Coral reefs in the Gulf of Eilat/Aqaba stopped growing for 3,000 years, likely due to a temporary drop in sea levels caused by global cooling, a new study shows. While the reef eventually recovered, scientists warn that modern threats such as climate change and pollution pose greater risks, making conservation efforts vital.

Coral reefs in the Gulf of Eilat paused growth for 3,000 years due to changes in sea levels, but have since recovered. Scientists warn that today's environmental threats could hinder future recovery.

A new study reveals that coral reefs in the Gulf of Eilat experienced a stunning 3,000-year "stasis" between about 4,400 and 1,000 years ago - possibly caused by a temporary drop in sea levels that could have been triggered by global cooling. This disruption mirrors similar events observed on coral reefs offshore Mexico, Brazil and Australia, suggesting widespread environmental changes occurred during that time. Although coral reefs experienced long pauses, they eventually recovered, with coral species reestablishing themselves from deeper waters, a testament to their natural resilience. However, researchers caution that modern challenges such as climate change, pollution and ocean acidification pose much greater risks, and conservation is urgently needed to protect these important marine ecosystems.

The study, led by Professor Adi Torfstein of Hebrew University and Professor Oren Levy of Bar-Ilan University, in collaboration with an international team of researchers, discovered this major pause in coral reef growth in the Gulf of Eilat/Aqaba in the northern Red Sea during the late Holocene. The findings, published in Global Change Biology, provide important insights into the historical resilience of coral reef ecosystems and how they respond to long-term changes in their environment.

Coral reefs play a vital role in marine biodiversity, supporting the ocean carbon cycle and acting as a natural barrier against coastal erosion and storm surges. Despite their importance, our understanding of how coral reefs respond to temperature fluctuations, sea level changes and human impacts has long been limited.

Key findings:

There was an apparent lull in coral reef growth between 4400 and 1000 years ago (BP), consistent with similar events recorded in Mexico, Brazil and Australia.

Coral diversity and abundance showed remarkable consistency before and after the pause, suggesting that reef ecosystems recovered by recolonizing from deeper coral communities.

The study attributes this temporary "pause" to a combination of tectonic activity and glacial-static sea level changes. Temporary sea level drops, possibly caused by cooling events, exposed the reefs and halted their growth.

Other analyzes of modern coral skeletons show significant changes in carbon isotope composition, reflecting the growing impact of human activities on the global carbon balance.

Members of the research team include Dr. BarFeldman from Bar-Ilan University, Professor Aldo Shemesh from the Weizmann Institute, Dr. Yonathan Shaked from the Inter-University Institute for Marine Science (IUI), Professor Mick O'Leary from the University of Western Australia, and Professor Huang Dunwei from the National University of Singapore.

The samples provide an unprecedented window into the reef's growth history over the past 10,000 years.

Despite the historic "closure," the findings highlight the resilience of coral reef ecosystems in the face of environmental challenges. However, the findings also highlight the urgent need for conservation efforts to combat modern threats posed by climate change, ocean acidification and human disturbance.

Dr Tofstein said: "Understanding how coral reefs responded to past sea level changes helps us predict their future resilience and inform conservation strategies. Our research shows that coral communities can recover after significant damage, but today's climate crisis poses unprecedented challenges that require urgent action."

Compiled from /scitechdaily