Lough Carra marl lake – protecting one of Ireland’s most unique and threatened habitats
Lough Carra in County Mayo is a unique lake in the west of Ireland and indeed in Europe, due to its marl habitat and its ecology consisting of unusual habitats and rare species.
The lake is included as a Priority Area for Action under the River Basin Management Plan for Ireland 2018-2021 and is currently the focus of local catchment assessment work. Peter Mitchell, Catchment Scientist with the Local Authority Waters Programme, outlines the work that is underway in the Lough Carra catchment and tell us about plans for managing the lake into the future.
The Local Authority Waters Programme (LAWPRO) first started working in the Lough Carra Catchment in 2016 and 2017, when the idea for a community association was being discussed, with many locals living within the catchment of the lake vocalising a real concern about the deteriorating quality of the lake, and what could be done to reverse the decline. Our Community Water Officer covering County Mayo Mick Kane met with several individuals in the catchment, and from there the seeds for the Lough Carra Catchment Association (LCCA) were sown. Part of the work of the LCCA was raising the profile of the lake amongst the local community, but also amongst key local and national stakeholders as Mayo County Council and the Environmental Protection Agency. Focused resources to investigate the causes of water quality deterioration observed in the lake were needed. As a result, Lough Carra was included as a Priority Area for Action (PAA) under the River Basin Management Plan for Ireland 2018 – 2021.
The Lough Carra Catchment Association (LCCA) was established after initial meetings held between the Community Water Officer and Lough Carra stakeholders in January 2018. Following an agreement from all parties the LCCA formed in April of 2018 with financial support for set up provided by The Local Authority Waters Programme. There have been monthly meetings held since April 2018 with up to 40 attendees. A keynote speaker presents at each meeting with topics that are relevant to the Lake, its community and solutions to the current water quality issues. Agencies involved include LAWPRO, Agricultural Sustainability Support and Advisory Programme (ASSAP), LEADER, National Parks and Wildlife Service (NPWS), Inland Fisheries Ireland (IFI), EPA, National Federation of Group Water Schemes (NFGWS), Mayo County Council, Galway and Mayo Institute of Technology (GMIT) Galway and Castlebar and other stakeholders.
The Local Authority Waters Programme catchment assessment team came on board in Summer 2018 and started work immediately on this PAA. The first step in the process was to undertake a desktop assessment which involved gathering the relevant spatial and temporal data available to us from various agencies and public bodies involved in water quality protection. The desktop assessment is a comprehensive study that brings together all available scientific data about the lake and its surrounding surface water catchment, together with its groundwater catchment given the karst nature of this area of County Mayo. It also forms the basis for the development of a work plan for the local catchment assessment of all water bodies influencing the quality of Lough Carra. A catchment drive around the Priority Area for Action helped cement what we learned from our desktop study prior to going out or getting our boots wet in the catchment.
The next step in the process was to hold a community information meeting which is key in encouraging and strengthening community stakeholder engagement. With an already active community group such as the LCCA, we knew we had lots to learn from the people living and working within the catchment of Lough Carra, and a key aim for the meeting was to learn as much as we could from them and use it to refine our knowledge and workplan.
The community information meeting was held within the Lough Carra catchment at the Carnacon Community Hall. During arrival and set up on the evening of 19 February 2019, it became apparent that we had little control over the things we often take for granted such as electricity. Strong winds earlier in the evening knocked out the power supply in the locality. This did not deter a turnout of some 32 attendees which included locals, representatives from Mayo County Council including their local councillor, the EPA, angler associations, third level institutions and a strong presence from the agricultural sub group and the education sub group of the LCCA. Fortunately, with the help of a local young farmer providing a generator and coupled with the meitheal like response of others whom gathered for the meeting, we managed to deliver an overview of who we were, what we were hoping to do and how we were hoping to work together with the community, without noticeable delay. A short presentation was delivered by our Community Water Officer Mick Kane and lead catchment scientist Ailbhe Douglas. A selection of A0 maps were posted around the hall along with a live sample of aquatic insects from a stream within the catchment.
Good conversations after the presentations helped us build on what we learned from the desktop assessment and influenced our local catchment assessment work plan. The attendees on the night offered us information about the location of karst features in the catchment, which we raised as an issue where there was a lack of mapped detail. We were also advised about the good water quality of the drinking water supply from the Carra Group Water Scheme which abstracts directly from the lake at Castleburke at the northern end of the lake. The community were interested to know what the issues were with the quality of the lake and what can be done to protect the lake into the future. Comments from the meeting included questions such as: •
- What impact does forestry potentially have on lakes?
- There is talk about a lot of focus on inputting rivers. Will LAWPRO be focusing on lake assessment at all and what methodologies would be used?
- People that fish the lake have noticed a deterioration in water quality over the last few years. The change in the marl substrate over time has shown that it has changed from a chalky white appearance to a grey and sticky consistency. If marl acts as a filter for contaminants and pollutants, maybe LAWPRO should assess the composition of the marl?
- Fish stocks have changed dramatically over time. No more dominant shoal of perch like in the past. Even if the Keel river is at good, do we acknowledge that there is an issue with Lough Carra?
