Exploring Oceans
- Created by: LMitchell1380
- Created on: 25-04-18 08:34
Distribution of the world's oceans
Oceans and seas = 71% of surface of earth
5 main oceans -
1. Pacific Ocean
2. Indian Ocean
3. Atlantic Ocean
4. Southern Ocean
5. Arctic Ocean
Structure of ocean basins
All oceans have similar structures
Structure -
1. Continential Shelf - starts at the edge of the continents and gradually deepens
Average width 70km, slope angle of under 2 metres per kilometer.
2. Continential Shelf --> Continential Slope - slope angle increases. Not continous as canyons and gullies cut into it.
Slope angle of 70 metres per kilometer.
3. Continential Slope --> Continential Rise - wide but gently sloping zone.
4. Continential Rise --> Abyssal plain - deepest parts of the ocean
Abyssal Plains
Abyssal plains = 50% of Earth's surface
> Whole mountain chains - called seamounts
Seamounts = 3000m above the abyssal plain
Guyots = 'peaks that are above the oceans surface'
Over time, erosion reduces there height below sea level.
Guyots can cause oceanic crust to subduct into the upper mantle due to the weight of it.
Mid-Oceanic Ridges
Crossing the Abyssal Plain are long chains of mountains = showing the location of mid-oceanic ridges.
Transverse faults = 1600km long at right angles to mid-oceanic ridges
Rift valley = at the centre of the ridge
Magma rises up from the upper mantle in the rift valley = pushes the crust apart
Mid-Atlantic Ridge = east side and west side of abyssal plain moves part at 1cm/year =
Process = sea floor spreading
Sea-floor spreading and paleomagnetism
1. Magma rises and cools - magnetic orientation of the poles is 'locked' in the iron particles of the new rock.
The polarity of the Earth's magnetic field flips = magnetic north becomes magnetic south
Flipping of the Earth's magnetic field = every 200,000 to 250,000 years
Evidence for flipping of the magnetic field - magnetic stripes either side of the ridges.
Paleomagnetism
Paleomagnetism and sea-floor spreading = evidence for theory of plate tectonics.
> Alfred Wegener, 1900s
> Increase in seismicity and paleomagnetism data, 1950s
= Produced radial theory of plate tectonics
Ocean margins have subduction zones =
Plates are converging - the one with the lowest density is forced into the mantle = results in a 'trench'
Deepest places in the abyssal plains = 7km to 11km
Affect of Salinity on the Ocean
Salinity = the concentration of sodium chloride (salt) in the ocean.
Salinity = gram of salt per 1000g of water.
Fresh water salinity = 0.05 ppt (parts per thousand) .v.s. sea water = 35 ppt
Salinity can vary with depth =
'Halocline - rapid change in salinity close to the surface'
Salinity influences water density --> density affects water movement vertically
EG. flow of ocean currents from tropics to poles moving heat will effect global climate.
Affect of temperature on the ocean
Oceans absorb, store, transfer and release heat = so, important in controlling climate and weather on global and local scales.
Water has a high specific heat capacity = can retain its heat.
Compared to land which heats up and cools quickly.
Thermocline = water temperature decreases rapidly as depth increases close to the surface.
The depth of warm surface layer varies with season and location.
Below 1km = water temperature hardly changes.
Warm and cold ocean currents
Warm water at the surface, cold water at depth.
> There is movement from low --> middle --> high latitudes
Polar regions - water temperature cools and more saline --> water becomes denser.
1. Water sinks and disperses
2. Deep current flows transport water back to equatorial regions where it rises again
The flow of water is called: 'hermohaline circulation' or 'ocean conveyor belt'
Gyres - surface circulation generated by wind.
EG. South and North ocean gyres in Atlantic and Pacific Oceans.
Souther gyre in Indian Ocean
Circulation in the North Atlantic
1. Warm saline water flows from coast of Florida TO the northeast = this is the 'Gulf Stream'
2. Gulf stream moves heat energy to mid-latitudes = impacts weather and climate in Europe
North-Atlantic Drift moves all the way to the Norwegian Coast and to the Arctic.
Water that sinks in the Arctic = takes 150-250 years to re-surface at the equator.
3. The water cools --> increases in density --> sinks.
4. Deep ocean currents form.
Circulation of the North Atlantic
Far northwest of Atlantic = Cold Labrador Currents flow southwards from the Arctic.
Ladrador current flows = causes cold winters in Canada
North branch of the gulf stream flows along west coast of Greenland = causes coast to be ice-free.
North Atlantic = major inflow from Mediterranean as it passes through straits of Gibraltar INTO Atlantic at 1000km
> Warm water = 13'c
> Saline water = 37.c ppt
Circulation of the North Atlantic
Climate change will affect North Atlantic circulation.
1. Melting of ice from polar ice caps due to climate change.
2. Large release of fresh water into the Arctic Ocean.
3. Reduction in salinity.
4. Reducing in water density.
5. Preventing sinking of water in North Atlantic
6. Disrupt thermohaline circulation.
7. Change climate and weather (social impacts for Europe - northwest Europe will cool)
(Salinity of fresh water: 0.05ppt .v.s. salt water: 35ppt)
Changes in light levels
Light energy from the sun is not evenly distributed across the ocean.
Light is most intense in eqatorial regions - increasing distance from equator equal light energy reduced (spread over a greater surface area)
Light can penerates water - with increasing depths, light reduces.
'Photic zone - layer of water where there is enough light for photosynthesis to occur'
Below the photic zone - organises use 'bioluminescence'
Changes in ocea temperatures
Ocean temperatures = due to transfer of energy from sunlight to water molcules.
