Fresh concerns over Mayo lake's elevated ammonia and phosphorus levels
A public meeting of the Lough Carra Catchment Association has revealed a number of interesting developments.
The event kicked off with updates from association director Chris Huxley, followed by a detailed progress report from Kieran Flynn, project manager of the Lough Carra LIFE Project.
One of the key speakers, Ann Marie Meaney, surface water officer for the Lough Carra LIFE Project, delivered an in-depth report on surface water testing conducted at 37 sites across the catchment.
During her presentation, Ann Marie highlighted Lough Carra’s sensitivity to nutrient levels and stressed the importance of achieving ‘high-status environmental quality standards’ to protect the lake.
Her findings raised concerns about elevated ammonia and phosphorus levels in certain areas and revealed that the catchment’s water quality is highly reactive to rainfall.
To address these issues, she emphasized the need for tree and hedge planting around the lake and inflowing streams to help naturally filter out excess nutrients before they enter the watercourses.
The association, in partnership with the LIFE Project, has also been closely monitoring the lake’s unique marl crust as part of baseline assessments to evaluate the ecosystem’s health.
Samples have been collected from strategic locations, including sites participating in the Lough Carra LIFE agri-environmental scheme and at the mouths of watercourses feeding into the lake.
Phillip Doddy provided a compelling presentation on this work, stressing the importance of preserving the marl, which serves as a key indicator of the lake’s overall health.
He also noted that rising nutrient levels are driving an increase in green algae and higher chlorophyll concentrations, further underscoring the need for urgent action.
Additional speakers included Cilian Roden, a specialist in underwater ecology, who presented concerning findings from his monitoring of Lough Carra’s underwater vegetation.
Cilian reported a troubling increase in pondweed species, which pose a threat to the lake’s native charophytes by out-competing them.
He also highlighted that the lake’s water is becoming progressively darker, and its marl crust continues to degrade, both signs of a deteriorating ecosystem.
Chris Huxley also gave an insightful presentation, focusing on the increased growth of bulrush and water milfoil, further emphasising the shifts in the lake’s vegetation.