Fish discards have declined ca. 30 per cent in the last 40 years but still, account for 27 million tonnes. Economically, they represent a loss of value to management and fishermen and, in nutritional terms, are an important fraction of protein that is wasted.

 

Discards result from the fact that different fishing gears have different degrees of selectivity and can capture more species than the ones that are the fishery target, resulting in very high numbers of rejected species.

 

In terms of fisheries assessment and management, species of higher commercial value are often subject to biological monitoring, unlike species of lesser value or of no commercial value, which their situation in population terms is unknown as well as the impact of their exploitation in the ecosystems.

 

Among the species with low commercial value, the blue jack mackerel Trachurus picturatus, the black seabream Spondyliosoma cantharus, and the gurnards (Triglidae) are of particular interest given their landings and the commercial value they may achieve. Among the species with no commercial interest two discarded species, the boarfish Capros aper and the comber Serranus cabrilla, are particularly abundant namely the former for which a preoccupation from the International Council for the Exploration of the Sea (ICES) exists given their high biomass levels.