The first year of SEALOR : Database of SEA-going observer surveys monitoring the local pelagic LOngline fishery based in La Reunion

This study is a preliminary presentation of the observer program carried out under the French National Database Plan (PNDB). In 2007, from April to December, and from July in 2008, one or two observers of the Institut de Recherche pour le Developpement (IRD) embarked on board pelagic longliners based in La Reunion. In order to implement this observer program, sampling forms were developed as well as the database SEALOR. To date, a number of 58 fishing operations totalizing 63525 hooks were observed on different fishing units with an overall length ranging from 9 m to 25 m (10 and 2 cruises were done in 2007 and 2008, respectively). All fishing units target swordfish and then develop a similar fishing strategy regarding the setting time, the hauling time, the type of bait, the deployment of the mainline, the use of lightsticks, .. . A descriptive analysis of a subsample of the data collected in 2007 highlights differences between landings (i.e. logbook data) and catches. If the number of species in landings is less than 10, at least 38 identified species were observed by observers with 1 species of sea turtle and of seabird (1 individual per species for each). The proportion of the weight of swordfish as the target species in major landings concerning tuna (Thunnus albacares, T. alalunga and T. obsesus) and swordfish is about 33%. For the same assemblage the proportion is about 37.9% from data collected on board (26.7% in number). Now regarding the number of swordfish caught compared to the total number of catches the proportion decreases to 17.1% and 44.6% are tunas. The proportion of bycatch (considering that swordfish and tuna species can be targeted at the same time) in observer samples reaches about 40%. A part of these bycatch such as the dolphinfish and billfishes are landed and commercialized (about 42% of bycatch in number) and the rest (26% of the total number of capture) is discarded alive, exhausted or dead. In our data, 31% of discards were blue sharks.