un convention on the law of the sea (unclos) coastal jurisdiction 12 n. miles exclusive economic...
TRANSCRIPT
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