Oceanografia y Ecologia Marina

Montevideo, Uruguay

Oceanografia y Ecologia Marina

Montevideo, Uruguay
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Basatnia N.,Gorgan University of Agricultural Sciences and Natural Resources | Hosseini S.A.,Gorgan University of Agricultural Sciences and Natural Resources | Ghorbani R.,Gorgan University of Agricultural Sciences and Natural Resources | Muniz P.,Oceanografia y Ecologia Marina
Brazilian Journal of Oceanography | Year: 2015

This paper aims to test the suitability of some biotic indices for their application in Southeast Caspian Sea. For this purpose, the ecological quality of the Gomishan lagoon was assessed using three biotic indices (AMBI, BENTIX, BOPA) during summer and autumn 2010. The results from the application of the biotic indices do not highlight a clear distinction between the stations. The results show that two of the indices (AMBI and BENTIX) are very close in terms of diagnosis (good and high) and seem to generally perform better than BOPA. In addition, Principal Component Analysis (PCA) based on abiotic parameters showed clear spatial and temporal differences in environmental variables. However, at this shallow sites with low human pressure and high water residence times, such benthic community composition can be associated with physical stress due to salinity increase and to changes in environmental characteristics, triggered by conventional seasonal variations. Natural variability of transitional waters is a crucial factor for a correct evaluation of the ecological condition of macroinvertebrate communities across the lagoonal system. © 2015, Universidade de Sao Paulo. All rights reserved.

Muniz P.,Oceanografia y Ecologia Marina | Pires-Vanin A.M.S.,University of Sao Paulo | Venturini N.,Oceanografia y Ecologia Marina
Marine Ecology | Year: 2013

The vertical distribution of macrobenthic fauna, heavy metals, and other physico-chemical and biological characteristics of the sediments were studied in three sediment layers (0-7, 8-14, 15-21 cm) at seven stations in the Ubatuba region, north coast of São Paulo State, Brazil at several temporal and spatial scales. Six stations were located in the inner bay near the riverine run-off, and one was outside the bay, distant from the riverine influence. The samples were collected four times in 1 year, on a seasonal basis. Sediments were basis comprised predominantly of very fine sand and the vertical distribution of grain size was uniform to a depth of 21 cm in all stations. Higher values of total organic matter, organic carbon, sulphur, heavy metals and phaeopigments were recorded at the inner Ubatuba Bay stations, probably due to the riverine influence. C/N ratios indicated a mixed origin of organic matter with a major contribution of terrestrial material in the inner stations. The vertical distribution of heavy metals showed a slight decline with sediment depth in the inner stations, indicating the present contribution. Most of the macrofauna was found at the surface sediment layer. Biological data showed that in the inner stations of Ubatuba Bay, which are under the influence of urban sewage and are moderately polluted, the fauna was distributed more superficially within the substrate than in St. 7, which is located in the external portion of the bay distant from sewage inputs. The environmental quality of the sites studied varied little throughout the year, at least in relation to the variables considered here. Temporal variation in the vertical distribution of benthic fauna was not evident in the four sampling surveys analysed. Only minor changes in the vertical distribution of the total fauna were detected in the seasonal scale, with the organisms located less deep within the sediment column in summer, indicating some influence of the tourism impact and/or rainy season. © 2013 Blackwell Verlag GmbH.

Souza F.M.,Federal University of Paraná | Brauko K.M.,Federal University of Paraná | Lana P.C.,Federal University of Paraná | Muniz P.,Oceanografia y Ecologia Marina | Camargo M.G.,Federal University of Paraná
Marine Pollution Bulletin | Year: 2013

We investigated the spatial scales of variation of macrofauna in intertidal flats subjected to different levels of contamination from urban effluents in two areas sampled in the Paranaguá Estuarine Complex. The scales considered were: Conditions; Tidal flats and Plots. Although the numerically dominant taxa showed the greatest variability at a scale of Tidal flats, the variability at the Condition scale was also significant. Tubificinae sp. 1, Laeonereis culveri and Heteromastus sp. were the most abundant organisms in the Contaminated area, while Heleobia australis was most abundant in the Non-contaminated area. Our results, contrary to those frequently observed in the literature, showed that the variability was significant at the scale of hundreds of metres (Tidal flats). At this scale, the intrinsic characteristics of each tidal flat are more important in determining macrofaunal distribution, while the effects of the urban sewage contamination represent the primary forces acting at a greater spatial scale. © 2012 Elsevier Ltd.

Albano M.J.,CONICET | da Cunha Lana P.,Federal University of Paraná | Bremec C.,CONICET | Elias R.,University of the Sea | And 6 more authors.
Marine Pollution Bulletin | Year: 2013

We evaluated benthic habitat quality along a presumed contamination gradient in the Mar del Plata port (Southwestern Atlantic) by coupling biological and chemical proxies in a multidisciplinary approach. Organic matter and photosynthetic pigment contents were higher in silty-clay bottoms of the inner port sites. Levels of all fecal steroids decreased from the inner sites to the port inlet. High concentrations of coprostanol in the inner sites seemed to derive from a permanent population of sea lions rather than from sewage outfalls due to coprostanol/epicoprostanol ratio (IV) values <2.5. PAHs levels were also higher in the inner sector, related to both biomass combustion and petroleum combustion associated to local marine traffic. High disturbance and low ecological status were reflected in low benthic diversity and high AMBI values in the inner sites. © 2013 Elsevier Ltd.

