Anja Murray: All is not well with Ireland's lovely lakes

As much as we don’t want to hear it, rain is one of the things that makes Ireland so special — more than 4,000 lakes adorn the Irish landscape but half of them are unhealthy, with pollution escalating

Kayaking on Lough Lein, Killarney National Park. Lakes are a defining characteristic of Ireland but half of all Irish lakes fail the Water Framework Directive's ‘good ecological status’. Picture: Valerie O'Sullivan

It feels as though it's been raining almost non-stop for a few weeks now. Light showers, heavy downpours, and even some persistent heavy rain with strong winds. The meteorologists on the radio offer commiserations as they deliver the forecast in apologetic tones.

As much as we don’t want to hear it, rain is one of the things that makes Ireland so special. In most parts of the country, it rains more than 200 days a year. All this rainwater feeds the many streams and rivers; it soaks into the once vast absorbent peat bogs, and fills the more than 4,000 lakes that adorn the Irish landscape.

It is still possible for lake ecosystems to recover, in some cases through active restoration, in other cases by simply reducing the influx of nutrients from surrounding catchments. Picture: Valerie O'Sullivan

Lakes are a defining characteristic of Ireland. We love a scenic lakeshore to walk along, to reflect, or share a family picnic. We can ponder clouds drifting across the lake surface and admire surrounding trees and hills reflected on the water. The lapping of a lakeshore has a calming effect on the nervous system. Lake swimming, canoeing and kayaking are all activities that have grown in popularity in recent years, especially since the pandemic. I adore being out in a lake with a 360° view of the world from the water.

Apart from providing us with enjoyment, a healthy lake is home to a wealth of wildlife. Specially adapted aquatic plants absorb enough sunlight to photosynthesise through layers of water, releasing oxygen for underwater animals to breathe.

One remarkable group of plants living in Irish lakes, the bladderworts, are carnivorous. They feed on small planktonic animals, using sophisticated mechanical bladder-like traps, which take only a split second to activate. Water lilies are in flower now, their leaves, flowers and seed cases all adapted with air-filled pockets helping them float. Freshwater sponges, classed as animals, have a mutually beneficial symbiotic relationship with photosynthesising algae.

Aquatic plants living in lake water provide habitat for a diversity of invertebrates — damselfly nymphs, aquatic snails, and the larvae of stonefly, mayfly and caddisfly. Many of these insects have impressive adaptions to life underwater. Caddisfly larvae, for example, make themselves tiny elaborate homes out of sand, gravel, stones, twigs and leaves.

Fish of every shape and size swim about eating the cornucopia of invertebrates that occupy every niche of a healthy freshwater habitat.  At this time of year, agile otters teach their young how to catch these fish, training their pups through play.

Kayakers at Errit Lake, Gorthaganny

On an island full of lakes, there is as much ecological variety as there is abundance of life. High mountain lakes within peaty catchments contain very different assemblage of plants and animals than lowland lakes in limestone catchments.

But it is a sorry state of affairs to have to report that half of Irish lakes are sufficiently polluted as to fail the ‘good ecological status’ required under the Water Framework Directive. This means that half of all lakes here are unhealthy, with pollution escalating.

Many of our once-thriving wild, freshwater fisheries have all but collapsed, along with the valuable angling tourism industry that they supported. As well as salmon and trout, many waterbird populations are now greatly reduced. Stunning crested grebes, tufted ducks, goldeneyes, mallards, moorhens, pintails and widgeon, have been suffering from the loss of habitat quality in lakes. Ireland has lost around half a million water birds — almost 40% of the waterbird population here — in less than 20 years.

We cannot continue to let this happen.

To tackle water pollution and restore good water quality across the aquatic environment, the European ‘Water Framework Directive’ sets objectives and approaches for each member state to implement nationally. In Ireland, successive ‘River Basin Management Plans’ have so far failed to deliver the changes needed, being too weak in ambition and scope to work properly. Under the Nitrates Directive, Ireland is required to reduce water pollution caused by nitrates and phosphates from agricultural sources, yet we have so far been failing in this endeavour too. In fact, trends have swung in the wrong direction, with nitrate pollution on the rise in nearly half of our rivers. This represents a 30-fold increase on pre-2015 trends for nitrates, when only a tiny proportion of sites were showing increases.

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Several main sources of pollution contribute to the problem. Insufficiently treated sewage from wastewater treatment plants is a major contributor. Commercial forestry contributes too. The most significant source of pollution impacting lakes is agriculture. Specifically, agricultural expansion and intensification is the leading cause of increased water pollution, which results mainly from the increased loading of fertilisers and slurry on land, which too often results in elevated levels of nitrates and phosphates in rivers and lakes. Excess nutrients entering rivers and lakes have serious impacts on water quality and wildlife.

The year is now 2022 and we have an excellent understanding of the pathways of pollutants. We have updated soil maps and technology that allows us to determine the carrying capacity of soils to absorb additional nutrients. We have better data than ever before about the sensitivities of our lakes and other aquatic habitats. We know where agricultural intensification can be sustained and where it cannot. State agencies, communities and farm organisations are all on board in agreeing that the pollution has to stop. Yet the required actions are still not being implemented. If we continue to pursue the temporary economic gains from the continued intensification of agriculture here, the price we will pay is the permanent loss of some of the most generous and valuable ecosystems on this island, our lakes.

There is an opportunity now for these unacceptable trends to be reversed. The next water management plan (the River Basin Management Plan) is currently being prepared by the Government — though the draft is weak and won’t work. Entrenched opposition to the implementation of necessary measures must be overcome. Urgent improvements are needed in policy and legislation, combined with investment to stop pollution.

It is still possible for lake ecosystems to recover, in some cases through active restoration, in other cases by simply reducing the influx of nutrients from surrounding catchments.

Ireland’s lakes were revered in ancient beliefs and values systems. Springs, wells and lakes were often held as sacred. It is time to re-assess how we treat our rivers and lakes today and take action to shape a different future. We know how; we just need to speak up for what matters, implement a river basin management plan that’s fit for purpose, and get a better bargain for us and future generations.