m useum
D
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Royal Belgian Institute of Natural Sciences (RBINS)
Operational Directorate Natural Environments (DO Naturel
no
B-FishConnect
VLIZ Young Marine
Scientists’ Day 2014
ILVO
LEUVEN
How sensitive is sole larval dispersal in the North Sea to the
parameterization of larval duration? A modelling study
Léo Barbut1'2. Sophie Delerue-Ricard2, Andreas V anden Bavière23, Johan Robbens3,
Filip A.M. V o lckae rt2, G eneviève Lacroix1
JL
1. R oyal B e lgian Institute o f N a tu ra l S cie n ce s (RBINS), O p e ra tio n a l D ire c to ra te N a tu ra l E nviron m en ts (O D N a tu re ), B elgium
2. L a b o ra to ry o f B iodiversity a n d E v o lu tio n a ry G e n o m ic s , K a th o lie k e LJnlversltelt L e uven (KIJ Le uven), B elgium
3. Institute fo r A g ric u ltu ra l a n d fisheries R esea rch (ILVO), O o s te n d e , B elgium
Objective
Introduction
To investigate the im pact of larval
stage duration parameterization on
sole larval dispersal and recruitment at
nurseries with a Larval Transport Model
Connectivity of flatfish remains an open question, especially at the early life stages. The case of sole ( Solea
solea) is of particular interest because it is one of the most valuable com mercial species in the North Sea. It
is crucial to understand how the spawning grounds and nurseries are connected and what are the
processes influencing larval retention and dispersal in order to propose appropriate m anagem ent measures.
Sole Larval Transport Model (LTM)
À
(
Y o lk -S a c L a rva e
Egg
The sole LTM results from the coupling between the 3D
hydrodynamic
model COHERENS and an Individualhy
Based Model (IBM) for sole larvae [1].
* Lacrea et a l . 2013
• Rochette et al 2012
• Fonds 1979
* Van der Land et a l . 1991
•— temperature mm/ma* m Belgian zone
— Mean temperature in Belgian zone
The larval stage duration depends on the environmental
conditions met by the larvae. In this study, we com pare
two parameterizations (tem perature dependent) issued
from [1][2] and derived from the same data set (mainly [3])
(Figs. 1 & 2).
i
«
a
w
m
w
»
1
a
First F e e d in g L a rv a e
\ 1\
I
»
O
U
•
It
M e ta m o r p h o s in g L a rv a e
»
B
• aT*
• aT8
c f i. d T . o
Fig. 2. Stage duration in
function o f temperature for
each stage and temperature
range in the Belgian zone.
s
-
temperature
Lacroix et al.
Egg
0
Embryonic
Egg
Yolk sac
Egg
larvae
larvae
2013 [1]
Rochette et al.
2012 [2]
1
Larval pelagic
2 I 3
4a
Settling
4b
5a
First-feeding
Metamorphosing
larvae
larvae
Larvae
Yolk sac
First-feeding
L a rv a l s ta g e d u ra tio n
Settled^
5b
Lacroix et a t . 2 0 13
Interval Lacroix/Rochette
Interval Bolle e t a l .2 00 5 [5]
Settlement if
suitable substrate
Fig. 1. Modelling o f larval stages between spawning and recruitment at
nurseries according to [1] and [2J.
The classification of Lagardôre et al. (1999) [4] is used as reference.
The
total
pelagic
stage
duration
shows
a
large
variation (Fig. 3) particularly
important when comparing
different models based on
different studies [1 ][2] and [5].
Fig. 3. Random combination
o f the pelagic phase
duration for different models
tem perature
Results
S p a w n in g
g ro u n ds
Four simulations, considering the minimum and maxim um pelagic stage duration
within the range of Fig. 3 (on the basis of [1][2]) for two m ean temperatures (10°C
and 15°C) have been performed for the year 1998. Fig. 5 shows the larval
distribution and the connectivity matrix (spawning grounds and nurseries in Fig. 4).
