Preprint volume - SIBM

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Topic 3: INTEGRATED COASTAL ZONE MANAGEMENT
Fig. 2 – nMDS plot of chemical composition of European anchovy otoliths from Sestri Levante
(Ligurian Sea). Centroids of each otoliths were plotted (C: core; J: juvenile sector).
Grafico nMDS relative alla composizione microchimica degli otoliti di acciuga campionati
a Sestri Levante (Mar Ligure). Sono riportati i centroidi di ogni otolite (C: ‘core’; J:
settore giovanile dell’otolite).
Otoliths from fish born in 2008 and 2007 (corresponding to anchovies 1 and 2 years
old, respectively, having been sampled in 2009) showed different microchemical
patterns. Otolith cores of anchovies born in 2008 (i.e. 1 year old anchovies; Fig. 3A)
showed a quite homogeneous chemical composition (except from a single specimen)
suggesting a single natal origin. Anchovies born in 2007 (i.e. 2 years old anchovies;
Fig. 3B), instead, showed 5 statistically different groups (suggesting multiple natal
origins).
Fig. 3 – Classification of otolith cores of anchovy (A: born in 2008; B: born in 2007). Dashed lines
indicate non-significantly different samples (SIMPROF, P>0.05).
Classificazione dei campioni di otoliti (cores) di acciuga (A: nate nel 2008; B: nate nel
2007). Le linee tratteggiate indicano campioni non significativamente differenti
(SIMPROF, P>0.05).
Conclusions – These first results suggest that:
1) direct comparisons among different otolith regions may come out with significant
differences. Such a general pattern can be attributed to both intrinsic differences in
absorption of microelements among the different stages of the life cycle (Green et al.,
2009) or effective habitat/spatial changes experienced by fish during the ontogenetic
development (Fontes et al., 2009 and references therein);
41 st S.I.B.M. CONGRESS Rapallo (GE), 7-11 June 2010
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