Hannah Macintyre, marine biologist and M&S’ aquaculture & fisheries manager, said the retailer knows how much its customers care about responsible fishing. “Transparency is an important part of the trust that our customers and stakeholders put in us,” she said, “that’s why we’ve published this smart tool which lays bare our whole fish supply chain, wherever it is in the world and however it is fished or farmed.”

The Marks & Spencer Seafood Map is the first website of its kind from any retailer. It shows the location of where the fish or seafood is caught by country, the catch method used and whether the fishery is certified or, if not, details of the improvement work taking place. For farmed fish, the map shows the location of the farm by country and region, the farming method, M&S Select Farm status and whether the farm is third-party certified.

Clarus Chu, WWF’s Seafood Manager, said: “All businesses need to take a responsible approach to seafood sourcing if we’re to protect and restore our precious oceans. It’s a great step for M&S to be increasing transparency in this way and showing how the fisheries they source from are improving.”

Marks & Spencer says that all the wild fish it sells is either sustainably sourced, part of a FIP (Fishery Improvement Project), or caught in conjunction with the World Wildlife Fund for risk assessment.