Incidental captures of sea turtles in the driftnet and longline fisheries in northwestern Morocco

Abstract

The Moroccan port of Tangier along the Strait of Gibraltar holds a very strategic position biologically, and fisheries and sea turtle populations inevitably interact in this region. The objective of this study was to assess the impact of fishing gear commonly used in Tangier – the driftnet and surface and bottom longlines – on sea turtles in Moroccan waters. Over the 4 years of the study (2003–2004 and 2006–2007), a total of 73 turtles were caught in the driftnets of the 7 vessels studied during 866 fishing days, and 13 turtles in the 4 artisanal longlines vessels evaluated during 593 fishing days. The average estimated catch by the entire fleet using driftnets in the region of Tangier during the years of study is 719 (SD=543) captures of loggerheads/year and 101 (SD=57) captures of leatherbacks/year. In the two longline fleets, the average estimated turtle capture in a year was 51 turtles (range=20–97 turtles; SD=31) by surface longline and 91 turtles (range=0–260 turtles; SD=62) by bottom longline. Drift gillnets appear to have the highest interaction with sea turtles, but new legislation requires that driftnets must be phased out by 2012. However, increasing vigilance will be needed as the port of Tangier plans to expand and increase its capacity and as driftnets are replaced by commercial longlines and other gear types. Given that Moroccan fisheries are impacting sea turtles originating from several nesting populations in the western and eastern Atlantic and the Mediterranean, evaluating and mitigating mortality of sea turtles in Morocco and creating a greater awareness for their protection are crucial to the survival and recovery of several nesting populations.