Projects

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 CO₂ stat 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 CO₂ stat 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 CO₂ control system uses a CO₂-Pro™ to measure pCO₂  and then controls input of CO₂ or 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”.

Summary

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.