It is no longer unusual in the course of an Irish summer to see green scum floating on the surface of a lake or river. The sight of fish lying belly-up is not infrequent. These are "real indicators that something is wrong or out of balance".
What is most disturbing, according to Patrick Buck, assistant manager of South Western Regional Fisheries Board, is evidence our water quality is deteriorating at an accelerating rate. "It may take only 20 years to significantly alter our water quality to such a degree as to be seriously detrimental to our salmon stocks, fish which have swum quiet happily in our rivers for the past 10,000 years."
Summer 1997. After some years of improvement, it is back to "river wipe-out", several hundred thousand fish killed by pollutants, drinking-water bans and restricted bathing. As usual, it is mostly a consequence of human activity, notably farming (40 per cent of cases). It shows in the discharge - usually accidental - of toxic substances into waterways.
Fish-kills might still be in decline (the running total for 1997 is 35) but the scale of devastation, not to mention the range of pollution types, adds new dimensions.
Accidental discharge of slurry from a piggery near Macroom was a typical "human error fish kill", even if the devastation made it among the worst ever in Munster - 100,000 fish dead over 10 miles of river.
Pollution of a waterway at Cahore Point, Co Wexford, is a not-so-gentle reminder that nature can pollute. It may also show water is vulnerable in flood as well as drought. A combination of stagnant water and rotting vegetation became a devastating black cocktail. The Mulkear fish kill in Co Limerick could be due to a similar phenomenon, although Shannon Regional Fisheries Board stands over its view it was "agricultural in nature".
The greening of Killarney's lakes is manifestation of the most insidious form: systemic pollution. A steady discharge of pollutants upsets the essential water balance in a lake/river. The process is eutrophication (which leads to a deficiency of oxygen), the chief culprits are phosphates; a consequence of too much fertiliser applied to land, human waste (particularly detergents) running into waterways and "industrial water", by-products of manufacturing or processing.
Water systems have a remarkable ability to survive what is known as "point pollution", the once-off discharge. A tank overflows, a sewage pipe breaks.
Provided conditions are right, a river can rehabilitate itself. Eutrophication, says Patrick Buck of SWRFB, is entirely different. It multiplies water vulnerability and is a problem which Ireland has yet to confront.
Inniscarra Lake in the Lee valley has huge populations of bluegreen algae, their proliferation triggered each year by sun and warm water. The lake provides a "micro-picture" of the vulnerability of our waterways. Over £400,000 is being spent on developing it as a tourism angling venue. "Eutrophication has the potential to scuttle the whole venture overnight."
The main culprit in the deteriorating water-quality picture is phosphate, of which 80 per cent comes from agriculture. Phosphate concentrations in soil are 10 times what they were in the 1950s. Fertiliser spread has increased by 350 per cent.
Farmers rightly defend themselves where they are not responsible, and highlight efforts to farm in a more environmentally-sensitive way. The IFA cites "tremendous progress through heavy investment in pollution control". The farm advisory body, Teagasc, has revised phosphate recommendations.
But evidence on Lough Leane shows farmers "have a major responsibility for recent pollution", says the Minister of State for the Environment, Dan Wallace. "The problem nationally is clear from the estimate that farmers could reduce phosphorus fertiliser purchases by £25 million annually without adversely affecting output. There is a run-off of 2,500 tonnes of phosphorus from land to water each year." The Minister for Marine and Natural Resources, Dr Woods, talks of an action plan underpinned by increased penalties for polluters and a new forum involving farmers. This contrasts with years of ineffective action by the State, and inadequate water-sampling which failed to show up the scale of eutrophication, says Tony Waldron, pollution officer with the Trout Anglers' Federation of Ireland (TAFI).
Making the polluter pay the full cost of water restoration/restocking, backed by the possibility of prison sentences, are the measures required, he says, for the Government to prove its sincerity. During 1996, 55 prosecutions were taken under the Water Pollution Act, 31 of which were successful.
The European Commission is pursuing court proceedings against Ireland for failing to comply with a directive on discharges into the aquatic environment. In recent correspondence with the Government, it notes an Irish plan for a catchment-based strategy against eutrophication. The Department of the Environment says the plan is comprehensive, with clear targets.
SWRFB's Patrick Buck notes the irony in licensing and monitoring heavy and light industry (responsible for close to 20 per cent of phosphate loading). "Yet the sector responsible for 80 per cent - agriculture - is not formally monitored or licensed. Something is wrong here."
On his desk sits a list of 10 fishkills in the south-west so far this year; "Not good". Some £19 million is being spent in developing tourism angling. Nevertheless, says Mr Buck, "Ireland's clean green image is fast disappearing."
