Less than 16 percent of the world’s coastal regions remain intact

Coastal regions are relied upon by millions of people for ecosystem services such as food and storm protection. They contain some of the most unique and biodiverse ecosystems such as wetlands, coral reefs and mangroves. Coastal areas also provide carbon sequestration and support climate change mitigation. 

New research led by the University of Queensland shows that only 15 percent of the world’s coastal areas remain intact, exposing the need for rehabilitation and conservation on a global scale. 

The study assessed anthropogenic pressures affecting coastal regions at a global scale and found that only 15.5 percent of coastal regions have “low human pressure.” Canada’s coastal regions were identified as the most intact at 53 percent, largely due to effective governance. 

Overall, nearly 48 percent of coastal regions are heavily affected by human impacts. In most countries, more than 50 percent of coastal regions were found to be degraded.

Furthermore, 26 nations were recognized as being highly exposed to human impact, or under “extreme human pressure.” The coastlines of these countries are considered to be zero percent intact, and many of them are island nations such as Aruba and Singapore. 

Around the world, there is no coastal region free from human influence. This is largely due to the fact that 74 percent of the global population lives within 50 kilometers of the coast. 

“Our results show that we need to act quickly and decisively if we hope to conserve those coastal regions that remain intact, and restore those that are heavily degraded, especially if we’re going to mitigate the effects of climate change,” said Brooke Williams, from UQ’s School of Earth and Environmental Sciences.

“The rate at which these regions are degrading poses massive threats to not only coastal species and habitats, but also to the health, safety and economic security of countless people who live or rely on coastal regions around the world.”

Human impacts on coastal regions involve complex socio-demographic factors and land-based activities like agriculture and wastewater management. These activities lead to nutrient runoff and chemical pollution, which can lead to hypoxia or even dead zones. 

“While we already knew how important it is to protect biodiversity and ecosystem services in these coastal regions, being able to clearly see how rapidly and how far this degradation has spread, is truly eye-opening,” said Dr. Amelia Wenger.

“Understanding why coastal ecosystems are under pressure can help us design and implement more targeted management strategies, and hopefully slow this degradation down and even turn it around.”

To meet global sustainability objectives, countries must take more aggressive action to preserve coastal areas. Researchers are urging decision makers to conserve the valuable remaining intact coastal regions, while restoring those that are degraded.

“We think our dataset will be a vital tool in achieving that ambition, which is why we’re making it publicly available and free to use,” said Dr. Wenger.

The findings of the assessment have been compiled into a free and usable dataset that can be accessed online. The study is published in the journal Conservation Biology.

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By Katherine Bucko, Earth.com Staff Writer