UN Convention on the Law Of the Sea (UNCLOS)

Coastal jurisdiction 12 n. miles Exclusive Economic Zone (EEZ)

200 n. miles 40% of ocean is under coastal

control Mineral & fishing rights Pollution regulation responsibility

Free passage for shipping International Seabed Authority

– regulates seabed mining

EEZs of the world

EEZ of United States

Fisheries Fish provide 15% of human protein

consumption One billion people rely on fish as their main

source of animal proteins Dependence on fish is higher in coastal areas Some small island nations depend on fish

almost exclusively Another 35 million tons are harvested from

aquaculture

Nitrogen influx is the main limiting factor

Primary productivity and is very important in determining fish carrying capacity

Increasing fisheries

By-catchSpecies caught incidentally Other fish species

As much as ¼ the total catch 20 - 40,000,000 tons of by-catch a year

Turtles Seabirds (e.g. Albatrosses) Dolphins

Tuna fishery & dolphins Driftnets

Mariculture 37% of total world fishery Fish Crustaceans

Shrimp and prawn most successful Bivalves (e.g. oysters)

Also successful Algae

Mainly seaweedsBUT there are problems…

Mariculture Sewage pollution Chemical treatments Antibiotics Escapes of non-native

species Parasites (sea lice) Marine mammal conflicts

Shooting seals Acoustic Harassment Devices &

cetaceans

Energy from oceans

Advantages Relatively non-polluting Huge potential

Amount of energy available greater than fossil fuels or uranium

Renewable Largely reliant on heat stored

in oceans & atmosphere – not directly from sun

Readily available along coasts

Power from

Offshore winds Currents – 2000 MW off Florida

alone

Waves Tides – only one being successfully exploited

Thermal energy (OTEC)

Current power

Wave power station

Potential Wave Power Hotspots

La Rance Tidal Power Plant

Potential Tidal Power Hotspots

Ocean Thermal Energy Conversion (OTEC)

Warm water near the surface heats a fluid (e.g. liquid propane or ammonia)

Liquid turns to gas – increase volume of gas turns a turbine

Cold water from the deep ocean cools down the fluid

Fluid become a liquid etc. etc.

OTEC system

Geological Resources

Petroleum95% of the economic value of non-living marine resources

Offshore about 30% of total world production (started in 1930s)

Likely to increase in futureEsp. Arctic, Asia, W. Africa & Brazil

Deeper ocean to be exploited

Geological Resources

Gas HydratesComposed of water and natural gas (e.g. Methane hydrate)

Occur under permafrost on land and under ocean floor

High pressure and cold temperatures trap gas in water crystal lattice

Created when bacteria breakdown organic matter in seabed sediments (creating methane & some ethane & propane)

Amount of organic carbon in Earth reservoirsOther category includes peat, soil & living organisms

Sand and gravel 2nd to petroleum

Phosphorite (sedimentary rock) Found at depths of <300m – usually

associated with upwellings Not currently mined but could be

used to produce phosphate fertilizer Some muds up to 18% content -

also nodules (25%)

Geological Resources

Metal sulfides Rich deposits of Cu, Pb, Zn & Ag Found near plate boundaries Metal enriched hot water exiting

boundary meets cold seal water – sulfides precipitate

Manganese nodules Discovered in 1872, scattered in deep

ocean Contain Mn & Fe (& Cu, Ni & Co)

Geological Resources

Divergent and convergent plates and metallic sulfides

Chemical Resources

Freshwater from desalination Distillation (water vapor boiled out of seawater

- but a lot of heat needed)

Electrolysis (Na+ & Cl- are removed from water by means of charged electrodes)

Reverse osmosis (water pumped in at high pressure forcing water through a semi-permeable membrane - which holds back salts etc)

Freeze separation (ice 70% lower salinity than seawater)

Reverse osmosis

Chemical ResourcesEvaporative salts – salts remaining when

water content of seawater evaporates

Gypsum – used in plaster of Paris and gypsum board (sheet rock)

Halite – table salt

Pharmaceutical drugs

Antibiotics Anti-inflammatory Anti-viral Anti-tumor Anti-cancer