Crustacean die off

Crustacean die off

In October 2021, dead and dying crabs and lobsters were washed ashore in high numbers along parts of the North East coast.

The Environment Agency led the initial emergency response, with Defra launching an investigation in December 2021 working with partners including CEFAS, NEIFCA, MMO, FSA and UKSHA which concluded in March 2022. This investigation considered a range of potential causes including licensed dredging activity, chemical contamination, offshore windfarm activity and presence of algal blooms and aquatic animal disease. Independent scientific and Government findings pointed to algal blooms as the most likely cause.

Despite Teesworks not undertaking any dredging up to the time in question, there was some  inaccurate reports that maintenance dredging work conducted by PD Ports as the Statutory Harbour Authority on the Tees had been carried out in respect of the Teesside Freeport and/or other work at Teesworks. This was despite repeated statements continuing to underline that no dredging had yet been carried out regarding the Teesworks South Bank Quay Project.

In May 2022, Defra published a summary of its findings from a comprehensive, multi-agency, scientific investigation into this issue, with the key findings below. It states dredging and chemical pollution – including pyridine – were highly unlikely to be the cause.



Chemical Pollution

Aquatic Animal Disease

Harmful Algal Blooms and Toxins

Scientists carried out extensive testing for chemicals and other pollutants including pyridine but concluded a naturally occurring algal bloom was the most likely cause. The amount of any chemical needed to cause a mortality event of this scale would have had to be huge and could not have escaped detection in the extensive sampling carried out at the time.

A link to the full report can be found here.

Not limited to the Tees or the UK 

This is not a situation that is unique to the North East or even the UK, with other similar instances taking place around the world.

Select Committee

A letter released by the cross-party Environment, Food and Rural Affairs Select Committee after hearings into crustacean deaths found dredging can continue.

Autumn 2022

A die-off of small crustaceans was reported to the Environment Agency at Hartlepool. Defra has said there is no evidence of a similar event occurring since the crustacean death incident in late 2021. The MMO and the Environment Agency are monitoring the North East coast carefully they have found no evidence of a similar event occurring – including since September 2022 when the Teesworks capital dredging started.

British Ports Authority

The British Ports Association represents the interests of over 100 port members, covering more than 400 ports, terminal operators and port facilities.

The BPA wrote to the Parliamentary select committee to express some concerns about recommendations on future dredging – and has called on Defra to continue to defend robust procedures already in place to assess and approve hundreds of dredge disposal licences.

It has also raised concerns about a report by a group of university researchers into dredging and sealife mortality stating:

Having reviewed a copy of the paper, which has not been formally published, the BPA is concerned that recommendations that could have far-reaching consequences for the ports industry are being made based on its conclusions. The BPA does not believe the conclusions reached in the paper are credible or even reflective of the results found by the researcher. The results in the paper suggest that over 5,000 dredge disposal events would have had to occur in a single day to have the impact stated in the report. The paper also contains a number of factual errors.

Link here: BPA: No New Restrictions on Dredging Without Credible Evidence – British Ports Association

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