Impact of ocean stratification on small-scale physical oases for pelagic life - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2017

Impact of ocean stratification on small-scale physical oases for pelagic life

Résumé

Physical forcing of the surface ocean includes a variety of energetic processes, ranging from internal wave (IW) to submesoscale and mesoscale. Recent works based on acoustic data showed that, off Peru, the vertical displacements of the oxycline depth provide a robust proxy of isopycnals displacements over a wide range of horizontal scales. These studies revealed the importance of ephemeral hotspots (oases), which concentrate organisms ranging from zooplankton to seabirds, enhancing trophic interactions. Here, we address the question of the potential impact of climate variability on these fine-scale oases for life. Indeed, temperature and salinity changes induced by climate change are expected to lead to an ocean near-surface stratification increase that could have a negative impact on the intensity of physical small-scale structures and, consequently, on patterns distribution of marine life. For that we use 35 000 physical structures from acoustic data collected during twelve scientific surveys conducted between 2002 and 2011 off Peru. We estimate the strength of these structures, its power of aggregation on zooplankton and small pelagic fish and also ocean stratification conditions. Results show that higher the ocean stratification, less the strength and the power of aggregation of the fine scale physical structures. Climate variability, and potentially climate change, could thus lead to a reduction of the size and density of organisms patches with a potential impact on consequent trophic interactions.
Fichier non déposé

Dates et versions

hal-01609848 , version 1 (04-10-2017)

Identifiants

  • HAL Id : hal-01609848 , version 1

Citer

Daniel Grados, Ronan Fablet, François Colas, Vincent Echevin, Ramiro Castillo, et al.. Impact of ocean stratification on small-scale physical oases for pelagic life. 2017 International Symposium Drivers of dynamics of small pelagic fish resources , Mar 2017, Victoria, Canada. ⟨hal-01609848⟩
339 Consultations
0 Téléchargements

Partager

Gmail Facebook X LinkedIn More