Just 15.5% of the world’s coastal regions remain ecologically intact, according to new research that calls for urgent conservation measures to protect what remains and restore sites that are degraded.
The study, led by researchers at the University of Queensland, used satellite data to examine the extent to which human activities have encroached on coastlines around the globe.
It found that up to 2013 – the latest year for which the data was available – few intact coastlines remained, with even remote areas such as the Kimberley region of Western Australia affected by fishing and mining.
The research, published in the scientific journal Conservation Biology, builds on previous work that examined human activities within terrestrial and marine ecosystems.
The small areas of coast that remain undamaged by pressures such as fishing, agriculture, urban development, mining and roads were mostly in Canada, followed by Russia, Greenland, Chile, Australia and the United States.
Very few intact areas and often high levels of degradation were found in island nations, much of Europe, and countries including Vietnam, India and Singapore.
Coastal regions containing seagrasses, savannah and coral reefs had the highest levels of human pressure.
Brooke Williams, the study’s lead author and a conservation ecologist at the University of Queensland, said because most of the world’s population live in coastal regions, the pressures on those ecosystems could take many forms and occurred both on land and at sea.
“Our paper really advocates for coastal region restoration quite urgently,” she said.
“That such a low proportion is at the higher spectrum of the intactness scale is alarming. It’s not good news.”
The situation certainly would not have improved since 2013, she said.
The coastal analysis was compiled by using two datasets called the human footprint (which examined land-based ecosystems) and the cumulative human pressure index (which examined pressures in marine environments).
Pressures were then mapped out to 50km on either side of the shoreline.
Williams said areas that were still largely intact were often more remote and thus more difficult to access.
In Australia, the Great Australian Bight remained relatively untouched, but Williams noted it had faced development threats in recent years.
Co-author James Watson, of the University of Queensland, said remoteness didn’t guarantee coastlines would remain intact, pointing to mining and particularly fishing as industries causing environmental decline in those places.
He said he had expected Madagascar, Namibia and northern Australia would all retain large areas of intact coastline, but it had not proved to be consistently the case.
“It shocks me how pervasive fishing is. It’s just everywhere. You can’t avoid it,” he said.
“These remote places around the world, you’re seeing fishing impacts.”
The researchers argue that protecting the world’s coastlines will require a range of measures, including legislation to protect undamaged regions and restoration work to improve places that have been degraded.
“You’ve got to increase those areas that are safeguarded,” Watson said.
“And in places that are heavily degraded we’ve got to have a much bigger restoration agenda not just for species but for water, for carbon, all of those things.”