Autor(es):
Nyitrai, Daniel 
; Martinho, Filipe ; Dolbeth, Marina ; Rito, João ; Pardal, Miguel A.
Data: 2013
Identificador Persistente: http://hdl.handle.net/10316/24947
Origem: Estudo Geral - Universidade de Coimbra
Assunto(s): Pomatoschistus microps; Pomatoschistus minutus; Mondego estuary; Environmental variables; River runoff; NAO
Descrição
Large-scale and local climate patterns are known to influence several aspects of the life cycle of marine
fish. In this paper, we used a 9-year database (2003e2011) to analyse the populations of two estuarine
resident fishes, Pomatoschistus microps and Pomatoschistus minutus, in order to determine their relationships
with varying environmental stressors operating over local and large scales. This study was
performed in the Mondego estuary, Portugal. Firstly, the variations in abundance, growth, population
structure and secondary production were evaluated. These species appeared in high densities in the
beginning of the study period, with subsequent occasional high annual density peaks, while their secondary
production was lower in dry years. The relationships between yearly fish abundance and the
environmental variables were evaluated separately for both species using Spearman correlation analysis,
considering the yearly abundance peaks for the whole population, juveniles and adults. Among the local
climate patterns, precipitation, river runoff, salinity and temperature were used in the analyses, and
North Atlantic Oscillation (NAO) index and sea surface temperature (SST) were tested as large-scale
factors. For P. microps, precipitation and NAO were the significant factors explaining abundance of the
whole population, the adults and the juveniles as well. Regarding P. minutus, for the whole population,
juveniles and adults river runoff was the significant predictor. The results for both species suggest a
differential influence of climate patterns on the various life cycle stages, confirming also the importance
of estuarine resident fishes as indicators of changes in local and large-scale climate patterns, related to
global climate change. This work was supported by the FCT
(Portuguese Foundation for Science and Technology) through a PhD
grant attributed to D. Nyitrai (SFRH/BD/48742/2008), a post-doc
grant attributed to F. Martinho (SFRH/BPD/63527/2009) and BIOCHANGED
project (PTDC/MAR/111901/2009), with funds from
POPH (Portuguese Operational Human Potential Program), QREN
Portugal (Portuguese National Strategic Reference Framework), and
MCTES (Portuguese Ministry of Science, Technology, and Higher
Education).
