Abstract
AbstractThe joint influence of local climatic and hydrological conditions on the vertical distribution of bloom‐forming phytoplankton was analysed for the Salto Grande Reservoir, a large and enriched subtropical system on the Uruguay River (South America). Threshold of physical factors hindering or impeding blooms was obtained and then contrasted with worldwide observations in reservoirs at similar latitudes. Inflowing discharge, water level, and wind velocity intensity interacted with temperature, producing mixing and light regimes with overriding influence on the vertical distribution of Microcystis spp., Dolichospermum spp., and Ceratium furcoides, hence affecting their maximum abundance and biomass. Cyanobacteria (Microcystis > Dolichospermum) showed the most heterogeneous distribution in the depth profile during strong thermal stratification, showing surface scums prone to horizontal displacements. C. furcoides was evenly distributed in the water column in correspondence to windy periods. Blooms of both Cyanobacteria and dinoflagellates did not occur when inflowing discharge exceeded 10,000 m3 s−1. Nutrient influence on phytoplankton vertical distribution appeared strongly subordinate to the effect of light. Highest microcystin concentrations (>WHO alert Level 2) occurred especially after blooms collapsed during highly turbulent situations.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.