Until very recently, even where there has been the best of intentions, the monitoring of Irish lake-water quality was little more than tokenism. The true state of water systems making up one of Europe's most precious environmental assets was clouded by lack of information.
Comfort was taken in the absence of glaring evidence, though anglers could sense it with simmering anger before the scientists saw it in their figures: high phosphate levels, high nitrates, low oxygen.
On a separate level there were indications of a related, sinister threat: increasingly abundant cyano-bacteria lurking in sections of our most important lakes, ready with a change in weather/wind, when combined with environmental stress, to suddenly proliferate to colossal numbers and form visible and often toxic algal blooms, surface scums and conspicuous shoreline accumulations when concentrated by the wind.
While those microbes sound like the precursors of Martians, they are naturally present in water and harmless in normal concentrations. But their take-over of a portion of a lake, or signs of accumulation just below the surface, are becoming all too real a sight, as was evident on Lough Mask in Co Mayo last summer. Fortunately, the conditions then did not contrive to facilitate a cyano-bacterial explosion.
It is equally fortunate that the Environmental Protection Agency saw fit to commission a European Regional Development Fund study over the 1996-98 period, co-ordinated by Dr Andrew Petersen of Cork Institute of Technology.
It has not produced all the answers, but more is now known about the key area of concern, harmful toxins associated with bloom formation, even if the exact environmental conditions for their production still escape scientists.
What is perhaps most disturbing in reports produced by the Petersen team was the ease with which cyano-bacteria "achieve plankton dominance" in what are essentially lowland limestone lakes, which account for some of Ireland's most important lakes.
"This tendency is endemic," it concludes, "and readily manifested by quite mild levels of eutrophication." In short, with Irish lakes generally there is a strong tendency to bloom formation.
In addition, the growing evidence of the link between bloom formation and the most enriched lakes should be put in the context of other EPA reports. These indicate a tightening, and in some instances deadly, grip of eutrophication (due to an increasing supply of plant nutrients, notably phosphorus) on lakes, many of which would have been classified as pristine 10 years ago.
The probability that cyano-bacterial toxicity in Irish surface waters is higher than indicated by survey figures needs to be urgently investigated. Such is the extent of the threat, the EPA has been told that water management strategies should take the approach of considering all blooms of cyano-bacteria as potentially toxic.