In Integrativ ive approach to ass ssess th the vu vuln lnerabil ilit ity of f European flo flounder popula latio ions in in str tressed envir vironments : : stress ecolo logy, ecotoxi xicolo logy and genetic ic tools ls Borcier 1 , G. Charrier 1 , V. Pichereau 1 , F. Martinho 2 , A. Amérand 3 , M. Théron 3 , J. Laroche 1 E. . Bo Elodie BORCIER - PhD student (1) LEMAR UMR 6539, IUEM, Université de Bretagne Occidentale, France (2) University of Coimbra, Center for Functional Ecology, Portugal (3) ORPHY EA 4324, Université de Bretagne Occidentale, France IFS10 th -2017 HQFISH
Introduction Model species Eggs Distribution area of Platichthys flesus Larvae Estuary MOUTH Adults (Spawning area) ESTUARY Southern limit (Nursery) of distribution area Juveniles Boreal species, from Norway to Portugal European flounder , Platichthys flesus Catadromous species → Sentinel species to assess the ecological status of Atlantic estuaries in Europe → Life cycle in estuaries → Low fishing pressure → Multiple stressors 2
7 ° C Introduction Context of the study England 50° ➢ European flounder → species of interest to explore the vulnerability Seine (polluted) of populations to environmental forcing : France Vilaine (ref) Climate warming 45° Multiple stressors in Chemical stress estuaries Hypoxia Portugal 40° Mondego Spain (warm) Consequences of global warming and hypoxia on flounder populations? Southern limit of distribution area 15 ° C Location of sampled estuaries Average winter I. Bioenergetic II. Demo-genetic temperature 3
England Populations " in natura " 50° I. Bioenergetic approach (Borcier et al ., 2016) Seine (polluted) ➢ Liver metabolism (gene expression) in juveniles Vilaine France (ref) CCO II (proxy of aerobiosis) 45° ▪ Mondego (South) : reduced metabolic activity vs Seine et Vilaine (North) Portugal Spain Local adaptation to warmer condition ? → Confirmed 40° Mondego (warm) Mondego Seine Vilaine in common garden (Pédron et al ., 2017) 12 S ( mitochondrial density) ▪ Lower inter-individual variability in Seine (heavy pollution) vs Vilaine (low contamination) Seine Mondego Vilaine Higher vulnerability to global changes ? → Confirmed 18 S in common garden : tolerance to thermal stress ( protein biosynthesis) reduced in Seine vs Vilaine (Lavergne et al ., 2015) Borcier et al. (2016), Journal of Xenobiotics 6(2) Lavergne et al. (2015), Marine Pollution Bulletin 95(2), 658-664 Pédron et al . (2017), Marine Environmental Research 129, 258-267 4 Seine Mondego Vilaine
" common garden " I. Bioenergetic approach ( Pédron et al ., 2017) ➢ Differential metabolic activities of flounder populations submitted to thermal and hypoxic stress (Pédron et al. , 2017) 7 ° C England COMMON GARDEN Canche 50° Northern pop. Acclimation or vulnerability to multistress ? Vilaine Canche and Vilaine France 45° JUVENILES Energy metabolism : aerobiosis vs anaerobiosis Lima Spain 40° Portugal Southern pop. Lima 15 ° C 5 Pédron et al. (2017), Marine Environmental Research 129, 258-267
" common garden " I. Bioenergetic approach ( Pédron et al ., 2017) ➢ Integration of bioenergetic responses in PCA (Principal Component Analysis) Northern population CANCHE Northern population in thermal and Markers hypoxic stress: 1. Aerobiosis metabolism in cold L.LDH HSI Aerobiosis condition (low energetic cost) M.CS Anaerobiosis M.CCO Local adaptation to " cold " M.LDH condition 2. Shift towards anaerobic metabolism in warm and hypoxic (very high cost Individuals of stress) Warm + hypoxic Vulnerability to combined effects of condition both stresses? Cold condition 6 Pédron et al. (2017), Marine Environmental Research 129, 258-267
" common garden " I. Bioenergetic approach ( Pédron et al ., 2017) ➢ Bioenergetic responses integrating in PCA (Principal Component Analysis) Northern population CANCHE Southern population LIMA Markers Markers Southern population in thermal and M.CCO hypoxic stress M.CS L.LDH HSI Aerobiosis HSI M.CS 1. Balance aerobiosis anaerobiosis in L.LDH Anaerobiosis M.CCO warm and hypoxic condition (lower M.LDH M.LDH cost of stress) Higher capacity of southern population to cope with both stresses Individuals Individuals Warm + hypoxic condition 2. Higher stress in " cold " condition Cold condition Local adaptation to " warm " environment ? 7 Pédron et al. (2017), Marine Environmental Research 129, 258-267
