Old River Shannon Foundation

17/08/2026

Ireland’s Migratory Fish #2: Atlantic salmon (Salmo salar).

The second species in my series on Ireland’s diadromous fish is probably our best-known migratory fish. Few Irish animals have comparable cultural importance to Atlantic salmon. Fionn mac Cumhaill and the Salmon of Knowledge remain embedded in Irish mythology, while Percy Metcalfe’s salmon has appeared on Irish coins since 1928. Salmon have also supported angling, commercial fisheries and rural economies for generations.

But that importance has also shaped how we manage them. We still tend to think of salmon primarily as an exploitable fisheries resource, rather than as a wild species within a functioning river ecosystem.

Atlantic salmon reproduce in freshwater, grow at sea and return to their natal rivers to spawn. This is an anadromous life cycle. Individual rivers support distinct populations adapted to local conditions. Salmon are also part of much wider ecosystems.

⚠️The pressures on salmon are enormous. The species is globally Near Threatened, while its conservation status in Ireland under the Habitats Directive is Bad and deteriorating.

⚠️Large hydroelectric schemes have severely altered salmon rivers across catchments covering nearly a quarter of the island of Ireland. More than 73,000 other potential barriers have been catalogued across the river network, yet only a very small proportion have been removed or mitigated.

⚠️Only around half of our surface waters are in satisfactory ecological condition. Many rivers have been straightened, deepened, embanked and disconnected from their floodplains, while the OPW still maintains approximately 11,500 km of river channel under the Arterial Drainage Act (1945).

⚠️Climate change is bringing warmer water and lower summer flows. Marine survival has fallen dramatically. Aquaculture, escaped farmed salmon, disease, invasive species, and illegal fishing add further pressures. When survival at sea deteriorates, restoring freshwater habitat becomes more important, not less.

Recreational angling is also a pressure on salmon. Yet salmon conservation remains strongly focused on providing fish for anglers to catch. A fisheries Conservation Limit tells us whether a population may support exploitation. It is not the same as restoring that population to favourable conservation condition. Yet catch-and-release angling, which is far from impact-free, can be allowed at only 65% of the Conservation Limit.

“Fisheries” also means more than catching adult salmon. It can include hatcheries, stocking, predator control, fish-counter weirs, gravel raking, boulder placement, bank clearance, and fish passes designed primarily around salmonids. These activities may have legitimate purposes, but they remain interventions in rivers and can negatively affect other sensitive aquatic species, the wider ecosystem, and even salmon populations themselves. They must not be presumed beneficial simply because they are labelled fisheries conservation or enhancement.

A fish-counter weir is still a structure in a river. A fish pass designed primarily for adult salmon can fail the rest of the aquatic community. A river engineered to produce parr is not necessarily a healthy river. A salmon hatchery can produce fish, but it does not restore a wild population. A calculated harvestable surplus is not favourable conservation condition. An open fishery is not evidence of conservation success.

✅Anglers have made major contributions to river protection, monitoring and salmon conservation. We need more people interested in rivers, not fewer. But angling must be treated like any other pressure on a protected species.

In Natura 2000 rivers, Atlantic Salmon are an Annex II qualifying interest. The legal objective is to maintain or restore them to favourable conservation condition. The fact that we also wish to catch salmon does not change that test.

⚠️The annual salmon regulations determine which rivers may be opened for salmon fishing, whether fishing is harvest or catch-and-release, and how many salmon may legally be killed where harvest is permitted. Yet these regulations do not proceed to Appropriate Assessment (AA); they are screened out each year.

AA is the legal process used to determine whether a plan or project could adversely affect a Natura 2000 site. Screening is not AA. It is the preliminary, precautionary test used to decide whether AA is required, and AA must follow where likely significant effects cannot be excluded on the basis of objective scientific information.

Against that test, it is difficult to see how the annual salmon regulations can credibly be screened out where they authorise the capture and killing of salmon within SAC rivers designated to protect the species.

Atlantic salmon are in bad and deteriorating conservation status, some stocks remain below even their fisheries Conservation Limit, and fishing takes place alongside barriers, pollution, altered flows, habitat degradation, climate stress and poor marine survival. In that context, the possibility of significant effects cannot reasonably be dismissed at screening.

