The Bouraké semi-enclosed lagoon (New Caledonia) – a natural laboratory to study the lifelong adaptation of a coral reef ecosystem to extreme environmental conditions

A thriving coral reef ecosystem in the Bouraké semi-enclosed lagoon (New Caledonia) defies expectations, surviving under extreme conditions of acidification, deoxygenation, and temperature fluctuations. Unlike projected future ocean scenarios, this lagoon experiences predictable, rapid changes in seawater pH (down to 7.2), dissolved oxygen (as low as 1.9 mg/L), and temperature (up to 6.5°C variation daily) due to tidal cycles. Despite these harsh conditions, the reef hosts a diverse community of corals (66 species), sponges (11 species), and macroalgae (28 species). The study used a multi-scale approach to map benthic composition and characterize physical-chemical parameters, revealing that environmental variability and nutrient imbalances may contribute to the resilience of these organisms. This natural laboratory offers unique insights into potential adaptive mechanisms for reef ecosystems facing climate change.

Maggioni, F., Pujo-Pay, M., Aucan, J., Cerrano, C., Calcinai, B., Payri, C., Benzoni, F., Letourneur, Y., & Rodolfo-Metalpa, R. (2021). The Bouraké semi-enclosed lagoon (New Caledonia) – a natural laboratory to study the lifelong adaptation of a coral reef ecosystem to extreme environmental conditions. Biogeosciences, 18(18), 5117–5140. https://doi.org/10.5194/bg-18-5117-2021