Our fieldwork plan was further refined on foot of information provided to us at the community meeting, including details for unmapped small streams which needed to be investigated. Our initial fieldwork commenced in June 2019 and covered the geographical area of the three river waterbodies within the PAA feeding into the lake, and also including its outflow, the Keel river.
Our initial fieldwork took the form of surface water characterisation and biological assessment of aquatic plant and animal communities. Physcio-chemical data such as dissolved oxygen concentrations, pH, temperature and conductivity were also recorded. We also gratefully took up the kind offer of a boat trip out on Lough Carra for a day, with a superb guide provided by Chris Huxley. As well as absorbing knowledge imparted from Chris about the lake at various landmarks and strategic locations during the trip, we also recorded physico-chemical data and pressures observations around the lake as we went.
Additional local catchment assessment work was undertaken in September 2019 to build on the earlier round of results and capture any seasonal variation throughout the PAA. Water chemistry analysis was also included on this occasion to assist in refinement of significant issues related to nutrient pressures on the lake (orthophosphate, ammonium). We also undertook catchment walks along strategic sections of streams and rivers feeding into the lake, where information related to specific pressures e.g. domestic waste water, agriculture etc., were noted from the desk study, and required validation and evidence from the fieldwork to confirm if they were impacting.
The Geological Survey of Ireland (GSI) spent several weeks during summer 2019 mapping karst features in the Carra catchment. Both LAWPRO and GSI were carrying out assessments in the catchment simultaneously. An example of both agencies working together was at Roxborough National School where LAWPRO recorded a low dissolved oxygen reading at a study site beside the school and interactions with GSI revealed that their mapping of karst features coincided locally with this low reading. The data from both organisations are helping tell the story of the groundwater and surface water interactions and studying where the pressures are coming from that may be impacting on the lake.
Our assessment within the PAA has determined a certain level of impact and this has shown up in a number of forms such as decreased dissolved oxygen saturation in the rivers and streams; abundant to dominant cover of vegetation often rooted in deposits of sedimentation in the channels in historical arterial drainage channels etc. This impact can be attributed to a number of pressures such as physical alteration of the natural morphology of the watercourses through channelization; mobilisation and deposition of sediment from agricultural land drainage works, and livestock access points to waters courses for drinking.
During and following on from local assessment work, the Catchment Assessment Team liaise and work closely with the Agricultural Sustainability Support and Advisory Programme (ASSAP). LAWPRO refer specific agricultural related issues to ASSAP based on significant issues detected during local catchment assessment surveys e.g. sediment. ASSAP provide a free and confidential service to farmers in the PAA and undertake a whole farm assessment focusing on the significant issue identified by LAWPRO.
In parallel with the local catchment assessment work in the PAA, the LCCA decided to apply to LEADER to fund a feasibility study with a view to development of a LIFE application which would focus on nutrient reduction and community awareness within the Lough Carra catchment. Mayo County Council and NPWS came together as co-ordinating beneficiaries for the application. Several other agencies agreed to commit to the LIFE bid as associated beneficiaries and stakeholders including LAWPRO. A Steering Group was formed to help advise and guide on the development of a concept note for submission to the EU LIFE office.
In addition, a strong LCCA education sub group formalised in mid-2019 with IFI, NPWS, LAWPRO, GMIT, LCCA, principals of local schools and community members. To date, all national schools have been visited by IFI delivering their Something Fishy workshop. All national schools have also been given the NFGWS workbook All About Water and the teachers are progressing through the modules with a strong focus on catchment management. The result of these actions has led to the development of a very strong Catchment Association with community engagement, school projects and funding supports. The model adopted in this project may be transferable to other catchments.
LAWPRO also were heavily involved in Heritage Week which was held from 17-25 August this year and included Water Heritage Day on Sunday 25 August, which is a new initiative as part of Heritage Week. Along with similar numerous water quality awareness events, the Ballinrobe River festival was held on the banks of the Robe at the Burrows in Ballinrobe town. LAWPRO had a pop-up stand in the Environment Tent alongside IFI and National Parks and Wildlife Services. It was a great family day in the sun and there were great water activities such as stand up paddle boarding in the river.
The UK and Ireland Lakes Conference was held in Westport in mid-October this year. The first day included a day of presentations by many public agencies at Hotel Westport. Both Chris Huxley and Tom Byrne from the association spoke at the event about the Lough Carra Catchment Association to date and progress with the LIFE bid concept note application. The second day began with a trip to the shore of Lough Carra at Church Island. A short video detailing the history and amenity value of the lake was shown, which was written and directed by EPA Biologist Bryan Kennedy. Phillip Doddy also recited a poem inside the church as well as playing a couple of tunes on the violin with reference to the lake. The trip to Lough Carra concluded with an informal information sharing discussion on the shoreline.
Work is ongoing between LAWPRO and ASSAP. ASSAP will continue to work with the farming community. Collaboration will also continue with GSI which will help in the understanding the groundwater and surface water interactions in the catchment. LAWPRO will continue to support the LCCA and providing information back to the community.