Steep population rise over 20 years near coastal areas endangers coral reefs: University of Essex research

 ·         Indian Ocean saw a 33% increase in populations within 100 KM of a coral reef and 71% at 5 KM

·         Coral reefs predicted to decline between 70-90% in the next decade and up to 99% if global warming reaches 2°C above pre-industrial levels

·         In India, 30 million more people lived within 100 KM of coral reefs in 2020 compared to 20 years ago

According to research by UK’s University of Essex, the steep rise in population growth in coastal areas over the past 20 years have increased the risk to coral reefs globally. Research from the University of Essex has found that the number of people living in coastal areas by coral reefs has grown to nearly one billion – a rise of 250 million since 2000, and rates are going up in these areas quicker than global averages. Worryingly, the areas closest to the coral reefs – where people’s direct livelihoods rely on these valuable ecosystems – has seen a population density boom which is now four times the global average.

The new study by University of Essex, published in the journal Global Change Biology, provides the most up-to-date and extensive statistics on global, regional and nation-level differences in coastal population trends living within 5-100 KM of coral reefs. The data from 117 coral reef countries found the Indian Ocean saw a 33% increase in populations within 100 KM of a coral reef and 71% at 5 KM. There are 60 countries with 100% of their population within 100 KM of coral reefs.

In terms of India, there are now 30 million more people living within 100 km of coral reefs in 2020 compared to 20 years ago. This equates to just over 145 million people living with 100 km (60 miles) of coral reefs in 2020 – about 11% of the total Indian population. Population density has also increased nearly 1.5 times at 5 KM compared to 2000.

Coral reefs cover less than 0.1% of the world’s oceans, are extremely biodiverse, hosting up to one quarter of all marine fish species and are among the most productive and complex ecosystems found in the world. However, previous research has predicted coral reefs will decline between 70-90% in the next decade and up to 99% if global warming reaches 2°C above pre-industrial levels. Of particular interest are Small Island Developing States (SIDS), where the dependency on marine ecosystems are particularly high and are recognised as a special group of countries that are disproportionately vulnerable to climate change. The study found that 94% of SIDS population live within 100 KM of a coral reef.

Human populations near ecosystems are used to indicate the dependency on those ecosystems, as well as an estimated threat. Climate change is the greatest threat facing coral reefs but in these coral adjacent coastal areas there is a balance to be found between the important services coral reefs provide to humans, such as protection against storms, food supply and livelihoods, and the potentially damaging human activities that occur there – from overfishing and pollution to destruction of corals for construction. Human activities also play a large role in coral reef health and survival.

Coastal populations are calculated as 100 KM (60 miles) from coastlines and the number of people living near coral reefs is often used in regional coral reef management and the evaluation of risk at regional and global scales.

Dr Amy Sing Wong, from University of Essex’s School of Life Sciences, who led the research, said: “Coral reefs are at the forefront of our climate catastrophe. They are also subject to many human-made impacts – from pollution and overfishing to tourism and extraction of raw materials. Yet, coral reefs are also a lifeline to millions, acting as a primary source of protein to some of the poorest people on Earth. Broadly, more people by coral reefs translates to more impacted coral reefs. Our research into understanding changes in human populations close to coral reefs is therefore crucial. We knew that global populations near coral reefs were high, but we did not expect nearly one billion people within 100km of coral reefs in 2020.”

The scientists are now hoping their findings will help identify areas at higher risk which will prove a powerful management tool to inform policies around coastal protection – something crucial for securing the future of our vulnerable coral reef ecosystems and the people who rely on them.

Dr Michelle Taylor, Senior Lecturer of Marine Biology at the University of Essex, said: “There is a concern regarding high coastal zone human population growth as it has been associated with the degradation of coastal and marine ecosystems.

“By providing country-level coastal population data we hope it can be used in global policy goals such as the Sustainability Development Goals (SDGs). Our study highlights the millions of people that have a potential dependency on coral reefs and are therefore vulnerable to climate-change impacts on these sensitive ecosystems.”

About University of Essex

Founded in 1964, University of Essex is one of the UK’s leading universities, which has grown from 122 students in the first year to 18,000+ now. The University maintains three campuses at Colchester, Southend and Loughton. Essex has three faculties which lead on delivering excellence in teaching and research: the Faculty of Arts and Humanities, Faculty of Science and Health, and Faculty of Social Sciences. It has close to 1,000 active researchers and 18,000 students from over 140 countries with an alumni strength in excess of 100,000. According to The Complete University Guide 2023, University of Essex is Top 40 in UK universities and 25th for international outlook in the Times Higher Education World University Rankings 2022.