Inland Fisheries Ireland publishes their River Shannon eel kill “investigation”


A major eel kill occurred on the Lower River Shannon on the night of the 7th to 8th December 2021. The eels were killed trying to pass downstream at Ardnacrusha hydroelectric station. A storm (“Storm Barra”) and high river flows created ideal eel migrating conditions. Storm Barra was a major storm event to hit Ireland with a red weather warning in place for the Lower River Shannon area from 16:00 on the 7th December 2021 – until the following morning.

On the morning of the 8th December, 2021 large numbers of dead and dying eels were found all along the river downstream of the hydroelectric station. These were adult “silver” eels on their spawning migration to the Sargasso Sea. The eels were killed because ESB was abstracting an excessive volume of water from the river (95% of the flow) – and they did not have adequate mitigation in place to protect the eels.

This is an ongoing problem at this site that has never been addressed. I have been highlighting this problem for several years. I usually find small numbers of eels but most of the eels killed are never seen. They sink, are washed away, are eaten by predators, or die out at sea days later. The fact that hundreds were visible along the Lower River Shannon on the morning of the 8th December 2021 indicated that thousands were killed.

Some of the dead and dying eels found on the Lower River Shannon on the 8th December 2021.

The ESB actually admit that thousands of eels are killed passing their hydroelectric station each year. They publish models that underestimate the eel run, exaggerate the benefits of their ‘Trap and Transport programme’, and overestimate escapement. Yet in 2020 they still estimated that over 7,000 eels were killed passing through the turbines at Ardnacrusha. The difference on the night of the 7th to 8th December 2021 was that thousands were killed in one night – rather than over several months.

The European Eel is a critically endangered species on the International Union for Conservation of Nature (IUCN) Red List of threatened species.

During Storm Barra the ESB were abstracting 95% of the flow in the Lower River Shannon SAC. There were no fish screens in place to stop eels from entering the turbines. The eels followed the abstracted water down the headrace and into the turbines.

Parteen Regulating Weir on the Lower River Shannon. The ESB abstract water here from the Lower River Shannon SAC and divert it down the headrace canal to Ardnacrusha Hydroelectric Station. On the night of the 7th to 8th December 2021 the ESB was abstracting 95% of the flow. The eels followed the water down the headrace into the unscreened turbines.
Ardnacrusha Hydroelectric Station on the Lower River Shannon. There are no fish screens and no bypass channels for downstream migrating fish. All the silver eels (and salmon smolts) arriving here have to go though the turbines. The way this scheme is operated has not changed since the 1930s.

The ESB claim that they were operating their silver eel ‘Trap and Transport’ nets at Killaloe that night – however the records from that night (7th to 8th December 2021) actually state that they caught no eels (zero) which is not credible. It has been shown that the ESB regularly do not operate their ‘Trap and Transport’ nets for eels. Even when all the nets are operated <30% of the eels are captured and moved around the dams.

On the 8th December 2021 I posted videos and photos of the eel kill on social media. I contacted Inland Fisheries Ireland (IF) and I encouraged others to report the fish kill to IFI via the fish kill hotline. I have been doing this since November 2015. IFI have to date ignored these reports and won’t treat an eel kill report in the same way as other fish kill reports. On the 8th December 2021, I called for IFI to be investigated if they did not investigate this event. This got a significant response on social media and on the 10th of December 2021 IFI confirmed (on social media) that they had launched an investigation.

However, over the coming days they never spoke to me during their “investigation” despite the fact that I found the eels, undertook my own investigation, and made myself available to make a statement to IFI on the matter on a number of occasions.

I first reported the eel kill to IFI on the 8th December 2021, again on the 9th December 2021. On the 10th December 2021 the story made international news with both IFI and I interviewed for the article. I was holding up turbine-killed eels in the article.

Turbine killed female silver eels found in the Long Shore area of the Lower River Shannon which is located juts downstream of the tailrace from Ardnacrusha Hydroelectric Station.

I offered again by email to both the Fisheries Environmental Officer and Fisheries Inspector on Monday 13th December 2021 to meet them and provide a statement.  My emails were ignored. It is not credible for IFI to not contact me if they were in fact doing an investigation on the eel kill.

I made a further offer on the 9th March 2022 to make a statement to the Fisheries Environmental Officer about the eel kill during a meeting on another matter. However, this offer was also declined. I also requested a copy of the report of the eel kill investigation but this was not provided.

