The Plastic Ocean Flashcards
Why are oceans important
Regulate the earth’s system- transferring heat around the world, driving climate and weather systems, plays a key role in the global Carbon system
Supply living and non-living resources- from fisheries to marine biotechnology, minerals to renewable energies
Provide social and economic goods and services- tourism and recreation, marine transport and security, coastal protection
Plastic consumption
300 million tons of plastic produced in 2015
Plastic comprise 50-80% of litter in the ocean
Found everywhere- arctic, Antarctic, souther ocean, deep ocean, surface to sediment
What are plastics
Polymers- extremely long repetitive models
Primarily made of carbon
Thermoplastics
Can be re-melted and essentially turned to their original state
Usually produced first in a separate process to create small pellets which are then heated and formed to make consumer and industrial products
E.g. Polyethylene, polypropylene, nylon, ployviynl chloride, polystyrene, polycarbonate etc
Thermoset
usually produced and formed into products at the same time
Cannot be returned to their original state
E.g. Vulcanised synthetic rubber, acrylics, silicone, polyurethanes, melamine, epoxies etc
(thermosetting plastics- links between polymer changes stops movement between them)
There are thousands of different plastics, each with its own composition and characteristics!
Where does plastic in the ocean come from?
80% from land-based sources illegal dumping and inadequate waste management Industrial activity Costal littering Discharge of storm water Combined sewer overflows Natural disasters 20% from ocean-based sources Fishing Shipping Offshore oil and gas platforms, undersea explorations
How much is out there?
Plastic pollution found on the ocean surface is dominated by particles smaller than 1cm in diameter
4.8 million to 12.7 million tonnes every year- very roughly equivalent to 500 billion plastic drinks bottles
5 trillion and 51 trillion pieces of microplastic floating in the oceans, with a total weight of 93,000 to 236,000 tonnes
Missing microplastic may derive from nano-fragmentation process, rendering the very small pieces undetectable to conventional sampling nets, and/ore transferred to the ocean interior
micro plastics make up most of the plastic in the ocean
Where is it
Digestive tracts of 49/64 anchovies (77%)
microplastics not only affect animal’s physiological but also its natural behaviours such as feeding choices, activity rates, reproduction, predator avoidance strategies etc
polystyrene- one of the 5 major types of micro-plastic debris found in the marine environment- and ingestion of polystyrene particles has been found to alter behaviours and distrust the fat metabolism
How is plastic affecting food web dynamics
Marine- seasoned micro plastics produce dimethyl sulfide (DMS) signature that is also a keystone odorant for natural trophies interactions
DMS serve as info-chemicals for microfauna to macrofauna
In pelagic ecosystems, DMS is produced by the enzymatic breakdown of DMSP in marine phytoplankton which increases during zooplankton grazing
DMS serves as foraging cue for many pelagic marine organisms, including highly olfactory procellariifrom seabirds
Procellariiform seabirds include- albatross, petrels & shearwaters; members of this order are highly olfactory, pelagic and wide-ranging, foraging over vast expanses of open ocean
Plastic ingestion many be linked to olfactory foraging across taxonomic groups
Birds think they’ll full due to plastic in their gut- don’t eat so die
Microplastics and biomagnicaton
Micro plastics can concentrate organic pollutants such as PCBs and DDT
These concentrated pollutants move up the food chain, in a process known as biomagnication
These chemicals include persistent, bioaccumulative and toxic substances (PBTs), dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs) and persistent organic pollutants (POPs)
Harmful to human health and the environment
Plastic resin pellets act as a sink for toxic chemicals in the ocean
Biofouling
The accumulation of microorganisms, plants and algae on wetted surfaces, leading to the introduction of invasive species
Breaking down of into secondary microplastics or even nanoplastic particles
Little reliable info about the degradation mechanism of highly weathers plastics in the environment
Adrift
Modelling tool used to analyse the pathways plastics take when released from UK shorelines
Most of the floating plastic that doesn’t beach ends up in the arctic
Boyan Slat
designed a passive system for concentrating and catching plastic debris drives by ocean currents
Non-profit group that by 2020 hopes to deploy a 100 km long floating barrier in the Great Pacific garbage patch
Aim to remove half the surface plastic
2013 founded- 2014 feasibility and crowd-funded- 2016 North Sea prototype- 2017 deploy pilot study- 2020 start Pacific cleaner up
What shall we do
clean up equipment near the coasts of China and Indonesia where much of the plastics pollution originates
Need to control the rubbish where it originated
US and UK ban microplastics from 2017
UK- ban microbeads by 2017
Ban in US for personal care products containing microbead july 2017, cosmetics by 2018
Global efforts
1972 London Convention- UN agreement to tackle ocean dumping
International Convention for the Prevention of Polution from ships MARPOL
Banned the dumping of most garbage and all plastic materials from ships at sea
A total of 122 counties have ratifies the treaty
MARPOL has helped to reduce the marine debris problem
the first country to ban plastic bags was Bangladesh (2002) - following a typhoon, it was discovered that millions of bags were clogging the countries system of flood drains, contributing to the descruticion