So: global sea surface temperatures --> related to variations in sunlight
eg: increasing depth = less light = lower temperatures
Occasionally, strong winds can move surface water = allowing deep cold water to rise to the surface
Changes in nutrient levels
Dissolved nutriens (from weathered rocks) move into rivers --> into oceans
1. Plankton use nutrients
2. Nutrients pass through ecosystems = consumers feed on producers (plankton)
Nutrients level = low at the surface
Very low away from continents where nutrients are running off land
Warm, equatoral waters = low in nutrients
1. Airborne nutrients used up quicky - little wind deposition
2. Cold water (containing nutrients from sea floor) arent brough to the surface as cold water is denser so cannot rise.
Changes in nutrient levels
Nutrient levels are HIGH - in locations where upwelling from thermocline
EG: locations like: Antartica have strong upward movement of deep water
1. Nutrients are brought to the surface due to upwelling
2. Nutrients support high biodiversity
Abyssal plains have little nutrients and light - still support life
Sun's energy is transferred to the abyssal plains by 'marine snow'
'Marine snow' - when dead organisms from the surface sink to the bottom. Deep water organisms feed on this --> creation of deep water foodchains and ecosystems.
Hydrothermal vents
Discovery of hydrothermal vents, 1970s at mid-oceanic ridges
Hydrothermal vents =
> High temperatures (380'c)
> Silica rich
> Hydrogen, sulphur and methane gases produced.
These conditions are suitable to sustain bacteria. (Bacteria are not dependent on sun energy - they can use chemical enery in the hot water)
Last 10 years, discovery of 'cold seeps' = they occur in shallow waters but have similar communities to hydrothermal events
Their communities use chemical energy rather than solar energy
Biodiveristy in the oceans
80% of all life is found in the oceans
250,000 different marine species - more species still to discover.
Marine ecosystems -
1. Producers - convert sunlight to chemical energy (Phytoplankton)
Food webs form around producers - life in the ocean varies with latitude and depth
Net Primary Productivity = how much sunlight is absorbed - gram of co2/per area/per year
Annual NPP = 100 billion tonnes/year = ocean key part of carbon cycle
Biodiversity in oceans
Highest NPP = occurs where greatest supply of dissolved nutrients
Percentage of NPP in coastal regions is low = due to areas and depth of water productivity is high.
1. Dissolved nutrients move into coastal zones through rivers - estuaries = high NPP
Coastal shelves maintain high NPP by run-off of nutrients
The deep ocean is relatively unproductive due to its volume of water
EG: Sub-tropical gyres = little nutrients supply = 'biological deserts'
In temperate coastal areas = kelp forests have biodiversity comparable to a tropical rainforst
Deep water ecosystems - Antarctic
'Pelagic - ecosystems away from coastal zones in deep waters
Marine NPP by region
Coastal region - estimated NPP: 250 g/cm2/year
Deep ocean regions - estimated NPP: 130 g/cm2/year
Antarctic marine ecosystem - deep-water ecosystem
> Low temperatues - BUT one of the most productive ocean region.
> Cold water = more oxygen dissolved (advantage for marine life)
> Phytoplankton productivity HIGH during the summer months (November to March)
> November TO March = 12 hours sunlight
Deep water ecosystems - Antarctic
Surface waters around Antarctic are nutrient rich:
1. Sea ice forms at the start of winter - some salt is released.
2. Increases the salinity of the water - water becomes more dense.
3. Surface water temperature is 0'c - saline water has a lower freezing point than freshwater.
4. Cold, saline water sinks.
5.Less salty (less dense) water rises - upwelling of nutrients.
6. Phytoplankton absorb the nutrients.
7. Ecosystem forms around phytoplankton (producer)
Affect of physical environment of ecosystem
Physical envrionment = seasonal changes in the extent of sea ice.
February = 3 million km2 of sea ice
September = 20 million km2 of sea ice
Marine ecosystems in the Antarctic are simple and biodiversity is LOW
EG: phytoplankton --> krill --> whales
Salt marsh ecosystems - inter-tidal ecosystem
Salt marshes = coastal wetlands when the ocean meets the land.
Salt marshes are common in mid to high latitudes
Zones between low and high tide = 'dynamic' = change in the volume of water.
Species that live in inter-tidal zone are adapted to rapid and freqeunt changes in environmental conditions.
Accumulation of sediment --> salt marsh fromation. Weathered and eroded material from land is carried to the coastal zone by rivers.
Salt marsh ecosystems - inter-tidal ecosystem
Salt marshes are highly productive ecosystems.
NUTRIENTS in inter-tidal ecosystems:
1. Nutrients run-off the land into rivers which transport the nutrients to the coastal zones.
2. Regular tidal movements - mix the water and nutrients
This ensures a nutrient supply is always avaliable
LIGHT in inter-tidal ecosystems:
1. Light levels vary seasonally - limiting factor only in winter periods
2. In the continential shelf - easily acess to light (in photic zone)
Salt marsh ecosystems - inter-tidal ecosystem
TEMPERATURE in inter-tidal ecosystems:
1. Seasonal variations in temperature - colder in winter months
2. Warmer surface water - little upwelling as colder water will not move up because it is denser.
BIODIVERSITY in inter-tidal ecosystems:
> Rhythm of tide = allows clear zones to develop.
Difference in the environmental conditions between zones - low tide covered in salt water most of the time .v.s. climax community where only very high tides reach.
Creates differences in abioitic factors = salinity and light.
'Zonation = (creates the different zones) vegetation changes due to 'plant succession' = this leads to biodiversity of other animals.
Value for biological resources
'Natural capital - a good that is not manufactured that has value to humans'
Examples of natural capital
1. Phytoplankton - responsible for photosynthesis
2. Fish
Natural capital --> results in natural income (harvest of krill)
Ecosystems as a service
Examples of 'Ecosystem Services':
1. Provisioning services - direct products of ecosystems (food)
2. Regulating services - advantages from natural regulation of substances (co2)
3. Cultural services - non-material benefits (swimming in the sea)
4. Supporting services - ecosystems which provide support to other services (nutrient cycles)
Opinions surround ecosystem services
If an ecosystem service can't be used = loss or cost to human caused
Varying opinion on ecosystems services due to different cultures
EG:
1. In the Arctic, whale hunting is apart of inuit culture.
.VS.
