Nutrients and Ocean Acidification (OA)

Nutrients and Ocean Acidification. Photographer Tomaz Szumski/ Copyright Marine Institute/ Photographer Andrew Downes/ Photographer Tomasz Szumski/ Photographer Tomasz Szumski/ Copyright Marine Institute.


Nutrients, in particular nitrogen and phosphorus, are essential, and indeed are a key controlling factor, for the biological productivity of our seas. While natural variability is high due to seasonal phytoplankton population dynamics, excessive inputs from human activities may cause accelerated algal growth in summer months. This can lead to undesirable disturbance of the ecosystem, in a process called eutrophication.

We measure nutrients in shelf and deep offshore waters around the Irish coast, complementing the EPA’s inshore work. We’ve been monitoring nutrient concentrations in the Irish Sea since 1990, and have built up an extensive dataset. This data is reported annually to ICES.

Ocean Acidification (OA) 

Changing ocean carbonate concentrations and pH since pre-industrial times. Graphic courtesy of

In addition to generating climate change, increased carbon dioxide (CO2 ) in the atmosphere due to anthropogenic activities, such as fossil fuel use, causes changes in ocean chemistry, leading to a decrease in the pH of seawater. This process is referred to as ocean acidification. With continued CO2 emissions, ocean acidification is likely to have widespread impacts for marine ecosystems and on sustainable marine resource management in this century. Potential adverse impacts include disruption of calcium carbonate shell and skeleton formation. Molluscs, our cold water coral reefs and the diversity these habitats support, some phytoplankton and many other organisms are likely to be  at  risk.

We have been researching seawater carbon chemistry and ocean acidification since 2008.  We undertake surveys to monitor ocean acidification from coastal waters to the deep off-shelf waters of the Rockall Trough. In 2010, a Marine Institute and NUI Galway research project published a policy advice report titled Ocean Acidification: An Emerging Threat to our Marine Environment


Our current chemical oceanography research areas include the biogeochemical cycling of nutrients and inorganic carbon in Irish waters.

Visit our Project Page for details of current and past research projects.

Contact us for further information.


Marine Chemistry Research ProjectsMarine Chemistry Publications