Nitrogen limitation, toxin synthesis potential, and toxicity of cyanobacterial populations in Lake Okeechobee and the St. Lucie River Estuary, Florida, during the 2016 state of emergency event
| Autor: | Jennifer A. Goleski, Kevin A. Meyer, Barry H. Rosen, Timothy W. Davis, Genesok Oh, Gregory J. Dick, Benjamin J. Kramer, Christopher J. Gobler |
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| Rok vydání: | 2018 |
| Předmět: |
Chlorophyll
Pigments 0106 biological sciences Salinity Chloroplasts lcsh:Medicine Marine and Aquatic Sciences Plant Science 010501 environmental sciences Toxicology Pathology and Laboratory Medicine Physical Chemistry 01 natural sciences Medicine and Health Sciences Toxins Biomass lcsh:Science chemistry.chemical_classification Multidisciplinary geography.geographical_feature_category biology Ecology Eukaryota Plants Plankton Chemistry Physical Sciences Florida Cellular Structures and Organelles Cellular Types Estuaries Water Microbiology Bloom Environmental Monitoring Research Article Freshwater Environments Microcystis Microcystins Algae Nitrogen Harmful Algal Bloom Plant Cell Biology Bacterial Toxins Toxic Agents Materials Science Microcystin Cyanobacteria Algal bloom Rivers Plant Cells Phytoplankton Animals Ecosystem Materials by Attribute 0105 earth and related environmental sciences geography Bacteria Organic Pigments 010604 marine biology & hydrobiology lcsh:R Ecology and Environmental Sciences Organisms Aquatic Environments Biology and Life Sciences Estuary Cell Biology Bodies of Water biology.organism_classification Invertebrates Lakes Chemical Properties chemistry Genes Bacterial Earth Sciences Environmental science lcsh:Q Emergencies Surface water Water Pollutants Chemical Saxitoxin |
| Zdroj: | PLoS ONE PLoS ONE, Vol 13, Iss 5, p e0196278 (2018) |
| ISSN: | 1932-6203 |
| Popis: | Lake Okeechobee, FL, USA, has been subjected to intensifying cyanobacterial blooms that can spread to the adjacent St. Lucie River and Estuary via natural and anthropogenically-induced flooding events. In July 2016, a large, toxic cyanobacterial bloom occurred in Lake Okeechobee and throughout the St. Lucie River and Estuary, leading Florida to declare a state of emergency. This study reports on measurements and nutrient amendment experiments performed in this freshwater-estuarine ecosystem (salinity 0-25 PSU) during and after the bloom. In July, all sites along the bloom exhibited dissolved inorganic nitrogen-to-phosphorus ratios < 6, while Microcystis dominated (> 95%) phytoplankton inventories from the lake to the central part of the estuary. Chlorophyll a and microcystin concentrations peaked (100 and 34 μg L-1, respectively) within Lake Okeechobee and decreased eastwards. Metagenomic analyses indicated that genes associated with the production of microcystin (mcyE) and the algal neurotoxin saxitoxin (sxtA) originated from Microcystis and multiple diazotrophic genera, respectively. There were highly significant correlations between levels of total nitrogen, microcystin, and microcystin synthesis gene abundance across all surveyed sites (p < 0.001), suggesting high levels of nitrogen supported the production of microcystin during this event. Consistent with this, experiments performed with low salinity water from the St. Lucie River during the event indicated that algal biomass was nitrogen-limited. In the fall, densities of Microcystis and concentrations of microcystin were significantly lower, green algae co-dominated with cyanobacteria, and multiple algal groups displayed nitrogen-limitation. These results indicate that monitoring and regulatory strategies in Lake Okeechobee and the St. Lucie River and Estuary should consider managing loads of nitrogen to control future algal and microcystin-producing cyanobacterial blooms. |
| Databáze: | OpenAIRE |
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