The fishery of black scabbardfish in Portuguese waters dates back to the seventeenth century off Madeira Island and to 1983 at grounds around Sesimbra port (ca. 40 km south of Lisbon) in mainland Portugal. The formerly used gear—the vertical longline—was replaced by a horizontal longline and, although the number of hooks has increased from an initial 3600-4000 to 4000-10000, the fishery in Portuguese waters still displays artisanal features, contrasting with the more industrialised fleets of deepwater freezer trawlers that began to operate in northern European waters in 1990. Reported landings in the NE Atlantic show differing patterns, with a relatively stable trend in Portuguese waters in the last decade (landings of around 3000 tonnes each in Madeira and mainland Portugal) and a sharp decrease in northern Europe since 2002.
The black scabbardfish stock structure is still unknown in European waters and, due to the scarcity of biological information, the International Council for the Exploration of the Sea (ICES) considers that there is a single stock unit in the NE Atlantic. In 2005, five Portuguese research institutions from mainland Portugal, the Azores and Madeira set up a scientific project to overcome the lack of knowledge on the biology of this species and to integrate the results of different methodologies (life history parameters, otolith shape analysis, parasites, landings-and-effort data and contaminants). The aim was to improve the characterisation of the black scabbardfish stock structure in the southern NE Atlantic and to ensure fish quality with regard to EU standards, providing valuable information for the correct identification of stocks and contributing to the formulation of future management measures.
We hope that we will soon be able to add information from northern European waters to obtain a full understanding of the stock structure of black scabbardfish in the whole NE Atlantic.