“MERFOLK” took to Piccadilly Circus in London today to protest at the devastating impact of industrial tuna fishing practices.

Campaigners from Ocean Rebellion opened a giant John West tin containing people dressed as merfolk ensnared by drifting Fish Aggregating Devices (dFADs) in front of a Tesco which sells the brand.

DFADS are floating debris — often plastic — that attract tuna and species including endangered sharks and turtles.

Once they have collected marine life, a large net is dropped into the ocean to hoist all the animals out.

Activists say that everything is slaughtered except the tuna.

Campaigners dressed as John West officials cheerfully watched the merfolk as they munched their tuna pasta salads.

Fishers held banners saying “MSC certified lies” referencing the Marine Stewardship Council , which certify dFAD tuna fisheries as sustainable.

Activist Michael Collins said: “If going to Tesco and buying John West tuna means you’re supporting cruelty to whales, dolphins and turtles, and destroying Indian Ocean ecosystems into the bargain, then just opt out.

“We can cut back on industrially caught tuna, and go elsewhere for our weekly shop.”