Courtesy: Scripps Institute of Oceanography

Seldom does a ship’s captain command global attention. In this instance, he is also a chemist, a scuba diver and former woodworking businessman, but these are hardly qualities that aid anyone in attaining celebrity status.

The big moment for Captain Charles Moore came more than a decade ago, when his boat ventured into an area of the Pacific not often visited by ships. Moore saw a sea of trash around him, most of it plastic. The area, a manifest global garbage dump, was at least twice the size of the state of Texas, and it took him a week to pass through it. Moore’s discovery stunned the international environmental community as well as many others. And in the last decade, things have only got worse.

Trash in the ocean is vying for the top spot among all environmental problems. It is close on the heels of climate change. “I am back from a 7,000-mile (11,300 km) trip in the Pacific,” says Moore. “And I saw plastic trash everywhere. In the last 10 years, the amount of garbage has been increasing, with new items arriving every day.”

Of the 200 million tonnes of plastic produced in the world every year, 10 per cent eventually ends up in the oceans. It accumulates in special places called ocean gyres — spots where swirling ocean currents cause the water and everything in it to churn in one place. The North Pacific gyre is 34 million square kilometres in size. There are gyres in the Atlantic and Indian Ocean as well.

Most people think of plastics as substances that live on and on. This is largely true on land, at least for practical purposes, but probably not always in the ocean. In a paper presented recently at an American Chemical Society (ACS) meeting, Japanese scientists from Nihon University said that polystyrene plastics decompose in the ocean rapidly at temperatures above 30 degrees centigrade. We do not quite know how toxic these materials are, but the research introduces a new twist to a rapidly complicated situation.

“Until now the plastics problem has been thought to be one that is visible,” scientist Katsuhiko Saido said at the conference. “But there is an unseen aspect as well to plastics in the ocean.”

Marine life in the ocean has been eating the plastic. Marine birds often confuse the debris with food and eat it and die. Birds like the Albatross regurgitate what they eat to their chicks, and the chicks too die. Fish constantly eat such stuff and die. The plastics degenerate into small bits and are eaten by small fish, which are then eaten by big fish. The latter in turn are caught by human beings. The material breaks into very small bits, converting large areas of ocean water into what Moore calls “plastic soup”.

These remain in the ocean for a long, long time. Many of the pieces — those that are heavier than water — sink slowly and settle at the bottom of the ocean, probably for ever. “The ocean bottom is a very different place,” says Moore. “We do not know whether the plastics there will ever decompose.”

Plastics are stable. That is why they are so widely used. They mostly remain intact no matter where they end up. In fact, it is quite possible that all the plastics that human beings have ever made, barring those incinerated, are still out there somewhere — in a landfill, a lake, the ocean or inside a fish. Saido and his team found that styrofoam decomposes when the temperature is right. This happens in tropical waters, but not elsewhere where the water is cold. Ocean plastic debris is thus a problem of monumental proportions, something that human beings might find as difficult to solve as the climate change problem.

For most of the 20th century, the health of the ocean — and its impact on the health of the earth — was not studied. It is only towards the end that scientists began to research the oceans deeply. We thus have a knowledge vacuum as far the oceans are concerned. A study done early this year by Ben Halpern of the University of California, Santa Barbara, concluded that humans have impacted 96 per cent of the oceans. This impact might soon be 100 per cent as what is still not impacted — the polar seas — are warming up and becoming amenable to human exploitation. We do not yet know how this impact will rebound on us.

Fortunately, several organisations are stepping in to tackle the ocean debris menace. Ocean Conservancy, a Washington-based not-for-profit organisation, has been organising annual clean-ups every year. Last year, 5,00,000 volunteers cleaned up the coastal waters in 100 countries by collecting seven million tonnes of waste, and 3,60,000 of them helped document the nature of waste. This year’s clean up will be performed on September 19, and the organisation expects a 15 per cent increase in participation. “Cigarette butts form the number one waste globally,” says Dianne Sherman, programme director. In India, high on the list are wrappers and plastic bottles.

“The data will help us start developing programmes to stop dumping the waste thus,” says Sherman. Since 50-80 per cent of the land waste ends up in the oceans, ultimately reaching the deep ocean, we will need special projects and new technology for a thorough clean up. A few not-for-profit organisations are attempting that too, with help from scientific labs.

Richard Sundance Owen, a scuba diving instructor and building contractor in Hawai, has formed the Environmental Cleanup Coalition to clean the North Pacific Gyre. A team of environmentalists, entrepreneurs and water sports enthusiasts in California have teamed up to conceive Project Kaisei, also to clean up the North Pacific Gyre. Project Kaisei has assistance from the Scripps Institute of Oceanography in the US. This institute has its own programme called the Seaplex, an acronym for Scripps Environmental Accumulation of Plastic Expedition. Two ships from Scripps went to the Pacific Gyro and returned a few days ago.

The aim of Seaplex is to study the science of plastic waste in the ocean: how it impacts the oceans and the food chain. Project Kaisei is aimed at finding technologies to clean up the mess. Current technologies do not let us do that efficiently as the plastics degrade into small particles. “I am happy that a major oceanography institution is now researching what I found 10 years ago,” says Moore, who has helped create a postdoctoral position in the University of Hawai to study the problem.

Clearly, the real work has just begun.