An underwater mini-lab off the northeast coast of Australia is giving scientists a novel way of seeing how ocean acidification is affecting coral reef ecosystems.
An underwater mini-lab off the northeast coast of Australia offers a novel way to focus coral reef conservation. Scientists from the University of Queensland’s Global Change Institute have developed an experimental system to study the impacts of ocean acidification on coral reef ecosystems.
Submerged just a few feet below the surface of the water at the southern tip of the Great Barrier Reef, this mini-lab, or FOCE (Free Ocean Carbon Enrichment) system, could prove instrumental in predicting the responses of our reefs to rising levels of atmospheric CO2, and therefore in directing conservation efforts.
Oceans absorb more than one quarter of atmospheric CO2, helping to slow the rate of climate change. But with an increase in dissolved carbon comes an increase in ocean acidity: bad news for coral reefs, which hold enormous value in terms of shoreline protection and the marine life which they support.
Until now, simulations of ocean acidification have been confined to labs and aquaria. This project, an international collaboration, led by Ove Hoegh-Guldberg and David Kline at Scripps Institute of Oceanography, is the first attempt to simulate the process of acidification on an actual reef, the advantage being that while conditions in the semi-enclosed mini-lab can be controlled, the organisms within it respond to future acidity scenarios in their natural environment. The system uses a network of sensors that monitor water conditions, ensuring through feedback control that experimental elevations in acidity are maintained relative to natural variations in pH.
Kline is now working to develop the next generation of the system, which he hopes to install globally within the next 5-10 years. It will be portable and deployable to greater depths, allowing comparative studies to be carried out across different reefs and reef zones. If successful, the implications for coral reef conservation will be great.
“Reefs around the world are going to experience ocean acidification at different rates”, says Lida Teneva, a Stanford PhD student involved in the study. “There will be winners and losers on the scale of whole reef systems as well as among organisms within reefs.” If the FOCE system could be used to identify those reefs most robust and resilient to ocean acidification – and therefore most likely to act as strongholds for the future – strategic steps could be taken by the conservation community to enhance this resilience through protection and careful management.
“This is just the beginning of a whole new approach for studying and understanding the effects of ocean acidification”, says Christopher Sabine, Director of the NOAA Pacific Marine Environmental Laboratory. “More work needs to be done to understand the limitations and potential of the system, but it is an exciting start and the scientific community will be watching closely to see what they do next.” – Annabelle Bladon
Photo: David I. Kline, 2012