A government department has been accused of a “cover up” over mass crab deaths on Teesside’s coast.

But Defra has insisted joint investigations into the deaths were thorough. Unrest, debate and protests over huge piles of dead crustaceans on Teesside’s coastline have rumbled on since problems first started last autumn at Seaton Carew, South Gare, Redcar, Marske and Saltburn.

An algal bloom was deemed to be the likely culprit by a Defra-led study. But this was countered by an independent report by Tim Deere-Jones after he was commissioned by those concerned in the fishing industry.

High levels of a chemical pyridine were noted by Mr Deere-Jones’s report. Mr Deere-Jones’ report also said algal blooms did not occur naturally in our coastal waters in October because the temperatures were too low.

Darlington and Stockton Times: Dead crabs and seals have been found on the Teesside coastlineDead crabs and seals have been found on the Teesside coastline

However, Defra officials ruled out chemical pollution as a potential cause for the mass deaths in the initial studies – with a review of dredging and water samples finding “no evidence of a link between the disposal of dredged sediment and the deaths”. It also pointed to satellite images in a joint report published in May showing signs of an algal bloom in late September 2021.

Councillors debated the problems at the latest full Middlesbrough Council meeting – with a Labour-led motion calling on the Tees Valley Combined Authority (TVCA) to take the lead and launch its own independent investigation into what had gone on. Cllr David Branson told the meeting fishing catches had been down by almost 95%.

He also told the chamber Defra had “relied on satellite images” for their algal bloom theory – and pointed to sea temperature doubts. More studies continued this year up to March.

But there were fresh concerns in May when piles of dead sea creatures including crabs, lobsters and razor clam shells were noticed littering the beaches at South Gare near Redcar and along the coast to Hartlepool and Saltburn. Defra’s most recent joint investigation, published in May, repeated dredging had been ruled out as a likely cause of the problems – with the probe stating the disposal of dredged sediment would not be stopped.

The review alongside partner agencies found a harmful algal bloom in the area was identified as of “significance” – but no single consistent causative factor was tracked down. It added the presence of a “harmful algal bloom” was “indicated by satellite imagery” and confirmed by the detection of algal toxins in washed up dead crabs and lobsters.

Darlington and Stockton Times: Locals have pointed to dredging on the Tees riverbed as a cause of the deathsLocals have pointed to dredging on the Tees riverbed as a cause of the deaths

But the significance of these toxins was not fully understood at the time. Similarly, the joint probe found it “could not support the hypothesis that pyridine was the cause of the mortalities”.

A March TVCA meeting heard how the UKD Orca had been dredging on behalf of PD Ports at the mouth of the Tees. Defra and agency studies have ruled out dredging as a likely cause of the deaths.

But Cllr Alma Hellaoui wasn’t convinced by what Defra had to say – accusing them of a “cover up of the real issues that face us”. She also accused Defra of trying to hide certain things – telling the chamber of sea life deaths in the estuary and disagreeing with the algal bloom theory.

Cllr Hellaoui said: “There is no chance on Earth it could be the algal bloom.” She added: “It’s like a notice of science-fiction that somehow you could get this algal bloom in the Tees estuary in October.

“Of the whole of the community in the fishing industry, no-one had seen signs of this bloom.” The member for Newport said work on the Teesside Freeport would require “massive” dredging operations – adding the historic sediment in the mud to be dredged up would be “really serious”.

Tests have already shown not all material dredged for the ongoing heavy lift South Bank Quay will not be suitable for disposal at sea. The Marine Management Organisation (MMO) will require a closed bucket to be used for material dug up between four co-ordinates off the river bank,

Earlier in the debate, Cllr Barrie Cooper said Defra “hadn’t closed the books” on what had gone on – adding the Environment Agency and Natural England were looking into it. The executive member for the Environment wanted to know why another report was needed – and who would pay for it.

Cllr Branson said the TVCA was the body “with the greatest interest” – pointing to the big economic implications being “quite considerable” He was also concerned Defra was “trying to brush the issue under the carpet” or had “not looked at things carefully enough”.

In response to the debate, a Defra spokesperson said: “Defra and partner agencies completed a thorough investigation into the cause of dead crabs and lobsters found washed up on the North-east coast between October and December 2021 and concluded that a naturally occurring harmful algal bloom was the most likely cause of the incident.

We ruled out a number of potential causes including chemical pollution, sewage, animal disease, and dredging.”

Darlington and Stockton Times: The fishing industry has struggled with a series of crises over the years from Brexit and the coronavirus pandemic to fuel prices. Picture: SARAH CALDECOTTThe fishing industry has struggled with a series of crises over the years from Brexit and the coronavirus pandemic to fuel prices. Picture: SARAH CALDECOTT

Defra officials said the MMO used the best available evidence to inform its decision making. They added there was no evidence to suggest the disposal of dredged sediment was responsible for the crab and lobster mortality – and would continue to work with partners to monitor “recent small-scale wash-ups”. 

Meanwhile, Tees Valley Mayor Ben Houchen urged any new investigation to be separate from the combined authority given the South Tees Development Corporation (STDC) still had an interest in the wider Teesworks project.

He added: “Defra has published a report into the dead crustacean problem, but people rightly still feel passionate about the issue and I’d welcome any new report that tries to get to the bottom of this worrying issue once and for all – though my fear is it’s not that simple.

“If Middlesbrough Council is calling for an independent report, then that can’t be something my team at the combined authority lead given our group interest in Teesworks – and we would want such a report to be rigorous, independent and something that the community can have confidence in. This is why Middlesbrough Council would be well placed to commission this work.

“I want to continue to make it clear that, to date, no dredging has taken place at Teesworks, or in respect of the Teesside Freeport.” The crabs motion is expected to appear at other Tees Valley councils in the coming weeks.