ocean pollution Flashcards
1
Q
key facts about ocean plastic
A
- in 1950, global plastic production amounted to 2 million tonnes; by 2015 this had risen to 381 million tonnes, including 141 million for packaging and 42 million in textiles
- between 4-8% of the world’s oil is used in plastic production
- China produces the most plastic waste, at nearly 60 million tonnes per year, the USA produces 38 million and Brazil 12 million
- by comparison it is 5 million in the UK and fewer than 1 million in developing nations
- most plastic produced is single use and does not decompose easily
- microplastics are fragments of plastic debris less than 5mm in diameter
2
Q
causes of ocean plastics
A
- illegal dumping of waste
- shipping accidents
- commercial fishing (the equipment, nets)
- microbeads (especially from cosmetic products)
- inadequate waste disposal
- sewage/drainage runoff
- carried by rivers
- rainwater and wind carries plastic waste into streams and rivers, and through drains from landfill
3
Q
plastic buoyancy
A
- plastics such as polypropylene found in bottle caps float and can be seen
- other plastic are heavier than the seawater density and sink, e.g. polyesthers resin found in textiles
4
Q
ocean currents and plastics
A
- the world’s oceans are a dynamic system and have thermohaline circulation
- thermohaline circulation and wind create cells
- eliminating ocean plastics has to be a global effort as cells are global
- e.g. if the ice caps melt, they release fresh water into the ocean, disrupting the fresh water/saltwater balance
- the geographic distribution of marine plastic debris is strongly influenced by its entry points and the different ocean pathways, which in turn are determined by the density of plastic debris coupled with prevailing currents, wind and waves
5
Q
gyres
A
- gyres are large scale circular (rotating) currents in the major oceans
- they are a product of wind patterns and the Coriolis force (a function of earth’s rotation) and ocean currents
- 8 garbage patches found in all 5 gyres
6
Q
north pacific garbage patch
A
- split in to eastern and western areas
- slowly rotating because of gyres
- each one in the size of Texas
- 1 million pieces of floating plastic per sq mile
7
Q
impacts of ocean plastics
A
- sea creatures become tangled in discarded plastic
- in Australia 5000-15000 sea turtles each year get entangled in discarded fishing nets
- sea birds and fish ingest plastic, which can block the gut or perforate the intestine
- it is estimated that 90% of seabirds have ingested plastic
- microplastics can be passed up the food chain, it is suggested that people who eat shellfish can eat 6400 microplastics per year with unknown impacts on human health
- large quantities of plastics can reduce the amount of sunlight able to reach phytoplankton, restricting their growth and impacting the marine food web
8
Q
despoiling wilderness
A
- plastic waste enters the oceans because of terrestrial run-off carrying waste from urban streets and landfill sites
- referred to as a ‘tragedy of the commons’
- this plastic waste makes landfall along the shorelines of many wilderness regions, far from civilization:
Pacific Hawaiian islands
Pacific islands e.g. Henderson Island - 38million tonnes of plastic
Arctic circle islands e.g. Muffin Island
Alaskan beaches
9
Q
plastic pollution management
A
- government legislation
- business led initiatives
- awareness campaigns
10
Q
business led initiatives
A
- several businesses are considering their use of plastics and are becoming more aware of environmentally conscious consumers
- e.g. burger king are phasing out the plastic toys from the children’s meals in an effort to reduce waste and they estimate this will save 320 tonnes of waste annually
- experts believe that UK supermarkets are producing 810,000 tonnes of single-use plastic every year
- this is in addition to over 1.1 billion single-use bags, 958 million ‘bags for life’ and 1.2 billion plastic bags for fruit and vegetables, which supermarkets produce annually
- in April 2018, many of the UK’s major supermarket chains signed up to the UK Plastics Pact, which aims to tackle plastic waste
- German supermarket chain Aldi has pledged to make all of its own-label packaging recyclable, reusable or compostable by 2022 (they did not make this target)
- Iceland has pledged to eliminate plastic packaging from its own label range by 2023 (have not met it yet, but are very close - more successful than Aldi)
- business led initiatives are very popular because they get headlines, which equals more profit, they can also encourage other business to do it as well because they also want the profit
- however, businesses do not always follow through
11
Q
government regulation
A
- plastic packaging tax:
- at budget 2018, the government announced that from April 2022 it would introduce a world-leading new tax on the production and import of plastic packaging with less than 30% recycled content
- plastic packaging accounts for 44% of plastic used in the UK
- the vast majority of this is made from new, rather than recycled plastic
- recycled plastic is often more expensive than using new plastic, despite its lower environmental impacts
- the government wants to shift the economic incentives involved in the production of more sustainable plastic packaging, encouraging greater use of recycled plastic and helping to reduce plastic waste
- governments exert soft power when doing this, and for some countries this is very attractive
12
Q
awareness campaigns
A
- world oceans day – 8th June
- organisations such as Surfers Against Sewage organise beach clean ups and aim to raise awareness of the plastic pollution problem.
- their #returntooffender campaign encourages people to post plastic packaging they find washed up on beaches back to the company (for example Coca-Cola) who made it explaining where they found it
- ‘Plastiki’ is a boat built using 12,500 plastic bottles and sailed through the North Pacific garbage patch to raise awareness of the pollution problem
13
Q
pollution from burning fossil fuels at sea
A
- ocean routes account for a great tonnage of goods and distances can be long, total emissions by shipping are significant at a global scale
- 90,000 - 100,000 ocean going cargo vessels plying the world’s oceans - those engines consume huge amounts of low grade oil (bunker fuel), which is high in sulphur and other pollutants
- largest vessels emit 5,000 tonnes of sulphur per year
- sea transport is responsible for 9% of annual NO2 emissions
- most of the air pollution from ships is released in the northern hemisphere, where the busiest international shipping routes (chokepoints)
- localised air pollution for cruise ships in popular destinations, e.g. Caribbean, is a big problem
- the concentration of very large vessels into restricted coastal inlets (e.g. Alaskan fjords) - heavy concentration of diesel fumes and the formation of haze
- slow streaming: cutting speeds from 27 knots to less than 20 (significant savings in fuel = reduced emissions)
14
Q
long beach, LA
A
- major US port
- 10th globally for the amount of tonnage handled (78 million)
- 30,000 jobs linked directly with the port
- major transport node on the pacific rim
- air pollution is 2-3x higher in the immediate vicinity of the port than further away
15
Q
pollution from domestic and industrial sources
A
- rivers discharge dissolved chemicals/solids into the sea
- pollutants in the atmosphere can be washed out by precipitation
- sea is a convenient place to dump waste, e.g. radioactive water from nuclear plants (e.g. Sellafield into the Irish sea)
- today, few developed countries routinely discharge raw sewage and industrial effluent into seas and rivers
- progress is beginning to made in EDCs but the environment isn’t a top priority for them at the moment
- LIDCs: the pollutants are many and some extremely toxic; suspended solids, organic waste, heavy metals (e.g. mercury), nitrates, phosphates (e.g. from dissolved detergents) and pesticides/fungicides/growth hormones from agriculture pollute waterways, lakes and inshore waters
