A huge whale with a plastic bucket stuck in its mouth, new-born dolphin calves being exposed to pollutants through their mother’s contaminated milk, and seabirds unsuspectingly feeding their chicks piece of plastic - these scenes from the BBC Blue Planet II documentary series were heart-breaking, and just a snapshot of the problems plastic pollution is causing in the oceans.
Effects of Plastic on Marine Life
Fish, marine mammals and seabirds are being injured and killed by plastic pollution, and its it believed that 700 species could go extinct because of it. Current estimates suggest that at least 267 species worldwide have been affected, including 84% of sea turtle species, 44% of all seabird species and 43% of all marine mammal species – but there are probably many more. Deaths are chiefly caused by ingestion of plastics, starvation, suffocation, infection, drowning and entanglement.
Its estimated that one in three marine mammals have been found caught up in some type of marine litter - lost fishing gear, nets and plastic bags for example - and that over 90% of seabirds have pieces of plastic in their stomachs. Seabirds who feed from the surface of the ocean are especially likely to ingest plastics that floats, and then feed this to their chicks. One study found that 98% of chicks sampled contained plastics, and that the quantity of plastic being ingested was increasing over time.
And even the deepest sea creatures can’t escape plastic pollution; samples taken by scientists at the Scottish Association for Marine Science off the Western Isles found that 48% of creatures had plastic in them, at a depth of 2,000 m. It was mostly polyethylene and polyesters from shopping bags and clothing - which makes it was into water via washing machine waste water - as well as microplastics, small pieces of plastic that have degraded from larger pieces and the small plastic beads found in cleaning products.
Problem of Plastic Pollution
Plastic has been slowly accumulating in the marine environment since the 1960s, to the point that we now have huge masses of plastic floating in the oceans and other waste plastics washing up on the once beautifully clean beaches around the world. Its estimated that there are 1 million pieces of plastic of varying size per square mile, with a further 8 million tonnes of plastic entering the oceans per year.
Much of it is single-use plastics so food packaging and bottles, carrier bags and other such products. Approximately 500 billion plastic bags are used worldwide per year – that’s over 1 million a minute, but this is perhaps unsurprising when the average working life of a carrier bag is considered 15 minutes!
However, its not just large pieces of plastic that are causing havoc with the marine environment. Household and cosmetic products are laced with microplastics designed to scrub and clean, and which are too small to be caught by water filtration systems. The microplastics enter water every time someone brushes their teeth or scrubs their face with products containing them.
These microplastics, along with nurdles - lentil sized pieces of plastic which are a by-product of various manufacturing products that end up in the oceans as a result of mis-handling or accidental spills - can be ingested by ocean wildlife and accumulate up the food chain, even reaching humans. It is also hypothesised that these smaller pieces of plastic can attract toxic chemicals released by industry and agriculture decades ago, the concentration of which also increases up the food chain.
Plastic is cheap and versatile, making it ideal for many applications, but many of its useful qualities have led to it becoming an environmental problem. The human population has developed a disposable lifestyle: it is estimated that 50% of plastics are used once before being thrown away. Plastic is a valuable resource but polluting the planet with it is unnecessary and unsustainable.
We need our planet – ocean and land included - to survive. As David Attenborough said:
There is no away – because plastic is so permanent and so indestructible, when you cast it into the ocean it doesn’t go away.
References and Further Reading