Cleaning up our streams

IRELAND is speckled with small lakes and streams, about which little enough is known scientifically.

Anyone who grew up in the country in the 60s and 70s will have memories of catching fish in the little rivers that were everywhere and that seemed to have an abundance of brown trout. Now, the trout are scarce, if there at all, as many waterways are polluted.

There’s growing interest in small water bodies and that august institution, the Royal Irish Academy, is putting a new focus on them and is encouraging research as well as action to reduce pollution before we lose such a vital part of our freshwater resources.

Small streams make up 77% of the river network and about 96% of lakes are under 100 acres in area. Their close connection to land means they are particularly vulnerable to pollution. This is most significant for drinking water supplies which mainly originate from such lakes and streams before ending up in reservoirs. The EPA has been tracking water quality in small streams, but due to their sheer length 57,000km), it’s impossible to fully capture the extent of the pollution.

The academy, which has published a collection of papers on the subject, highlights their necessity for spawning, pointing out streams no wider than 1m can be important for fry production. “Their contribution when summed over the extensive stream network can be substantial and critical to the sustainability of downstream fisheries,’’ say the editors, Mary Kelly-Quinn and Jan-Robert Baars.

They note that the streams are impacted by growing urbanisation and farming and forestry operations, saying forestry poses a significant threat.

We have around 12,000 small lakes and, in a paper, Martin McGarrigle reveals less than 2% are actively monitored under the Water Framework Directive (WFD). But, he does strike a hopeful note in alluding to a growing realisation in the EU that “small is beautiful’’ and that more needs to be done to prevent the continuing decline of small water bodies.

Mr McGarrigle, however, stresses blanket regulations can only go so far and it’s necessary to have “boots on the ground’’ to deal with varied pollution problems. Local authorities have the final responsibility for implementing measures to ensure good water quality.

The task for each local authority, he adds, is to prioritise sites for monitoring in an effort to track down pollution sources. It’s only logical that improving the quality of small streams is essential if the bigger receiving waters downstream are also to improve, he explains.