World's marine wilderness rapidly dwindling: Study

The first comprehensive map of ocean wilderness has revealed that just 13 per cent of the world's oceans remain untouched by the damaging impacts of human activities, scientists said today.

The researchers from the University of Queensland (UQ) in Australia and international colleagues identified marine areas devoid of intense human impacts by analysing 19 stressors including commercial shipping, sediment runoff and several types of fishing.

They said most of the remaining marine wilderness was unprotected, leaving it vulnerable to being lost.

"Marine areas that can be considered pristine are becoming increasingly rare as fishing and shipping fleets expand their reach across almost all of the world's oceans, and sediment runoff smothers many coastal areas," said Kendall Jones, a PhD candidate at UQ.

"Improvements in shipping technology mean that even the most remote wilderness areas may come under threat in the future, including once ice-covered places that are now accessible because of climate change," said Jones.

In the study published in the journal Current Biology, the researchers found little wilderness remaining in coastal habitats such as coral reefs, because of nearby human activities.

Most marine wilderness was located in the Arctic and Antarctic or around remote Pacific island nations such as French Polynesia.

The findings highlight an immediate need for conservation policies to recognise and protect the unique values of marine wilderness.

"Marine wilderness areas are home to unparalleled levels of life, holding massive abundances of species and high genetic diversity, giving them resilience to threats like climate change," said James Watson, a professor at UQ.

"We know these areas are declining catastrophically, and protecting them must become a focus of multilateral environmental agreements. If not, they will likely disappear within 50 years," said Watson.

Jones said preserving marine wilderness also required regulating the high seas, which had proven difficult historically, as no country had jurisdiction.

"Late last year the United Nations began developing a legally binding high seas conservation treaty, essentially a Paris Agreement for the ocean," he said.

"This agreement would have the power to protect large areas of the high seas and might be our best shot at saving some of Earth's last remaining marine wilderness," said Jones.