✅The regulations should therefore proceed to Appropriate Assessment. That does not mean every fishery must close. It means applying the Habitats Directive correctly. The legal question is not simply whether enough salmon remain to permit exploitation; it is whether the proposed fishery, alone and in combination with other pressures, can be shown not to adversely affect the integrity of the Natura 2000 site in view of its conservation objectives.

Irish rivers are divided between an extraordinary number of State bodies, while major river systems remain controlled under archaic sectoral legislation. The OPW manages rivers for drainage. ESB manages major systems for hydropower. Waterways Ireland maintains navigation and more than 50 navigation weirs. Uisce Éireann abstracts water and discharges wastewater. The EPA licences discharges and abstractions. IFI is expected to conserve fish while also managing fisheries and developing angling. NPWS manages many of the other protected species living in exactly the same rivers.

⚠️No single institution has overriding responsibility for restoring the ecological integrity of the river itself. The response to the major Blackwater fish kill in 2025 illustrated the problem: multiple agencies became involved, yet the event exposed how unclear responsibility had become.

⚠️ESB has recently rebranded the rivers affected by its hydroelectric operations as “ESB Sustainable Rivers”. The underlying fish passage problems, turbine impacts, flow regulation, and fragmentation of salmon habitat remain - the only significant change has been the branding. That is symptomatic of the wider problem in Irish river management: fundamental reform is delayed, existing pressures are normalised, and inaction can be repackaged as environmental progress.

A salmon river is also a lamprey river, an otter river, a kingfisher river and, in some catchments, a freshwater pearl mussel river. These species need many of the same things - clean water, natural flows, intact riparian habitats, functioning floodplains and connected channels. Rivers cannot be effectively restored one species at a time.

✅Ireland needs river-specific wild salmon recovery plans, major barrier removal, real hydromorphological restoration, riparian buffers, floodplain reconnection, and more natural flows. We also need serious action against pollution, including wastewater, intensive agriculture, and industrial discharges.

➡️This should be delivered through a new dedicated aquatic conservation agency whose overriding purpose is ecological restoration - not fisheries exploitation. IFI should continue to manage fisheries, angling and fisheries enforcement. But the body deciding whether a wild population has recovered sufficiently to withstand exploitation should not itself have fisheries development embedded within its purpose.

✅We do not need another layer of environmental law to save Ireland’s wild salmon. We need to fully implement the laws we already have, particularly the Habitats Directive and Water Framework Directive. Properly applied, they could become the strongest mechanisms we have for driving wild salmon recovery.

✅Atlantic salmon are culturally and economically important. But they are first and foremost a native wild species. If we genuinely want to save them, we need to stop managing salmon primarily as an exploitable fishery and start managing our rivers as ecosystems.

➡️This is the second article in my series on Ireland’s migratory fish. Next, I will be looking at Ireland’s two Shad species: Twaite Shad (Alosa fallax) and Allis Shad (Alosa alosa).

11/08/2026

30/07/2026

People who depend on eel fishing for the bulk of their income are now waiting to hear what support they may get from Stormont.

Read more here: https://bbc.in/45crAkR

29/07/2026

Eutrophication in Lough Gur, Co. Limerick, last week. Lough Gur is one of Ireland’s most important archaeological landscapes, with evidence of human occupation extending back more than 6,000 years. It is also an ecologically important shallow, high-alkalinity lake which should support extensive stonewort (Chara) communities.

The lake’s hydrology was significantly altered during the 19th century when an artificial drainage channel was constructed from its north-western shore. This lowered the lake level by an estimated 2.1 metres. The lake is fed mainly by groundwater, rainfall and runoff from the surrounding land.

Lough Gur has a long history of nutrient enrichment. Sediment studies indicate that phosphorus and nitrogen increased progressively after 1950 and rose steeply from around 1990, associated with agricultural intensification, settlement, and tourism. The lake remains below the Good status required by the Water Framework Directive.

The known external pressures are agriculture and domestic wastewater treatment systems. Nutrients can reach the lake through runoff and groundwater because soils are thin or poorly drained and groundwater vulnerability is extreme.

The public toilets beside the visitor centre may also have been underestimated as a historical source. The older toilets discharged to a septic tank and percolation area only around 30 metres from the lake. A 2012 planning condition required the outlet to be blocked and the tank made watertight, but a 2022 LAWPRO study could not confirm that this had been done.

