Année de publication
2018

Journal

Aquatic Living Resources
Volume
31
Ticket
19
Date de publication
08/2018
Nombre de pages
1-9
DOI
https://doi.org/10.1051/alr/2018007
URL
https://www.alr-journal.org/articles/alr/abs/2018/01/alr170158/alr170158.html
Catégorie HCERES
ACL - Articles dans des revues internationales ou nationales avec comité de lecture répertoriées par l'HCERES ou dans les bases de données internationales
Résumé

<p>Post-settlement dispersal potential of four commercial bivalve species (<em>Mytilus edulis</em>, <em>Pecten maximus</em>, <em>Venus verrucosa</em> and <em>Ruditapes philippinarum</em>) were studied through the assessment of recruits' sinking velocities by using a sinking velocity tube of five meters height. In parallel, dynamics of shear stress were monitored for five months on a tidal habitat characterized by the presence and the dispersal of the four species. By coupling both datasets we propose first theoretical estimates of temporal windows of secondary migrations. These experiments revealed interspecific differences in migration potential relate to shell shapes and behaviour, especially to secretion of byssal threads. The sensitivity to passive and active post-settlement migrations seems to rely on the&nbsp;synchronisation between the arrival on the sediment, the tidal regime (spring tide, neap tide), but also the rate of growth of the recruits. The present study confirms that patterns of secondary migrations of bivalve recruits result from a close physical-biological coupling involving benthic boundary layer (BBL) hydrodynamics and shell morphology as well as eco-ethological responses to environmental conditions but clearly modulated by the growth dynamics until a threshold size when drifting is no longer possible.</p>