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Project title

Biogeochemical cycling of nitrates in Irish Estuaries

Primary Funding Agency

Environmental Protection Agency

Co-Funding Organisation(s)

n/a

Lead Organisation

National University of Ireland Galway (NUIG)

Lead Applicant

Cindy Smith

Project Abstract

Estuaries are the major conduit between land and sea, through which nutrient run-off from human activity flows into coastal systems. As a result increased concentrations of nitrates are entering nitrogen limited estuarine and marine systems stimulating primary productivity. However, estuaries are not passive channels and microbially driven processes within sediments mediate the nitrogen levels passing though them. These include nitrate reduction, whereby nitrate is reduced to nitrite, which subsequently can be reduced by denitrification (DN) (the stepwise reduction of nitrite to dinitrogen gas) or via dissimilatory nitrate reduction to ammonium (DNRA). Depending on the pathway (DN or DNRA) nitrate is either removed or conserved within the system, directly affecting the nutrient status of the estuary and coastal ecosystems. The specific aims of the research project are to determine potential rates of nitrate reduction, DN and DNRA in three Irish estuaries of contrasting nutrient status over various time and spatial scales. This will be achieved, using a combination of estuarine sediment microcosm experiments to determine potential rates and molecular techniques to target and quantify the microorganisms within the sediments responsible for the processes. Finally, using actual rate process data generated, a biogeochemical model of nitrogen in Irish estuaries will be constructed.

Grant Approved

�73,498.00

Research Hub

Natural Environment

Research Theme

Improve our Knowledge on the State of our Water Resources and Pressures

Start Date

01/09/2013

Initial Projected Completion Date

01/09/2016