Despite acknowledging that sewage could reach the lake, LAWPRO concluded that the toilets were not a significant pressure. This was based on a speculative calculation assuming that only 10% of visitors used the older toilets. Monitoring beside the amenity centre had recorded unusually high phosphorus concentrations, but the report suggested that resident and migratory birds might explain these results.

The wastewater system was subsequently described publicly as “non-conforming”, and Limerick City and County Council carried out a substantial upgrade during 2024-2025, including new storage tanks, a pumping station and rising main.

This does not prove that the toilets were the main source of pollution, and the upgrade may now have resolved the risk. However, it shows that the wastewater arrangements required major intervention after LAWPRO had ruled them out as a pressure.

The lake may also continue to suffer from legacy pollution. Phosphorus accumulated in the sediments over decades can be released during periods of low oxygen, decomposition and sediment disturbance. The conditions shown in this video may therefore reflect continuing agricultural and wastewater inputs, historical pollution, and internal recycling of nutrients from the lakebed.

Lough Gur is an internationally important archaeological landscape, an ecologically valuable lake, and an important recreational area. Restoring it will require all nutrient sources to be investigated objectively. Blaming birds while inadequately investigating a potentially controllable wastewater source was never an adequate response.

28/07/2026

How a riverside greenway has affected the River Inny at Ballymahon: changes between 2022 and 2026.

This video documents the construction of the riverside greenway in 2022, the partial recovery of the river corridor by 2024, and the renewed clearance of riverside trees and vegetation in 2026.

The greenway was originally constructed by Longford County Council in 2022. I highlighted the environmental damage at the time, including the absence of an Appropriate Assessment and ecological surveys. There was a clear pathway for effects on Lough Ree SAC and SPA, while otter habitat was being directly disturbed and a mammal-proof fence was installed along the river. Otter is a qualifying interest of Lough Ree SAC.

The construction works caused extensive loss of the riparian area and substantially altered the river corridor. Despite this damage, the riverbank began to recover once the works had finished. When I revisited the site in June 2024, much of the disturbed area had revegetated.

This recovery appears to have been assisted by the retrospective installation of a geotextile mat along the edge of the walkway following complaints about the original works, as well as the initial retention of most of the riverside trees. It also demonstrated the resilience of nature when disturbed habitats are given sufficient time and space to recover.

However, when I returned a few weeks ago, the trees and other vegetation along this section of the river had recently been cleared. The recovering riparian corridor had again been severely damaged.

It is unclear who carried out these works or precisely why they were undertaken. Given that the River Inny forms part of an arterial drainage scheme maintained by the OPW, it is possible that the clearance was undertaken as drainage maintenance. The infilling and constriction of the original riparian area to accommodate the walkway may have reduced the conveyance capacity of the channel and increased local flood risk, subsequently creating pressure for removal of the trees.

It is also possible that the trees were removed to provide more open views of the river from the walkway. Whatever the reason, a significant ecological impact has occurred. The biodiversity and hydromorphological condition of the river corridor have again been degraded, with no evident environmental assessment of the works or their cumulative effects.

Hydromorphology refers to the physical form, flow and functioning of a river. It includes the channel, banks, floodplain, substrates, water depths, flow patterns and riparian vegetation that create habitat for aquatic and terrestrial wildlife.

Protecting these physical characteristics is a central requirement of the Water Framework Directive. The Directive is intended not only to improve polluted rivers, but also to prevent further deterioration in their ecological and hydromorphological condition. The works along the River Inny have severely reduced the ecological quality and natural functioning of this nationally important river.

Any project capable of significantly affecting a Natura 2000 site must also be subject to Appropriate Assessment. This obligation cannot be avoided by dividing a larger scheme into separate paths, bridges, extensions, maintenance works or incremental planning applications.

The development along the River Inny extends for several kilometres and connects with other greenways, paths and bridges. Much of it has been delivered through a series of individual projects and upgrades. As with the section shown here, ecological assessments have either been absent or inadequate. There has been no overall assessment of the cumulative effects of this continuing urbanisation of the river corridor.

Riparian zones are biodiversity hotspots. They provide wildlife corridors, protect water quality, stabilise riverbanks, sequester carbon and help reduce flood risk. In intensively managed landscapes, they are often among the last remaining refuges for wildlife. The mammal-proof fence creates an additional barrier by separating the river from the surrounding landscape and restricting the movement of animals along and across the corridor.

