WILLEMSTAD – The Global Coral Reef Monitoring Network (GCRMN) today released its latest report assessing the “health” of coral reefs across the Caribbean. The publication compiles 23,742 surveys conducted by roughly 200 scientists to document how Caribbean reefs have changed over the past five decades. The report is co-published by the United Nations and is intended primarily for policymakers responsible for reef management.
However, the report has sparked controversy. In evaluating coral cover across 44 Caribbean countries, the authors used a mathematical model that generated estimates for locations where no direct measurements existed. “In principle, such a model can be useful, but in this case, the estimates for places where coral cover is actually well-known—such as Curaçao—differed drastically from the real, measured values,” says Mark Vermeij of CARMABI, who contributed to the report for a year before withdrawing due to the number of errors he and other scientists discovered.
“The overall message hasn’t changed—the Caribbean is losing coral at an alarming rate. But some islands have now been assigned far more or far less coral cover than they actually have because of the model used by GCRMN. We reported these issues to GCRMN, but nothing was done with the feedback,” Vermeij says.
The model also claimed that storms such as Tropical Depression Felix (2008) and Isidore (2004) caused major damage to Curaçao’s reefs, something scientists say never happened. “I had to look up which storms these even were, because no one here remembers them causing reef damage. Meanwhile, storms that did cause damage—like Lenny and Omar—are not mentioned anywhere in the report,” Vermeij notes.
Other discrepancies raise questions about the model’s accuracy. According to the GCRMN report, Curaçao has 103 km² of coral reef. “The island has almost no reefs along the north coast, and given that Curaçao is about 70 km long, this would imply the reefs on the south coast extend more than a kilometer offshore. Everyone knows that is not the case. It’s unfortunate that GCRMN places more trust in a model than in what we actually measure on the islands,” Vermeij adds.
Long-Term Decline Continues
Despite the concerns, the primary causes of reef decline remain consistent with earlier GCRMN reports: pollution, coastal development, overfishing, climate change, overtourism, and disease. Average coral cover in the Caribbean fell from 40–50% in 1970, to 28% in 1985, and now stands at just 15% in 2024.
Curaçao follows this general trend, though CARMABI emphasizes that averages mask important local variation. “Some reefs on Curaçao are still among the best in the entire Caribbean, as clearly stated in the previous GCRMN report from 2013,” says Manfred van Veghel, director of CARMABI. “Reefs at Oostpunt, Klein Curaçao, and Kaap Marie remain exceptional, though coral diseases and bleaching are visible there as well. These healthier reefs recover much better from stress than many others around the island.”
A Missed Opportunity
CARMABI views the new GCRMN report as a missed opportunity to present an accurate, unified overview of reef conditions in the region. “We are now working on our own updated report on the status of Curaçao’s reefs, which will offer far more detail than the GCRMN publication. We hope to share it soon so the public can better understand both the threats and the unique reef systems that still exist around the island,” Vermeij concludes.