Invasion of Ceratium furcoides in subtropical lakes in Uruguay: environmental drivers and first fish kill record

2021 ◽  
Author(s):  
Juan Pablo Pacheco Esnal ◽  
Carlos Iglesias Frizzera ◽  
Guillermo Goyenola ◽  
Franco Teixeira de-Mello ◽  
Claudia Fosalba ◽  
...  
Keyword(s):  
Cyanobacterial Bloom ◽  
Eutrophic Lake ◽  
Oxygen Depletion ◽  
Environmental Drivers ◽  
Fish Kill ◽  
Prochilodus Lineatus ◽  
Subtropical Lakes ◽  
Physico Chemical ◽  
Extreme Wind ◽  
Wind Events

Abstract The invasive freshwater dinoflagellate Ceratium furcoides is extending its distribution in South America with increasing environmental impacts associated with its blooms. We here report two events related to C. furcoides distribution expansion in Uruguay: 1) the first appearance and main environmental drivers (physico-chemical variables, extreme wind events and zooplankton composition) of the bloom of C. furcoides in 2012 in a subtropical eutrophic shallow lake (Lake Blanca, Uruguay), and 2) the fish kill event of Prochilodus lineatus likely caused by C. furcoides in 2016 in a deep eutrophic lake (Puente de las Americas, Uruguay), which is the first fish kill attributable to C. furcoides registered in the world. The bloom of C. furcoides in Lake Blanca started in spring 2012 (October) during a clear water period with high phytoplankton species replacement after a cyanobacterial bloom of Raphidiopsis raciborskii. Extreme wind events during this period resuspended cysts from the sediments, which likely started the C. furcoides bloom. High nutrient availability and low zooplankton grazing, allowed the bloom to expand and reach 96% of the phytoplankton biomass. Our results further indicate that the fish kill of Prochilodus lineatus in Lake Puente de las Americas was likely promoted by the high biomass of C. furcoides bloom, causing gill damage and clogging together with oxygen depletion in the benthic zone. Our study is the earliest record of C. furcoides in Uruguay and it shows the drastic consequences of C. furcoides bloom in freshwaters and its potential of inducing massive fish kills.

Invasion of Ceratium furcoides in subtropical lakes in Uruguay: Environmental drivers and fish kill record during its bloom

2021 ◽  
Author(s):  
Juan Pablo Pacheco ◽  
Carlos Iglesias Frizzera ◽  
Guillermo Goyenola ◽  
Franco Teixeira de-Mello ◽  
Claudia Fosalba ◽  
...  
Keyword(s):  
Environmental Drivers ◽  
Fish Kill ◽  
Subtropical Lakes

scholarly journals Occurrence of a single-species cyanobacterial bloom in a lake in Cyprus: monitoring and treatment with hydrogen peroxide-releasing granules

2021 ◽  
Vol 33 (1) ◽  
Author(s):  
Eleni Keliri ◽  
Christia Paraskeva ◽  
Angelos Sofokleous ◽  
Assaf Sukenik ◽  
Dariusz Dziga ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Animal Health ◽  
Cyanobacterial Bloom ◽  
Single Species ◽  
Eutrophic Lake ◽  
Liquid Hydrogen ◽  
Bioactive Metabolites ◽  
Forest Park

AbstractBackgroundExcess loads of nutrients finding their way into waterbodies can cause rapid and excessive growth of phytoplankton species and lead to the formation of cyanobacterial harmful algal blooms (cyano-HABs). Toxic cyanobacteria produce a broad range of bioactive metabolites, some of which are known as cyanotoxins. These metabolites can negatively impact the ecosystem, and human and animal health, thus their presence needs to be closely monitored and mitigated. This study aimed to monitor St. George Lake (Athalassa National Forest Park, Cyprus) for its water quality characteristics, and initiate a new methodology to control the bloom that occurred in the lake during summer 2019, by comparing hydrogen peroxide treatment with novel metallic peroxide granules as source of hydrogen peroxide.ResultsLake monitoring showed that pH, salinity, total dissolved solids and conductivity varied throughout the year, and nutrients concentration was high, indicating a eutrophic lake. The cyanobacteriumMerismopediasp. bloomed in the lake between June and September 2019, comprising up to 99% of the phytoplankton biovolume. The presence of microcystin synthase encoding gene (mcyB, mcyE) was documented, however microcystins were not detected by tandem mass spectroscopy. Treatment with liquid hydrogen peroxide in concentrations 1 to 5 mg L−1had no effect on the phycocyanin fluorescence (Ft) and quantum yield of PSII (Fv/Fm) indicating an ineffective treatment for the denseMerismopediabloom (1 million cells mL−1 ± 20%). Metallic peroxide granules tested for their H2O2releasing capacity in St. George Lake water, showing that CaO2released higher H2O2concentration and therefore have better mitigation efficiency than MgO2granules.ConclusionThe present study highlights the importance of monitoring several water parameters to conclude on the different actions to be taken to limit eutrophication in the catchment area. The findings demonstrated that testing for the presence of genes involved in cyanotoxin production may not be sufficient to follow cyanotoxins in the water, therefore it should be accompanied with analytical confirmation. Treatment experiments indicated that slow release of H2O2from peroxide granules may be an alternative to liquid hydrogen peroxide when applied in appropriate doses, but further investigation is needed before it is applied at the field.Graphic Abstract