2. See as unacceptable practice in the AC - campaigns against hunting traditions.
Case study: Krill
Background information
> Habitat - upper parts of the water column
> Occur in swarms - biggest swarm recorded (2 million tonnes up to 400km2)
> Make up most of the Antarctic food chains and webs
Case study: Krill
Human impacts on Krill
> Commerical harvesting began in 1970s
> Significant industry in southern ocean - used in human products
> Five countries harvesting Krill - Chile, China, South Korea, Norway, Ukraine
> Annual catch = norway 50%, China 18%, South Korea 18%
> 1970s and 1980s = concerns that exploitation would lead to collapse in Krill stocks (threshold for sustainable fishing is exceeded)
> Krill stocks declined 80% since 1970s
Case study: Krill
MANAGEMENT of Krill
1. Comission for the Conservation of Antarctic Marine Living Resources (CCAMLR) set up in 1982
2. 25 members starts agreed ot the commission
3. Monitoring and regulating commerical interst in Krill
Commission for the Conservation of Antarctic Marine Living Resource uses a holisitc approach to look at the Krill and dependent ecosystems
Decline of Krill linked to warming sea = likely to increase in future.
Krill feed on algae that forms under sea ice --> little sea ice --> little algae that can support Krill populations
Case study: Krill
MANAGEMENT of Krill
1. Commission for the Conversation of Antarctic Marine Living Resources (CCAMLR) sets a total allowable catch (TAC)
TAC = aim to allow enough Krill to survive for populations and predators
Current TAC = 620,000 tonnes/year
This causes issues because it is significantly lower than the catch limit = 5.6 million tonnes/year.
CONFLICTS of management
> If the TAC was increased it would need to be spread out across the whole region to avoid over-fishing
> This would impact the fishing industry
Case study: Krill
STAKEHOLDERS in Krill populations
> Krill fisherman
> Environmentalists
> Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) members.
ATTITUDES of stakeholders
> CCAMLR - monitor illegal fishing, balancing fishing, predict impacts of climate change
> Krill fishermen - stick to TACs
> Environmentalist - balancing and making fishing sustainable
Case study: Krill
SOCIO-ECONOMIC STATUS of stakeholders
> Fishermen - lower economic status but they provide krill to the population - influence of fishermen is huge.
> Environmentalist - dependent on the size of the coroporation and its approach to the situation.
> CCAMLR - hugh influence on Krill because they set a TAC.
POLITICAL STATUS of stakeholders
> Fishermen - little political influence can only influence economically
> Environmentalist - can put protests forward
> CCAMLR - huge poltical influence because it brings countries together to organise a ban.
Case study: Krill
RESILIANCE of Krill
> Decline of Krill populations - 80% since 1970s
> Collapse of fishing stocks
> If the TAC was met - populations would rise again
Threats:
> Over-fishing
> Warming seas - melting ice berms - reducing food supply of algae
Case study: Krill
THRESHOLDS to initiate management
Large scale expolitation --> collapse of Krill stocks (threshold for sustainable fishing is exceeded)
Concerns in 1980s Krill stocks would fllow a 'Boom and Bust' pattern - due to large scale exploitation
Krill catch - evidence of boom and bust
1980 - 530,000 tonnes
1985 - 120,000 tonnes
Use of ocean energy and mineral resources
Oil expoitation
> Oil drilling = began 1900
> First oil rig = 1930s
Demand is growing --> technology has advanced --> industry into deeper and hostile waters
Oil and Gas
> Non-renewable resources (finite)
> Growing demand since 1950s = increase in exploitation (on the edge of continential shelf)
> Advance in technology = made drilling possible in deeper locations
Use of ocean energy and mineral resources
Current commerical rigs - drill to 2000m
Future commerical rigs - drill to 3500m
Oil and Gas
> Volatile - sensitive to changing demands
Variations in margins - difference between cost of production and market price.
Use of ocean energy and mineral resources
POSITIVE impacts of oil and gas exploitation
1. Employment - for people working on oil rigs
2. Wealth creation - oil and gas generate profit
3. Products (can be used for lots of products) - promotes a higher standard of living
4. Oil rigs can create biodiversity - can create localised reefs for some organisms
Use of ocean energy and mineral resources
NEGATIVE impacts of oil and gas exploitation
1. Local communitities - become dependent on 1 industry
2. Ecosystem disturbance - noise pollution
3. Visual impact - not natural
4. Oil spills - pollution
Gulf of Mexico
Mini case study - use and management of ocean energy resources
Undersea geology is rich in hydrocarbons
> 70 years of drilling - upgrades in technology allow deep water exploration
> 75% of US's Gulf oil production = wells at depth of 300m
> Recent oil discoveries = 1500m
> 40,000km2 of pipeline across sea floor
> 45% US oil processing occurs along coast
Gulf of Mexico
Energy industry
Rise in energy industries economic fortunes + fall in energy prices
-->
Positive socio-economic impact
Due to multipler effect --> jobs are created --> stimulates wealth, employment and services
Idea of 'success breeding success'
> 240,000 jobs created by US Gulf oil industry
Renewable ocean resources
> Fossil fuels = 75-80% of global energy consumptions
New energy supplies will be needed:
1. demand for energy will increase with rising standards of living
2. burning of fossil fuels linked to climate change
Possible renewable resources
> Tidal energy
> Wave energy
These are flow resources = naturallty generation by the Sun and moon
Renewable ocean resources: tidal energy
Tidal energy = energy from the rise and fall of the tide
Tidel power potential = dependent on physical geography (shape of coastline + tidal range)
Advantages of using tidal energy
1. Tides are regular and reliable
