Acoustics surveys in North-West Africa reveal a spatial shift of small pelagic fish related to intense warming [résumé]

Archive ouverte

Sarre, A. | Demarcq, Hervé | Keenlyside, N. | Krakstad, J.O. | El Ayoubi, S. | Jeyid, A.M. | Faye, S. | Mbaye, A. | Sidibeh, M. | Brehmer, Patrice

Edité par CCSD ; ICES -

ICES. Working Group of Fisheries Acoustics, Science and Technology (WGFAST)., Somone, SEN, 25-/04/2022 - 28/04/2022. In the southern part of the CCLME, northward shifts in the distribution of sardinella and other species have been attributed to an intense warming trend in sea surface temperature. Such warming is higher than 0.5 °C per decade in the southern part of the CCLME, the greatest in-crease in SST observed in the tropical Atlantic. The acoustics abundance of Sardinella aurita, the most abundant species along the coast, has increased in the subtropics and fallen in the inter-tropical region. Small pelagic acoustics assessment surveys confirm a robust northward shift of around 180 km per decade in S. aurita habitat, while S. maderensis did not move significantly. Spatial shifts in biomass from 70 to 230 kilometres were observed for six others exploited small pelagic species during the last 20 years, at similar ranges to those recorded for surface isotherms in their habitat. The change occurs more quickly in the central part of the CCLME. This shift widely overlaps national boundaries and combined to overexploitation adds a new threat on the pelagic fish resources. Such results are an advocacy to continue to lead acoustics survey on small pelagic in the West Africa.

• Description
• Sujet/Public
• Outil
• Outil d'anticipation
• Mémoire et thèse
• Gestion