MEPS 546:213-223 (2016)  -  DOI: https://doi.org/10.3354/meps11636

Stable isotope signatures reveal small-scale spatial separation in populations of European sea bass

Giulia Cambiè1,*, Michel J. Kaiser1, Andrew L. Marriott2, Jennifer Fox1, Gwladys Lambert1, Jan G. Hiddink1, Thomas Overy1, Sarah A. Bennet3, Melanie J. Leng4, Ian D. McCarthy

1School of Ocean Sciences, Bangor University, Askew Street, Menai Bridge LL59 5AB, UK
2Inorganic Geochemistry Facility, Centre for Environmental Geochemistry, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
3School of Life Sciences, Gibbet Hill Campus, The University of Warwick, Coventry CV4 7AL, UK
4NERC Isotope Geosciences Laboratory, British Geological Survey, Keyworth, Nottingham NG12 5GG, UK
*Corresponding author:

ABSTRACT: Scientific information about European sea bass Dicentrarchus labrax stocks in the NE Atlantic is limited and a more accurate definition of the stock boundaries in the area is required to improve assessment and management advice. We investigated the connectivity and movement patterns of D. labrax in Wales (UK) using the stable isotope (δ13C and δ15N) composition of their scales. Analysis of δ13C and δ15N values in the last growing season was performed on 189 adult sea bass caught at 9 coastal feeding grounds. Fish >50 cm total length (TL) caught in estuaries had very low δ13C, which is characteristic of freshwater (organic/soil) input, indicating the primary use of estuaries as feeding areas. A random forest classification model was used to test for any differences in δ15N and δ13C values between north, mid and south Wales and whether it was possible to correctly assign a fish to the area where it was caught. This analysis was restricted to fish of a similar size (40-50 cm TL) caught in open coastal areas (n = 156). The classification model showed that about 75% of the fish could be correctly assigned to their collection region based on their isotope composition. The majority of the misclassifications of fish were of fish from north Wales classifying to mid Wales and vice versa, while the majority of fish from south Wales were correctly assigned (80%). Our findings suggest that 2 sub-populations of sea bass in Welsh waters use separate feeding grounds (south vs. mid/north Wales), and may need separate management.


KEY WORDS: Dicentrarchus labrax · Stable isotopes · Random forest classification model · Feeding ground · Stock boundaries


Full text in pdf format 
Cite this article as: Cambiè G, Kaiser MJ, Marriott AL, Fox J and others (2016) Stable isotope signatures reveal small-scale spatial separation in populations of European sea bass. Mar Ecol Prog Ser 546:213-223. https://doi.org/10.3354/meps11636

Export citation
Mail this link - Contents Mailing Lists - RSS
- -