How sensitive is sole larval dispersal in the North Sea to the
param etrization o f larval duration? A m odelling study
Barbut Léo12, Geneviève Lacroix1, Filip A.M. V olckaert2
1 Royal Belgian Institute o f Natural Sciences (RBINS), DO ‘ N ature’
Gulledelle 100, B-1200 Brussels, Belgium
E-mail: L.Barbut@mumm.ac.be
2 Biodiversity and Evolutionary Genomics, Katholieke U niversiteit Leuven (KULeuven)
Ch. D eberiotstraat 32, B-3000 Leuven, Belgium
C onnectivity th ro u g h o u t the life cycle o f fla tfis h remains an open question, especially at the early
life stages. The case o f sole (Solea solea) is o f particular interest because it is one o f the m ost
valuable com m ercial species in the North Sea. It is crucial to understand how the spawning grounds
and nurseries are connected and w hat are the processes influencing larval retention and dispersal in
order to propose appropriate m anagem ent measures. Especially, dispersal durin g the larval stage is
still poorly known. The tra n sp o rt o f sole larvae fro m the spawning grounds to the nurseries is
driven by hydrodynam ic processes but the fin al dispersal pattern and larval abundance at nurseries
m ig ht be affected by biological processes and environm ental factors. Larval T ra n spo rt Models
(LTMs) coupled to Individual-Based Models (IBMs) are more and more com m only used to assess the
relative c o n trib u tio n o f these processes on the larval dispersal. IBMs allow to take into account
grow th to estim ate the duration o f dispersal based on environm ental co nd itio ns m et by the larvae.
These m odels may be sensitive to process param etrization and may give d iffe re n t results fo r
param etrizations derived fro m the same data set. The La r v a e & C o m odel (Lacroix e t al., 2 0 1 3 ) used
in the fram e o f B -F i s h C o n n e c t p roject couples the 3 D hydrodynam ic m odel C o h e r e n s w ith an IBM o f
sole larvae. It is used here to investigate the im pact o f param etrization o f the stage duration on the
dispersal o f sole larvae in the North Sea. In th is study, we compare tw o param etrizations (Rochette
e t a i, 2 0 1 2 and Lacroix e t a i, 2 0 1 3 ) o f the stage duration (tem perature dependent) derived fro m
the same data set (m ainly Fonds, 1 9 7 9 ) . We show th a t o nly small differences o f the stage duration
param etrization may induce sign ifican t differences o f the dispersal pattern, connectivity and larval
recruitm ent at nursery. This h ig hligh ts the im portance to param etrize biological processes w ith
accuracy and the need to collect su fficie n t data (samples, genotypes and o to lith s) and conduct
experim ental studies to derive biological processes param etrizations in ord er to im prove m odel’s
reliability.
References
Fonds M. 1979. Laboratory observations on the influence o f tem perature and sa lin ity on
developm ent o f the eggs and grow th o f the larvae o f Solea solea (Pisces). Marine Ecological
Progress Series 1:91 -99.
Lacroix G., G.E. Maes, L.J. Bolle and F.A.M. Volckaert. 2013. M odelling dispersal dynamics o f the
early life stages o f a marine fla tfis h (Solea solea L.). Journal o f Sea Research 84:1 3-25.
Rochette S., M. Huret, E. Rivot and O. Le Pape. 2012. C oupling hydrodynam ic and individual-based
models to sim ulate long-term larval supply to coastal nursery areas. Fisheries Oceanography
21:229-242.
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