Overfishing, pollution and acidification are among the chief threats to ocean ecosystems, where conditions for wildlife have been in decline for many decades. “It’s a Wild West on the high seas,” said actor and environmental activist Leonardo Dicaprio, during a recent US State Department conference. Activists and business and government leaders from more than 80 countries gathered to assess the state of science and determine concrete actions to protect ocean ecosystems. “The ocean fuels our trade. It provides much of the food we eat and the air we breathe. It is home to vast extraordinary ecosystems - from the coral reef to the kelp forests,” Secretary of State John Kerry said. “But today this incredible resource is threatened - by unsustainable fishing, pollution and climate change. Indeed, how we respond to these challenges is literally going to help determine the future of our planet.” About 80 per cent of marine pollution originates on land. Nutrient pollution has diverse sources, including agricultural runoff and sewage discharge, and can change the chemistry of seawater - creating oxygen-depleted ‘dead zones’, where marine life cannot thrive. Marine debris, a second category of ocean pollution, is 75 per cent plastic, according to Richard Thompson, professor of Marine Biology at Britain’s Plymouth University. About half the plastic that finds its way into the oceans is from packaging or single-use products. Three-quarters of marine wildlife encounters with human debris are with plastics, Thompson said. Plastics are lightweight and so the litter can spread easily. They also contain toxic materials known to be harmful to both humans and sea life, and which take centuries to break down. “The essential qualities that make plastics so easy to use are also its inherent design flaws,” said Daniella Dimitrova Russo, Chief Executive of advocacy group Think Beyond Plastic. One solution to the removal of marine debris came from 19-year-old Boyan Slat, designer of a passive collection system that is calculated to capture 80 per cent of the plastic it encounters. The system, which he presented at the Washington conference, can clean a single rotating current of plastic, known as a gyre, within five years, according to Slat’s non-governmental organisation, The Ocean Cleanup. Russo and Thompson agreed that the simplest solution to prevent plastic pollution is to reduce single-use items, which make up such a large chunk of marine debris. “Clean-up doesn’t make any sense in isolation,” Thompson said. “Clean-up will only really work if we can take measures further up the chain - to reduce use.” For example, Think Beyond Plastic has devised coffee lids made of clay and paper pulp, and a biodegradable alternative to plastic utensils.
Read More...