamite / poisons - destroy habitat, pollution, destruction of mangroves, coral reefs and population growth. Disadvantages of drift net fishing on p. 4 Illegal fishing practices

18. Drift net fishing • Indestructible nylon-mesh • 15 meters deep and is up to 65 kilometres (40 miles) long • Intend to catch squid, tuna, swordfish, sea trout and salmon

19. Disadvantages of drift net fishing • Not only depletes the target species but also kills dolphins, turtles, seals, sharks or even whales that entangled in the fine mesh of the nets • Ghost net entangled and kill fish, • marine mammals and birds year-round • for centuries.

20. Various types of water pollution: Chemical pollution Thermal pollution Oil pollution Acid rain Water pollution

21. Nitrates Through series of decomposition Aerobic bacteria Sewage Algal bloom Oxygen depletion Chemical fertilizer Death of aerobic organisms Chemical pollution - organic and inorganic wastes

22. Taken in by fish Form toxic compound Heavy metal DDT Being accumulated along the food chain Death of fish DDT Chemical pollution - toxic chemicals

23. Hot water discharged from power station:  solubility of oxygen in water  metabolic rate   the oxygen consumption Favours the growth of algae. Thermal pollution

24. Oil spillage causes the death of fish by: Oil is toxic. Oil cuts off the oxygen supply: It prevents the oxygen from dissolving into the water. It prevents the entry of sunlight. Green plants cannot carry out photosynthesis. Oil pollution

25. Exhaust gases from vehicles, factories, incinerators & power stations contain acidic gases. They dissolve in rain water to form acid rain.  acidity of water  death of fish and other organisms. Acid rain

26. Case studies on p. 3: Peruvian anchovy catch • Reasons for decline of Peruvian anchovy to commercial extinct: i. El Nino - Southern Oscillation kills phytoplankton which are the major food for Peruvian anchovy. ii. Government keep on financing fishing industry in order to pay off the loans and avoid people out of work. In 1953, Peru livestock feed 20% of annual commercial fish catch. However, between 1971 and 1978, the Peruvian anchovy became commercially extinct.

27. Group discussion on any possible solutions and the difficulties arised • Report and give summary

28. How to conserve? Conservation Government Individual

29. Control the rate of removal - rate of removal  rate of production What government should do FISH HALTING in South China Sea

30. iv. Better management1982 United Nations Convention on the Law of the Sea by 159 countries.This treaty gives all coastal countries the legal right to control fishing by their own fishing fleets and by foreign ships within 364 kilometers (200 nautical miles) of their coasts.

31. If enforced, this treaty can reduce over-fishing. However, 22 countries refused to sign or ratify the treaty because (1) Conflicts between countries and islands. They disagreed the mineral and living resources in the open ocean belonging to the entire world so as to share their resources and profits with other countries especially the LDC. (2) Difficult to control.

32. Stop fish bombing & poisoning Promote fish breeding along coastline & at inland pond What government should do

33. Regulate the discharge of waste - treated before discharge Control the use of fertilizer - no excess amount is used What government should do

34. Educate people about the importance of conservation of fish Use fuel of low sulphur content - minimize the amount of sulphur dioxide produced What government should do

35. What individual should do Control of fishing gear Avoid the consumption of Humphead Wrasse and Giant Grouper Reduce the consumption of wild-caught live reef food fish e.g. Leopard Coralgrouper Avoid the consumption of sexually immature species

36. i. Consume new species Processing the new species to acceptable taste. ii. Aquaculture (e.g. Salmon in Norway) Change to substitute such as cultured LRFF and freshwater fish High technologies required, to avoid destruction of natural habitats and causes pollution.) .

37. THE END