Prsentation PowerPoint Ecole Chercheurs Thiebaut

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INFLUENCE OF CLIMATIC CHANGES ON LARVAL DISPERSAL
AND DYNAMICS OF A BENTHIC MARINE METAPOPULATION
IN THE ENGLISH CHANNEL
E. THIEBAUT(1), P.H. GUYARD(2), C. ELLIEN (1),
M.T. JOLLY(3) D. JOLLIVET (3) (1) Université
Pierre et Marie Curie Muséum National
d Histoire Naturelle, Paris, France (2)
University of Portsmouth, UK (3) Station
Biologique de Roscoff, France
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PECTINARIA KORENI
UK
France
Semelparous species Reproductive period
April-September Larval life span 2 weeks Patchy
distribution in fine sediments
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528 larval dispersal simulations using wind and
tide data from 1980 to 2003 Release dates
ranging between April and September Larval
mortality set to 0.06 d-1
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RETENTION RATES
Frequency
Retention ()
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CORRELATIONS OF RETENTION RATES The case of the
Bay de Somme population
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EXCHANGES AMONG POPULATIONS
Significant exchanges gt 10-2
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EXCHANGE RATES AND HYDRODYNAMIC CONDITIONS The
case of the Pays de Caux population
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VARIATIONS OF EXCHANGES AMONG POPULATIONS
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THE NORTH ATLANTIC OSCILLATION The dominant mode
of climate variability in the North Atlantic
Difference of normalized sea-level pressure
between Azores and Iceland
Hurrell et al., 2003

• Major impacts of a positive NAO index on Northern
  Europe
• Mild and wet winter
• Positive anomalies of sea surface temperature
• Stronger and more frequent westerlies

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NAO INDEX AND WIND REGIME IN THE ENGLISH CHANNEL
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CONCLUSIONS
(1) All populations of Pectinaria koreni in the
English Channel are ore or less connected to
distant populations (2) Retention rates and the
degree of connectivity among populations are
highly variable and related to meteorological
conditions (3) Retention rates and the degree of
connectivity among populations do not covary at
the scale of the English Channel (4) The
dynamics of the metapopulation is probably
chaotic (5) Over the last 25 years, changes in
wind parameters during Pectinaria koreni
reproductive period are just partly related to
NAO index and insufficient to predict changes in
the dynamics of the metapopulation