North East

Crustacean Die-off:

The Crab Are

Long Gone

But The

Smell Still Lingers

Photo courtesy of Masaaki Komori on Unsplash

Scott Hunter

17 October 2024

When crab and lobster started washing up at Teesmouth in vast numbers in the autumn of 2021 there was a great deal of speculation that this was the result of pollution. However, the official explanation of the event produced by Defra in January 2022, was that this was not, in fact, due to pollution, but was probably the result of naturally occurring Harmful Algal Bloom (HAB) which satellite imagery showed may have been present in the water in that region at that time. A dispute arose between those who accepted this explanation (everyone with a vested interest in Teesworks and the freeport being built there) and those who didn’t (the fishers from Hartlepool to Whitby who were being put out of business by the die-off, followed shortly by the large swathes of the local public).

The dispute eventually reached parliament and a hearing of the EFRA committee, where it was decided that there was to be a review of the available evidence from both sides. By this time the fishers had twice commissioned research into the possibility that the die-off was caused by the compound, pyridine. A panel of independent experts was duly convened in mid-December 2022, and a report produced in January 2023.

That report concluded that it was definitely not HAB, but neither was it pollution. The balance of probability was that it was the work of an unknown pathogen. The end? No.

In November 2023, Defra published a report based on research carried out by one of its partner agencies, Cefas, that showed that, although the Environment Agency, in 2021, had found high levels of pyridine in the tissue of affected crab, they were definitely wrong to conclude that this was what killed them, and in any case they had overestimated the amount of pyridine present.

So that was that? Again, no.

In August 2024 a report by three of the independent experts from the panel was published in the journal, Environmental Sciences: Advances, under the title, Why there is no evidence that pyridine killed the English crabs.

And while we scratched our heads and wondered just how many times we needed to be told the die-off was absolutely, definitely, 100% not due to pyridine, the same authors, Alex Ford, Crispin Halsall, and Mark Fitzsimons, then produced another report, this time in the magazine, The Conversation, explaining why they had felt the need to write the previous one.

Inaccurate Media Coverage

They explained that the ‘pyridine hypothesis’ was “… based on inaccurate and unpublished science, and the theory was propagated through mistrust in government, toxic local politics, and inaccurate media coverage.”

In other words, as one of the authors implied in a comment on that article, the independent experts had acquired something of an image problem while going about their legitimate business and adjudicating on the dispute: “actually the piece is defending our integrity and not DEFRAs”.

Tees Valley Monitor was involved in that media coverage more than most, and we have appended here a list of articles we published on the die-off and the dispute that followed. So, we think it not inappropriate to defend our own integrity here. But for most people, the event in the autumn of 2021 is yesterday’s news. The public’s attention has shifted on to other things. Why the need to defend their integrity now? And why use a publication like the Conversation to air their grievance?

If you haven’t heard of The Conversation there’s a reason for that. It is a magazine funded by universities, that publishes the work of academics. And attracts a small, select audience of people whose approval matters to the authors. We are not privy to the conversations that have been going on in the nation’s ivory towers, but the fact that Ford et al. have gone public suggests that they don’t like the reputation they have gained.

And they don’t really help themselves with their article in The Conversation. The gist of their defence of their work for the panel appears to be that, irrespective of the actions of Defra, the panel are professional scientists who looked at the evidence impartially. No mention of the fact that their examination of evidence was determined by terms of reference set by Defra.

They also seem to think that their audience at The Conversation don’t do dates. So, of the ‘inaccurate media reports’, one is by George Monbiot in The Guardian. The hyperlink is to an article published in June 2022, before even the EFRA hearing had taken place. Another is by Jenni Russell in The Times, which criticises the way the expert panel was set up but which was published some two weeks before the CMEP report was published. Both of these are criticising Defra, and the criticism levelled against them by Ford et al. amounts to a defence of Defra’s actions. This, despite the fact that Dr Ford insists they are defending their own integrity and not Defra’s.

By the summer of 2022, kelp beds were also subject to die-off (Hartlepool)

The Independent Experts and Defra: Indifferent Research

Go back to the 2023 Independent_Expert_Assessment (CMEP) to find its conclusions. These were that the cause of the die-off was unlikely to be HAB, as Defra had maintained, while pyridine contamination as claimed by researchers was even more unlikely. Instead, they conclude, “[a] novel pathogen is considered the most likely cause of mortality (despite the lack of direct evidence of such a pathogen)”. (Their assessments were entirely based on ‘likelihoods’, by the way).

