Observations on interaction between seabirds and the Spanish surface longline fishery targeting swordfish in the Atlantic ocean during the period 1993-2017

A total of 7.6 million hooks targeting swordfish using night setting surface longline style were scientifically observed during the 1993-2017 period in broad areas of the North and South Atlantic in relation to the interaction with seabirds. The areas observed correspond to those with greater historical fishing intensity by this fleet in the Atlantic. A total of 38 individual seabirds interacted with the total observed hooks during the 25-year period. 74% of the interactions occurred in a single trip made in 1995 under non-standard fishing operations in areas in which other vessels-trips-years had few or null interactions. 13% of the interactions occurred in a fishing prospecting survey carried out in southern areas where this fleet does not carry out regular fishing activity. The generally oceanic fishing areas, the type of nocturnal style, the low lighting during the set, together with the type of fishing practice regularly carried out by the vessels, were identified as probably being the main factors to explain the generally zero or low interaction with seabirds in most of the Atlantic fishing areas and trips observed.