The sailing cargo ship Kwai docked in Honolulu last month after a 25-day voyage with 40 tonnes of fishing nets and consumer plastics aboard, gathered from what has become known as the Great Pacific Garbage Patch.

The latest annual clean-up voyage by the non-profit Ocean Voyages Institute (OVI) used satellite imagery to specifically target discarded fishing gear. More than half a million tonnes of plastic nets - so-called ghost nets - are abandoned each year in oceans across the world, entangling and killing up to 380,000 sea mammals.

The circulating ocean current known as the North Pacific Gyre is believed to contain 1.8 trillion plastic items weighing over 80,000 tonnes. Covering an expanse of ocean three-times the size of France, the Great Pacific Garbage Patch lies between Hawaii and California.

OVI has mounted nine previous clean-up voyages to the area but says its latest haul was the largest and most successful to date.

“It is very disturbing to be sailing through what was only decades ago a pristine ocean wilderness and find it filled with our all-too-familiar garbage,” says OVI founder and lifelong sailor Mary Crowley.

The Great Pacific Garbage Patch. Image: The Ocean Cleanup

A critical mass

Pressure to clean up the Pacific is mounting after the discovery that tiny Henderson Island, a UNESCO World Heritage site in the remote Pitcairn Archipelago, is littered with 38 million pieces of plastic.

An estimated 20 tonnes of plastic waste washes up every year on Midway Atoll near Hawaii, threatening the world’s largest population of Laysan albatrosses, which end up feeding a quarter of it to their chicks. Midway is a United States National Wildlife Refuge.

Laysan albatross chicks amid the plastic rubbish littering Midway Atoll in the North Pacific. Image: Wikimedia

Taking action

The UK and Pacific island nation Vanuatu launched the Commonwealth Clean Oceans Alliance last year. Countries including New Zealand, Australia, the Barbados and Canada have signed its pledge to clean up the oceans.

Pacific nations are taking action to reduce waste and boost recycling, too. Fiji, which plans to phase out single-use plastic bags by 2025, introduced a plastic bag levy two years ago which has dramatically reduced plastic use. Kiribati’s sustainable waste management system pays citizens for every aluminum can and plastic bottle they recycle. And the South Pacific island state of Niue is building a waste recycling plant and will phase out single-use plastic bags this year.

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.