Water Quality in the Shannon Catchment

Pollution

Water quality still remains the most serious threat facing fisheries in the Shannon Region. Progress is being made with the main polluters. Local Authorities are finally putting in place the sewage infrastructure needed. The agricultural community has become more aware of the problems they are causing to the countries waters. However the main threat continues to be non-point agricultural runoff and farm waste mismanagement. The continuing malpractice of land spreading liquid manures at inappropriate times such as during frosty and wet weather conditions, is of continuing concern to the Board. 

Further success was reported on the river Maigue where, during the year, the Board worked with the agricultural community to reduce the agricultural pollution. Work needs to be done both locally and nationally  to acquaint some farmers of their responsibility in this area. The issue of inadequate storage capacity on many of the farms needs to be addressed and measures are required at national level to solve this problem.

An improvement in water clarity was noted in Lough Derg, which has been attributed by the EPA to the aquatic mollusc, the Zebra mussel. Although initially this may appear to be a positive development, the implications of the zebra mussel are far reaching and potentially catastrophic. This introduced pest, has no effective predator in Ireland, and has now spread throughout the Shannon River in less than five years. It has a very high reproductive capacity, colonising any available hard surface. It can alter the food chain necessary for a healthy fish community and eliminate other invertebrate species sharing the same habitat.

Although water clarity has increased in Lough Derg, phosphate inputs into Lough Derg are still unacceptably high. The Board urges the implementation of the Lough Ree/Lough Derg  Monitoring Groups recommendations as soon as possible.  To date there is no indication of an improvement in the aquatic ecology in these lakes.  The introduction of recent Bye Laws under the Local Government (Water Pollution) Acts will be of assistance in combating diffuse discharges of nutrients, in particular phosphorous, excessive levels of which lead to eutrophication. For these Bye Laws to be successful proper enforcement will be essential.

The implementation of the Water Framework Directive is greatly welcomed by the Board. The WFD, which sets out definite criteria for the improvement of water quality, has the capability of enabling real progress to be made on our water quality issues and we look forward to working with DOE and Local Authorities on its implementation in the coming years.

Fish Kills

Nine fish kills were reported during 2000. Although this is less than that recorded for other years, it should be remembered that the number of reported fish kills only reflects the number of serious pollution events when fish are present.  In seriously polluted areas, fish kills may not occur due to elimination of fish by previous or continuing pollution inputs. All recent reports indicate an increase in moderate pollution which causes degeneration of the fish habitat and kills fish stocks silently.