Trophic environments influence size at metamorphosis and recruitment performance of Pacific oysters
|Author(s)||Lagarde Franck1, 2, Richard Marion1, Bec Beatrice3, Roques Cecile3, Mortreux Serge1, Bernard Ismael4, Chiantella Claude1, Messiaen Gregory1, Nadalini Jean-Bruno5, Hori Masakazu6, Hamaguchi Masami6, Pouvreau Stephane7, Roque D'Orbcastel Emmanuelle1, Tremblay Rejean5|
|Affiliation(s)||1 : Univ Montpellier, CNRS, IRD, MARBEC Ifremer, F-34200 Sete, France.
2 : Sorbonne Univ, Coll Doctoral, F-75005 Paris, France.
3 : Univ Montpellier, CNRS, MARBEC Ifremer, IRD, F-34095 Montpellier, France.
4 : Eureka Modelisat, F-22740 Lezardrieux, France.
5 : Univ Quebec Rimouski, Rimouski, PQ 65L 2Z9, Canada.
6 : NRIFEIS, JFREA, Hiroshima 7390452, Japan.
7 : CNRS, LEMAR Ifremer, IRD, UBO, F-29280 Plouzane, France.
|Source||Marine Ecology Progress Series (0171-8630) (Inter-research), 2018-08 , Vol. 602 , P. 135-153|
|WOS© Times Cited||9|
|Keyword(s)||Larval ecology, Recruitment, Prodissoconch II, Crassostrea gigas, Oligotrophication, Cryptophytes, Thau lagoon|
Reproduction and recruitment of benthic invertebrates are influenced by the climate and by the ecological structure of marine ecosystems, along with local anthropogenic pressures such as eutrophication or oligotrophication. Using the Pacific oyster Crassostrea gigas as a biological model, we tested the hypothesis that the variability in prodissoconch II (PII) size (i.e. size at metamorphosis) depends on ecological functioning. Settlement and recruitment were assessed at 5 sampling sites on the French Mediterranean shellfish farmed Thau lagoon during the main summer recruitment events in 3 consecutive years (2012-2014). Hydrobiological and planktonic analyses were conducted at 3 sampling sites. Our results showed that recruitment was extremely heterogeneous, ranging from 0 to 260 ± 27 SE ind. dm-2 throughout the ecosystem and was linked with variability in PII size, which ranged from 180 to 296 µm. The annual temporal pattern of PII sizes appeared to be controlled by temperature during the settlement period, whereas the spatial pattern depended on phytoplankton biomass and on the trophic functioning of the ecosystem. Smaller PII sizes were significantly correlated with the highest phytoplankton biomass, while larger PII sizes were positively correlated with mixotrophic cryptophyte abundance. We found an inverse relationship between PII size and survival after metamorphosis, showing that recruitment success was associated with smaller PII sizes. Regional climate conditions and local trophic functioning appear to be key factors in metamorphosis and consequently contribute to recruitment heterogeneity. Further studies should be performed in other ecosystems following an oligotrophication trajectory to generalize this result.