Tiny larval fish in the nursery waters off the coast of Hawaii have a new and plentiful source of food, which has no nutritional value, is high in toxins, and can take decades to break down.

In these waters, plastic fragments outnumber baby fish by a ratio of seven to one, a recent study revealed.

Scientists have found bite-sized pieces of plastic invading ocean 'slicks' where baby fish feed and grow.

Life for many of the planet’s ocean fish species begins at the water’s surface, where naturally occurring slicks meander through the ocean. These thin strips of smooth water are a rich source of plankton, making a perfect nursery habitat for tiny larval fish eager for nutrition.

For every fish dwelling in Hawaii’s surface slicks there are seven plastic fragments.
Ocean slicks - a perfect nursery habitat for larval fish
Image: PNAS

But, as the graphic shows, the same ocean movements that bring together this concentrated food supply also accumulate floating plastic fragments, which young fish mistake for plankton and ingest as food.


The study dissected hundreds of larval fish from Hawaii’s coastal slicks and found 8.6% of individuals had ingested pieces of plastic, almost two and a half times more than larval fish from nearby ambient waters.

Of the eight fish families analysed, seven contained plastic fragments. These include commercially targeted species such as swordfish, and flying fish which are a common food source for larger fish like tuna and seabirds.

What's the World Economic Forum doing about the ocean?

Our oceans cover 70% of the world’s surface and account for 80% of the planet’s biodiversity. We can't have a healthy future without healthy oceans - but they're more vulnerable than ever because of climate change and pollution.

Tackling the grave threats to our oceans means working with leaders across sectors, from business to government to academia.

The World Economic Forum, in collaboration with the World Resources Institute, convenes the Friends of Ocean Action, a coalition of leaders working together to protect the seas. From a programme with the Indonesian government to cut plastic waste entering the sea to a global plan to track illegal fishing, the Friends are pushing for new solutions.

Climate change is an inextricable part of the threat to our oceans, with rising temperatures and acidification disrupting fragile ecosystems. The Forum runs a number of initiatives to support the shift to a low-carbon economy, including hosting the Alliance of CEO Climate Leaders, who have cut emissions in their companies by 9%.

Is your organisation interested in working with the World Economic Forum? Find out more here.

Plastic menu

There is insufficient data to determine if eating plastic is detrimental to the health of baby fish, but researcher Dr. Gareth Willians of the UK’s Bangor University, says the situation could leave larval fish vulnerable.

“The fact that they're eating these non-nutritious particles at the point when eating is so critical for their survival in those first few days, it can only be a bad thing," he told the BBC.


There are certainly repercussions for species further up the food chain, including potentially our own health.

Plastic pollution can harm biodiversity, damage ocean ecosystems and impact marine life. According to UN figures, around 13 million tonnes of waste plastic finds its way into our oceans each year.

A beach covered in plastic waste.
Economic damage from plastic pollution costs $13 billion annually.
Image: Reuters/Eduardo Munoz

But there is also an economic cost to this pollution. The UN Environment report, The State of Plastic: World Environment Day Outlook 2018, estimates that waste plastic causes $13 billion of economic damage to the global marine ecosystem each year.

There’s no quick fix to this global environmental threat, but urgent action is needed.

Plastic has myriad uses and is cheap, lightweight and easy to make. All factors which led to the global boom in its use. And, although the planet can’t cope with the amount of plastic currently produced, demand will continue to climb over the next decade or two.

The path to a more sustainable future lies in finding alternatives to single-use plastics, while developing initiatives that help reduce our dependence on them.