Allianz and Afloat - Supporting Irish Boating

Ireland's sailing, boating & maritime magazine

Potentially "Life-Threatening" E.Coli Found in Survey of Irish Bathing Waters Prompts Calls to Revise EU Quality Criteria

2nd June 2021
The E. coli called Shiga-toxigenic E.coli (STEC) can lead to potentially life-threatening infection in about 10% of cases, the researchers state
The E. coli called Shiga-toxigenic E.coli (STEC) can lead to potentially life-threatening infection in about 10% of cases, the researchers state" title="Shiga-toxigenic E.coli (STEC) Credit: courtesy Microbe Notes

New research on potentially harmful bacteria in Ireland’s seas, lakes and rivers highlights the need to revise current EU bathing water quality monitoring criteria, NUI Galway (NUIG) researchers have said.

Analyses of 111 samples taken from 50 locations in Galway city and county, Cork city and county and Fingal, Dublin, between 2016 and 2019 detected a pathogenic form of E. coli .

This form of E. coli called Shiga-toxigenic E.coli (STEC) can lead to potentially life-threatening infection in about 10% of cases, the researchers state.

As Afloat reported earlier, the bacteria was detected in 57% of 84 sea waters where samples were collected – all of which are deemed of “good” or “excellent” quality, based on current EU bathing water monitoring criteria.

STEC was also detected in 78% of the 27 lake and river samples tested.

Shiga-toxigenic E.coli (STEC) is carried naturally by cattle and sheep.

The NUIG Antimicrobial Resistance and Microbial Ecology (ARME) research team says that a microscopic quantity has the potential to do serious harm to humans.

It warns that ingestion could cause serious illness including bloody diarrhoea while about 30% of STEC cases require hospitalisation and about 10% develop haemolytic uremic syndrome, a potentially fatal complication that causes renal failure.

Ireland has the highest rate in Europe, the team states. Figures from the Health Protection Surveillance Centre record that in 2016 Ireland reported 16.6 cases of STEC per 100,000.

This is higher than the next worst offenders - Switzerland (8.2/100,000 population) and Norway (7.3/100,000 population) respectively- they point out.

“These findings highlight the need to consider revision of current EU bathing water quality monitoring criteria to consider characteristics of the organisms present,”Prof Dearbháile Morris of ARME says.

Her team is asking people to take the survey. It aims to “build a picture of what is stopping people from fully utilising our seas, lakes and rivers, and to help identify problem areas”.

The survey is part of the four year PIER project (Public Health Impact of Exposure to antibiotic Resistance in recreational waters), funded by the Environmental Protection Agency (EPA).

The researchers are asking the public to take the survey to help identify the barriers and enablers for people’s interaction with blue spaces - our beaches, seas, lakes and rivers.

“The most recent bathing water quality data reports that 96% of our identified natural bathing waters meets the minimum required standard,” Prof Morris, who is principal investigator on the PIER project,says.

“However, our research has revealed the presence of organisms of public health concern in waters designated as of excellent quality in some cases,” she points out.

NUI Galway researchers will use the findings from the PIER project to create a systems map to identify problem areas, identify and prioritise collaborative change strategies and explore stakeholder engagement opportunities.

“No matter how much or little you engage with our waters, your contribution will help co-design strategies to maintain and protect our waters for future generations,” Dr Sinead Duane, postdoctoral researcher with the project, says.

For more information and to take part in the survey visit

Published in Sea Swim
Lorna Siggins

About The Author

Lorna Siggins

Email The Author

Lorna Siggins is a print and radio reporter, and a former Irish Times western correspondent. She is the author of Everest Callling (1994) on the first Irish Everest expedition; Mayday! Mayday! (2004) on Irish helicopter search and rescue; and Once Upon a Time in the West: the Corrib gas controversy (2010).

We've got a favour to ask

More people are reading than ever thanks to the power of the internet but we're in stormy seas because advertising revenues across the media are falling fast. Unlike many news sites, we haven’t put up a paywall because we want to keep our marine journalism open. is Ireland's only full–time marine journalism team and it takes time, money and hard work to produce our content.

So you can see why we need to ask for your help.

If everyone chipped in, we can enhance our coverage and our future would be more secure. You can help us through a small donation. Thank you.

Direct Donation to Afloat button
Who is Your Sailor of the Year 2021?
Total Votes:
First Vote:
Last Vote:

Featured Sailing School

INSS sidebutton

Featured Clubs

dbsc mainbutton
Howth Yacht Club
Kinsale Yacht Club
National Yacht Club
Royal Cork Yacht Club
Royal Irish Yacht club
Royal Saint George Yacht Club

Featured Brokers

leinster sidebutton

Featured Associations

isora sidebutton

Featured Webcams

Featured Events 2022

Featured Sailmakers

northsails sidebutton
uksails sidebutton
quantum sidebutton
watson sidebutton

Featured Chandleries

CHMarine Afloat logo
osm sidebutton

Featured Marinas

dlmarina sidebutton

Featured Blogs

W M Nixon - Sailing on Saturday
podcast sidebutton
mansfield sidebutton
BSB sidebutton
wavelengths sidebutton

Please show your support for Afloat by donating