Freshwater resources form an essential part of our landscape and provide a range of habitats supporting a wealth of wildlife including fish, birds and invertebrates. They are essential to Irelandís biodiversity. Freshwater biodiversity is vulnerable as freshwater is a resource for humans that may be extracted, diverted, contained or contaminated in ways that compromise its value as a habitat for organisms.
There are over 11,000 lakes in Ireland located primarily in the midlands, west and northwest. Together rivers and lakes comprise nearly 1,500 km2. There are a number of different types of lakes in Ireland each with their own characteristic species and habitats. The classification of lakes is generally based on the trophic or nutrient status of the water. Typical lakes species include pondweed, a variety of lilies and mosses. Our most interesting type of lake is probably the turlough, which is practically unique to Ireland occurring mainly in the west. This is a seasonal lake in basins or depressions in limestone areas and supports a wide variety of aquatic, amphibious & terrestrial species.
Rivers can be divided into two types of river Ė upland and lowland. Common plant species found in rivers include aquatic mosses, lichens, liverworts mainly in upland rivers while lowland rivers have such species as waterlillies and reeds. Irelandís rivers support a variety of fish including salmon, trout and pike. Birds that can be seen on the river verges include kingfishers and herons.
Overall, our water quality is good, which means there is a diverse range in the flora and fauna present in our freshwater systems. However, there are a number of pressures that have been identified as having an adverse effect on our rivers and lakes. These include enrichment of watercourses with nutrients such as nitrogen and phosphorous from agriculture activities and inefficient waste water treatment mainly in the form of septic tanks. Nutrient enrichment (or eutrophication) of water leads to an over growth of algae and aquatic plants, which in turn cause a depletion of oxygen in the water, leaving it unable to sustain other forms of life. Other threats to the biodiversity of Irelandís freshwaters include:
- changes in land use e.g. clearing of land or planting of coniferous trees which may increase the acidity of the water and increase siltation; and
- The introduction of non-indigenous species e.g. zebra mussel which has caused serious problems for some fish since it was introduce here.
What can I do to protect freshwater biodiversity?
∑ The Water Framework Directive encourages the participation of all citizens, organisations and industries to actively take part in the development of management plans for their particular River Basin District. Tourism groups, anglers associations, Tidy Towns committees and members of the public should make their views known. To find out how you can get involved, go to http://www.wfdireland.ie/ under the River Basin Management section.
∑ All septic tanks should be constructed in accordance with regulations. Consult the EPA Wastewater Treatment Manual ĎTreatment Systems for Single Housesí before constructing a septic tank (see http://www.epa.ie/ under Technical Guidance and Advice/Guidance Documents
∑ Septic tanks need to be desludged regularly to ensure efficient operation so DO desludge when necessary!
∑ Never discard household hazardous liquids by flushing into drains or down the sink or toilet. E.g. paint thinners, solvents, oil, unused paint or pesticides. If in doubt read the label on the product and check for hazard warnings.
∑ Ensure that soiled water (from sinks, washing machines, dishwashers etc.) is discharged into a sewer and not into a surface water drain
∑ Always bring home your rubbish. Litter finding itís way into watercourses can cause damage to fish gills and can clog up spawning grounds.
∑ One the Farm - Keep all dangerous substances stored safely and safe guard against accidental spillage. E.g. pesticides, veterinary products, oil, and artificial fertiliser. Any accidental spillages of harmful substances should be reported to the local authority. This is a requirement of law and failure to report an accidental spillage or discharge to waters may result in prosecution.
∑ Control and manage the collection and storage of all farmyard wastewater, including cattle manure, cattle slurry, silage effluent, soiled water from yards, manure heaps and dairy washings.
∑ Under the Nitrates directive there are specific requirements for the storage and spreading of livestock manure and other fertilisers. For more information, see Nitrates Information.
For more information of Freshwaters including types of freshwater systems in Ireland, interesting and rare species associated with freshwaters, threats to freshwaters and the legislation that protects them download Freshwater Factsheet