2. Two high and low tides every 24 hours
Disadvtanges of using tidal energy
1. Only few places where electricity demand is high enough - to jusify huge development costs
Renewable ocean resources: tidal energy
Method of collecting tidal energy
Use of barrage - dam like structure across the coast
As tide rises - gates open
At high tide - gates close creating a tidal lagoon
As tide falls - stored water is released through barrage turbines
Renewable ocean resources: tidal energy
Shiwa Lake Scheme
> South Korea
> World's largest tidal power station
> 254 MW (maximum output)
> Opened in 2011
Use incoming tide only
When sea wall was build (previous defence) - water quality declined
Water is released at low tides to flush out pollution
Renewable ocean resources: tidal energy
Tidal Lagoon Swansea Bay - mini case study
> 320 MW tidal power station planned
> 9.5 km long breakwater
> Area of 11.5km2
> 16 tubines
> Using incoming and outgoing tides
> Will power 155,000 homes
> £1 billion
Tidal Lagoon Swansea Bay
Advantages of tidal energy station created
>Renewable energy resource
> 16 hours of electricity every 24 hours
> Low CO2 emissions + lifetime carbon footprint small
> 120 years working life
> Using already exsiting technology
> Will generate employment
> Create recreation and tourism opportunities
Tidal Lagoon Swansea Bay
Impact of tidal lagoon
> Sediment movements in the Bay
> Reduced water quality - due to limited sediment movement
> Marine ecosystem disturbance - noise, habitats, vibrations
> Inshore fisheries
> Cornwall environment (conservation zone) - stones for breakwater will be quarried
Ocean renewable resources: wave energy
Wave energy = potential energy is huge (more than tidal energy)
Obstacle to development
> For it to be efficient = high wave energy is required
> In place where wave energy is high enough = many devices can't survive the rough seas
> Making them more robust (= increasing size and weight)
> Reduced efficiency of energy conversion
> Increasing energy cost
Wave energy machinery
Technology 1 = Waveroller
> Series of large flaps sticking up vertically from the sea bed
> Moves back and forth = power generated is provided to an electrical generator
Technology 2 = Pelamis
> Elongated steel tube
> As the wave passes = the structure rises and falls = turn generators to produce electricity
Technology 3 = CETO Buoys
> Buoys float the surface moving up and down
> Create hydrostatic pressure = sent to an onshore generator
Sea-floor mining
'Ferrous' deposits = contains iron
'Non-ferrous' deposits = doesn't contain iron
> 300m coast of South Africa diamonds are found
> 40 years ago = interst in manganese nodules in Pacific
Increase in prices of minerals (silver, gold) havere-ignited commerical interst in sea-floor mining
Sea-bed mining and minerals
Growth in the use of REE (Rare Earth Elements)
elements used in technology
Politcal = used in technology for military hardware
The use of REEs are likelty to influence decisions about permission to mine in EEZs (Exclusive Economic Zones)
Mining is concentrates around mid-oceanic ridges and hydrothermal vents
Lack of knowledge = difficult to access potential damage to ecosystems
Sea-bed mining and minerals
WHY is sea-bed mining advantageous
Oceanic minerals are found in higher concentrations than land-based minerals
EG: copper ore
Land = 4% metal content
Oceanic = 40% metal content
SO, less matieral needs to be mined to obtain the same quanity of mineral
Sea-bed mining and minerals
WHY is sea-bed mining a concern
> Little knowledge of locations for mineral extraction
> How to dispose of mining waste = tailings
Tailings = cloudy/turbid water
This sediment in the water can settle on sea floor --> can smother sea-bed ecosystems
As the demand for minerals increases = more pressure will be placed on sea-bed mining
Oceans as a 'global commons'
'Tragedy of the Commons', Garrett Hardin
Description = the interest of every (the common good) .vs. self-interest
'The tragedy of the commons - describes a situation in a shared-resource system where individual users acting independently according to their own self-interest behave contrary to the common good of all users by depleting or spoiling that resource through their collective action.'
'Global commons' - a resource that belongs to everyone (sea/atmosphere)
People exploit the resource without considering the impact.
Advantage to the individual is greater, becasue the cost is shared amongst many
Short term = individuals take all they can otherwise someone else will
Ocean management zones - UNCLOS
Four management zones created by UNCLOS
1. Territorial waters - country has complete control over all activities
2. Contiguous zone - country has sovereignity and legal rights
3. Exclusive Economic Zones (EEZs) - country has rights to sea-bed resources. All countries have right to sail and fly in this zone,
4. High seas - No country has soverignity or legal right. International agreements apply.
UNCLOS - United Nations Convention on Laws of the Sea = interntional agreement that defines zones
Coastal zones can be disputed by countries - boundaries are disputed as countries try to maximise their rights
Management by UNCLOS
Management issues of UNCLOS
Issues not management
> Ocean acidification
> Bio-prospecting - 'search for species which medicinal drugs and other commercially valuable compounds can be obtained'
> Fishing
> Lack of agreement in establishing marine reserves in high seas
> Absence in regulating under-water noise and its impact on marine life
Management by UNCLOS
UNCLOS established International Seabed Authority
International Seabed Authority - manage the exploitationod sed-bed resources
The International Seabed Authority are increasing in importance because of increasing tensions of sea-bed mineral mining
Hydrothermal vents had not been discovered whe UNCLOS was created - so they are not included.
