Larval connectivity of pearl oyster through biophysical modelling; evidence of food limitation and broodstock effect. (5th December 2016)

• Record Type: Journal Article
• Authors: Thomas, Yoann; Dumas, Franck; Andréfouët, Serge
• Is Part Of: Estuarine, coastal and shelf science. Volume 182:Part B(2016)
• Page Start: 283
• Page End: 293
• Publication Date: 2016-12-05
• Subjects: Pearl oyster -- Lagoon -- Biophysical modelling -- Connectivity -- Population dynamics -- DEB model; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2016.03.010
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: The black-lip pearl oyster ( Pinctada margaritifera ) is cultured extensively to produce black pearls, especially in French Polynesia atoll lagoons. This aquaculture relies on spat collection, a process that experiences spatial and temporal variability and needs to be optimized by understanding which factors influence recruitment. Here, we investigate the sensitivity of P. margaritifera larval dispersal to both physical and biological factors in the lagoon of Ahe atoll. Coupling a validated 3D larval dispersal model, a bioenergetics larval growth model following the Dynamic Energy Budget (DEB) theory, and a population dynamics model, the variability of lagoon-scale connectivity patterns and recruitment potential is investigated. The relative contribution of reared and wild broodstock to the lagoon-scale recruitment potential is also investigated. Sensitivity analyses pointed out the major effect of the broodstock population structure as well as the sensitivity to larval mortality rate and inter-individual growth variability to larval supply and to the subsequent settlement potential. The application of the growth model clarifies how trophic conditions determine the larval supply and connectivity patterns. These results provide new cues to understand the dynamics of bottom-dwelling populations in atoll lagoons, their recruitment, and discuss how to take advantage of these findings and numerical models for pearl oyster management. Highlights: We coupled a bioenergetics growth model (DEB) with A 3D lagrangian transport model. Larval dispersal and recruitment were simulated in two real contrasted conditions. Spat supply and connectivity pattern were mainly affected by trophic heterogeneity. Despite an unbalanced sex-ratio the reared broodstock mostly supplied spatfall. We offer key clues for pearl oyster population management in atoll lagoons.