Facts and FAQs

Activists state that they believe millions of tonnes worth of sediment is going to be removed from the Tees and worry about the effects on the local environment. They worry it could contribute to further shellfish mortalities in the area – equating the planned dredging with the potential future ecocide of the North Sea – and that the economic gains of the Freeport are being privileged over the protection of the North Sea and the livelihoods of the fishing community.

Studies of the planned freeport dredging found that a certain area of the Tees had the potential to be toxic to marine life and must be brought to land for safe disposal. Contributors state that they find it hard to believe that certain sections of the area can be fine to dispose of at sea whilst others in close proximity have the clear potential to be harmful. As a precaution they believe money should be spent on bringing all dredged material to land for safe disposal.

Where can I find a copy of the independent multi-agency report into the mass crustaceans die off ?

A copy of the full report can be found here

Where can we find all information, licences and other documentation in relation to the dredging for the South Bank heavy lift quay?

Every piece of information is all publicly available here ->  https://marinelicensing.marinemanagement.org.uk/mmofox5/fox/live/MMO_PUBLIC_REGISTER/view-case?case_ref=MLA/2020/00506 

Regarding the contaminated portion of the dredge, the 5% that was identified as toxic – what were those toxins and which agency identified them?

At only one borehole location of the dozens of locations undertaken during testing, the concentrations of cadmium, chromium, copper, mercury, lead, and zinc exceeded the respective Cefas action level 2 (AL2) thresholds. Results above AL2 means the material is not suitable for disposal at sea. No other toxins were identified or exceeded mandatory thresholds.

Who did the tests for the licence to be granted for September?

Royal HaskoningDHV – a world leading port company that designs and builds a third of all ports globally

Which other agencies are involved in the ongoing investigations until March and what is the scope of their work?

In terms of dredging, it is understood that PD Ports – as the Statutory Harbour Authority – was permitted to dredge a total of 2,889,700 wet tonnes last year to be disposed of at sea. By comparison, the South Bank Quay project has identified that the contaminated dredge represents just 5% (125,000m³) of the material permitted to be dredged from the river each year, so it is actually a relatively minimal process.

We would also like to know to what extent the dredging that has taken place to deepen the Tees estuary channel has led to pyridine being found in a variety of sea creatures? If none, then how do you account for the proven higher levels found in such marine life – it is not algal bloom.

The only dredging activity in the Tees thus far has been carried out by PD Ports which, holding the status of Statutory Harbour Authority, has the legal responsibility for a 12-mile stretch of the River Tees, which includes a section three miles out into the North Sea. The Statutory Harbour Authority (PD Ports) is responsible for overseeing all vessel traffic management, ensuring safe navigation and maintaining necessary channel depths for the thousands of commercial vessels that use Teesport each year.

The Tees Valley Mayor sympathises massively with fishermen whose livelihoods have been affected by the mass mortality of shellfish on the east coast. He has personally met numerous fishermen to discuss this issue and has had extensive communications with our local MPs, Defra and Government ministers to lobby for assistance to those in the fishing community that have been adversely affected.

It is absolutely right to challenge and scrutinise decisions taken to dredge the Tees. The Mayor has had numerous meetings and his team have spent many days forensically going through all documentation in relation to the licences to dredge, to seek further assurances this activity is safe and does not harm our marine environment. It is concerning that there is so much fixation from the media and other sources surrounding pyridine when there is, to date, no validated scientific evidence that pyridine is the cause of the incident. Pyridine is found in high concentrations within water sampling and crustaceans in other areas of the UK and has not been linked to any other mass crustacean die-off events that have periodically taken place in other regions around the UK coast.

For further information, the UK is signed up to the London Protocol and the Convention for the Protection of the Marine Environment of the North-East Atlantic (Ospar Convention) both of which address preventing marine pollution from disposal at sea. The Marine Management Organisation controls the disposing of dredged materials at sea through issuing marine licences and uses guidelines produced by Ospar to regulate this activity. A marine licence to dispose of dredged materials at sea therefore requires the sediments to be examined to allow any potential adverse environmental effects of disposing of the material to be considered.