Therefore on Monday 14th March 2022 I submitted a request under the Environment (AIE) Regulations 2007-2018 to obtain the report on the eel kill investigation. On the 6th April 2022 IFI quietly published a redacted version of the report on their website – presumably in response to my AIE request – and provided the full report to me under the AIE Regulations on the 13th April 2022.

The IFI eel kill investigation report states that “there were no reports to the office or staff of IFI Limerick concerning the eel mortalities from any persons with direct knowledge of the incident”. This is untrue as I reported the fish kill directly to IFI both by email and via social media.

In the report, IFI said that due to weather and tide constraints they were unable to launch a boat on the 9th December 2021. I note that I visited Ardnacrusha hydroelectric station by boat on this day and collected more turbine-killed eels. It was a dry calm day and boating conditions were ideal. IFI said instead that “investigations took place on foot. All accessible riverbank from Ardnacrusha to the Abbey River and including Corbally was walked”. However, there are very few areas of the riverbank accessible by foot. They say that “no eels were located during these searches”.

IFI claims to have done “a more comprehensive survey of the river” on the 10th December 2021. However, it seems that they were only on the river at high tide – and it is very difficult to find the eels at high tide. All the eels I found were collected during low tide. They state in the report that “despite these extensive searches staff managed to recover only one eel from the Abbey River”. This is meaningless as they were only out at high tide which is an unsuitable time to find turbine-killed eels. This was also over two days after the main eel kill event. Despite finding a dead eel they state in their report that “it is impossible to say whether [the cause of the eel death] was due to turbine strike to a predator or other post-mortem damage”. However, they give no details of how the eel was examined and provide no account of any injuries/damage apparent on the subject eel. It is not “impossible” to ascertain the likely cause of death of an eel.

The ‘Trap and Transport’ nets at Killaloe are regularly not operated. I confirmed that there were not operating in the days before the eel kill in December 2021. They were also not operated on the night of Storm Dudley in February 2022. Even when the nets are operated <30% of the eels are captured and moved around the turbines.

In the report they state that “An unknown quality of eels was also taken by Mr. Will O’Connor of Ecofact as can be seen in his social media posts detailing the event. While his reports initially said thousands of eels had been killed, he later clarified this to be an estimate based on the numbers of eels he observed”. I note that my title is “Dr” and my accreditation was awarded for a Ph.D. thesis I submitted to the National University of Ireland, Galway regarding eels on the River Shannon. I also hold an M.Sc. degree in Applied Hydrobiology from the University of Wales which included formal post-graduate training in fish kill investigations. IFI do not explain why if they were aware of my posts documenting the kill why they did not meet with me and obtain a statement. I also offered to do this repeatedly to them.

In the “summary” of their investigation, the following is stated:- 

“Data provided by the ESB on the catches at Killaloe the week of Storm Barra show that there was an increase in the number of eels running with the highest catch of 110kg on the morning of December the 8th. This 110kg was caught from nets set at 17:30 on the evening of December 7th to 06:00 on the morning of December 8th i.e., covering the period during which it was reported that a run of thousands of eels had taken place. At an average weight of 300/500g this would be a catch of approximately 360/220 eels”.

However, they have made an error reading the ESB results presented in the “Table of ESB data on Silver eel catches at Killaloe for the week of Storm Barra”. This table actually records a catch of zero eels for that night and claims that the nets were put down at 17:30 and raised at 06:00 – in the middle of a red weather warning for Storm Barra that was described as a “weather bomb”. The weather conditions given are “raining, strong wind” as this was the night of the storm. The following night (8th to 9th December 2021) the weather is given as “no wind” and this is the night when the 110 Kgs of eels were caught. So the ESB data table presented in the IFI report actually contradicts what IFI are saying in the same report.

I brought some of the dead eels I found to Ardnacrusha Hydroelectric Station and asked to see the ESB Fisheries Manager. I was told he was “never there” and he has still not contacted me even though I left my details (which he had already) with the front desk security.

The evidence seems to show that no nets were set on the night of Storm Barra or during the previous days. It is not credible to get a catch of zero on these nights.  

I also sent an AIE request to ESB to obtain the correspondence between IFI and ESB in relation to the eel kill. My request was partially refused. However, I was provided with a redacted letter from the Fisheries Manager to IFI. In this letter the following is stated:-

Whilst no staff were present [at the Killaloe eel weir] due to the unsafe conditions, nets were in the water to capture eels. They were subsequently transported away from Killaloe and safety discharged downstream when the conditions were safe for staff to do so”.