International Whaling Commission (IWC)
International Whaling Commission - manage whale species
> 88 member countries
> 1986 - banned commerical whaling
> Limiting catchs for communities where it is vital to their culture and economy
> Food sources - regulating the Krill stocks to conserve whales
Link to krill case study
Krill are main producer in antarctic ecosystems - they are the start of the food chain
Marine reserves
Marine reserves are the marine version of national parks
3% of world's oceans are marine reserves
Marine reserves:
1. unique biological, geological, historical and cultural features
2. increasing the oceans resislience to impacts of climate change - water warming + acidification
2010 - International Convention on Biological Diversity = would establish 10% as Marine Protected Areas (MPAs) by 2020
Marine reserves in the UK
UK = 207 Marine Protected Areas
'No Take Zones' - Bristol Channel = no human disturbance can occur
Protect underwater reefs - Western Isles of Scotland
UK has 14 oversees territories (previous colonies)
Area = 6.8 million km2
The Chagos Marine Reserve
Chagos Archipelgo
'Archipelgo' - group of islands
> Indian Ocean
> 1 of 14 UK oversees territories
> 2010 - designated a compete 'No Take Zone'
> Marine reserve = 640,000km2
Features in chagos archipelgo = corals, seamount, ocean trenches, abyssal plains
Comparable marine biodiversity to the Great Barrier Reef, Australia
The Chagos Marine Reserve
All extractive activities are banned - fishing + ocean bed mining
Chagos reefs - damaged by the effects of global warming (coral bleaching events)
As the human impact is SMALL, the corals haver recovered STRONGLY
Some of the cleanest water in the world
Protection maintains biodiversity
Variety of pollutants
'Pollution' - when human activity adds a substance to the environment that affects organisms adversly
'Point source pollution' - release of pollutants from a signle identifiable location (leaking pipeline)
'Non-point source pollution' - pollutants are released from several areas
Original beliefs - the ocean would dilute the pollutants to make them harmless
Now - some pollutants are so toxic they seriously damage marine ecosystems and food chains
Run-off transports pollutants into oceans/ precipitation from the atmosphere
Not just chemical but also noise
Pollution - combustion of fossil fuels
Combusion releases several pollutants
Combustion of fossil fuels in SHIPPING
Long ocean routes --> large use of fossil fuels --> large total emission by shipping
this is significant at a global scale
> 90,000-100,000 cargo vessels
> Operate 24 hours on 280 days a year (average)
> Use lots of low grade oil = bunker fuel
Pollutants - combustion of fossil fuels
Large cargo vessels = 5000 tonnes sulphur a year
Sea transport = 9% annual sulphur dioxide emissions
15-30% annual nitrogen dioxide
Shipping = 3.5 - 4% of all greenhouse gas emissions from
Most release is in the northern hemisphere around busy shipping routes
Pollutant - combustion of fossil fuels
1. Growth in the use of shipping
2. Growth in the size and number of ships
Growth in number and size of cruise ships = serious localised issues of air pollution in cruise destinations
Increasing the concentration of fumes in coastal inlets
Pollution - combustion of fossil fuels
Reduce impact of air pollution from shipping
> Increase fuel effiency = saves cost and reduces emissions
> Using low sulphur fuel
> Reducing ship speeds = 'Slow steaming' (cuts speeds from 27 knots to <20 knots)
> Better ship design = improve fuel efficiency
> Greater use of wind power
Pollution - domestic and industrial sources
Chemicals dissolve into water systems - rivers --> into the sea
Chemicals in the atmosphere - transferred to oceans by percipitation
Coastal communities - use rivers or the sea to remove raw sewage and industrial waste
ACs - little untreated pollutants are discharged into the sea
EDCs - improvements are being made (but environmental progress not top priority)
LIDCs - no consideration for the environment or human health
Some of the pollutant put into water sources in LIDCs are highly toxic
> Heavy metals - mercury
> Organic waste - nitrates, pesticides
Pollution - domestic and industrial sources
Some of the pollutants can effect water sources - algae bloom
Algae bloom = eutrophication
Caused from chemicals in fertilisers (nitrates and phosphates)
Lead to a reduction in the oxygen content of the water
Prevents aerobically respiring organisms from surviving
Organisms die
Pollution - radioactive waste
Nuclear industry increases after Second World War
Production of nuclear waste - thoughout it would dispear throughout the large volume of water
1946-1993 = 13 countries disposed of radioactive waste in the oceans
> Reactor vessels - with nuclear fuel
> Tens of thousands of steel dums
> 8 nuclear submarines
1 of the 8 submarines is on the Arctic sea floor (issues due to high marine life) = nuclear reactor with uranium fuel remains on board in protective shield (overtime will corrode and will release high-level radioactive material
Pollution - radioactive waste
Fukushima nuclear power plant meltdown
Radioactive material released due to 2011 tsunami
Radiation accumulates in the food chain (bioaccumulation) (environmental impact)
> Strict ban on catching and consumption of fish in the area surrounding Fukushimna power plant (economic impact)
Air-borne radiation - can travel to other areas (coast of northwest USA) - generally little threat to Pacific. Serious impacts on a local scale not global
Case study: Deepwater Horzion Oil Spill
Background information
> April 2010
> 40 miles off Louisana coast
> 1500m water depth
> 11 died, 17 injuried
> 87 days oil spilled
> 4.9 million barrels spilled
> 180,000 km2 of the Gulf was affected
> 1,600 km shoreline was polluted
Case study: Deepwater Horzion Oil Spill
Impact on marine ecosystem and physical environment
> 1,600 km coastline polluted
> 180,000 km2 of the gulf was affected
Mainly short term impacts
> High mortality rate of organisms - birds, fish
Long term recovery
> Some species show NO long-lasting effects
>Oil does still wash up in some places
> Oil deposits on the sea bed - cover coral
> Salt marshed = oil accumulated in mud = oil not broken down in anaerobic conditions
Case study: Deepwater Horzion Oil Spill
Economic impacts - on human activities
> Gulf fishing industry is one of the most productive in the world
> Important for the regional economy and employment
Short term impact - fishing stopped --> loss of income for fishermen
>Tourism industry affected - less people wanted to come
> Media images of oil-covered beaches and wildlife
> Causing economic and social hardships
> Loss of tourism --> loss of income --> unemployment --> downward spiral of decline
Rate at which the ecosystem recovered was big. 5 years after the spillage Gulf fish and oyster industries can sell + beaches are open
Case study: Deepwater Horzion Oil Spill
Management of the spill and its impacts
Closing of the well: 'top kill' = heavy and dense muf and concrete poured into the well
Strategies to deal with escaped oil:
1. Skimming surface oil = booms towed by small boats collecting oil
2. Burning surface oil = oil collected by fire-proof boom then burnt
3. Dispersants = chemicals to prevent oil slicks. 1.84 million gallons. Evapouration and degradation
4. Artificial barrier islands = constructed off shore to prevent oil from getting to beaches (soon washed away from strong current in gulf)
5. Beach cleaning = oil that mixed with sand on beaches was taken and 'washed'. Sand was returned oil taken for processing
Case study: Deepwater Horzion Oil Spill
What happened to the oil that wasn't collected
> The crude oil produced in the disaster: light crude oil
Light crude oil - dissolves more readily in water than heavy crude oil
1. Some oil came to the surface (could be extracted)
2. Some oil was trapped in ocean layers at 1000m
3. Some sank to ocean floor
Gulf is not a clean ocean = 2,000,000 gallons leak naturally per day
Pollution spread by ocean currents
Marine debris = global ocean pollution problem
Marine debris = plastics, rubber, etc
Ways marine debris enters oceans:
> Rivers and beaches
> Dumping off the sides of ships
Impact of marine debris
> Marine organisms can become entangled in fishing nets
> Plastics do not biodegrade - but break down into smaller plastics (microplastics)
Microplastics = produced by photodegredation = action of sunlight
Plastics start as nurdles = found in every ocean system = issues of bioaccumulation
Case study: Great Pacific Garbage Patch
Great Pacific Garbage Patch = accumulate of plastic in North Pacific Ocean Gyre
Background information
'Ocean gyre' = circular currents formed by wind patterns and rotation of the earth
Once debris is at the centre of the gyre it will stay there
> The plastic is at the surface and several meters below
Areas where the concentration is made of large derbis
Much of the debris is actually microplastics
Case study: Great Pacific Garbage Patch
Causes of accumulation
The Great Pacific Garage Patch is not a continous mass of debris stretching across the Pacific = has two principle areas of accumulation
1. Western Pacific Garage Patch
2. Eastern Pacific Garbage Patch
The gyre causes the debris to stay in this system once it is here
It will not move out once it is in
Case study: Great Pacific Garbage Patch
Impact on the marine ecosystem
> Large pieces of plastics can become trapped aorund animals
> Smaller plastics can be ingested = lead to bioaccumulation (potential effect for humans)
> Chemicals can be contained in the plastics = poison animals that ingest them
Pacific not the only ocean that is polluted
Plastics are long-lived at do not break down.
