Zooplankton distribution in a temperate estuary (Mondego estuary southern arm: Western Portugal)

a b s t r a c tThe influence of climate variability on the diversity and distribution patterns of zooplankton communities was investigated in the Mondego estuary (Portugal) during four consecutive years characterized by highly variable precipitation and, consequently, river flow regime. Monthly samples were collected along the estuarine gradient at five sampling stations. Seasonal, inter-annual and spatial distributions were evaluated by multivariate analyses and three diversity indices were applied (Species number, Shannon Diversity and Average Taxonomic Distinctness). A two-year drought period presented significant differences in salinity values, especially in 2005 (extreme drought event). During the study period, copepoda was the main dominant group and Acartia tonsa the most abundant species, with the exception of autumn 2006, where high abundances of the cladoceran Penilia avirostris were noticed. Multivariate analysis indicated that zooplankton communities changed from a pre-to a post-drought period indicating the influence of hydrological parameters in communities' structure. The dry period was associated with an increase in zooplankton density, a reduction in seasonality and higher abundance and prevalence of marine species throughout the year. Seasonally, winter/spring communities were distinct from those in summer/autumn. Spatially, salinity-associated differences between upstream and downstream communities were reduced during the drought years, but during the post-drought year, these differences were detected again.

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“…Azeiteiro et al, 1999Azeiteiro et al, , 2000Vieira et al, 2003) and also on the northern arm (e.g. Marques et al, 2006Marques et al, , 2007a.…”

Section: Introductionmentioning

confidence: 99%

Changes in zooplankton diversity and distribution pattern under varying precipitation regimes in a southern temperate estuary

Primo

Azeiteiro

Marques

et al. 2009

Estuarine, Coastal and Shelf Science

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“…In addition, anthropogenic influences may contribute to enhancing natural trends, both directly and indirectly. Although several studies have focused on the zooplankton of the southern branch of the Mondego estuary during the last years (Azeiteiro et al, 1999;Gonçalves et al, 2003;Vieira et al, 2003) a lack of knowledge about the assemblages in the northern branch and a clearly comparative analysis of the communities of both contrasting arms, with different hydrographical conditions, seems to be missing. The aims of the present study, therefore, were: (a) to describe the spatial, temporal and tidal dynamics of the zooplankton communities and (b) to compare the community structure of the zooplankton in the two contrasting branches on tidal, temporal and longitudinal scales.…”

Section: Introductionmentioning

confidence: 99%

Zooplankton distribution and dynamics in a temperate shallow estuary

et al. 2007

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The spatial, temporal and tidal dynamics of the zooplanktonic community of the Mondego estuary was studied from January 2003 to 2004. The monthly sampling procedure included the measurement of hydrological parameters (salinity, temperature, Secchi transparency, chlorophyll a and nutrients) and the collection of zooplankton with a Bongo net of 335 lm mesh size. Zooplankton composition, distribution, density, biomass and diversity were determined. The principal component analysis (PCA) revealed the existence of a spatial gradient with the upstream sampling stations, associated to high values of nutrients, in opposition to the downstream stations characterized by higher salinity and transparency values. The Copepoda was the main dominant group and Acartia tonsa revealed to be the more abundant taxon. The spatial and temporal dynamics of zooplanktonic communities analysed by non-metric MDS showed the existence of four assemblages of species-sites, reflecting differences in zooplankton composition between both branches of the estuary. The results suggest that abundance, biomass and diversity of the zooplanktonic community are strongly influenced by the hydrological circulation pattern and by direct or indirect human impacts that occur in each branch. The northern branch is dominated by the river flow suffering from regular dredging activities and the southern branch is dominated by tidal circulation suffering from an ongoing eutrophication process.

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“…Species belonging to the genus Oithona is typical of the region estuaries (Işinibilir et al, 2008, Vieira et al, 2003, Sterza and Fernandez, 2006. We found three species of Oithonidae (Oithona helgolandica, Oithona nana ve Oithona plumifera), Oithona nana and Oithona plumifera was seen as dominant taxa at 2 and 3 rd stations, but Oithona helgolandica were found only at 1 st station.…”

Section: Resultsmentioning

confidence: 51%

Abundance and Diversity of Zooplankton in the Köprüçay Estuary, Turkey

Erdoğan¹

2015

J Aquacult Eng Fish Res

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Abstract:The physicochemical features and species composition and density of zooplankton of Köprüçay estuary investigated monthly sampling from selected 5 stations between January and December, 2009. In this study, Zooplankton which are Rotifera (20), Cladocera (6), Copepoda (34), and Cnidaria, Tubilariidae, Foraminifera, Tintinida, Cirripedia, Gastropoda, Polychaeta, Chaetognatha, Decapoda, Ichthyoplankton one of each of determined 70 taxons in Köprüçay River estuarin zone. The dominant taxa in Köprüçay River estuarin zone consist of Oithona nana, Clausocalanus arcuicornis, Acartia discaudata, Paracalanus parvus, Euchlanis dilatata and Cephalodella gibba and these species are eurohalin character types of zooplankton. In Köprüçay River estuarin zone, the highest and the lowest Copepoda density semptember (25627.33 ±8369 ind./m

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Zooplankton distribution in a temperate estuary (Mondego estuary southern arm: Western Portugal)

Cited by 71 publications

References 13 publications

Changes in zooplankton diversity and distribution pattern under varying precipitation regimes in a southern temperate estuary

Changes in zooplankton diversity and distribution pattern under varying precipitation regimes in a southern temperate estuary

Zooplankton distribution and dynamics in a temperate shallow estuary

Abundance and Diversity of Zooplankton in the Köprüçay Estuary, Turkey

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