Tracking the bluefin tuna
December 21, 2020CNRS
Despite their size, weighing as much as hundreds of kilos, bluefin tuna are difficult to study. Researchers have developed instruments to monitor these animals’ migrations as well as various physiological parameters, including those linked to their reproduction.
Over the years the bluefin tuna has become emblematic of overfishing. In point of fact, the name is used to designate three different species: the Atlantic bluefin (Thunnus thynnus), the southern bluefin (Thunnus maccoyii) and the Pacific bluefin (Thunnus orientalis). Despite large-scale catches, little is known about the migration patterns of this fish, whose large size and high mobility make it difficult to monitor. Today a new research collaboration seeks to shed light on its dynamics and offer precious data for managing and protecting its populations. “The Atlantic bluefin tuna was overfished in the mid-1990s, but since 2012 its numbers have improved,” reports Tristan Rouyer, an IFREMER researcher at the Marine Biodiversity, Exploitation and Conservation (MARBEC) laboratory.1 “It’s an iconic species, with a life expectancy exceeding 40 years and a weight that can reach 700 to 800 kilos – the size of a cow.”