Defra is continuing to work with numerous experts, including leading independent scientists who are not related to Government and arm’s-length bodies, and has published a report into the crustacean die-off occurrence in May 2022, which concluded that dredging was not likely to be the cause. The link for the report is here: Joint agency investigation into Teesside and Yorkshire Coast Crab and Lobster mortalities – GOV.UK (www.gov.uk)

Defra has also committed to ongoing water testing in the Tees, carried out by the Environment Agency on a monthly basis, and further investigative work into the crustacean die-off by all agencies and experts.

The alternative viewpoint that has been put forward so far, linking the maintenance dredging conducted on the Tees for decades with the sudden existence of pyridine and then on to the crustacean die-off, goes against internationally accepted scientific evidence. It has been prepared by someone who has a history of producing similar reports across the UK that have subsequently been found to be specious.

The Tees Valley Mayor does not have any control, legislative remit or authority over the whole of the Teesmouth. PD Ports is the Statutory Harbour Authority and, as such, is responsible for any dredging activity to date on the Tees.

What has been done to collect samples from the River Tees?

The Environment Agency collected samples at sites within the Tees Estuary and along the coast from the Tyne to Flamborough Head. It tested the water, sediments, biological samples, and industrial / sewerage permitted discharges for many types of chemicals, looking for evidence of a possible pollution event. None of the results from these tests showed levels of any contaminants that could have caused an event of this scale or duration. 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 that was carried out at the time. Chemical pollution was therefore ruled out as a likely cause for the incident. Though elevated indicative levels of pyridine were detected in crab tissue samples, this could not be linked to any significant source of pyridine in the local environment. Pyridine was also detected in otherwise healthy crabs outside the impacted area of the incident. It is important to note that pollution events in exposed tidal/coastal areas such as this tend to be localised in effect and of short duration due to the huge dilution effect of the sea. Indicative modelling undertaken by Cefas added further evidence which supported the conclusion made by the EA on pyridine. Sampling and testing has taken place during and after dredging activity in the River Tees this autumn.

Could dredging be a cause of the mass die off of crustaceans?

Dredging has been ruled out as a likely cause. Before a marine licence can be granted to allow dredged sediment to be disposed of, samples of dredge material must be tested, and they must meet the highest international standards protecting marine life before it is permitted to be disposed of at sea. If samples analysed for contaminants do not meet the standards, the disposal to sea of that material will not be licensed.

There is no evidence to suggest that the disposal of dredged sediment was responsible for the crab and lobster mortality – this has been tested in accordance with international (Ospar – Oslo/Paris convention (for the Protection of the Marine Environment of the North-East Atlantic) obligations.

I thought it was impossible for there to be an algal bloom at that time of year?

Algal blooms need only nutrients and light and, while most algal blooms in the UK are usually detected between spring and autumn, they can occur at any time of the year. There were calm seas and sea temperatures were higher than normal (>15 °C until 26 September) – perfect conditions for algal blooms.

Satellite data showed an algal bloom occurred from 20 to 26 September at high values, persisting until 1 October, a week prior to the onset of the mortality event.

The high levels of DSP toxins found in some crustacean samples confirmed the presence of a DSP toxin-producing bloom(s) in this incidence, noting that toxins can remain in the tissues of some marine organisms for many months after the bloom has finished. Cells of a range of harmful algal species were also detected in water samples, providing further evidence for this theory.

This along with other testing led to the likely cause of the mass crustaceans die off was linked to an algal bloom, the full report can be found here 

Is investigation by Defra being reopened? 

A Defra spokesperson said:

“A summary of our findings from our comprehensive investigation into this issue was published in May and we are not re-opening that investigation. We continue to monitor shellfish stocks and carry out further testing as part of our standard duties.

“Government 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.”

The Centre for Environment, Fisheries & Aquaculture Science (Cefas) is carrying out further work to better understand the underlying science – this is not a new investigation but will look to develop a precise detection method for pyridine in crabs and lobsters, which will be applied to help to further the science in this complex area.

Is it true the Tees Valley Mayor has complained to the BBC about a recent broadcast?

Yes, a copy of the letter can be found here 

The TVCA has also got a live complaint with Ofcom regarding a recent broadcast referring to dredging on Channel 4.

What are the timescales for dredging?

The first phase of dredging of just under 125,000m3 of material is complete – with material deposited on land.
The second phase of dredging is due to start in Q1 of 2023.

How much material is being dredged?

Just over 900,000m3 of material is currently licensed to be dredged.

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