Recent reports have shown an increase in potentially harmful phytoplankton in Santos bay (Southeastern Brazilian Coast), located in a highly urbanised estuarine complex. Prediction of blooms is, thus, essential but the phytoplankton community structure in very dynamic regions is difficult to determine. In the present work, we discriminate bloom forming microphytoplankton dominance and their relationship to physical and meteorological variables to look for patterns observed in different tides and seasons. Comparing 8 distinct situations, we found five scenarios of dominance that could be related to winds, tides and rainfall: i) Surfers, diatoms occurring during high surf zone energies; ii) Sinkers, represented by larger celled diatoms during spring tide, after periods of high precipitation rates; iii) Opportunistic mixers, composed of chain forming diatoms with small or elongate cells occurring during neap tides; iv) Local mixers, microplanktonic diatoms and dinoflagellates which occurred throughout the 298 sampling stations; and v) Mixotrophic dinoflagellates, after intense estuarine discharges. Results suggest alterations in the temporal patterns for some bloom-forming species, while others appeared in abundances above safe limits for public health. This approach can also illustrate possible impacts of changes in freshwater discharge in highly urbanised estuaries.
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http://dx.doi.org/10.1590/s1519-69842012000100012 | DOI Listing |
Environ Pollut
December 2024
Univ Brest - CNRS - IRD - Ifremer, UMR 6539 LEMAR, IUEM-Université de Bretagne Occidentale, Rue Dumont D'Urville, 29280, Plouzané, France.
Mar Pollut Bull
September 2024
University of Newcastle, Ourimbah Campus, NSW 2258, Australia.
Anthropogenic noise has been identified as one of the most harmful forms of global pollutants impacting both terrestrial and aquatic ecosystems. As global populations continue to increase, coastlines are seeing substantial increases in the level of urbanisation. Although measures are in place to minimise stress on fauna, they rarely consider the impact of anthropogenic noise.
View Article and Find Full Text PDFMar Environ Res
July 2024
School of Natural Sciences, Macquarie University, NSW, 2109, Australia.
Organisms respond to their environment in various ways, including moving, adapting, acclimatising or a combination of responses. Within estuarine habitats, organisms are exposed to naturally variable environmental conditions. In urbanised estuaries, these natural variations can interact with human stressors such as habitat modification and pollution.
View Article and Find Full Text PDFJ Hazard Mater
October 2023
Joint Laboratory of Guangdong Province and Hong Kong Region on Marine Bioresource Conservation and Exploitation, College of Marine Sciences, South China Agricultural University, 510642 Guangzhou, China. Electronic address:
To comprehensively elucidate the ecology of the bacterial community and antibiotic resistance genes (ARGs) in urbanised coastal ecosystems, this study investigated the variations of bacterial community and five common types of ARGs, the impacting factors and assembly of bacterial community, as well as their co-occurrence relationships in two ecosystems of the Pearl River Estuary (PRE). The bacterial community composition and structure of the nearshore ecosystem (NSE) and the eight mouths of the PRE (EPR) markedly differed, with 38 phyla shared between these two ecosystems. The abundances of 10 ARGs and bacterial community diversity were significantly higher in the EPR than NSE.
View Article and Find Full Text PDFWater Res
September 2023
University of Technology Sydney, School of Life Sciences, 15 Broadway, Ultimo NSW 2007, Australia; Sydney Institute of Marine Sciences, Mosman, New South Wales 2088, Australia.
Microbes are sensitive indicators of estuarine processes because they respond rapidly to dynamic disturbance events. As most of the world's population lives in urban areas and climate change-related disturbance events are becoming more frequent, estuaries bounded by cities are experiencing increasing stressors, at the same time that their ecosystem services are required more than ever. Here, using a multidisciplinary approach, we determined the response of planktonic microbial assemblages in response to seasonality and a rainfall disturbance in an urban estuary bounded by Australia's largest city, Sydney.
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