Leigh-on-sea cockle fishery achieves sustainable fishing achievement

September 2, 2025

With the start of the new cockle harvesting season, the Thames Estuary Cockle Fishery is celebrating its renewed recognition as one of the UK’s most sustainable shellfish operations.

Operating out of Leigh-on-Sea in Essex, and Whitstable and Queenborough in Kent, the historic fishery has supplied cockles to British and international markets for centuries. Now, it has once again been certified by the Marine Stewardship Council (MSC), meeting the organisation’s globally respected standard for sustainable fishing.

The MSC’s blue ecolabel — the world’s most recognised mark for sustainable seafood — assures consumers that the cockles have been responsibly harvested with minimal impact on the marine environment.

The re-certification marks a major milestone in the fishery’s remarkable recovery. Once on the brink of collapse in the 1980s due to overfishing, the fishery first achieved MSC certification in 2019. Today, it is a model of careful management and environmental stewardship.

With the 2025 season now underway, both UK seafood lovers and international buyers can enjoy Thames Estuary cockles with confidence — and a clear conscience.

Alex Holdgate, MSC Fisheries Manager, said: “Thames Cockle is an outstanding example of a traditional fishery operating in a modern, forward-looking way, sustaining a thriving business in the Thames Estuary while also ensuring they protect this area of outstanding beauty and environmental importance that’s home to many wildlife species. The Thames Estuary Cockle Fishery continues to be a beacon of sustainable fishing and one the fishermen there can be proud of.”

There are 14 licensed vessels who form the MSC certificate, which is managed by the Leigh Port Partnership. Limiting the catch to specific months of the year and only harvesting cockles of a minimum size makes sure the shellfish have time to reach maturity and reproduce, a key part of fishing sustainably. It also factors in the needs of estuary wildlife such as wading birds that overwinter on the tidal banks where the cockles are found, catching a third, leaving a third for the local seabird population, and leaving a third to help with stock health for the following season.

Andrew Rattley, Leigh Port Partnership spokesperson, said: “The Leigh Port Partnership, along with the licensed cockle fishing boats of the Thames regulated cockle fishery, are looking forward to a fantastic start of the cockle season having gained the MSC stamp of sustainability again.

“Our commitment to only cockle in this way for the last 50 or so years, taking limited catches, has certainly been rewarded and allows us to continue our committed sustainable path for the future years and generations to continue.”

Independent assessors concluded that the fishery, first certified in 2019, operates under a well-established and effective management system, with healthy cockle stocks.

The fishery, regulated by the Kent & Essex Inshore Fisheries and Conservation Authorities, (IFCA), is the fifth MSC certified cockle fishery in the North Atlantic, along with Poole Harbour and the Dee and Burry Estuary fisheries in the UK.

Thames Cockles and the Osborne family fishing business spearheaded the MSC’s Sustainable Seafood September campaign in 2024.