Council denies lake’s algal bloom a cause for concern

Despite the presence of algae in Killarney’s largest lakes last year pollution is not expected to worsen this year, scientists have said.

Higher than normal levels of the algae were detected in Lough Lein between Sept and Nov 2011.

Concerns have again been raised about water quality in the lake, which has been battling with pollution for more than 30 years.

One of the worst algal blooms — a telltale sign of pollution — was evident in 1997 but the algae has not reached the same level since then, according to Kerry County Council.

Cllr Michael Gleeson raised the issue, asking if current levels of oscillittoria — a common blue green algae — in Lough Lein was a cause for concern.

Oscillittoria, the council said, was found in many Irish lakes, including Lough Currane, a well-known sea trout fishery in Waterville along with loughs Sheelin and Owel in the Midlands.

A council spokesperson said the extent of the bloom in Lough Lein last year did not pose a threat to the health of the lake.

The causes of the bloom, low phosphorous levels, were “at their lowest and best” for 18 years, he said.

“Our experience and that of outside consultants would seem to indicate that reasons for growth were largely due to lower summer/autumn temperatures in the lake combined with one of the dullest summers in record.”

He said the organisms involved thrive in low light conditions. If inputs to the lake are kept at a manageable level, as in other years, there should be no deterioration in the health of lake in 2012, he added.

The Killarney sewage treatment plant discharges to the lake. The European Court of Justice, meanwhile, has highlighted Lough Lein as an example of Ireland’s failure to comply with EU waste water directives.

Following the 1997 algal bloom, the Lough Lein Working Group, including representatives of statutory and voluntary bodies, was set up to draft a management plan for the lake.

Every river within a 10-mile catchment area was surveyed and sources of pollution, including farms and septic tanks, were traced.