Only 15.5% of the Earth’s coastal areas remained ecologically intact as of 2013, researchers report.
The finding is the result of a study that for the first time merges both terrestrial and marine human impact maps in a global assessment of the anthropogenic pressures affecting coastal regions.
“We found that intact coastal areas have already become relatively rare, based on the most current data available from 10 years ago,” says Benjamin Halpern, executive director of the National Center for Ecological Analysis & Synthesis at the University of California, Santa Barbara and coauthor of the paper in Conservation Biology.
“Pressures to these coastal areas are not subsiding, so the amount of intact coastal area today is almost certainly less.”
The findings are a stark reminder of both the heavy reliance humans have on the coast, and the dwindling amount of intact coastal area that we have left.
“Coastal regions contain high levels of biodiversity and are relied upon by millions of people for ecosystem services such as food and storm protection,” says lead author, Brooke Williams from the University of Queensland.
“Our results show that urgent action is needed to conserve those coastal regions that do remain intact and restore those that are degraded, especially to help mitigate climate change.”
Previous studies of human impact on the coast have tended to “focus strictly on either the terrestrial or the marine realm.” This comprehensive look at the human impact on the world’s coastal areas reveals not only the locations, but also the extent of these pressures.
“Coasts are where the land meets the sea, and yet conservation and management almost always treat them separately,” says Halpern, who is also a professor in the Bren School of Environmental Science & Management at UC Santa Barbara.
“By evaluating them together, we helped identify where these connected land and seascapes are relatively untouched, and the many places where they are not.”
According to the study, coastal regions containing seagrasses, savannah, and coral reefs had the highest levels of human pressure—a swath that encompasses most of Europe, Asia, Africa, the Americas, and the South Pacific.
The study also shows that in most coastal countries, more than 50% of their coastal regions were degraded, and that nearly half of protected areas across coastal regions were exposed to high human pressures.
Canada, according to the study, is responsible for the largest expanse of coastal region that remains intact, with large expanses also located in Russia, Greenland, Chile, Australia, and the United States.
But even in the far north, where a large proportion of intact coasts exist, coastal areas are not safe, Halpern says.
“Climate change is quickly melting sea ice and opening up coastal areas to development, resource use, and environmental damage,” he says. “Time is short to protect the last of these intact places.”
To preserve and enhance what is left, and to minimize further damage to these essential land and seascapes, the researchers call for increased, proactive protections and specific restoration targets.
“Understanding why coastal systems are under pressure can help us design and implement more targeted management strategies,” says coauthor Amelia Wenger, a research fellow at the University of Queensland.
As nations discuss new climate change action at the United Nation’s Conference of the Parties, the team urges governments to proactively conserve the valuable remaining intact coastal regions that they are responsible for, while restoring those that are degraded.
To facilitate and promote the conservation coastal regions, the authors have made the dataset of intactness across coastal regions publicly available through and free to use.
Written by Sonia Fernandez.
