Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu archipelago, French Polynesia)

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1 Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu archipelago, French Polynesia) Jonathan Fournier, Dupuy Christine, Marc Bouvy, Marine Couraudon-Réale, Loïc Charpy, Stéphane Pouvreau, Gilles Le Moullac, Marcel Le Pennec, Jean-Claude Cochard To cite this version: Jonathan Fournier, Dupuy Christine, Marc Bouvy, Marine Couraudon-Réale, Loïc Charpy, et al.. Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu archipelago, French Polynesia). Marine Pollution Bulletin, Elsevier,, (-), pp.-. <./j.marpolbul..0.0>. <hal-010> HAL Id: hal Submitted on Jan HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.

2 Pearl oysters Pinctada margaritifera grazing on natural plankton in Ahe atoll lagoon (Tuamotu archipelago, French Polynesia) Jonathan Fournier a, Christine Dupuy b, Marc Bouvy c, Marine Couraudon-Réale a, Loïc Charpy d, Stephane Pouvreau e, Gilles Le Moullac a,, Marcel Le Pennec f, Jean-Claude Cochard g a IFREMER, Centre du Pacifique, BP 00, 1 Taravao, Tahiti, French Polynesia b CNRS and University of La Rochelle, LIENSs, UMR, Batiment ILE, rue Olympe de Gouges, 000 La Rochelle, France c IRD, UMR, ECOSYM, University of Montpellier, Place Eugène Bataillon, 0 Montpellier Cedex, France d IRD, CNRS and University of Méditerranée, UMR UPB, BP, Papeete, French Polynesia e IFREMER, RBE, LPI, UMR 0, Presqu île du Vivier, Argenton, France f University de la Polynésie Française, EA, BP 0, 0 Faa a, Tahiti, French Polynesia g IFREMER, ODE, ER, Technopole de Brest-Iroise, BP 0, 0 Plouzané, France Abstract : In atoll lagoons of French Polynesia, growth and reproduction of pearl oysters are mainly driven by plankton concentration. However, the actual diet of black-lip pearl oysters Pinctada margaritifera in these lagoons is poorly known. To fill this gap, we used the flow through chamber method to measure clearance rates of P. margaritifera in Ahe atoll lagoon (Tuamotu Archipelago, French Polynesia). We found: (i) that pearl oysters cleared plankton at a rate that was positively related to plankton biovolume, (ii) that nanoflagellates were the main source of carbon for the pearl oysters, and (iii) that the quantity and origin of carbon filtrated by pearl oysters was highly dependent on the concentration and composition of plankton. These results provide essential elements for the comprehension of growth and reproduction variability of pearl oysters in atoll lagoons of French Polynesia 1. Introduction For the last years, farming of the black-lip pearl oyster Pinctada margaritifera has been the main aquaculture activity in French Polynesia atoll lagoons. In, production and annual exportation of black pearls reached up to metric tons, worth approximately million Euros, making this industry the nd source of income for French Polynesia after tourism (Service de la Perliculture, pers. com.). However, this industry entirely relies on spat collection successes, which strongly depends on natural reproduction rates and on environmental conditions (Pouvreau et al., 00a; Thomas et al., ).

3 1 1 1 e. g a P. margaritifera in situ P. margaritifera in situ P. margaritifera P. margaritiferap. margaritifera

4 1 1 1 a MATERIAL AND METHODS Study site a Environmental parameters

5 Phytoplankton concentration a a a a a. a a a aaa a a Picoplankton concentration Synechococcus sp.prochlorococcus sp., Prochlorococcus sp. Synechococcus sp.

6 1 1 1 Prochlorococcus sp. Synechococcus. sp. Prochlorococcus sp., Synechococcus sp. Prochlorococcus sp. Synechococcus sp. Nanoplankton and microplankton concentration

7 1 1 1 Flow through chambers in situ Pinctada margaritifera

8 a Pearl Oysters

9 1 1 1 Clearance rates a Carbon retention rates P. margaritifera P. margaritifera Statistics X

10 1 1 1 a aaposteriori a aa A posteriori RESULTS Temperature, salinity, wind direction and speed Chlorophyll a : concentration and clearance rates and carbon retention

11 1 1 1 aa aa aa a aa aa aa aa aa a a aa aa Planktonic microorganisms : concentration, clearance rates and carbon retention

12 1 1 1 DISCUSSION Plankton concentration a a

13 1 1 1 Clearance rates Isochrysis galbanap. margaritifera P. margaritiferacrassostrea gigas P. margaritifera P. margaritiferac. gigas P. margaritifera in situ

14 1 1 1 P. margaritiferain situ Amphileptus sp Strombidium sp. Carbon retention rates a a a a a ca

15 1 1 1 in situ Mytilus eduliscrassostrea gigasc. gigas M. edulis C. gigas M. edulis P. margaritifera Conclusion and perspectives in situp. margaritifera P. margaritifera

16 1 1 1 ACKNOWLEDGEMENT REFERENCES in situ

17 1 1 1 Crassostrea gigas P margaritifera Perna canaliculus Pinctada margaritifera Pinctada margaritifera

18 1 1 1 Pinctada margaritifera Pinctada margaritifera In situ Pinctada margaritifera Pinctada margaritifera Dreissena polymorpha

19 1 1 1 Mytilus edulis L Pinctada margaritiferap. maximabivalvia:pteriidae Pinctada margaritiferap. maxima

20 Table(s) Table 1 n aa a n n n n n Table Table a aa a a a a a a Table a a df F p a a

21 a Table a aa a a Table a a aa rp a a a a r p r p r p r p r p r p Table : a a Synecocochus Prochlorococcus.

22 Table : a aa a a

23 Figure Captions Click here to view linked References Figure 1 Figure Figure aa Figure a Figure

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