Reis Lake is located in the municipality of Caracaraí, state of Roraima (Brazil) and is subject to fluctuations in water level. The aim of this study was to analyze the structure of the phytoplankton community on the nictemeral and seasonal scales and determined the influence of limnological variables. Sampling was performed in the rainy season (June/2006) and dry season (November/2006), considering two nictemeral cycles. The phytoplankton community was assessed with regard to composition and density, abiotic variables were analyzed simultaneously. The lake had low concentrations of oxygen, clinograde profile and water stratified during the day and homogenous at night, with low concentrations of nutrients and waters ranging from slightly acidic to alkaline. The phytoplankton was represented by 43 taxa, 35 species in the dry season and 29 species in the rainy season. Low densities of phytoplankton occurred in both nictemeral cycles, with accentuated vertical gradient. The highest densities were recorded in the dry season. Reis Lake exhibits characteristics that classify it as a polymythic and oligotrophic environment. The variability in the data was more important seasonally than on the nictemeral scale, supporting the hypothesis of the influence of the hydrological cycle on the dynamics of phytoplankton communities in floodplain lakes.
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http://dx.doi.org/10.1590/S0001-37652013000200012 | DOI Listing |
mSystems
January 2025
Department of Ecology, Behavior and Evolution, University of California San Diego School of Biological Sciences, La Jolla, California, USA.
Unlabelled: Biological diversity is declining across the tree of life, including among prokaryotes. With the increasing awareness of host-associated microbes as potential regulators of eukaryotic host physiology, behavior, and ecology, it is important to understand the implications of declining diversity within host microbiomes on host fitness, ecology, and ecosystem function. We used phytoplankton and their associated environmental microbiomes as model systems to test the independent and interactive effects of declining microbiome diversity with and without other stressors often caused by human activity-elevated temperature and altered nutrient availability.
View Article and Find Full Text PDFMicrob Ecol
January 2025
IRD, UMR ENTROPIE, 15 Avenue René Cassin, CS 92003, 97744, Saint Denis Cedex 9, La Réunion, France.
The marine microbiome arouses an increasing interest, aimed at better understanding coral reef biodiversity, coral resilience, and identifying bioindicators of ecosystem health. The present study is a microbiome mining of three environmentally contrasted sites along the Hermitage fringing reef of La Réunion Island (Western Indian Ocean). This mining aims to identify bioindicators of reef health to assist managers in preserving the fringing reefs of La Réunion.
View Article and Find Full Text PDFISME J
January 2025
Australian Antarctic Program Partnership (AAPP), Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, TAS, 7004, Australia.
Iron plays a pivotal role in regulating ocean primary productivity. Iron is supplied from diverse sources such as the atmosphere and the geosphere, and hence iron biogeochemical research has focused on identifying and quantifying such sources of "new" iron. However, the recycling of this new iron fuels up to 90% of the productivity in vast oceanic regions.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, College of Life Science, South China Normal University, West 55 of Zhongshan Avenue, Guangzhou 510631, China. Electronic address:
Domoic acid (DA), a well-known marine neurotoxin, is produced by toxic Pseudo-nitzschia species. However, the knowledge of DA in Chinese coastal waters remains limited, and the primary biological sources in these waters are still unknown. In this study, 200 surface phytoplankton samples were collected during summer and spring, covering the entire Chinese coastline.
View Article and Find Full Text PDFEnviron Pollut
January 2025
School of Fisheries, Aquaculture, and Aquatic Sciences, Auburn University, Auburn, AL. Electronic address:
Harmful algal blooms (HABs) cause severe economic and environmental impacts, including hypoxic events and the production of toxins and off-flavor compounds. Chemical treatments, such as copper sulfate pentahydrate (CuSO·5HO), are often used to mitigate the damaging effects of algal blooms. However, treatment effects are usually short-lived leading to waterbodies requiring repeated CuSO·5HO applications to control persistent algal blooms, particularly in highly eutrophic systems, such as aquaculture ponds or small agricultural impoundments.
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