The range of juvenile movements of estuarine and coastal nursery dependent flatfishes: estimation from a meta-analytical approach

Olivier Le Pape (1) , Noriane Cognez (1, 2)

1 ESE - Écologie et santé des écosystèmes
2 AGROCAMPUS OUEST

The juvenile pleuronectiforms need specific feeding and sheltering conditions in order to succeed in the critical period following their metamorphosis. This dependence to restricted nurseries grounds is the reason why movements are limited along this stage of flatfish development relative to the larval planktonic stage. However, a controversy remains about the home range of young-of-the-year coastal and estuarine-dependent flatfishes: both a limited home range and the capacity of considerable movements are alternatively reported. In the present meta-analysis based on a review of existing literature on pleuronectiforms, we gathered information about young-of-the-year flatfish movements, in order to better understand the scale of their dependence to local habitat (i.e., whether and at which scale they move between different habitats of a nursery area). For this meta-analysis, two different methods were retained to estimate the range of movements: the daily maximal distance of displacement and the minimal distance of segregation between distinct pools of flatfishes (contrasted patterns in natural tracers, growth, and fitness). We analysed patterns in daily movements and distances of segregation with respect to habitat features and to fish life history, accounting for discrepancies linked to methods of estimation. The scale of movements depends on both semi-passive tidal transport, linked to tidal amplitude, and the ability of individuals to move, which is related to body length of the group-0 flatfishes, but remains limited (few 100 s meters without tidal cyclic migration). These moderate movements lead to segregation among patches of juvenile fish at small scales in upstream downstream estuarine gradients (5 km), and of moderate scales along the coastline (10 km). This meta-analytical approach allowed for the resolution of strong dependence of young of the year flatfishes upon local nursery habitats.

Mots clés: Juvenile flatfish; Movement; Connectivity; Nursery; Estuaries and coasts

Domaines: Sciences du Vivant [q-bio]

Olivier Le Pape, Noriane Cognez. The range of juvenile movements of estuarine and coastal nursery dependent flatfishes: estimation from a meta-analytical approach. Journal of Sea Research (JSR), 2016, 107, pp.43-55. ⟨10.1016/j.seares.2015.06.001⟩. ⟨hal-01601998⟩