3 research outputs found
PROJET GALION. Gestion alternative de la pĂȘcherie chalutiĂšre du Golfe du Lion
AmĂ©liorer la gestion des ressources marines est donc un impĂ©ratif au maintien des entreprises de pĂȘche, câest pourquoi les pĂȘcheurs chalutiers du golfe du Lion ont lancĂ© lâinitiative du projet GALION pour permettre de dĂ©finir de nouveaux modes de gestion pour cette pĂȘcherie. Le projet intĂšgre plusieurs phases de collecte de donnĂ©es en mer dans le cadre dâun partenariat entre scientifiques, pĂȘcheurs et Ă©conomistes. Plusieurs actions sont menĂ©es au cours des trois annĂ©es du projet :
1. Cartographier la distribution des captures et rejets. 2. DĂ©finir des habitats sensibles ou Ă risque. 3. Analyser la sĂ©lectivitĂ© des engins de pĂȘche et leur impact Ă©conomique. 4. Proposer des stratĂ©gies de pĂȘche limitant les rejets.
Ainsi le projet GALION vise Ă fournir aux pĂȘcheurs une aide Ă la dĂ©cision pour la meilleure stratĂ©gie de pĂȘche Ă adopter.
Ce projet est portĂ© par lâAMOP, en partenariat avec lâIfremer, le projet DISCARDLESS, le CĂ©pralmar, CapacitĂ©s Mer et SEANEO. Il a Ă©galement bĂ©nĂ©ficiĂ© des soutiens financiers de lâassociation France FiliĂšre PĂȘche, de la RĂ©gion Occitanie, de la RĂ©gion Provence Alpes CĂŽtes dâAzur, du Conseil DĂ©partemental du Gard et du Conseil DĂ©partemental de lâHĂ©rault
Evidence that Pacific tuna mercury levels are driven by marine methylmercury production and anthropogenic inputs
Pacific Ocean tuna is among the most-consumed seafood products but contains relatively high levels of the neurotoxin methylmercury. Limited observations suggest tuna mercury levels vary in space and time, yet the drivers are not well understood. Here, we map mercury concentrations in skipjack tuna across the Pacific Ocean and build generalized additive models to quantify the anthropogenic, ecological, and biogeochemical drivers. Skipjack mercury levels display a fivefold spatial gradient, with maximum concentrations in the northwest near Asia, intermediate values in the east, and the lowest levels in the west, southwest, and central Pacific. Large spatial differences can be explained by the depth of the seawater methylmercury peak near low-oxygen zones, leading to enhanced tuna mercury concentrations in regions where oxygen depletion is shallow. Despite this natural biogeochemical control, the mercury hotspot in tuna caught near Asia is explained by elevated atmospheric mercury concentrations and/or mercury river inputs to the coastal shelf. While we cannot ignore the legacy mercury contribution from other regions to the Pacific Ocean (e.g., North America and Europe), our results suggest that recent anthropogenic mercury release, which is currently largest in Asia, contributes directly to present-day human mercury exposure
Evidence of connectivity of bigeye tuna (Thunnus obesus) throughout the Indian Ocean inferred from genome-wide genetic markers
IOTC-2020-WPTT22(AS)-16In order to resolve the population connectivity of bigeye tuna (Thunnus obesus) within the Indian Ocean, we analyzed thousands of genome-wide markers of individuals from a broad geographic area of the Indian Ocean as well as from locations in the Pacific and Atlantic Oceans. Our results support a single panmictic population of bigeye tuna within the Indian Ocean isolated from the Atlantic and Pacific Oceans