Understanding the Effect of Ocean Acidification on Organisms

The Scenario

As anthropogenic CO2  builds in the atmosphere, the oceans are becoming more acidic. This change in pH (or reduction in CO3 2– ) not only affects the ocean capacity to absorb CO2, it also reduces the capability of organisms such as corals, foraminifera and shellfish to precipitate hard parts.

The Challenge

The effects of ocean acidification on organisms can be studied using a system that maintains constant CO2  in water at concentrations representing pre-industrial, current and various predicted future levels.

The Solution

Working with Dr. Sophie Dove and Dr. David Kline with the Global Change Institute’s (GCI) Coral Reef Ecosystems Laboratory  at the University of Queensland, Australia, Pro-Oceanus scientists and engineers developed two COstat systems that simulate acidification conditions typical of: pre-industrial, current, and levels that are expected in the next 50 to 100 years. The larger of the two COstat systems was installed on Heron Island to control CO2  levels in 7500 liter tanks of seawater in what is one of the largest and most accurately controlled ocean acidification and warming experimental systems in the world. The COcontrol system uses a CO2-Pro™ to measure pCO2  and then controls input of COor air to adjust levels to the preset points. Results to date show that at higher levels of CO2 “the types of algae are different and the growth rate of the coral appears to have slowed”.


Pro-Oceanus scientists and engineers worked with University of Queensland researchers to develop a pCO2  stat system to control CO2  levels in large tanks of seawater for studying how past, current and future levels of CO2  in the atmosphere will affect coral development and coral reef growth.