Fast forward to their Why there is no evidence research paper of August 2024. What is most revealing about it is what it fails to mention, rather than what it does. Given that these authors own that ‘unknown pathogen’, they exhibit a remarkable lack of curiosity about it. It gets only a rather equivocal mention at the very end:

“Through several investigations, neither the EA, CEFAS nor the independent panel of scientists (CMEP) were able to identify a … [causal] factor. The CMEP categorized parasites and/or disease as ‘as likely as not’ on the basis that crustaceans had presented a pathology …”

So, the purpose of their ‘research’ (which is actually only a review of previously published material) is entirely negative. They exhibit no continuing interest in what actually did cause the die-off, only in what, in their opinion, didn’t.

Surprisingly, or perhaps unsurprisingly, scientists at Defra partner agency, Cefas, have been similarly indifferent to the unknown pathogen. It was Cefas that, in 2021, carried out tests for pathogens on crab tissue samples. In response to a FOI request from us, they stated the following:

“Given that these analyses did not reveal any significant evidence of known or novel pathogens, nor consistent clinical histopathological signs which would explain the cause of the mortalities observed, a further non-targeted molecular analysis was not deemed experimentally valid in this situation.”

To return to the matter that they deemed worthy of further research – the possibility of pyridine contamination – they conclude

“… that pyridine did not kill the Teesside crabs because there is no credible evidence that it was present in sufficient concentrations to cause acute toxicity and a localized die-off. The sampling that led to the hypothesis that pyridine was responsible was done using a very limited number of crabs (n = 4 per location) and using a methodology that was not validated. When this methodology was optimized and samples were reanalyzed, the caution recommended over their accuracy was vindicated. It therefore becomes even less credible that a die-off could have occurred across at least 70 km of coastline. The evidence presented to the EFRA committee and across media outlets claiming that pyridine was ‘exceptionally toxic’ to crustaceans is not substantiated by the published literature. Crabs were presented as uniquely sensitive to pyridine but again the literature suggests otherwise. The unpublished data presented to the committee is not without several limitations in the study design, as highlighted”.

Where the reference to “when the samples were reanalyzed” is the Defra report of November 2023 which is the one where the original sample in which pyridine was detected were reanalysed using a different technique. This time the results showed that there weren’t raised levels of pyridine in the samples after all. Criticism of the methodology of that study was presented in our article Political Science: Defra Gaslights with Cefas Research Report . But Ford et al. were not involved in that research and so can not be held responsible for its failings.

The situation is different with regard to the ‘research’ and the CMEP report where in each case they are guilty of asking and answering all the wrong questions.

Wash-up on one of the region's beaches

All in a Day’s work for the Independent Expert

When the ‘Independent Expert Panel’ was convened its remit was to evaluate to evidence for two incompatible versions of events behind the die-off, one from Defra and its partner agencies, the other from a group of northern universities. The panel was convened by Defra’s Chief Scientific Advisor, Gideon Henderson.

The first question the independent experts needed to ask, therefore, was “What’s Gideon Henderson doing here?”

Second question: Whose idea was it to get him to convene this?

Third question: Where’s Patrick Vallance? Is he just providing some kind of celebrity endorsement of the report?

We intend no criticism of Gideon Henderson personally. But his presence there robbed the panel of its independence before a word had been written. The consequent lack of impartiality did not prevent the panel from criticising Defra’s evidence. But it prevented any evaluation of Defra’s agenda and its conduct of the investigation. This, in turn, has impacted some of the later work of Ford et al.

As the conclusion to their ‘research’ observes, the observation by EA of high levels of pyridine in crab from the affected area was based on a very small sample (four, to be precise). Yet there were tens of thousands of dead and dying crustaceans on the beaches.

Fourth question: Why didn’t EA send more samples for analysis?

In fact, in emails we have obtained through FOI, it turns out that in early November 2021, EA asserted that they had commissioned analysis of more samples. The simple fact that these further samples were not referred to in Defra’s research report of November 2023 indicates that this analysis never actually took place.

On 27 November 2021, responsibility for the investigating the die-off passed from EA to Defra (according to emails we have obtained through FOI), at which point analysis of samples came to an abrupt halt. Within days of the handover, hundreds of octopus were found washed up at Runswick Bay (even the CMEP commented on how unusual this was). As we detailed in our article, Poison Earth part 4: Who Killed the Octopus at Runswick Bay?, tissue samples collected by North East IFCA and sent to Cefas were never analysed. During the spring of 2022, North East IFCA logs submitted to the panel in evidence show that samples from further batches of crustaceans washing up on local beaches, as well as moribund lobster obtained from merchants, were sent to Cefas for analysis. Were any of these analysed? We believe they were not. Had they been, investigators at Cefas would have been able to access the results for the research published in November 2023.