There is no environmental necessity to place cycleways, walkways, fencing and other urban infrastructure directly beside rivers. A scheme does not become environmentally sustainable simply because it is labelled a “greenway”. Where its construction removes riparian habitat, constrains a floodplain, damages wildlife corridors and creates a need for drainage maintenance, the term becomes a serious misnomer.

The River Inny is the second-largest tributary of the River Shannon. Its name is associated with the mythological Princess Eithne, who is said to have drowned at the rapids at Tenelick. Those rapids were lowered when the river was deepened and channelised during the Inny Arterial Drainage Scheme between 1960 and 1968. The river recovered to some extent from that historic engineering, but it remains under pressure from declining water quality, ongoing arterial drainage maintenance and the continued development of its riparian corridor.

This is not simply a story about damage done to rivers in the past. We are still narrowing, clearing, fencing and urbanising them today, despite the protections of the Water Framework Directive and the Habitats Directive. Princess Eithne’s rapids may have been lost decades ago, but the dismantling of the River Inny’s remaining natural character is still continuing.

27/07/2026

Pollution from a municipal sewage discharge into a salmonid and lamprey stream in Co. Roscommon. This recent video documents the ecological conditions in the receiving watercourse.

The video begins upstream of the discharge, where the stream supports clean gravel substrates and stands of Water-crowfoot (Ranunculus sp.) and Water-starwort (Callitriche sp.). These pollution-sensitive plants are indicators of good water quality and are characteristic components of the EU Annex I habitat type 3260.

Within metres of the outfall, the stream undergoes a dramatic ecological deterioration. The diverse upstream aquatic community is replaced by one dominated by only the most pollution-tolerant invertebrates, resulting in the lowest possible biological water quality classification: Q1 – Bad. Filamentous algae, cyanobacteria and sewage fungus become widespread. A warning sign on the first downstream bridge advises the public to avoid contact with the river, highlighting the seriousness of the pollution. This warning sign is about the watercourse – not the actual outfall. Although there is some downstream recovery, the effects of nutrient enrichment and eutrophication persist for several kilometres.

The final two clips show the Bella River approximately 5 km downstream, at an Environmental Protection Agency (EPA) water quality monitoring station. This site was assigned an unpolluted Q4 (Good Status) rating in 2024. However, the heavily eutrophic conditions now apparent are difficult to reconcile with that classification. The wastewater discharge is considered likely to be a significant contributor to cumulative nutrient enrichment within this catchment.

Further downstream, the river system flows into Lough Gara, which is designated as a Special Protection Area (SPA) under the EU Birds Directive. The lake is also an important public water supply source for north Roscommon, with water abstracted from its lower basin.

Water quality in this area is also affected by pressures from agriculture, forestry and peat harvesting. Hydromorphological alteration is another significant pressure. This sub-catchment was dredged and channelised as part of the Boyle Arterial Drainage Scheme between 1982 and 1992 and has never fully recovered.

Addressing diffuse pressures from agriculture, forestry and historical drainage works is both difficult and costly. Municipal wastewater treatment plants, however, are regulated point-source discharges that should not be causing severe ecological deterioration, warnings for the public to avoid contact with the receiving river, downstream impacts on a public drinking-water source, or a pollution pathway to a Natura 2000 site.

The conditions documented in this video should not exist in a regulated municipal wastewater system. They are not consistent with the objectives of the Water Framework Directive or with the protection of downstream Natura 2000 sites. Our rivers, wildlife and communities deserve better.

16/07/2026

Couldn’t resist this one!

23/05/2026

Today is World Fish Migration Day 2026. To mark this day, I want to highlight the extraordinary migration and challenges facing the European Eel (Anguilla anguilla).

This video shows juvenile eels (elvers) attempting to migrate upstream at Ennistymon Falls on the River Inagh, Co. Clare. These falls are natural but have also been modified for hydroelectricity generation. Very few of these elvers make it to the top. Eels migrate thousands of kilometres across the Atlantic Ocean, only to encounter migration barriers almost immediately upon entering the lower reaches of most Irish rivers.

The European Eel is now classified as Critically Endangered. Despite this, very little has been done in Ireland to facilitate eel migration, and we are still waiting for the first functional elver pass to be installed on an Irish river.

