Multi-site application of the DEB model to the Pacific oyster Crassostrea gigas along the French Atlantic coast

Transcription

1 What the DEB theory can tell us (Season 2) Multi-site application of the DEB model to the Pacific oyster Crassostrea gigas along the French Atlantic coast Baie des Veys Rade de Brest Baie du Mont-Saint-Michel Y. Bourlès 1, D. Maurer 2, O. Le Moine 2, P. Geairon 2, J. Mazurié 2, A. Gangnery 2, M. Alunno-Bruscia 1*, S. Pouvreau 1 Baie de Quiberon Marennes-Oléron Bassin d Arcachon 1. Ifremer / PFOM / Argenton 2. Ifermer / LER

2 Introduction The DEB-model for Crassostrea gigas: The French-version: Pouvreau et al. 26, Bacher & Gangnery 26, Bourlès et al. (JSR 29) a single set of constant parameters (except X k ), tested with various food quantifiers The New Zealand-version: Ren & Schiel 28 Objective: To test the oyster-deb model (Pouvreau et al. 26, Bourlès et al. in press) on different culture sites of the French Atlantic coast Food quantifier: phytoplankton enumeration ( selected phytoplankton, see Season 1) Methods: testing the model in 6 different culture sites in different years Forcing variables (trophic conditions, T C): Rephy (Ifremer) network Growth data of C. gigas: regional Ifremer networks (LER laboratories)

3 Methods and data One single set of DEB parameters (Bourles Bourles et al., JSR 29) Except X k : the only free-fitted parameter (variable among sites)

4 Methods and data One single set of DEB parameters (Bourles Bourles et al., JSR 29) Except X k : the only free-fitted parameter (variable among sites) One-single food quantifier: phytoplankton enumeration Mont-Saint-Michel Bay Baie des Veys applied in different sites & for different years ( ): Rade de Brest Quiberon Bay Baie du Mont-Saint-Michel Large range of mean phytoplankton enumeration ( cell.l -1 ) Wide T C range (3-3 C) Large MIP range (- mg.l -1 ) Different cohorts (spat & adult) Marennes-Oléron Bay Arcachon Bay

5 Arcachon, Temperature and phytoplankton enumeration in Arcachon bay in 1993 and ,,8,6,4,2, enumeration ( 1 6 cell.l -1 ) 8 C < Temp < 24 C 1 < phyto < 6 (1 3 cell.l -1 ) Observed and simulated dry flesh mass in Arcachon bay in 1993 and , (1 3 cell.l -1 ): Contrasted growth pattern 2, 1, 1993 = = 34, Data source: Ifremer / LER-Arcachon & Rephy

6 Marennes-Oléron: Ronce-Perquis,, Temperature and phytoplankton enumeration in Marennes-Oléron bay from 1997 to , 1,6 1,2,8,4, enumeration ( 1 6 cell.l -1 ) C < Temp < 22 C 1 < phyto < 13 (1 3 cell.l -1 ) Observed and simulated dry flesh mass in Marennes-Oléron bay from 1997 to , 1, 1,, (1 3 cell.l -1 ): 1997 = = = 4, Data source: Ifremer / LER-PC & Rephy

7 Marennes-Oléron: D Agnas,, 27 Temperature and phytoplankton enumeration in Marennes-Oléron bay in May 1 st August 1 st November 1 st 3, 2,4 1,8 1,2,6, enumeration ( 1 6 cell.l -1 ) 6 C < Temp < 21 C 1 < phyto < 2 (1 3 cell.l -1 ) Observed and simulated dry flesh mass in Marennes-Oléron bay in 27 3, 2, 1, (1 3 cell.l -1 ): 27 = 7, May 1 st August 1 st November 1 st Data source: Ifremer / LER-PC & Rephy

8 Marennes-Oléron: oyster pond, 26 (Bourlès et al. JSR 29) Temperature and phytoplankton enumeration in an oyster pond in 26 extreme temperature range April 1 st July 1 st October 1 st 4, 3,8 3, 2,3 1,,8, enumeration ( 1 6 cell.l -1 ) 3 C < Temp < 3 C 1 < phyto < 3 (1 3 cell.l -1 ) Observed and simulated dry flesh mass in an oyster pond in 26 spring & autumnal growth (1 3 cell.l -1 ): 26 = 18 April 1 st July 1 st October 1 st Data source: Ifremer / LER-PC & Rephy

