Trophic links and riverine effects on food webs of pelagic fish of the north-western Black Sea
Daniela Bănaru A B and Mireille Harmelin-Vivien AA Centre d’Océanologie de Marseille, Université de la Méditerranée, DIMAR UMR CNRS 6540, Station Marine d’Endoume, rue de la Batterie des Lions 13007 Marseille, France.
B Corresponding author. Email: daniela.banaru@univmed.fr
Marine and Freshwater Research 60(6) 529-540 https://doi.org/10.1071/MF08005
Submitted: 9 January 2008 Accepted: 14 December 2008 Published: 19 June 2009
Abstract
Improving the knowledge of trophodynamics in coastal marine ecosystems is important for fisheries management. The present study was designed to assess the influence of Danube River inputs on Romanian coastal marine food webs of the European sprat (Sprattus sprattus), the European anchovy (Engraulis encrasicholus) and the horse mackerel (Trachurus mediterraneus). Gut content analyses coupled with carbon and nitrogen stable isotope analyses described food web variations with fish size, season and distance from the Danube delta. Sprats fed on zooplankton, horse mackerel fed on polychaetes and small fish, and anchovies had an intermediate diet. The δ13C and δ15N ratios and mean trophic levels increased from sprats to anchovies and then to horse mackerel. Season strongly influenced the δ15N values of the three fishes, with lower values in spring than in autumn linked to higher Danube inputs into coastal waters in spring during the flooding period. Fish condition was related to diet and environmental factors, with higher conditions recorded in the north area in autumn and in the south area in spring. Danube River inputs influenced the diet, stable isotope ratios and condition of the main commercial pelagic migratory fishes of the north-western Black Sea.
Additional keywords: Danube River, particulate organic matter, relative condition factor.
Acknowledgements
We are grateful to the captains and crews of the Romanian fish vessels Chefalul 10, Meduza II, Meduza IV and Morunul and the research vessel Steaua de Mare, and to the following fishermen, A. Marin, R. M. Boboc, G. Butalchin, P. Braniste, M. Iordan and C. Stanica, for their help in sampling. The stable isotope analyses were carried out at Mylnefield Lipid Analyses, Scotland, UK. In particular, we thank two anonymous referees and Professor Andrew Boulton, Editor of Marine and Freshwater Research, for their comments, which improved this manuscript. D. Bănaru was financially supported by a grant from the French Government and is leading a project funded by the Romanian National Council of Scientific Research and Superior Education (CNCSIS). The sampling and work for this study comply with the current laws, collecting and ethics permit numbers of the countries (Romania, France and UK) in which the work was carried out.
Augley, J. , Huxham, M. , Fernandes, T. F. , Lyndon, A. R. , and Bury, S. (2007). Carbon stable isotopes in estuarine sediments and their utility as migration markers for nursery studies in the Firth of Forth and Forth Estuary, Scotland. Estuarine, Coastal and Shelf Science 72, 648–656.
| Crossref | GoogleScholarGoogle Scholar | CAS |
Bănaru, D. , Harmelin-Vivien, M. , Gomoiu, M.-T. , and Onciu, T.-M. (2007). Influence of the Danube River inputs on C and N stable isotope ratios of the Romanian coastal waters and sediment (Black Sea). Marine Pollution Bulletin 54, 1385–1394.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Becker, A. , and Laurenson, L. J. B. (2007). Seasonal and diel comparisons of the diets of four dominant fish species within the main channel and flood-zone of a small intermittently open estuary in south-eastern Australia. Marine and Freshwater Research 58, 1086–1095.
| Crossref | GoogleScholarGoogle Scholar |
Kerr, S. R. , and Ryder, R. A. (1992). Effects of cultural eutrophication on coastal marine fisheries: a comparative approach. The Science of the Total Environment (Suppl. 2), 599–614.
Pauly, D. , Christensen, V. , Dalsgaard, J. , Froese, R. , and Torres, F. C. (1998). Fishing down marine food webs. Science 279, 860–863.
| Crossref | GoogleScholarGoogle Scholar | CAS | PubMed |
Phillips, D. L. , and Gregg, J. W. (2003). Source partitioning using stable isotopes: coping with too many sources. Oecologia 136, 261–269.
| Crossref | GoogleScholarGoogle Scholar | PubMed |
Porumb, F. , and Porumb, I. (1983). Importance du zooplancton pour la répartition des poissons pélagiques dans les eaux du plateau continental devant le littoral roumain de la mer Noire. Rapports du Congres de la CIESM 28, 147–148.
Staicu, I. , Radu, G. , Maximov, V. , Radu, E. , and Anton, E. (2004). Etat des populations des principales espèces de poisson à veleur marchande du secteur marin roumain (1990–2002). Recherches marines 35, 153–172.
Vizzini, S. , and Mazzola, A. (2006). Sources and transfer of organic matter in food webs of a Mediterranean coastal environment: evidence for spatial variability. Estuarine, Coastal and Shelf Science 66, 459–467.
| Crossref | GoogleScholarGoogle Scholar |
Voss, M. , Liskow, I. , Pastuszak, M. , Rüh, D. , Schulte, U. , and Dippner, J. W. (2005). Riverine discharge into a coastal bay: a stable isotope study in the Gulf of Gdańsk, Baltic Sea. Journal of Marine Systems 57, 127–145.
| Crossref | GoogleScholarGoogle Scholar |
Xu, J. , Zhang, M. , and Xie, P. (2007). Size-related shifts in reliance on benthic and pelagic food webs by lake anchovy. Ecoscience 14, 170–177.
| Crossref | GoogleScholarGoogle Scholar |