“I remember being told plastic doesn’t decay, it’s wonderful.” – Sir David Attenborough, FFI vice-president

Plastic has helped humanity progress in ways unimaginable only a century ago. It has revolutionised healthcare, made homes more energy efficient, and reduced pressure on the extraction of natural resources, such as wood and cotton, by creating plastic alternatives. Its durability means we should be wasting less, not more; plastic takes hundreds – potentially thousands – of years to degrade. And herein lies the best, and the worst, property of plastic: it lasts forever.

Plastic is devastating to nature. Natural ecosystems operate on a cycle of renewal: plants and animals grow, die, and become food for the next generation. These ecosystems have no place for substances that do not degrade. Our wonder material has now escaped the urban environment and is reaching every corner of the natural world, from the deepest point of the Mariana trench to the top of Mount Everest.

 

What impact is plastic having on the ocean?

The ocean is perhaps the most vulnerable environment to plastic waste. Once plastic enters the sea, it has no boundaries – waves and storms can carry plastics to even the furthest reaches of the ocean, where they accumulate into large gyres on the high seas or become embedded in shorelines and delicate coastal ecosystems; they’ve even been found on uninhabited islands. After some months or years at sea, plastic breaks down into smaller and smaller pieces, battered by waves and storms, eventually to sizes smaller than a grain of sand. This makes retrieving plastics from the ocean extremely difficult – almost impossible.

 

100,000

marine mammals estimated to be killed by plastic every year

12,700,000

tonnes of plastic reaches the ocean every year

How does plastic affect marine species?

It is estimated that marine plastics are contributing to the death of more than 100,000 marine mammals every year. Plastic can affect marine species in a variety of ways, from entanglement and injury to ingestion and toxic contamination. The major determining factor is the size of the plastic, which can adversely affect different species in different ways – and on different timescales.

Macroplastics

Size: Plastics larger than 20mm
Examples: Fishing gear, six-pack rings, plastic bottles
Threats: Large items of plastic can capture and entangle marine mammals and fish and stop them from escaping, usually leading to starvation, injury and predator vulnerability. Discarded fishing nets can also smother and break coral reefs, preventing healthy growth.

Mesoplastics


Size:
Plastics between 5-10mm
Examples: Plastic pellets, fragments of broken-up larger plastics
Threats: Small but visible plastic fragments can sit on the surface of the water and be mistaken for food by seabirds and other marine species, leading to issues including suffocation, starvation and toxic contamination over time.

Microplastics and Nanoplastics

Size: Plastics smaller than 5mm, small microscopic particles
Examples: Granules in face scrubs and toothpaste, microfibres from textiles, disintegration from larger plastics
Threats: Microplastics are invisible to the naked eye, making them easy for wildlife to consume. They also have the ability to adsorb toxins, which can transfer to the fatty tissues of the organisms that ingest them. Because microplastics are a reasonably new discovery, their long-term impacts are yet to be determined.

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What species are most affected by marine plastic pollution?

Whales and other marine megafauna

Credit: Adobe

Large marine mammals are highly vulnerable to plastic entanglement, particularly from ghost fishing gear. Fishing ropes, nets and pots that have been discarded or abandoned at sea are often made from plastic, and can trap and entangle a variety of marine life, from blue whales to small crabs. An estimated 300,000 whales, dolphins and porpoises a year die from ghost gear entanglement. Marine megafauna are also vulnerable to plastic ingestion; in 2019, one whale was found washed up with 40kg of plastic in its stomach, predominantly comprising plastic bags.

Sea turtles

turtle plastic fishing net

Credit: Umeed Mistry/Ocean Image Bank

Turtles often mistake plastic for food. Plastic bags look similar to jellyfish, the staple diet of leatherback turtles, and fishing nets can look like delicious seaweed. When turtles eat plastic bags, it can make them feel full, eventually leading to starvation. A recent study found that all seven species of sea turtle from the Atlantic and Pacific Oceans and the Mediterranean Sea had traces of microplastics in their gut. Sea turtles also fall victim to entanglement from six-pack rings, which can get caught around their shells and necks.

Seabirds

seabirds plastics

Credit: Harry Collins/Adobe Stock

For millennia, seabirds have fed from the surface of the ocean, swooping down and scooping up small fish and algae. It’s no surprise, then, that seabirds are now mistaking small plastic fragments that sit on the water’s surface for food. When ingested, these small pieces of plastic can lead to starvation or suffocation. Some seabirds are able to regurgitate pieces of plastic, but petrels, for example, find this difficult. Northern fulmars are known to ingest plastic pellets and consequently the species is now monitored as an indicator of pellet pollution levels in the North Sea. Many species of seabird have also been found feeding plastic pieces to their young. Plastic debris is said to cause the deaths of more than a million seabirds each year.

Fish and molluscs

Credit: Vincent Kneefe/Ocean Image Bank

Hundreds of fish species, including many that humans consume, have been found with traces of microplastics in their bodies. In a study summarising over 100 research papers on fish and plastic ingestion among 500 fish species, over two-thirds had consumed plastic. Fish often mistake small plastic pieces, such as pellets, for food.

When molluscs such as mussels and oysters filter seawater to feed, they also take in human-created pollutants, including microplastics. In a recent study of mussels sourced from UK waters, 100% of samples were found to contain microplastic pieces.

Apex predators

Credit: Andy Casagrande/Ocean Image Bank

Apex predators are species that sit at the top of the food chain. A large, yet understudied, threat to marine apex predators such as great white sharks and orcas is the cumulative impact of microplastics in the food chain and the bioaccumulation of toxic chemicals found in plastics. A recent study has shown that a single plastic particle can adsorb up to one million times more toxic chemicals than the water around it.

Biomagnification occurs when chemicals build up in the fatty tissues of animals that have eaten other contaminated species. The higher up the food chain you go, the greater the concentration of toxins. Orcas have been found with some of the highest deposits of chemicals in their fatty tissues and in their breast milk, which is fed to their young. Academics around the world are working hard to understand the link between microplastic pollution and biomagnification of toxic chemicals.

How can we reduce plastic pollution in the ocean?

Stopping the problem at the source

FFI believes that the most effective way to stem the tide of marine plastic pollution is to focus on preventing the problem at source. This includes measures to minimise plastic leakage into the natural environment, making plastics less toxic, and increasing the likelihood that plastics can be reused, repurposed or recycled effectively. We need to see a shift in how we view and use plastic, and move away from treating plastic as a ‘waste’ material.

What has FFI done so far?

FFI has already had notable success in tackling direct sources of damaging microplastics. In 2016, we worked in collaboration with NGOs and government agencies to secure a ban on the use of microbeads in rinse-off cosmetic products, such as face scrubs and toothpaste. We are working to influence policies that would eliminate pellet loss from global supply chains on land and at sea and we are helping textile manufacturing companies better understand where their operations are at risk of generating microplastic fibre pollution – in anticipation of emerging legislation on this issue.

Read more about how FFI is working to reduce plastic pollution here.