9 Quiberon bay,, Temperature and phytoplankton enumeration in Quiberon bay in 1999, 2 and ,,8,6,4,2, enumeration ( 1 6 cell.l -1 ) 6 C < Temp < 21 C 1 < phyto < 92 (1 3 cell.l -1 ) Observed and simulated dry flesh mass in Quiberon bay in 1999, 2 and 21 Spat 1,,8,6,4,2 (1 3 cell.l -1 ): 1999 = 26 2 = = 28, Data source: Ifremer / LER-MPL & Rephy

10 Rade de Brest, 28 Temperature and phytoplankton enumeration in Rade de Brest in May 1 st August 1 st November 1 st 2, 1,6 1,2,8,4, enumeration ( 1 6 cell.l -1 ) 9 C < Temp < 2 C 1 < phyto < 17 (1 3 cell.l -1 ) Observed and simulated dry flesh mass in Rade de Brest in 28 Growth record (1 3 cell.l -1 ): 28 = 3 May 1 st August 1 st November 1 st Data source: Ifremer Argenton & REPHY

11 Mont-Saint-Michel Michel bay,, 23 Temperature and phytoplankton enumeration in Mont-Saint-Michel bay in May 1 st August 1 st November 1 st 2, 1,6 1,2,8,4, enumeration ( 1 6 cell.l -1 ) 7 C < Temp < 2 C 1 < phyto < 14 (1 3 cell.l -1 ) Observed and simulated dry flesh mass of 3 cohorts in Mont-Saint-Michel bay in 23 3 cohorts same year (1 3 cell.l -1 ): 1-y old = y old = y old = 32 1-year old 2-years old 3 -years old Data source: Ifremer / LER-MPL & Rephy

12 Baie des Veys,, Temperature and phytoplankton enumeration in Baie des Veys in 22 and July 1 st 22 Nov 1 st 22 March 1 st 23 July 1 st 23 2, 1,6 1,2,8,4, enumeration ( 1 6 cell.l -1 ) 6 C < Temp < 22 C 1 < phyto < 16 (1 3 cell.l -1 ) Observed and simulated dry flesh mass (DFM in g) in Baie des Veys in 22 and 23 4 (1 3 cell.l -1 ): 18-months growth mesure = 4 July 1 st 22 Nov 1 st 22 March 1 st 23 July 1 st 23 Data source: Ifremer / LERN & Rephy

13 Results: general validation & variable X k General validation on all the datasets coming all along the French Atlantic coast With varying : 8 6 Multi-site 18 < < cell.l -1 (1 3 cell.l -1 ) 4 2 Arcachon (Season 1) 22 < < cell.l Annual mean enumeration (1 3 cell.l -1 )

14 Results: : variable X k General validation on all the datasets coming all along the French Atlantic coast With varying : 8 6 Multi-site 18 < < cell.l -1 (1 3 cell.l -1 ) 4 2 y =,8444x + 17,44 R 2 =,6876 Outside point: oyster pond Annual mean enumeration (1 3 cell.l -1 ) At a similar phytoplankton abundance of cell.l -1 : 2 < < cell.l -1 food quality: different phytoplankton species and dynamics varies over life stages (i.e. oyster age) and with size

15 Conclusion & perspectives 1 st global validation of an individual model built with one-single set of parameters generic validation in various & contrasted culture sites (more than 3 datasets along the French coasts) Robustness of the model structure (energy allocation to growth, reproduction, maintenance, ) Validation of the phytoplankton enumeration as an appropriate food quantifier in various culture sites is dependent on food quantity & quality (Variation for a same phyto enumerat =>e.g. phytoplankton sp., PIM) Perspectives Variability of X k : phytoplankton quantity & quality (species): => estimation of X k for the main phytoplankton species, various food sources, across seasons, => MIP effect Which other food quantifiers to track the real ingested food? composition not always available, and heavy to measure Chlo data largely available => correction needed (Grangeré, tomorrow) Studying the trophic ecology of C. gigas by coupling isotopic tracers and DEB modelling Spawning mechanisms: partial and/or several spawning, sex, etc. new PhD (A. Emmery s poster) next DEB211 symposium!!