Student Research Reports
Tides of Contamination: The Effects of Tidal Estuaries on Water Quality of Local Beaches
Organization(s):Mount Saint Michael, Rosscarbery
Country:Ireland
Student(s):Anna Brinkman
Holly Murray
Orla McCarthy
Grade Level:Secondary School (grades 9-12, ages 14-18)
GLOBE Educator(s):Bernadette Power
Contributors:We collaborated with the following
Aidan Holland, CEO Acorn Water Laboratories
Dr. Frank Mullins, Laboratory and Operations Manager, Acorn Water Laboratories
Paul O'Callaghan, Water Research Scientist, Blue Tech Labs
Paul Melody, Owner, Lagoon Activity Centre
Councillor Isobel Towse
Report Type(s):International Virtual Science Symposium Report
Protocols:Freshwater Macroinvertebrates, Nitrates, pH
Presentation Poster:
View Document
Language(s):English
Date Submitted:03/05/2025

Our objective in this project is to investigate E. coli levels on a beach with
an estuary (The Warren Strand) compared to neighbouring beach without
(Owenahincha Strand).
In February we began testing rivers feeding into the lagoon in Rosscarbery
for nitrates using dip tests and assessed river water quality using two
minute kick samples. We have continued testing monthly until November.
The consistent results from these tests have led us to believe that
agricultural runoff is not the leading cause of E. Coli in our local beaches
as if slurry were the primary cause, nitrate levels would show significant
increase during springtime when fertiliser (which would be included in
the run-off) is spread. We then pointed towards storm water drainage and
poor sewage discharge systems as the main cause of pollution.
We then tested the Estuary, Owenahincha and the Warren Beach as well
as the streams feeding into the estuary for E. Coli and Nitrates. We took
various samples and sent them to Acorn Waters in Bandon to be assessed.
We sampled water on three separate occasions using 12 samples in total.
We took samples on ongoing tide, low tide, and outgoing tide after a
period of heavy rainfall.
From these results we can conclude that beaches located at the mouth of
a tidal estuary show higher readings than one that is not and that E. Coli
outbreaks occur after periods of rainfall.