Larval dispersal and ju ven ile dynamics o f flatfish in the Southern
North Sea
Vanden Bavière Andreas', Johan Robbens1, Filip V olckaert2, Sophie Delerue-Ricard2, Geneviève
Lacroix3 and Léo Barbut3
1 Institute fo r A g ricu ltu ra l and Fisheries Research, A nkerstraat 1, B-8400 Ostend, Belgium
E-mail: andreas.vandenbaviere@ ilvo.vlaanderen.be
2 Laboratory o f Biodiversity and Evolutionary Genomics, Katholieke U niversiteit Leuven,
Ch. D eberiotstraat 32, B-3000 Leuven, Belgium
3 O perational D irectorate Natural Environm ent (form erly MUMM), Royal Belgian Institute o f Natural
Sciences, Gulledelle 100, B-1200 Brussels, Belgium
Marine populations display some o f the m ost extrem e patterns o f spatial and tem poral
heterogeneity in dem ographic factors. Over the past few decades, many marine fisheries have
declined or even collapsed. This is in large part, due to clim ate change and d etrim ental
anthropogenic influences (e.g. habitat degradation and overfishing). Due to a hig hly com plex
optim al w indow between biological needs and favorable environm ental factors, marine species are
very susceptible to natural p erturbations. This leads to unpredictable reproductive success, high
m o rta lity and obscure population delineations. Preventing a com plete collapse o ffis h stock requires
a th orou g h knowledge o f the recruitm ent dynamics. With the B-FishConnect project we w ant to
disentangle the physical and biological factors influencing dispersal and recruitm en t in fla tfish.
W ithin the project, we w ill focus on fo u r com m ercially im p o rta n t fla tfis h species in the North Sea:
sole, plaice, tu rb o t and brill. To q u a n tify the role o f physical and biological factors on the
population dynamics, a com bination o f hydrodynam ic and dem ographic-genetic models w ill be
applied. The o u tp u t o f these m odels w ill be compared to em pirical field data. The focus o f this
project w ill be on the post-larval and juve nile stages o f fla tfis h . Inform ation on the spatial-tem poral
dynamics o f larvae and juveniles w ill be gathered by an intense sam pling campaign along the coast
as well as on sea. A d d itio n a l inform a tion w ill be obtained th ro ug h historical datasets. The larval
dispersal history w ill be inferred by analysing the o to lith m icrostructure o f juvenile fla tfis h . The
effect o f the larval h istory and local habitat characteristics on the fu tu re survival and co ndition o f
juvenile fla tfish w ill be investigated. This w ill be accom plished by using biom arkers and co ndition
indices. The derived inform a tion on life -h isto ry traits, population structure and spatio-tem poral
dynamics w ill be used to validate the dispersal m odels (Lacroix et al., 2013). In a later phase this
w ill allow us to te st d iffe re n t ecological hypotheses and to assess the im pact o f various scenarios
related to clim ate change and human im pact on fla tfis h in the North Sea. C onsequently these data
w ill be vital fo r fisheries and conservation management.
References
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.
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