Fifth question, why were so few of the samples sent in by NEIFCA analysed?

Capital dredge for construction of South Bank Quay in late 2022, undertaken without proper environmental protections in place

Resurgence of Unusual Mortality in 2022

It was always a bit of a stretch for Defra’s partner agencies to deny any connection between the die-off in 2021 and subsequent events down the same coastline in 2022. So, we can, tentatively, provide part of an answer to question 4.

It was in late January 2022 that Defra informed local fishermen of their conclusion that the die-off was due to HAB. But HAB is short lived. So, when there was further die-off, with no sign of HAB in the vicinity, Defra had little choice but to insist that it was unconnected to the 2021 event. The independent panel (and the fishers), however, disagreed, on the grounds that the crustacean (now predominantly lobster) were exhibiting much the same symptoms as in the initial die-off.

While Defra, in May 2022, stated the following in a published report:

“Healthy crabs and lobsters are now being caught in the region and, while crab and lobster stocks will continue to be monitored, the investigation was closed in March 2022.”

While both this report and the NEIFCA log showing that samples of dead and moribund lobster were sent to Cefas (also in May 2022) were made available to the CMEP, they were clearly too polite to notice the discrepancy.

The problem was neatly sidestepped by the panel, however. In their report they rejected the view that HAB caused the die-off and instead asserted that it was likely to have been the work of an unknown pathogen. The need to deny the link between the 2021 and 2022 events was thus eliminated.

This did not, in itself, eliminate the need to analyse the samples collected in the spring of 2022, of course. But, had anyone been interested to look for the unknown pathogen of the CMEP report, they might have come in handy.

Dispatch note for samples sent by NEIFCA to Cefas, 12 January 2022

Bioaccumulation

There is another respect in which the CMEP report diverged from both Defra and the scientists who proposed that the cause of the die-off was pyridine contamination, which is that these both claimed that transmission could not be through bioaccumulation (in lay terms, transmission through the food chain). The CMEP, on the other hand, has this to say about the octopus die-off:

“It is also possible that octopus may have died from eating contaminated crabs, or died of the same things as the crabs…

“… However, the large mortalities of a major food resource might have a knock-on effect through the food chain, so some deaths could be attributed as a secondary effect”.

This is the last time that transmission through the food chain is mentioned, so we are left wondering why they didn’t make more of this either at the time or in subsequent research. In other respects, the panel had no difficulty in contradicting the claims made by Defra and by the researchers into pyridine contamination.

Transmission through the food chain is interesting firstly as, in addition to octopus, it might affect other species that like to dine on dead crab; live crab, for example. Furthermore, if the legendary ‘unknown pathogen’ could be transmitted in this way, could pyridine also? We know, if only by default, that Ford et al. do not countenance this. In Why there is no evidence they consider transport of pyridine only in the water column and in sediment, not via bioaccumulation. If there is good reason for this, they have never seen fit to mention it. And without it, their investigations appear a bit lop-sided, to say the least.

And without it, their article in The Conversation is nothing more than a diatribe, a weak attempt to shore up their reputations in the face of media criticism of their participation in the CMEP. In reality, the ‘right answers’ they present in Why there is no evidence simply serve to obscure rather than clarify the issues at stake.

When the article was published, we wrote to The Conversation to request the opportunity to reply to the highly contentious criticism the authors make of the media coverage of the CMEP report. We received no response. This, it appears, is something that the editors of The Conversation don’t want to talk about, leaving us somewhat in the dark about what precisely it is about this publication that merits its title. We can think of others that suit it better.

For the time being, its editors appear to be more than happy to provide Ford et al. with shelter from criticism, providing them a refuge from the harsh reality that they remain accused of putting their science at the service of dysfunctional government. We think that’s not a good look but it’s one that the editors of The Conversation seem to be happy with.

Appendix 1

Tees Valley Monitor Conversation Word Game

How many words of four letter or more can you make out of ‘The Conversation’?

Here are a couple to get you started:

1. arse

2. cover

Appendix 2

10 January 2024 Teesworks Demolitions and the Tees Bay die-off: Update

6 December 2023 Joining the Dots: Tees Freeport and the Mass Destruction of Sea Life

12 November 2023 Political Science: Defra Gaslights with Cefas Research Report

30 June 2023 Marine die-off: How North East Fishers got their Brexit Dividend

20 June 2023 Poison Earth part 4: Who Killed the Octopus at Runswick Bay?