Nitrate and phosphate over-use is blamed for coastal pollution

Excessive use of nitrate and phosphate fertilisers by farmers is polluting Ireland's coastal areas to a "very worrying" degree…

Excessive use of nitrate and phosphate fertilisers by farmers is polluting Ireland's coastal areas to a "very worrying" degree, according to the latest Coastwatch survey, published yesterday.

The survey, carried out by local authority officials and a large number of volunteers, covered 1,102 stretches of coastline, each 500 metres long, 911 in the Republic and 191 in Northern Ireland. It confirmed that pollution of all kinds continues to be a major problem.

Ms Karin Dubsky, co-ordinator of Coastwatch Europe, said Ireland has an unusually large number of inflows into coastal areas, with direct discharges from the hinterland an "obvious" pollution threat.

Of these inflows, 147 showed discolouration, scum or froth from pollution, while 141 had dumped debris, with plastic bags the most common. Sewage or sewage fungus was observed at 73 inflows.

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Oil was seen on 24 inflows and dead fish in 19. But most alarming was the high incidence of nitrate pollution, with 40 per cent of the 242 inflows tested showing levels of 25 or more milligrams per litre, and 15 producing "stunning" readings of 100 milligrams or more.

Ms Dubsky said that "massive" phosphate levels were also recorded and there was a need for "immediate research" to establish the extent of the problem, caused by the excessive nitrate and phosphate fertilisers used on farms.

She also noted an increase in the number of algal blooms, including toxic species. The suspected causes were a mix of fertiliser, slurry, sewage and food industry discharges.

Dr Harry Gracy, of the Department of Agriculture in Belfast, said intensive farming meant lower water quality, as the soil in Ireland was being "overloaded" with fertilisers.

He said Ireland, North or South, was "heading the world" for the phosphate content of its soil, with levels of up to 125 microgrammes per litre recorded in Lough Neagh. The message for farmers was that phosphate levels "don't need to be sky-high."

Ms Dubsky said Ireland's coastline had the most rubbish in northern Europe, with plastic waste "massively worse".

She called for the introduction of a mandatory "deposit and return" scheme for all drinks containers, including plastic bottles and aluminium cans. This could be done by ministerial order under the Waste Management Act and would dramatically reduce the problem.

Materials from landfill dumps were also common, followed by large metal objects, parts of bridges, cars, fridges, prams and supermarket trolleys in urban areas. Furniture was found on 22.5 per cent of survey sites.

Household refuse in piles or bags was found on the same proportion of sites, indicating that some people were still engaged in "purposeful dumping" of their refuse over the side of the road, or cliff. A total of 816 used tyres were found, with a peak count of 75 in one area.

The incidence of household refuse rose to a peak of 31 per cent of sites surveyed in 1992, due to the introduction of "pay by the bag" domestic refuse removal charges. It decreased to 24 per cent this year, though there had been a "startling rise" in fishing-related waste.

In terms of perceived threats, coastal erosion scored the highest, followed by dumping, sewage and recreational abuse. Curiously, construction ranked quite low as a threat despite the recent surge in development work, often affecting important wildlife habitats.

Ms Dubsky welcomed the publication yesterday of a draft coastal zone management plan. But she said there was a need to involve all participants "genuinely working together", rather than having the Government "going it alone".

Frank McDonald

Frank McDonald

Frank McDonald, a contributor to The Irish Times, is the newspaper's former environment editor