Increased demand for plastics in industry
Acidification: impact of climate change
Background information
The ocean is a significant carbon sink
30% of anthropogenic carbon dioxide produced over 250 years has been absorbed by the oceans
Anthropogenic carbon dioxide = proportion of co2 in atmophere at is produced directly by humans
Without this uptake by oceans - most likely we would have already gone past tipping point = causing increase in temperatures and sea level rise
Increase in co2 = changes the oceans pH
Ocean acidification fallen from 8.2 --> 8.1
pH scale is logarithmic = so this is a 30% increase
Forecast for 2100 = ocean ph 7.2-7.1
Acidification: impact of climate change
Impact of acidification on marine ecosystems
Crustaceans = more acidic oceans = less able to accumulate calcium carbonate for there shells
More susceptiable to predation --> less likely to reach maturity --> secondary consumers lose there food source
Whole ecosystem at risk from breakdown in trophic levels (if the organisms at the base collapse - entire system at risk)
= 1. loss of biodiversity in oceans
Acidification: impact of climate change
Impact of acidification on marine ecosystems
Disturbe the balance and equilibrium of marine ecosystems
some predators may thrive in warmer + acidic conditions (jellyfish)
increase predation in oceans
smaller species will die out
Acidification: impact of climate change
Impact on people of depleting fish stocks due to acidification
1. Change in marine ecosystems = change marine harvests (provisioning ecosystem service)
2. Early life stages of fish are vulnerable to acidic sea water (200 million tonnes of seafood annually produced from aquaculture - like fishfarms)
This issue of less fish harvest is significant for EDCs and LIDCs (The Gambia)
> In these countries, fish makes up 50% of their protein in diet
> ACs gain provisioning services from marine harvests
> By 2050 - increased population and acidification = stress on fishing in tropics
Warming oceans threat to coral reefs
Impact of acidification on marine ecosystems
Coral support other marine organisms - algea
Corals require specific environmental conditions
> Temperature: 26'c
> Salinity: 30,000-32,000 ppm
> Water depth: 25m depth of less
> Light: light needed for photosynthesis
> Clear water
> Wave action: some wave action to be well oxygenated
Warming oceans threat to coral reefs
Impact of acidification on marine ecosystems
Temperature is significant due to the symbiosis of the algae and the coral
1. Algae releases nutrients for the coral to feed on
2. Coral provides algae with shelter
If temperature exceeds desired. The algae is released. Coral bleeching occurs
Coral bleaching since 1980s = grown in frequency, intensity and geographical extent
In eastern pacific = 80% of coral is bleached
The Great Barrier Reef: coral bleaching
Impact of acidification on marine ecosystems
> High biodiversity = 25% of all marine life live on coral reefs (1500 fish species, 350 corals, 6/7 turtle species in the world)
> Efficient recycling of energy = nuritents used by reef organisms
Coral maintain an ecosystem because they are a food source to mainly primary consumers which sustain secondary consumers
The Great Barrier Reef: coral bleaching
Threats to the biodiversity of coral reefs from CLIMATE CHANGE
1. Increased sea water temperatures = coral bleaching
2. Sea level rise = increasing water depth = reducing light levels
3. Increases wave energy = physically damage corals
4. Ocean acidification = reduce ability to build calcium carbonate structures
Reduces the corals ability to survive --> reducing niches
The Great Barrier Reef: coral bleaching
Threats to local communities (from distruption of coral ecosystems)
Direct and indirect impacts
1. Reduced provisioning, regulating, cultural and supporting ecosystem services
2. Act as a barrier for high energy waves - loss of beaches will be greater
Global economic value of coral shoreline protection = US$10 billion annually
3. Act as nursery for fish species - fishing can occur (useful in EDCs and LIDCs due to malnurishment)
Important because small communities will be vulnerable to small changes --> little resilience due to lack of resources
4. Fishing - employment and income (multipler effect)
5. Recreational activities - tourism
Recent sea level change
In past 2 million years --> sea level risen 120m
Changes in sea level =
1. Eustatic changes = changes in the volume of ocean (global scale) - melting ice caps
2. Isostatic changes = changes in the height of the land (localised) - earthquakes
Sea level rise = studied by the Intergovernmental Panel on Climate Change (IPCC)
Have decided that over recent years - a eustatic rise in sea level is occuring at an accelerated rate
Average rise of 3 mm per year
Recent sea level change
Causes of sea level rise
1. Thermal expansion of water:
global warming --> increasing temps --> sea water density decreases --> increase in water volume in ocean basin
2. Melting of glaciers and ice caps:
global warming --> increasing temps --> ice caps melt --> meltwater increases --> sea level rises
3. Melting of Greenland and Antarctia ice sheets:
global warming --> increasing temps --> ice sheets melt --> meltwater increases --> sea level rises
Case study: The Maldives
Background information
> Group of small coral atolls
> in Indian Ocean
> Low-lying islands
> Popular tourist destination
Case study: The Maldives
Threats to island communities
> Highest point 2.4m above sea level = will be affected
> total population of 400,000 = large population for the density of island (total land area 300km2)
> Strong population growth (issues of resources)
> Lots of emigrants - reducing avalibility of jobs
> Little fresh water = 0.01 cubic km/year out of 0.03 cubic km/year avalible
> 30% of economy is based on tourism = tourism falls with sea level rise = rising unemployment +worsen by emigration
> Unemployment rate = 28%
> Long term threats from acidification - loss of coral, biodiveristy, fish stocks
> Sea water will containminate crops
Case study: The Maldives
