National River Macroinvertebrate Surveys Data in Ireland

Home National River Macroinvertebrate Surveys Data in Ireland

The Environmental Protection Agency (EPA) in Ireland is responsible for the ecological monitoring and assessment of over 13,000 km of river channel nationwide. Our national macroinvertebrate dataset, collected for WFD purposes from 2007 onwards is now available for download.

Why monitor rivers?

Ireland is as much blue as green. Our island has over 84,000 km of river channels and more than 12,000 lakes. Rivers act like the land’s capillaries and blood vessels, carrying water from mountains to the sea. Because rivers and streams are closely linked to surrounding land, they are vulnerable to pollution from human activities. Monitoring helps protect drinking water, wildlife habitats, and the benefits rivers provide for food, tourism, and recreation.

Ireland’s River Monitoring Programme

The Environmental Protection Agency (EPA) monitors over 13,000 km of river channels nationwide. Ireland has one of Europe’s oldest river monitoring programmes, starting in 1971 and focusing primarily on benthic macroinvertebrates (i.e. larval insects (e.g. mayflies, stoneflies, caddisflies, beetles, etc.) together with crustaceans (e.g. shrimps), snails and bivalves, worms, and leeches).

Since the EU Water Framework Directive (WFD) in 2000, monitoring has focused on ensuring all our waterbodies (rivers, lakes, groundwater sources, estuaries and coastal waters) remain healthy and restoring those that are polluted. EPA ecologists assess more than 2,800 river stations at least once every three years.

Our most recent results are available on the EPA Geoportal (Water Quality and Monitoring tab)

Person collecting a macroinvertebrate sample in a shallow rocky stream surrounded by dense green trees. The individual is wearing gloves and using a kick sampling net in the River Owenass, Co. Laois, Ireland.
Collecting a macroinvertebrate sample from the River Owenass, Co. Laois, Ireland.

What are macroinvertebrates and why they matter

Macroinvertebrates are small animals without backbones that live on riverbeds, such as:

  • Insect larvae (mayflies, stoneflies, caddisflies, beetles)
  • Crustaceans (shrimps)
  • Snails and bivalves
  • Worms and leeches

These species are excellent indicators of water quality because they respond to pollution over time, showing long-term changes in river health.

How surveys are carried out

The majority of data is collected using a standard 2-minute kick sample with benthic macroinvertebrates identified and roughly counted on the bankside before being returned to the river. This biological monitoring is combined with chemical tests for a full picture of water quality.

What the data tells us

These surveys provide a spatial and temporal dataset that reveals how pollution affects rivers and tracks trends over time. The data shows strong links between macroinvertebrate communities and:

  • Land use: urbanisation and agricultural intensity
  • Catchment pressures: human and livestock densities
  • Chemical indicators: phosphorus, ammonia, nitrogen, oxygen demand, pH, and conductivity

This information is vital for assessing ecological status under the WFD and planning measures in River Basin Management Plans.

More background information can be found in our paper published in Scientific Data in 2020: A national macroinvertebrate dataset collected for the biomonitoring of Ireland’s river network, 2007–2018 | Scientific Data

Learn more

Cover of EPA report titled Ireland’s National Water Quality Monitoring Programme 2022–2027. Shows a calm lake with a small boat near the shore, surrounded by green hills under a partly cloudy sky. EPA logo at the top.

Ireland’s National Water Framework Directive Monitoring Programme, 2022-2027

The EPA runs a national monitoring programme to check water quality under the WFD. It covers rivers, lakes, coastal waters, and groundwater using long-term checks and targeted surveys where problems are likely. This data tracks progress toward environmental goals and informs River Basin Management Plans.

River Monitoring – Aquatic Invertebrates

This fact sheet explains how the EPA monitors river water quality using aquatic invertebrates as indicators of pollution. It outlines why they are important and describes the kick sampling method used to collect and assess them under the Water Framework Directive.

EPA fact sheet titled River Monitoring – Aquatic Invertebrates. Includes text explaining what aquatic invertebrates are and how they are surveyed in rivers. Shows photos of various invertebrates such as mayfly larvae, caddisfly cases, and freshwater snails, plus images of field sampling and identification.

Who is involved?

Quite simply, everyone in Ireland has a role to play. This can be from something as simple as making sure you don’t pollute your local stream, or a local community working together to establish a Rivers Trust to enhance the rivers and lakes in their area, to a Government Department or Agency helping a Minister implement a new policy to help protect and enhance all our water bodies.

This website has been developed and is maintained by the Environmental Protection Agency, and is a collaboration between the Department of Housing, Planning and Local Government, the Environmental Protection Agency, and the Local Authority Waters Programme.

LAWCO

Local Authority Waters Programme

The Local Authority Waters Programme coordinates the efforts of local authorities and other public bodies in the implementation of the River Basin Management Plan, and supports local community and stakeholder involvement in managing our natural waters, for everyone’s benefit.

EPA

Environmental Protection Agency

The EPA is responsible for coordinating the monitoring, assessment and reporting on the status of our 4,842 water bodies, looking at trends and changes, determining which waterbodies are at risk and what could be causing this, and drafting environmental objectives for each.

DECLG

Department of Housing, Local Government and Heritage

The Department is responsible for making sure that the right policies, regulations and resources are in place to implement the Water Framework Directive, and developing a River Basin Management Plan and Programme of Measures to protect and restore our waters.