(BBC) Three-quarters of the world’s coral reefs are at risk due to overfishing, pollution, climate change and other factors, says a major new assessment.
And two nations in the Caribbean – Grenada and Haiti – are among the most socially and economically vulnerable if the reefs are degraded or lost.
The Reefs at Risk Revisited report collates the work of hundreds of scientists and took three years to compile.
The biggest threat is exploitative fishing, the researchers say, though most reefs will be feeling the impact of climate change within 20 years.
In more than 20 countries or territories in the Caribbean region, all reefs are rated as threatened, the report said.
The researchers say that there are measures that can be taken to protect at least some.
The report is compiled by a group of more than 20 research and conservation organisations, led by the World Resources Institute (WRI) in Washington.
Exploitative fishing
“This report serves as a wake-up call for policymakers, business leaders, ocean managers, and others about the urgent need for greater protection for coral reefs,” said Jane Lubchenco, head of the US National Oceanic and Atmospheric Administration (Noaa).
“Local and global threats, including climate change, are already having significant impacts on coral reefs, putting the future of these beautiful and valuable ecosystems at risk.”
The report revisits some of the territory explored in the original Reefs at Risk project, published in 1998, but in much greater detail.
Over the 13 years intervening, the area at risk of destruction has increased by nearly a third.
The main reason for that change has been a massive increase in damage from exploitative fishing.
Altogether, more than half of the world’s reefs are threatened by the ways in which fishermen use them.
Human impact
These range from simply catching more than nature can replace to the use of extremely damaging fishing methods such as dynamiting fish to stun or kill them – which also blasts coral formations to smithereens.
Other major threats are pollution carried in rivers, coastal development, and climate change.
If climate projections turn into reality, then by 2030 roughly half of the world’s reefs will experience bleaching in most years – rising to 95% during the 2050s.
Regionally, southeast Asia is the worst affected region, with 95% of reefs on the threatened list.
But in terms of the impact on human society, threat is only part of the equation.
The researchers reasoned that societies most affected by reef degradation would be those where the threats are high, where a big proportion of the population depends on reefs for their livelihood, and where people’s capacity to adapt is low.
Combining these criteria, the countries highest on the risk register are Comoros, Fiji, Haiti, Grenada, Indonesia, Kiribati, Philippines, Tanzania and Vanuatu.
Reduce reliance
“They have high ratings for exposure to reef threat and reef dependence, combined with low ratings for adaptive capacity,” the study said.
“These countries merit the highest priority for concerted development efforts to reduce reliance on reefs and to build adaptive capacity, alongside reducing immediate threats to reefs.”
Against this bleak backdrop, the researchers have been at pains to emphasise that there are things that can be done to reduce the damage.
“There are reasons for hope,” said Lauretta Burke, senior associate at WRI and a lead author of the report.
“Reefs are resilient; and by reducing the local pressures, we can help buy time to find solutions to global threats that can preserve reefs for future generations.”
Research has shown for example that allowing a diversity of life to flourish on a reef keeps it healthy and more resistant to rising water temperatures.
