2014-2015 (Ifremer)

Analyses of fisheries data (historical series) on albacore tuna  Thunnus alalunga, in the Northeast Atlantic.

Fishing catches and vessel characteristics have long been used to assess the abundance of stocks of marine resources. In order to access indices of abundance of exploited species, CPUEs can be used, as is the case for pelagic species such as tuna. The relationship between CPUEs and abundance can be very weak. Indeed, CPUEs can also reflect changes in catchability (Clark, 1985) which depends on the behavior of the fish in the water column, weather conditions, the gear used, and the fishermen. The work carried out during this training period has provided data on albacore tuna exploited by the French fisheries in the North Atlantic as well as a better understanding of these data through classical statistical approaches. This internship also touched on the aspect of change in environmental parameters and abundance using scripts for the extraction of environmental data (e.g. surface temperatures) and the use of linear and additive models. Troll and live bait (with rods) catch data from 1967 to 1986, on the French fleets and albacore in the Northeast Atlantic, were used to estimate indices of stock abundance, via CPUEs in previous studies (Goujon, 1996). The models have allowed the standardization of CPUEs in order to assess albacore stocks and provide a diagnosis for fishery managers. Concerning our data on French pelagic trawlers from 1991 to 2014. 

Trainee: Audrey Patucca (Master II UPPA)

Report here: Analyses de données halieutiques (séries historiques) sur le thon germon, Thunnus alalunga, en Atlantique Nord-est (ifremer.fr)