The future of Caribbean reefs is at risk due to a concerning phenomenon affecting the elkhorn coral in Cozumel.
This coral, vital for the health of reefs, has lost its ability for synchronized spawning, essential for its reproduction. Researchers have observed that although they continue to produce gametes, the release is no longer simultaneous, decreasing the chances of fertilization.
During eight years of study on the Mexican island, experts have monitored the colonies of this coral and have found that the massive spawning, normally observed during full moon nights, has practically stopped.
Environmental stress and climate change are emerging as the main culprits of this disturbing change, affecting a coral that has already suffered a loss of more than 95% since the 1980s.
The research, published in the journal Diversity, reveals that the 33 colonies studied on beaches like La Caletita and Playa Tikila produce gametes, but the absence of simultaneous release seriously compromises fertilization.
The team, led by marine biologist Johanna Calle Triviño and Cinvestav, has conducted night dives during the months of August and September, when spawning should occur.
Scientists have noticed a near-complete absence of synchronization in spawning. Analyses confirm that the corals generate gametes, but it seems they have entered a “survival mode,” prioritizing tissue repair over environmental stress instead of reproduction.
The elkhorn coral
This change in the behavior of the elkhorn coral has severe implications for the marine ecosystem. This coral is known as the “reef architect” for its structures that provide habitats to various marine species. Its decline represents a direct threat to biodiversity and the health of the Caribbean reefs.
Factors such as sea warming, reaching temperatures of up to 33 °C, along with tourist pressure —with more than 4.7 million visitors in 2025 in Cozumel—, intensify the stress on these ecosystems.
The International Union for Conservation of Nature (IUCN) has already listed the coral as critically endangered.
Protecting isolated colonies will not be enough to reverse this situation. Scientists suggest that improving environmental conditions is crucial to restore the coral’s spawning capacity.
Conservation and restoration policies must be implemented immediately to avoid irreversible consequences.
In summary, the reproductive collapse of the elkhorn coral is an alarming sign of the effects of climate change and human activity on marine ecosystems. Restoring optimal conditions is essential to ensure its survival and that of the Caribbean reef.
