The bycatch estimate of threatened marine megavertebrates in Moroccan fleets operating in the Mediterranean Coast

Abstract

This study addresses the information gaps by a descriptive analysis of bycatch of vulnerable species (i.e. seabirds, sea turtles, seals, marine mammals, sharks and rays’ species) in in Moroccan Mediterranean area. The present study is one of the first researches to provide an evaluation of the bycatch of different threatened species in relation with fishing activities. The bycatch monitoring was conducted on board commercial fishing vessels operating in the Mediterranean coast of Morocco from March 2019 to Jun 2022. A total of 2203 days at sea observations, a total of 5792 questionnaires were performed to collect information on the interactions between these groups of vulnerable species and the three main vessels groups operating in the country (i.e. trawlers, long liners and purse-seiners). Considering all threatened taxa of monitored vulnerable species, sharks and rays had the highest percentage with 93% of the total bycatch in number. They are the most threatened by fishing among the megafaunas. The bycatch rate of common dolphins made up more than 0.03%. For sea turtles and sea birds it’s less than 0.02 %. Those estimates rates could underestimate the real rates in comparison to the quantities caught by the target species. Despite the incidental captures of those species were very low, there is an urgent need for their conservation given their crucial role in the ecosystems. Finally, some mitigations trials were proposed and additional research will be implemented to improve knowledge on bycatch estimates, fully understanding fisheries practices and achieves the goal of bycatch-reduction in these fisheries