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OCEANS AND FISHERIES - Coggle Diagram

- - - - true fish / finfish
      - shellfish
      - 90 million tonnes a year
        
        80 million tonnes from the sea
  - - - 3,5% of seawater = dissolved substances = products of erosion dragged into oceans via rivers
        
        salt
        
        magnesium
        
        gold
        
        titanium
        
        tin
        
        diamonds
        
        more in the ocean but harder to get
        
        construction industry
        
        sand
        
        gravel
        
        crushed rock
        
        OIL
        
        most well known chemical
        
        offshore drilling
        
        largest offshore field is the Gulf of Mexico with 4000 rigs
  - - - if we could, we'd be able to double our energy production
      - few power stations in regular use now a days
        
        Limpet (Scotland)
        
        Aguçadoura Wave Farm (Portugal)
        
        NOT active
        
        biggest in the world
        
        Tidal Power Station (S.Korea)
        
        Largest FUNCTIONING one in the world
  - - - PROFITABLE
        
        windsurfing
        
        jet skiing
        
        snorkelling
        
        sunbathing
        
        diving
        
        whalewatching
        
        replacement for the hunting of whales, which became illegal
        
        gives over 2 billion dollars to the world economy
  - - - high importance over history
        
        transporting people
        
        transporting goods
      - now a days
        
        PLANES ARE A THING
        
        ships
        
        less important for transport
        
        over 50 000 registered merchant ships
        
        pleasure cruises are still profitable
  - - - salty water = unsafe
        
        can be made safe by desalination
      - 0,3% = surface water
        
        the rest is underground
- - - - Largest one in the world
        
        nutrient rich = a lot of phytoplankton
        
        a lot of phytoplankton = a lot of fish (over 12 million tonnes at its peak)
        
        disturbed every 10-15 years by an event callen "EL NIÑO"
        
        warm, nutrient poor currents
        
        less nutrients = less phytoplankton = less fish
  - - - causes
        
        increasing demand for fish as food
        
        technology and improved fishing methods
        
        bigger boats
        
        huge nets
        
        can scoop up everything in the area, including bycatch
        
        drift nets
        
        seine nets
        
        trawl nets
        
        dredge nets
        
        SONAR
      - 75% of the world´s fisheries are threatened
        
        due to overfishing, there were hardly any fish herrings by the 1970s
  - - - nutrients levels depend on the temperature of the current
    - - final direction depends on the shape of the land around the current
  - - - phytoplankton
        
        needs light to do photosynthesis
        
        light only reachs up until 200
        
        continental shelves are rather shallow, so they are perfect for phytoplankton to grow in that aspect
        
        needs minerals and nutrients
        
        depend on the currents
        
        warmer currents are nutrient poor, and so the phytoplankton population will dwindle
- - - - for every shrimp caught, 6 other fish are also caught
  - - - fish are able to breed and so the species is preserved
    - - the UN Convention on the law of the Sea (UNCLOS) is created
      - countries can control their waters and fisheries within a 200 nautical mile area surrounding its coastline
    - - the most efficient form of mariculture (farming sea fish) is salmon
      - can have problems
        
        the most efficient form of mariculture (farming sea fish) is salmon
        
        wastes from the fish cages can pollute the envoirment
        
        fish escaping from farms can cause problems in the local envoirments
      - response to the decrease of fish population