Chapter 17: Marine Resources

Laws and regulation

Mare Liberum Territorial sea 1958 to 1982 UN Law of the

Sea Ratified in 1993 International law

Law of the sea

Coastal jurisdiction 12 n. miles EEZ Exclusive Economic Zone

200 n. miles Free passage International Seabed Authority Law of the Sea Tribunal

EEZ of world

EEZ of United States

Fig. 17-1

Fisheries Fish caught commercially Five ecosystems

Non-tropical shelves Tropical shelves Upwelling Coastal and coral systems Open ocean

Fish recruitment

Fertilization of eggs Survival of fish larvae Survival of juvenile fish

Mortality losses huge until fish matures

Primary productivity and fisheries

Relationshipto nitrogeninflux

Fig. 17-2

More nitrogen at upwelling Duration of upwelling Rates of upwelling

Moderate Too slow Too fast

World catch

Fish production Potential world fishery

about 100 to 120 million metric tons

Overfished areas Intended catch and bycatch

Bycatch

Caught incidentally Tuna and dolphins

Marine Mammals Protection Act Driftnets or gill nets

Banned in 1989

Fisheries management

Difficulties Regulation of fishing vessels Catch limits Many countries Migrating fish Human activities in one area impact

another Economic concerns of fishers

Mariculture 37% of total world fishery Fish Crustaceans

Shrimp and prawn most successful Bivalves

Also successful Algae

Mainly seaweed

Energy from oceans

Advantages Nonpolluting Huge Renewable Readily available along coasts

Power from

Offshore winds Currents Waves Tides Thermal energy (OTEC)

Mineral resources

Petroleum Offshore about 30% of total world production

Likely to increase in future Deeper ocean to be exploited

Gas hydrates Sand and gravel Phosphorite Metal sulfides Manganese nodules and

crusts Cobalt (strategic)

Divergent and convergent plates and metallic sulfides

Chemical resources

Freshwater from desalination Distillation Solar humidification Electrolysis Reverse osmosis Freeze separation

Reverse osmosis

Fig. 17-24

Evaporative salts Halite, common table salt Gypsum building material Chemical industrial uses

Pharmaceutical drugs from the sea

Soft-bodied marine organisms chemical “warfare”

Antibiotic Anti-inflammatory Anti-viral Anti-tumor Anti-cancer

End of Chapter 17: Marine Resources