MinlO
M a x i 0.
ngitude ( E)
-ongitude ( E)
M ini 5
M axi 5
IO6
C o n n e c tiv ity :
Fig. 4. Up: main spawning grounds in the North
Sea and mean number o f eggs spawned.
Eastern Channel (EC), Belgian Coast (BC),
Texel (Tx), German Bight (GB), Norfolk (N) and
Thames (Th). Down: nurseries. France (FR),
Belgium (BE), The Netherlands (NL), Germany
V(GE), Norfolk (No), Thames (Tha).
Fr
Be NI
Se No Tha
Be NI
Ce No Tha
Fig. 5. Left: Fina! larval distribution for eggs spawned in the BC spawning grounds. Right: connectivity matrix between spawning
grounds and nurseries (see in Fig. 4). MinlO: minimum larval stage duration at 10°C, Max10: maximum larval stage duration at
10°C, M ini 5: minimum larval stage duration at 1S°C and MaxIS: maximum larval stage duration a t 15°C (Fig. 3, based on [1][2]).
Conclusions & Perspectives
M any biotic and abiotic parameters might influence dispersal patterns.
Before building more com plex models, it is necessary to better represent the
biological processes influencing the dynamics of marine species.
This study highlights the im portance to parameterize biological processes
with accuracy and the need to collect sufficient data and conduct
experimental studies to derive biological processes parameterizations in
order to improve m odel’s reliability.
Acknowledgements:
This work has been carried out in the framework
of the B-FishConnect project (G.0702,13N)
funded by Het Fonds Wetenschappelijk
k_______ Onderzoek - Vlaanderen (FWO)_______
/'w w w .m u m m .ac.b e/
Fr
I High (m o re 55% )
M e d iu m (25-55% )
Sm all (0% -10% )
I No c o n n e x io n
Small differences in the '
pelagic
stage
duration
parameterization
may
induce
significant
differences in the dispersal
pattern (Fig. 5, left), larval
recruitment at nursery and
connectivity (Fig. 5, right).
Connections
appear
or
disappear when the highest
values [max] of the range
are considered instead of
the lowest values [min]:
+1/-1 at 10°C and +3 at 15°C.
Such differences might be of
great importance in fisheries
m anagem ent.
RECOMMENDATIONS:
Cross models of larval duration to maximize the
likelihood
• Take into account result uncertainties
PERSPECTIVES:
Model validation with other approaches
(otoliths, genetic, dem ography).
REQUEST
We are looking
for life-history
data of sole to
validate the
model
References:
[1] Lacroix G., Maes G. E., Bolle L. J., Volckaert F. A. M. 2013. Modelling dispersal dynamics of the early life stages of a marine flatfish [Solea solea). J. Sea Res., 84,13-25
[2] Rochette S., Huret M., Rivot E., Le Pape 0 . 2012. Coupling hydrodynamic and individual-based models to simulate long-term larval supply to coastal nursery areas. Fish. Oceanogr. 21,229-242.
[3] Fonds M. 1979. Laboratory observations on the influence of temperature and salinity on development of the eggs and growth of the larvae of Solea solea ( Pisces). Mar. Ecol. Prog. Ser, 1, 91-99.
[4] Lagardère F., Amara R., Joassard.L. 1998. Vertical distribution and feeding activity of metamorphosing sole, Solea solea, before immigration to the Bay of Vilaine nursery (northern Bay of
Biscay, France), in: Copp G.H., Kovác V., Hensel K. (Eds.). When Do Fishes Become Juveniles?, Developments in Environmental Biology of Fishes. Springer Netherlands, pp. 213-228.
[5] Bolle L. J., Dickey-Collas M ., Erftemeijer P. L. A., van Beek J.K.L. and others. 2005. Impacts of Maasvlakte 2 on the Wadden Sea and North Sea coastal zone. Track 1: detailed modelling
research. Part IV: fish larvae. Baseline study MEP Maasvlakte 2. Lot 3b: fish larvae. RIVO Report C072/05, RlVO-Netherlands Institute for Sea Research, IJmuiden.
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leo.barbut@mumm.ac.be