Impact on island communities
Short term impacts:
Social: little income, loss of housing, little opportunities, loss of culture
Economic: high unemploymen, little opportunities, loss of tourism
Long term impacts:
Social: loss of food, loss of land, loss of communities
Economic: loss of industry, loss of land, economic decline, continued loss of tourism
Case study: The Maldives
Adaptations of governments and communities (short and long term)
Short term
Goverment: 50 more tourist resorts to be opened by 2018
Communities: maintain the attraction of tourism (economically critical)
Long term
Government: purchase land elsewhere so the population could relocate + geoengineering projects
Communities: fight to maintain way or life, culture, employment
Climate change effects oceans
Climate change has the most impact on high latitude oceans - Arctic and Southern Oceans (Antarctia)
Sea water freezes at -2'c not 0 due to its salt content
> At high latitudes, annual heat budget = net deficit (more heat leaves than is input) = due to angle that the sun's hit the earth
Lower angles --> energy is less intense --> spread over a greater surface
> Ice has a higher albedo = so it reflect back
Global warming and sea ice
IPCC mainly concerned about Arctic
Concers due to: area and thickness
> Monitoring by satellites all year around
Positive feedback cycle:
1. Low area of Arctic sea ice --> higher albedo --> Arctic temperatures increase --> sea ice melts + less sea water freezes
1978-1996 = 2.9% of sea ice decreased per decade
April is begining of sumer = April 2015 lowest observations of sea ice recorded since observation began
Ice cover of 4 million km2 compared to original of 15 million km2 average (1981-2010)
Global warming and sea ice
Thickness
> Navies deploy submarines beneath ice in Arctic ocean - use satellites to find each other
1960s - Arctic sea ice 4m thick at centre
2018 - Arctic sea ice 1.25m thick at centre
Point of threshold - major decline of area of sea ice and the ice thinning threshold will be crossed
Arctic ice dramatically reduced --> solar radiation not reflected by absorbed --> warming Arctic Ocean = positive feedback cycle created
Observed current Arctic sea ice in extent and thickness = greater than predicted by models.
Case study: Arctic Sea Ice
Impact of indigenous people
> 4 million people on coasts of Arctic Ocean
> Indigenous communities fish in Arctic Ocean - Inuit
Social impact - sustainable harvests affected by sea ice + weather patterns
Environmental impact - marine ecosystem decline =
Social impact - hunting becomes less reliable
Social impact - decline of indigneous communities
Social impact - reducing in food diversity and avalibility
Case study: Arctic Sea Ice
Geo-political implications of sea ice changes
> Geographical positioning of the Arctic - USA and Russia confront over a short distance (superpowers)
> Interest of Canada and Europe in the Arctic
Conflict between powers over claims over areas of the Arctic ocean
Claims: Russia, Canada and Denmark
A country can claim sea bed up to 280km beyond its EEZ - rights to natural resources.
A country must prove that the sea bed is an extension of its continential shelf
Russia - claimed underwater mountain chain (Lomonsov Ridge) will be determined by UNCLOS
Militarisation of the Arctic is accerlating - all nations bordering have military infastructure
Case study: Arctic Sea Ice
Impact of minerals in Arctic
> Incentive for countries is the mineral wealth held in the Arctic
90 billion barrels of oil
47 billion m3 of gas
Can only be accesses due to advances in technology
TNCs becoming interested in recovering the resources
Case study: Arctic Sea Ice
Impact of Transport Routes in the Arctic
Threats
> Increased fuel consumption - more pollution
Opportunities
> Minerals that are exploited can be transported
2014 - first cargo ship was escolated through by an ice breaker
Northern Sea Route across Siberia is growing
> Shipping companies could reduce transportation costs
Case study: Arctic Sea Ice
Managing the Arctic Ocean
> Arctic doesn't have treaties protecting it - so mineral and energy extraction can happen
Arctic Council, 1996 - governs the Arctic
Members of the Arctic Council - Canada, USA, Russia, Norway, Denmark, Sweden, Finland, Iceland. Indigenous people are represented
Globalisation in shipping
Process of globalisation
> Movement of people short distances - ferries between UK and France
Freight dominates maritime transport
Globalisation = longer and bigger connections led to increasing interdependence between places and people
Total world trade has trebled = 45% of global GDP since 1950s
Oceans have lead to space-time compression = world is considered small as connections grow
> Technology has increased connectivity
> Development of ocean transport - increased speed and reliability of delivery
Globalisation in shipping
Patterns of global shipping
East-west corridor =
>Links North America, Europe and Asia
> Through Suez Canal, Strait of Malacca and the Panama Canal
Factors influencing global shipping
> Physical geography - shape of coastline, winds, currents, water depth, sea ice
> (East-west routes) long detour around Cape Horn and Cape of Good Hope
Globalisation in shipping
Suez and Panama Canal
Suez canal, 1869 Panama Canal, 1914
> Most significant maritime shortcuts
Suez canal - Red Sea to Mediterranean, 14 hours to sail, saves 8,900km, saves 10 days
Panama canal - Atlantic to Pacific, 17 hours to sail, saves 13,000km, saves 20 days
Both canals are being updated to accomodate more ships.
Physical geography of ports important: water depth, tidal range, sheltered.
Globalisation in shipping
Direction and types of trade
Connection of producers to consumers
Type of trade is dependent on the market size for individual products
Indicators of market size
> Total population - more people purchasing products
> Income levels - affects ability to purchase products
> Types of good traded - influence volume and direction of trade
Globalisation in shipping
Marine technology: transport
Containerisation - allows globalisation to occur.