Gimenez L.,Bangor University | Venturini N.,Oceanografia y Ecologia Marina | Kandratavicius N.,Oceanografia y Ecologia Marina | Hutton M.,Oceanografia y Ecologia Marina | And 4 more authors.
Journal of Sea Research | Year: 2014

Estuaries vary considerably in geomorphology, hydrology and in the properties of sediments. Structure of benthic communities may respond to the interaction of these estuarine characteristics, resulting in between site differences. This work evaluated several hypothetical scenarios to explain variation in macrofaunal communities in permanently open estuaries and open/closed coastal lagoons of the coast of Uruguay, South America. Of particular relevance were three hypothetical scenarios: (1) that sediment characteristics, temperature or conductivity may explain variation in fauna between estuarine habitat types (estuaries vs. lagoons), (2) that fauna may not vary between habitat types, but may vary among sites in response to environmental variables and (3) that fauna differed between habitat types but patterns were not clearly being mediated by the measured environmental variables. Scenario 1 was discarded because none of the observed environmental variables showed a significant habitat effect. Patterns of species richness differed between lagoons and estuaries in accordance with scenario 3; richness was higher in open/closed lagoons than in estuaries. The abundance of three important infaunal species supported scenario 2: these species varied considerably among sites in response to the proportion of different sand fractions. Fine sands, common in all estuaries and in a lagoon, were characterised by polychaetes (Laeonereis acuta and Alitta succinea) whereas coarse sands, found in two lagoons were characterised by a bivalve, Erodona mactroides. Another three species responded to sediment but did not show clear site to site variation in abundance. Lagoons differ from estuaries in their higher site to site variation in sediment composition and in the diversity of community variants: lagoons may therefore increase regional diversity as compared to estuaries. We conclude that sediment type played a strong role in explaining variations in macrofaunal abundance among estuaries and lagoons. © 2013 Elsevier B.V.

Muniz P.,Oceanografia y Ecologia Marina | Hutton M.,Oceanografia y Ecologia Marina | Kandratavicius N.,Oceanografia y Ecologia Marina | Lanfranconi A.,Oceanografia y Ecologia Marina | And 3 more authors.
Ecological Indicators | Year: 2012

Biotic indices based on benthic communities have become an important tool in the assessment and monitoring of marine pollution. These communities vary at several spatial and temporal scales giving rise to scale-dependent patterns of distribution, being of particular importance because results from the application of ecological indices, and the subsequent classification of communities, could reflect these variations at several scales. We test some of the most widely applied indices for the evaluation of coastal benthic communities, using a hierarchical spatio-temporal sampling design, within two sets of estuarine habitats in the Atlantic coastal zone of Uruguay. Results showed that ecological indices can vary at different spatial scales, with important variation at small scales. So, independently from the used index, an appropriate sampling design should be taken into account considering different scales (both spatial and temporal). At some of the scales studied, indices appear to reflect natural variations in disturbance through currents rather than variation in anthropogenic effects. At the large scale, variation is low consistent with a preliminary classification of sites according to the putative levels of human activity. The low level of similarity between all indices could be denoting some degree of inconsistency in the assignment of the categories to an ecological status. © 2011 Elsevier Ltd. All rights reserved.

Lanfranconi A.,Oceanografia y Ecologia Marina | Brugnoli E.,Oceanografia y Ecologia Marina | Muniz P.,Oceanografia y Ecologia Marina
Aquatic Invasions | Year: 2013

The veined whelk Rapana venosa (Valenciennes, 1846) is an active, Asian, invasive mollusk predator that has been present along the coastal zone of Maldonado, Uruguay since 2004. The feeding rate of R. venosa on native mussels was estimated in a laboratory experiment. A flume with a constant water flow was used, in which the mean (± SD) temperature was 25.4 ± 1.8 °C, the mean (± SD) salinity was 18.5 ± 1.6, and a 15:9 light-dark schedule was followed. Each experimental trial lasted 9 days and a constant prey supply was maintained. Three size classes of predators and three size classes of prey (Brachidontes rodriguezii and Mytella charruana), were used. For all sizes of predator combined, the average (± SD) absolute consumption rate was 0.88 ± 0.3 g day-1, and the relative consumption rate was 0.057 ± 0.034 g g-1 day-1. No significant differences were found between the number of prey and total grams consumed among the three size categories of snails. However, for the relative consumption rate, small snails consumed significantly greater (0.10 g g-1 day-1) amounts than intermediate and large snails (0.04 and 0.02 g g-1 day-1 respectively). All sizes of snails consumed significantly more intermediate- than small-sized mussels. This study provides important knowledge for future research to assess the impact of this invasive species on native bivalve resources. © 2013 The Author(s).

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