Human activity impacts 97 percent of the world's coastline

Human activities are placing major strain on coastal areas across the globe, according to a study led by the University of Queensland. The researchers mapped the presence and extent of major coastline stressors, and discovered that 97 percent of coastal areas are significantly impacted.

Study lead author Hannah Allan said the research outlined the spatial extent and magnitude of 10 major land-based stressors and 10 major marine stressors that occur across coastlines globally.

“The threats human activity pose to coastal ecosystems and biodiversity come from both the land and sea, sometimes arriving far from human activity,” said Allan. “Therefore, coastal conservation must incorporate land-sea connections. Human population size, tourism, and roads were some of the biggest contributors to the terrestrial component of Australia’s coastal human footprint.”

“As for marine stressors, increasing sea surface temperatures, nutrient pollution, and shipping were found to be major drivers of human pressure on Australian coastlines.”

Professor Noam Levin noted that a map of this kind, which assembles both terrestrial and marine stressors and presents the coastal human footprint globally, has rarely been attempted.

“This research offers valuable insights that could help decision-makers and managers identify where to mitigate particular impacts,” said Professor Levin. “For example, the database underlying the human footprint can show specific areas with high oil and gas operations, such as in Western Australia.”

“This can help develop preparedness procedures for the very realistic chance of environmental disasters that impact coastal areas, such as oil spills.”

“An added benefit of our new global map is that it helps prioritise these decisions based on how widespread the potential pressures of our human footprint in certain areas of the world might be.”

“Coastal areas, where 90 percent of Australians live, were not immune to these stressors. For Australia, the highest human footprint was found in the coastal cities, in the order of Melbourne, Sydney, Perth, Adelaide, and Brisbane.”

Professor Levin said the team mapped 160 areas on the planet with the most pristine coastal areas, including several in Australia. “Of those, nearly 40 percent were totally unprotected – opening an opportunity to identify coastal areas for further conservation actions.”

“A key finding was that light pollution is increasing, with more white LEDs being used, placing great strain on areas of high importance for biodiversity, disrupting the natural patterns of wildlife.”

Professor Salit Kark said the team was surprised at the sheer extent and far-reaching impact revealed by the footprint map.

“There is hardly anywhere on the planet, outside of the polar and arctic regions, that does not show some form of human pressure on their coastline,” said Professor Kark. “In essence, we have influenced the majority of coastal areas globally. We therefore should aim to map and understand our impacts, and also leave some untouched coastlines.”

The research is published in the journal Ocean and Coastal Management.

–—

By Chrissy Sexton, Earth.com Editor

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.