Illegal, unreported and unregulated fishing accounts for more than 50% of the total catch in almost all fisheries, depleting fish stocks, destroying marine habitats and harming fishermen who carry out their activity in a legal and responsible manner (Eticonsum, "Illegal, unreported and unregulated fishing"),

This practice also causes potential damage to public health by allowing the marketing of seafood or fish that is not sanitary controlled and could be contaminated.
According to the report "Te lo vas a comer" of La Sexta broadcast in June 2019, the so-called "Japanese clam" illegally fished in Portugal and sent to treatment plants throughout Spain (mainly Galicia), from where its commercialisation is laundered, reaches the markets and supermarkets as legal clams, even of Galician origin in some cases...

Tropical tuna fishing is one of the most punished by the interference of illegal fleets around the world. Currently, according to the FAO, illegal fishing is a global business of between 9 and 23 billion dollars.
Consumers have the right to know what is on their plates, where it comes from, how it is caught, what species it is and also to be certain that the fish they buy is legal.
Most of the tuna on supermarket shelves comes from foreign fleets - the ones most suspected of illegal fishing. In Spain, 70% of fresh, frozen and canned fish is bought in supermarkets, so they have a key role to play in helping to increase and improve the sustainability of the fishing sector and its product offer