title A decadal trend of juvenile European sea bass (Dicentrarchus labrax, L.) responses to climate patterns in the Mondego estuary, Portugal
authors Eduardo G. Bento, Tiago Grilo, Marina Dolbeth, Dániel Nyitrai, Miguel Â. Pardal and Filipe Martinho
author full name Eduardo Manuel Castro Antunes Granja Bento
nationality internacional
language English
conference title XV European Congress of Ichthyology
conference date 7-11 September, 2015
conference location Porto, Portugal
author keywords European sea bass, Recruitment variability, Climatic changes, Mondego Estuary, Large-scale patterns
abstract Estuarine systems support the life cycle stages of commercially important marine fish and are influenced by large and local-scale climatic patterns. Also, extreme events triggered by climate changes may influence the functioning of nursery grounds and recruitment for several fish species. In this study, performed in the Mondego estuary, Portugal, we used an 11-year database (2003-2013) for analyzing the variability in the population of a marine juvenile migrant fish, the European sea bass Dicentrarchus labrax, regarding changes in abundance, population structure, growth rates and secondary production and annual day of peak abundance. Higher densities and production occurred at the beginning of the study, but no differences in 0-group growth could be observed. In order to detect change points in both biological and climatic data, the cumulative sum (CUSUM) of the deviations from the mean for the 2003-2013 period were determined for each parameter. The relationship between large- and local-scale drivers and 0-group abundance, secondary production and day of peak abundance were evaluated using a Pearson correlation analysis of CUSUM of biological and environmental data, considering the correspondent yearly values and with a time-lag of 1 year. The North Atlantic Oscillation (NAO) index, sea surface temperature (SST) and their respective winter values were tested as large-scale factors, while river runoff, salinity and water temperature were considered as local climate patterns. River runoff was the significant factor explaining D. labrax 0-group abundances and the NAO and water temperature were also significant predictors considering the 1-year lag. Regarding D. labrax 0-group secondary production, salinity and water temperature were the significant predictors. The NAO with 1-year lag was also negatively correlated with the day of peak abundance. The observed variability regarding yearly trends in abundance of juvenile fish was mostly linked to local-scale climate patterns, which can influence habitat use patterns, whereas large-scale factors (NAO, SST) seem to operate at a wider time frame, as observed by the lag of 1-year on their influence on juvenile sea bass abundance.
author address University of Coimbra, Centre for Functional Ecology - CFE, Department of Life Sciences, Coimbra, Portugal
e-mail address edugraben@gmail.com
publication date 27 Nov 2015
year published 2015
subject category Fish life cycles, migration and connectivity
link http://www.frontiersin.org/myfrontiers/events/abstractdetails.aspx?abs_doi=10.3389/conf.fmars.2015.03.00144
CFE authors
Dániel Nyitrai
Eduardo Granja Bento
Filipe Martinho
Marina Dolbeth
Miguel Pardal
Tiago Grilo