> Reduces the cost of transportation
> Reduces 'loose cargo' handling - reducing cost
Adds to the 'economies of scale' - lots of containers can be moved by one ship = reducing time to transport goods
> Loading and unloading is highly mechanised - own unique code = reducing time to transport
Largest container = 440,000 tonnes oil, 400,000 tonnes iron ore
1960s - 130m containerships
2014 - 400m containerships
Globalisation in shipping
Importers and exporters
Largest exporter countries
1st: EU - 38% of world trade
2nd: China - 17% of world trade
3rd: USA - 10% of world trade
Largest importer countries
1st: EU - 33% of world trade
2nd: USA - 14% of world trade
3rd: China - 9% of world trade
Globalisation in shipping
Marine technology: transport
Cruise ships
Largest = 225,000 tonnes, 360m, 6000 passengers
Transport people to different places = example of space-time compression
Globalisation in shipping
Example of containerisation
Port of Singapore
20% of the world's containers handled
130,000 ships docked
33 million containers handled - evidence of the economies of scale
A conclusion could be:
Much of globalisation is as a result of the internet - however, the revolution of transport is the driver of globalisation, as a result of space-time compression leading to the globa economy.
Political influence of oceans
Use of oceans by countries
> 1950s - telephone cables labelled
> More recently - fibre optic cables (allow internet access - secondary factor to globalisation)
> Submarine cables
Oceans are used to exert naval power
> Rival countries have argued about the right of ships to sail freely across the oceans
> Marine boundaries can be disputed - established by international law of EEZs
(There will be increasing tension in the Arctic as the regions warms and becomes more accessible)
Political influence of oceans
China's growing naval power
> Significant investment into their navies
> Economically strengthing - growing GDP
> Economic strengh is increasing technological capabilities
> Technology advances - navy can expand and modernise at a rapid rate
'Blue water navy - establishing naval bases in other countries so China's navy can operate in other areas'
Blue water naval bases in: Dijbouti, Sri Lanka, Pakistan
4 home naval ports: Dinghai, Sanya
Political influence of oceans
China's growing naval power
Blue water navy in the Indian Ocean for China is a concern for India
China has a naval base in Pakistan
Pakistan and India have bad relations
However: the level of infastructure of these naval bases in not developed enough to support substanial Chinese miltary power
Political influence of oceans
Marine conflict: South China Sea
Background information
> Conflict over 2 island chains - Paracels and Spratlys + Scarborough Shoal
> Countries conflicting: China, Vietnam, the Philippines, Taiwan, Malaysia and Brunei
China - claims because of the 'nine-dash line'
Taiwan and Beijing - old claims to the region
Vietnam - claims over sovereignity. Use to the rule the two islands.
Philippines - geographically the closest to the island chains
Malaysia + Brunei - in their Economic Exclusive Zone (have small islands near Spratlys)
Political influence of oceans
Recent conflicts in the South China Sea
> 1974, 1988 - armed conflict between China and Vietnam
> 2012 - China and Philippines accuse each other of invasion in Scarborough Shoal
> 2012 - China creates Sansha city in Paracels (Vietnam + Philippines protest)
> 2013 - Philippine challenges China's building of Sansha city under UNCLOS
> 2014 - China set up drill rig near Paracels (collisions between Chinese and Vietnamese vessels)
> 2015 - US satelitte show China building infastructure on Spratlys.
US has significant interest - US$1.2 trillion to US economy. Allies with Tiawan
Piracy
'Piracy - the act of boarding any vessel with intent to commit theft or any other crime, and with an intent or capacity to use force in furtherance of that act'
Rise in transcontinential shipping (globalisation) --> increase in piracy
The geography of trading routes shows where piracy occurs most
> Western Indian Ocean
> Southeast Asia
> Gulf of Quinea
Indian Ocean - Gulf of Aden and Red sea leading to the Suez canak
Southeast Asia - the Malacca and Singapore straits
Piracy
Piracy - attacks in Indian Ocean
> Large vessls - containerships
Seasonal pattern to piracy
Moonsoon season and summer months = little piracy = winds are strong = can't control small boats from which pirates opperate
International action after increase in attacks
Maritime coalition: EU, NATO, USA and other countries (Russia, India, China, Japan, SKorea)
These members patrol the most vulnerable areas = and attacks have decreased
Piracy
Gulf of Guinea
Miltary defence has increased in the Gulf of Guinea
Petro-piracy has increased
Issues causing piracy
> Poverty
> Disfunctional government
> Unemployment + lack of opportunities
> Connects to organised crime networks - money laundering
> Loss of traditional fisheries - lost to industrial scale fishing
Oceans as escape routes
Routes for refugees
Reason for migration - positives outway the negatives for the benefits at the destination.
Economic migrants - trying to achieve a higher standard of living
Asylum seeker - escaping political or relgious persecution that present safety issues
Sea-borne refugees come from landlocked countries
UN Refugee Convention
'Refugee - a person that has a well founded fear of being persecuted for reasons of race, religion, nationality, membership to a social group or political opinion, is outside of the country of their nationality
Also related to a person that is escaping natural disaster
Oceans as escape routes
Refugees in the Mediterranean and Asia
Migrants acrossing the Mediterranean from Africa to Europe - wealthy western European countries
Strong historical links between countries = increased migration
What are the motivations for movement
> Continued political instability
> Lack of raising living standards - allowing traffickers to exploit people
Oceans as escape routes
Refugees in the Mediterranean and Asia
> Move from sub-saharan Africa and Middle East
> Increase in armed conflict - Syrian's fleeing civial war
> By the time they reach the Mediterranean they have already crossed the Sahara desert
Traffickers take advantage of desperate refugees
Often, lots of migrants die because of the poor conditios of the boats used
Oceans as escape routes
Response to people trafficking
> International response (global governance)
1. United Nations High Commissioner for Refugees (UNHCR)
2. EU
Aim: to manage the flow of forced migrants
> Patrols in the Mediterranean - rescue refugees and resettle them
> Managing refugee camps (The Jungle) - stop this becoming a permanent home for displaced people
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