The biogeochemical cycling of macro- and micro-nutrients such as nitrate, phosphate, silicate, iron, copper, and a whole range of other naturally occurring substances, forms a network of processes fundamental to the development and survival of marine ecosystems. The amount and bio-availability of many substances in seawater determines the primary production of organic material by marine phytoplankton. This all-important first step in the marine food chain controls the fertility of the ocean, all the way up to harvest fish. Cycling of macro-nutrients, particularly nitrogen-based forms, and also many metals, through muddy sediments in shallow coastal zones, strongly controls the amounts of these land-derived substances reaching the ocean via estuaries. The role of groundwater inputs to coastal waters is increasingly being recognised as an important control on the biogeochemistry of coastal waters, and of inputs to the global ocean.

People

Dr. Rachel Cave Earth and Ocean Sciences Phone: (091) 49 2351; Email: rachel.cave@nuigalway.ie ——— Dr. Cave’s research focuses on ocean chemistry, groundwater-seawater interactions, and biogeochemical cycling in coastal waters.

Tiernan Henry Earth & Ocean Sciences Phone: (091) 49 5096; Email: tiernan.henry@nuigalway.ie ——— Tiernan Henry is a graduate of Trinity College Dublin and the University of Wisconsin-Madison. He has a number of years of consultancy experience in groundwater and surface water management in Ireland (working with mining companies, quarries, local authorities, companies and individuals) and has been lecturing at NUIG since 2004. His current research interests include:  better understanding the relationship between structural geology and groundwater movement and groundwater chemistry around the Tynagh mine area; understanding the nature of the relationship between groundwater and seawater at the coastal interface in karst zones; and, hydraulic fracturing of rocks in an Irish context. He is a member of the International Association of Hydrogeologists (IAH) and the International Mine Water Association (IMWA). He should know better by now, but he continues to play football most weeks. He is also a board member of the Galway Arts Festival.

 

Some Current Projects

Griffiths Geoscience project – Groundwater Study: This study is carrying out research in coastal aquifers, and includes research into how intertidal and submarine groundwater discharges affect the biogeochemistry of coastal waters along the karstic south Galway and Clare coast. This project is funded by the GSI.

Metals in the Marine Environment project – MIME: This project aims to develop semi-autonomous voltammetric methods for the measurement of both total and bio-available trace metals in estuarine and marine waters, allied to research on the uptake of trace metals by macroalgae, and their effect on the production of algal exudates. The project is funded by the SFI and IRCSET.

Marine Rapid Climate Change Project: Impacts of increased atmospheric CO2 on marine chemistry and ecosystems. The pH of marine waters strongly affects the biogeochemical cycling of nutrients, trace metals and other substances, both by directly driving chemical changes in a given direction, and indirectly by affecting biological processes in organisms such as bacteria and phytoplankton involved in biogeochemical cycling. If atmospheric CO2 continues to increase, its uptake by the ocean will lower the pH, making ocean waters more acidic. This project aims to build capacity in Ireland to measure marine carbon parameters such as dissolved inorganic carbon, total alkalinity and pCO2, to measure these baseline ocean acidification parameters in Irish waters, and to develop a strategy for their future monitoring. The project is funded by the Marine Institute.