I. Bioenergetic approach CONCLUSIONS Flounder 0+ juveniles ➢ Chronically polluted populations (Seine) loss of phenotypic diversity Higher vulnerability to global warming ? ➢ Southern populations (Mondego, Lima) local adaptation to warm environment But… ➢ Highly variable 0+ recruitment success at the southern limit Decline in recruitment Spawning adults and/or larvae more sensitive to global change than juveniles? Abundance of 0+ flounder in the Mondego estuary (Marthino et al ., 2009) 8 8 8 Marthino et al. (2009), Coastal and Shelf Science 83(4), 460-468
II. Demo-genetic approach Rationale ➢ Weak recruitment and low genetic diversity in Mondego Low genetic diversity of Mondego population High interannual variability in recruitment (Pédron, 2016) success (Martinho et al ., 2009, 2010) 7,1 6,9 + Multi-locus allelic richness (Ar) 6,7 6,5 Loss of genetic diversity 6,3 6,1 5,9 5,7 5,5 7 Strong genetic drift? Allellic richness (microsatellites markers) per population, in natura (Pédron 2016) Marthino et al. (2009), Coastal and Shelf Science 83(4), 460-468 9 Marthino et al. (2010), Journal of Applied Ichthyology 26(6), 843-852 9 Pédron, 2016, Doctoral dissertation, Université de Bretagne Occidentale, Brest
II. Demo-genetic approach Effective size DEMOGRAPHY GENETIC (Ne) DIVERSITY GENETIC DRIFT 10
II. Demo-genetic approach Effective size DEMOGRAPHY GENETIC Strong genetic drift : (Ne) DIVERSITY Random loss of alleles Loss of adaptability Vulnerability in the short, medium and long term ? GENETIC DRIFT 10
II. Demo-genetic approach Effective size MONDEGO POPULATION N demographic size DEMOGRAPHY GENETIC Strong genetic drift : (Ne) DIVERSITY Random loss of alleles Loss of adaptability Vulnerability in the short, medium and long term ? GENETIC DRIFT 10
II. Demo-genetic approach Effective size MONDEGO POPULATION N demographic size DEMOGRAPHY GENETIC Strong genetic drift : (Ne) DIVERSITY Random loss of alleles Loss of adaptability Vulnerability in the short, medium and long term ? GENETIC DRIFT 10
II. Demo-genetic approach Effective size MONDEGO POPULATION N demographic size DEMOGRAPHY GENETIC Strong genetic drift : (Ne) DIVERSITY Random loss of alleles Ne Loss of adaptability Vulnerability in the short, Small effective size ? medium and long term ? GENETIC DRIFT Estimation of Ne proxy for intensity of genetic drift 10
II. Demo-genetic approach Results England 300 juveniles 0+ per pop, in 2010 20 microsatellites Vilaine France GTCTCG TATATATATATATA TGCCTG (ref) VILAINE MONDEGO Num. of Ne Vilaine [mean (CI)] Estimation method Ne Mondego [mean markers (CI)] Portugal Espagne Mondego 4485,3 (918,1 - ∞ ) 20 Linkage disequilbirum 472,5 (316,6 – 862,2) (Warm) Spain 2521,9 (719,1 - ∞) 464,7 (299,5 – 928,2 ) 18 Linkage disequilibrium ➢ Limits : strong uncertainty in the Vilaine, 1 single cohort (2010) ➢ Lower Ne in Mondego ➢ Mondego : demographic vulnerability in the short or medium term ? 11
II. Demo-genetic approach Results England 300 juveniles 0+ per pop, in 2010 20 microsatellites Vilaine France GTCTCG TATATATATATATA TGCCTG (ref) VILAINE MONDEGO Num. of Ne Vilaine [mean (CI)] Estimation method Ne Mondego [mean markers (CI)] Portugal Espagne Mondego 4485,3 (918,1 - ∞ ) 20 Linkage disequilbirum 472,5 (316,6 – 862,2) (Warm) Spain 2521,9 (719,1 - ∞) 464,7 (299,5 – 928,2 ) 18 Linkage disequilibrium ➢ Limits : strong uncertainty in the Vilaine, 1 single cohort (2010) ➢ Lower Ne in Mondego ➢ Mondego : demographic vulnerability in the short or medium term ? 11
C ONCLUSION & P ERSPECTIVES Local adaptation of southern and northern populations: contrasted BIOENERGETIC in vulnerability to global changes? natural environment & in laboratory Higher vulnerability of heavily VULNERABILITY OF Multi-estuaries polluted population to global change ESTUARINE Comparison POPULATIONS TO COMBINED EFFECTS OF GLOBAL AND LOCAL STRESSORS Demographic risk of southern DEMO-GENETIC population Flounder population indicator of the ecological status of large European estuaries And now … coupling between ➢ Flounder « Caging » experiment to evaluate the quality of estuaries at local scale ➢ Proteo-genomics : more accurate assessment of flounder responses to environmental stressors 12
Thanks for your attention! 18
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