Just over half (50%) of the 3,192 river water bodies assessed nationally are in satisfactory ecological health being in either good or high status. The remaining almost 50% are in moderate, poor or bad ecological status. There has been a 1% decline in the number of monitored river water bodies in the satisfactory condition since the 2013-2018 period.
Of the 319 river water bodies designated with a high status objective in the 2016-2021 period, only 137 (43%) are currently meeting the objective. Of the total high status objective river water bodies, 43 improved in ecological status and 47 declined since the last assessment. This represents an overall net decline of 4 river water bodies or 1% in the high status objective water bodies over this period.
The catchments with the lowest percentage of monitored satisfactory river water bodies are located mainly in the northwest, east, southeast and midlands. The Munster Blackwater, Nore and Suir catchments in the south and southeast have the highest number of declines in status.
Excess nitrogen in the east and southeast continues to affect water quality in these areas. High phosphate concentrations in parts of the east, northeast, southwest and southeast of the country are a problem for our rivers in these regions. These excess nutrients coupled with physical habitat damage are harming the ecology of our rivers.
The net improvement in river water quality in the Priority Areas for Action reported here is a good sign but these improvements need to be understood and the learnings expanded to other water bodies as a matter of urgency.
Nationally, 557 lakes (69%) are in good or better ecological health and the remaining lakes (31%) are in unsatisfactory condition. There has been a 2.7% decline in the number of monitored lakes in satisfactory ecological health since 2013-2018. The majority of declines in lake status are being driven by increasing total phosphorus concentrations that are in turn causing excessive algal blooms which damage the lake ecology.
The majority of high and good ecological status lakes are found in the southwest, west and northwest of the country while the majority of moderate or worse ecological status lakes are located in the northeast of the country. This distribution tends to reflect the difference in the level of human activity, hydrogeology and soil conditions in these regions. Lakes in the northeast of the country have the highest total phosphorus concentrations that are also rising. Restoring these lakes to at least good status by 2027 represents a significant challenge as they often contain a historical legacy store of phosphorus in their sediments that is slowly being released over time.
The majority (91%) of our groundwaters are in a satisfactory condition, which is a positive outcome. As with our rivers and marine environment, groundwaters in the south and southeast of the country have elevated nitrate concentrations and are showing an increasing trend.
There are localised issues in our groundwaters with elevated nutrients and chemical substances affecting an increased number of drinking waters. In addition to this, chemical pollution related to historical mining, industrial and waste sites still persists in some areas.
36% of transitional water bodies and 81% of coastal waters are in high or good ecological status. Transitional and coastal waters have seen a significant decline in status in the 2016 to 2021 assessment, which is particularly worrying. The increase in nutrient inputs to the marine environment are likely a strong driver of these declines. Most of these increases in nutrient inputs have been seen in the south and southeast of the country. This continued pressure is now having impacts on the biology of both the estuarine and coastal waters.
The latest details on water quality in Ireland, including maps showing water quality to the end of 2018, is available on the “Catchments.ie – Water, from source to sea” website (www.catchments.ie).
Ireland’s marine environment is one of the largest in the European Union (EU) and is nearly 10 times its land area. The temperate waters that surround Ireland are highly productive and provide a rich mosaic of marine life, including hundreds of species of invertebrates and fish, 24 species of whales and dolphins, breeding colonies of both the common and grey seal and some of the largest breeding populations of seabirds in Western Europe. The assessment of this wider marine areas is covered under the EU Marine Strategy framework Directive.
Ireland’s location in the Atlantic Ocean on the edge of the European continent has meant that its marine environment has remained relatively unpolluted. In recent years, however, the level of environmental stress, from both internal and external sources, has increased. Coastal development, particularly during the 1990s, has resulted in an increase in the range and magnitude of pressures that have the potential to impact negatively on the quality of Ireland’s tidal waters.