The ESB letter does not provide any information about when the nets were set or lifted, how many nets were set, or what catches were made. However, in the IFI report this information is provided and it is stated that the nets were lifted at 6am on the 8th December 2021 which would have been in the middle of the storm (a “weather bomb”) and an active red weather warning. The ESB letter states that “no staff were present due to the unsafe conditions”. The table of ESB “data” gives a zero catch for eels for each of the nights of the 5th-6th, 6th-7th, and 7th– 8th December 2021. This contradicts what IFI are saying. In my opinion, the evidence shows that the ESB only started operating the nets properly after the eel kill as they had been severely embarrassed by what I had exposed. This is supported by the table provided in the IFI report.

The claimed catch then of c.300 eels (for the following night of the 8th – 9th December, after the storm) is used by IFI to try to undermine my evidence that a major fish kill event occurred. However, the data presented in their report actually shows a zero catch on the night of the storm (7th to 8th December with a claim that the nets were lifted at 6am (which is clearly not true based on the letter from the ESB Fisheries Manager). The c.300 eels are claimed to have been caught on the following night when the nets were supposedly set on the  8th December 2021 at 17:30 and lifted on the 9th December 2021 at 6am. The weather conditions on that night is given as having “no wind” according to the table – so obviously this was not the night of the storm.

Another batch of eels that were collected by boat in the Corbally area on the 8th December 2021. Many large female eels were present in this sample. Some the the eels were still alive.

The IFI “investigation” also failed to review flow or hydroelectric generation records for the time when the eel kill occurred. This was important information to consider and was not reviewed in the report. On the night of the main eel kill the ESB were abstracting 95% of the flow in the river and this was the key cause of the eel kill. The evidence suggests that the ESB had no mitigation whatsoever in place for migrating eels on that night – and yet continued to abstract the absolute maximum amount of water they could take from the river. A Natura 2000 river.

The table in the IFI “investigation” is clearly made up and they could not even bother to get it right. They mixed up their nights and filled in the same times for lifting nets even though the ESB fisheries manager had already said that the nets were not lifted during the storm.

In the ESB fisheries manager letter to IFI it is stated that “It is our current plan to continue to fish the Shannon at Killaloe for eels until late January or early February, at which point based on the catches at the time, we should be able to predict that the adult eel run should be complete for this season”. The nets were set for a few nights in January 2022 but then the fishing stopped again. Eels migrate all year round and large runs can occur in February, March, and even into the spring and early summer.

I have regularly shown that the ESB do not operate the Trap and Transport nets at Killaloe even during the key migration periods. Also, they don’t have nets all the way across the river and the catch efficiency at this site is very low. Even the ESB estimates put the efficiency at 30% which is an overestimate. It is noted that during Storm Dudley on February 16th to 17th 2022 the ‘Trap and Transport’ nets were again not operated. I was not able to survey for turbine killed eels during the days after this storm. It takes a very large effort to find and record these eels and I can’t go out on the river every day.

On the 29th November 2021 the nets were not being operated when I checked. On the 1st of December a few days before the eel kill I exposed that the ESB were yet again not operating the ‘Trap and Transport’ nets at Killaloe. The following night on the 2nd of December only a few of the eel nets were down but the larger nets and the one on the navigation channel were not being used.

More eels found below Ardnacrusha Hydroelectric Station after Storm Barra.
Critically endangered eels found below Ardnacrusha Hydroelectric Station after Storm Barra.

The IFI report then goes on to say, without any evidence, that “there is no doubt that the turbines at Ardnacrusha are causing mortalities of eels at an estimated rate of 21% of the total run of down-migrating eels”. This is a totally unsupported statement and the figure of 21% is an ESB underestimate of the turbine passage mortality that is disputed. They then go on to say that “IFI does not have a role in regulating the operations of the ESB at Ardnacrusha as the ESB are the fishery owner”. They do not explain however why my evidence was not taken into account. Moreover, they do not explain why they have a fish kill hotline yet have failed to do a proper investigation into this obvious fish kill on the Lower River Shannon.

A major fish kill did occur that night and it is likely that thousands of eels were killed. Hundreds of dead and dying eels were present along the river downstream of Ardnacrusha hydroelectric station after the storm had passed during the late morning of the 8th December 2021. It is known that only a very small percentage of the turbine killed and dying eels are ever seen.  This is a very large tidal river with a major flood present after Storm Barra and the eels were migrating under the darkness of night. Most of the turbine killed or injured eels were either washed away, eaten by predators, sank, or died out at sea days later. The ESB depends on this being a problem that mainly goes unseen and this is how they have been able to continue operating the hydroelectric scheme in the exact same way as they did in the 1930s.