Migration barriers, hydropower infrastructure, habitat loss, declining water quality, pollution, and climate change are all contributing to the collapse of eel populations across Europe.

World Fish Migration Day highlights not only the importance of reconnecting rivers for migratory fish, but also the deep historical and cultural connections between people, rivers, and fisheries.

Ireland banned traditional commercial eel fishing in 2009. However, traditional eel fishing was never the primary cause of the collapse and, when properly managed, could potentially form part of a sustainable future for the species. Historically, fishermen often rescued elvers trapped below these falls. Eel fishing also represented an important part of Ireland’s cultural and fishing heritage, connecting local communities with rivers, estuaries, and wetlands for generations.

European Eels remain locally abundant in some areas, and we can still do far more to help them. With proper fish passage, habitat restoration, improved water quality, and targeted conservation measures, we can help this remarkable species recover while also restoring part of our lost aquatic heritage.

12/05/2026

Ballintra Gates on the upper River Shannon, April 2026. This dam is located at the outflow of Lough Allen and is operated by ESB.

The structure includes a so-called “submerged or***ce” fish pass, but this does not work and upstream fish passage into Lough Allen remains effectively blocked. Excessive turbulence and poor attraction flow at the entrance prevent fish from locating and successfully ascending the pass. These issues have been known for decades and concerns regarding fish passage here date back at least to the 1990s.

Even if this pass operated more effectively, submerged or***ce fish passes are inherently unsuitable for many fish species.

Historically, Atlantic Salmon (Salmo salar) migrated into the upper Shannon catchment through this route and European Eels (Anguilla anguilla) moved freely between the Shannon system and Lough Allen. These species are now rare in the upper Shannon, and this barrier also isolates the rare endemic Pollan (Coregonus pollan) population in Lough Allen from the other remaining populations of this unique Irish glacial relict species.

The structure also disrupts local movements of Brown Trout (Salmo trutta), cyprinids, Perch (Perca fluviatilis), Pike (Esox lucius), and other aquatic fauna. Wider ecological connectivity for species such as Otter (Lutra lutra) is also affected.

Despite the strategic importance of this site within the Shannon catchment, there are currently no specific plans to address fish passage at Ballintra Gates.

None of the major dams and weirs along the River Shannon currently provide adequate multi-species fish passage.

PS: I am fully aware that there are ongoing plans relating to fish passage on the Shannon. However, there have been “plans” to address these barriers for decades, while the same structures continue to block migration today.

There is a major difference between producing reports and delivering practical action. Despite years of announcements, there have still been no meaningful fish passage improvements provided at any of the major weirs and dams along the River Shannon. Even obvious opportunities continue to be missed. Meelick Weir was upgraded recently at a reported cost of approximately €3.2 million, yet no fish passage improvements were included in the works.

Until actual on-the-ground measures are delivered, it is important to continue highlighting these long-standing barriers and the ecological impacts they are causing. See less

29/04/2026

Termonbarry Weir on the upper River Shannon last week. The video shows a so-called “temporary” fish pass that was installed here approximately 25 years ago.

This weir is located upstream of Lough Ree and blocks fish passage to a substantial portion of the upper Shannon catchment, including the Boyle and Lough Allen systems.

This “temporary” fish pass does not work, and fish migration remains obstructed at this site. This structure was installed following a failed proposal for a hydroelectric development and was never designed as a properly engineered fish pass. It is loosely based on a pool pass but does not meet the requirements of a standard design.

In practice, it provides limited attraction flow, and fish are unlikely to locate the entrance. Flow through the pass is low, the gradient is too steep, and the structure includes excessive jumps. Angular edges present an additional risk of injury. Leakage beneath the structure further disrupts flow patterns, drawing fish away from the entrance into dead-end areas.

Pool pass designs are also inherently unsuitable for species such as eels and lampreys, meaning that even if the structure functioned as intended, it would not provide passage for key migratory species. There is no evidence that the pass is used by any fish species, and no monitoring has been undertaken. The weir and fish pass are owned and managed by Waterways Ireland.

Historically, large runs of salmon passed through Termonbarry on their way to spawning areas in the upper catchment, and this section of the river also supported important eel fisheries. While the most significant barriers on the Shannon are the hydroelectric dams in the lower river, structures such as Termonbarry Weir have also contributed to the long-term loss of migratory fish from the system.

None of the dams and weirs along the River Shannon provides adequate fish passage.