The MMO have not yet received a request for a licence or for advice to sample in the relevant area. Sampling of sediment from the seabed does not necessarily require a Marine Licence from the Marine Management Organisation (MMO) if certain criteria are met. Information on when a licence from MMO may be required for sediment sampling can he found here https://www.gov.uk/guidance/marine-licensing-sediment-analysis-and-sample-plans.

The Crustacean Mortality Expert Panel (CMEP) actively sought data and input from external scientists (including scientists from Universities) who have investigated this issue and did consider the evidence they provided. The scientists were invited to submit any evidence they thought relevant throughout the review period, including on industrial toxins. This evidence was shared with the independent expert panel to consider as part of their assessment and formed an active part of their consideration. The CMEP followed up with questions and communication via written correspondence.

The Crustacean Mortality Expert Panel were unable to identify a clear and convincing single cause for the unusual crustacean mortality but considered a novel pathogen or disease to be, as likely as not (33 to 66% probability), the cause of the mass mortalities reported in the north-east of England in autumn 2021. This likelihood is based on key observations including mortality over a sustained period and along 70 km of coastline, the unusual twitching of dying crabs and the deaths being predominantly crabs rather than other species.

The panel concluded it was very unlikely that pyridine or another toxic pollutant caused the crab deaths, given there could not be sources of any significant volume of pyridine during the period of the crab deaths. Seawater measurements (by the Environment Agency and by York University) could not detect levels of pyridine sufficient to cause mortality during this period. Environment Agency tests for pyridine in crab tissue in the affected north-east coastal region as well from Penzance, Cornwall, and the Norfolk Wash indicated that pyridine can be found in crab tissue in most samples regardless of location. Sediment levels of pyridine from dredged material and other toxic chemicals found in sediments were significantly lower than the levels which would cause crab mortality.

The Crustacean Mortality Expert Panel (CMEP) were asked to review all the available evidence of the unusual crustacean mortality event in the north-east of England (between September and December 2021) using all relevant available data at the time of their investigation. The CMEP were given access to a variety of data (including imagery, monitoring surveys, logs; a full list of the evidence used in the CMEP report has been published alongside the report) and they reviewed published data on similar events from other locations globally. Using this evidence the CMEP provided an independent scientific assessment of the possible causes of the mass crustacean mortality incident. The remit of the CMEP did not include the collection of additional data.

The panel were asked to conduct and complete their work in a timely fashion. The full CMEP met on three occasions between December 2022 and January 2023, with subgroups meeting to analyse aspects of the issue between meetings.

Details of all the evidence received and considered by the panel have been published alongside the report in the document ‘Evidence gathered for the assessment of unusual crustacean mortality in the north-east of England in 2021 and 2022’ which is available on the gov.uk website. Where possible, the panel has published the evidence considered. Where this has not been possible either a link has been provided to where the data has already been published or details of the organisation which owns the evidence have been provided.