However many people like me have been working hard to expose this problem. So it is quite shocking to see Inland Fisheries Ireland the so-called “state agency responsible for the conservation, protection, management, marketing, development and improvement of our inland fisheries” make no effort to investigate this fish kill and prepare such an incomplete, misleading, contradictory, insincere, and unsatisfactory report. This is a cover-up – no doubt about it. If a serious investigation was undertaken then IFI would have taken a statement from me. I am professionally qualified to undertake a fish kill investigation and they know that I investigated this fish kill and collected large numbers of dead and dying eels.

I am very interested to see what exactly was in the correspondence between ESB and IFI about this incident. They refused to release this information as they claimed that “this record contains items which constitute personal information of individuals who have not provided consent to the release of that information”. However, what is of interest here is not who said it, but what was actually said. The names and contact details could have been redacted. My name was given in the Inland Fisheries Ireland report without my permission and without discussing the eel kill with me. My social media posts were misrepresented in the report to support IFI’s flawed conclusions.

If a serious investigation was undertaken then IFI would have taken a statement from me. I am professionally qualified to undertake a fish kill investigation and they know that I investigated this fish kill and collected large numbers of dead and dying eels.

ESB have been caught lying about their ‘Trap and Transport’ programme in the past. Inland Fisheries Ireland assisted the ESB at that time and backed the ridiculous claim that the elver traps were “down for two hours maintenance”.

No prosecution was brought for any of the other major eel kills at ESB hydroelectric stations. In May 2014 over 350,000 eels died at the ‘Trap and Transport’ traps at Cathaleen’s fall hydroelectric station. I also exposed this fish kill and no action against ESB by taken by IFI or the authorities in Northern Ireland.

The ESB has continually failed to operate an effective elver trap and transport programme on the Lower River Shannon – missing all the large runs in the last decade – so eels are becoming scarcer upstream of the hydroelectric scheme. There have been major eel kills at Ardnacrusha since the 1930s but the one that occurred in December 2021 is probably the last big one that will ever be seen – as the eels will not be there in future years. This fish kill happened as all the eels came at once in the storm. So rather than small numbers being killed every night over several months thousands were killed in one night. Most of the turbine killed and injured eels are never seen and the relatively small numbers killed every night are quickly eaten by predators or washed away.  But so many were killed on the night of the 7th to 8th December 2021 that there were dead eels all along the river downstream of the hydroelectric station.

When I saw all these dead eels and was able to post the shocking videos and photos I thought that this was the event that would finally change things. I am both saddened and angered by what I see as a deliberate and coordinated attempt by ESB and IFI to downplay this event to ensure that no action is taken. There is certainly something fishy going on here and investigations into the dealings between ESB and IFI now need to be undertaken.

This is not the only issue that needs to be investigated on the Lower River Shannon. The ESB have failed to maintain the “fisheries” of the River Shannon – a statutory obligation placed on them under the Shannon Fisheries Act 1935. There are no fisheries left – so they obviously have not been maintained. The way the Shannon is being managed is also breaching the legal requirements of the EU Habitats and Water Framework Directives. Over 15km of Natura 2000 river is affected by the unstainable abstraction of up to 97% of the flow of the river at Parteen Regulating Weir.

It is not only eels that are killed passing the Shannon Hydroelectric Scheme. Downstream migrating salmon smolts also follow the water to the unscreened turbines. No efforts are made to reduce the abstraction or use spillways during the smolt run. Indeed the ESB deliberately run the salmon smolts through the turbines and call it a “smolt generation protocol”. This is presented as if it is a positive for smolts – yet it is the total opposite and shows the cynicism of ESB Fisheries.

The Shannon Hydroelectric Scheme can be managed in a more sustainable way than it is. We don’t need to wait for the big engineering solutions to do this. The key issue is the excessive water abstraction. It is not acceptable in 2022 for the ESB to taking up to 97% of the flow from the Lower River Shannon SAC. Most of the problems caused by this scheme are linked to water management. In 2015 I called for the ESB to turn off the turbines to save to eels – and basically, this means reducing the abstraction and making use of spillways when the eels are running. Similarly when salmon smolts are running a system needs to be put in place to use spillways and the boat lock to allow fish to pass downstream without going through the turbines. The ESB can do this right away and it would cost nothing. They can still generate hydroelectricity during the day. But there has to be independent monitoring of what ESB is doing. It is clear that this independent oversight is not being provided by Inland Fisheries Ireland based on their “investigation” into the December 2021 eel kill. New legislation will ultimately be required to provide for the licensing and regulation of hydroelectric stations.