The Extreme Wind Events in the Ross Island Region of Antarctica

2016 ◽  
Vol 31 (3) ◽  
pp. 985-1000 ◽  
Author(s):  
Nicholas J. Weber ◽  
Matthew A. Lazzara ◽  
Linda M. Keller ◽  
John J. Cassano
Keyword(s):  
Structural Damage ◽  
Ross Sea ◽  
Enso Event ◽  
Central Pacific ◽  
Island Region ◽  
Back Trajectories ◽  
Extreme Wind ◽  
Mcmurdo Station ◽  
Wind Events ◽  
Upper Level

Abstract Numerous incidents of structural damage at the U.S. Antarctic Program’s (USAP) McMurdo Station due to extreme wind events (EWEs) have been reported over the past decade. Utilizing nearly 20 yr (~1992–2013) of University of Wisconsin automatic weather station (AWS) data from three different stations in the Ross Island region (Pegasus North, Pegasus South, and Willie Field), statistical analysis shows no significant trends in EWE frequency, intensity, or duration. EWEs more frequently occur during the transition seasons. To assess the dynamical environment of these EWEs, Antarctic Mesoscale Prediction System (AMPS) forecast back trajectories are computed and analyzed in conjunction with several other AMPS fields for the strongest events at McMurdo Station. The synoptic analysis reveals that McMurdo Station EWEs are nearly always associated with strong southerly flow due to an approaching Ross Sea cyclone and an upper-level trough around Cape Adare. A Ross Ice Shelf air stream (RAS) environment is created with enhanced barrier winds along the Transantarctic Mountains, downslope winds in the lee of the glaciers and local topography, and a tip jet effect around Ross Island. The position and intensity of these Ross Sea cyclones are most influenced by the occurrence of a central Pacific ENSO event, which causes the upper-level trough to move westward. An approaching surface cyclone would then be in position to trigger an event, depending on how the wind direction and speed impinges on the complex topography around McMurdo Station.

scholarly journals The Role of Nitrogen Fixation in Cyanobacterial Bloom Toxicity in a Temperate, Eutrophic Lake

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e56103 ◽  
Author(s):  
Lucas J. Beversdorf ◽  
Todd R. Miller ◽  
Katherine D. McMahon
Keyword(s):  
Nitrogen Fixation ◽  
Cyanobacterial Bloom ◽  
Eutrophic Lake

scholarly journals Dissolved iron (II) in the Baltic Sea surface water and implications for cyanobacterial bloom development

2009 ◽  
Vol 6 (2) ◽  
pp. 3803-3850 ◽  
Author(s):  
E. Breitbarth ◽  
J. Gelting ◽  
J. Walve ◽  
L. J. Hoffmann ◽  
D. R. Turner ◽  
...  
Keyword(s):  
Baltic Sea ◽  
Surface Waters ◽  
Cyanobacterial Bloom ◽  
Euphotic Zone ◽  
Strong Wind ◽  
Ferrous Ions ◽  
The Baltic Sea ◽  
High Concentrations ◽  
Wind Events ◽  
The Baltic

Abstract. Iron chemistry measurements were conducted during summer 2007 at two distinct locations in the Baltic Sea (Gotland Deep and Landsort Deep) to evaluate the role of iron for cyanobacterial bloom development in these estuarine waters. Depth profiles of Fe(II) were measured by chemiluminescent flow injection analysis (CL-FIA) and reveal several origins of Fe(II) to the water column. Photoreduction of Fe(III)-complexes and deposition by rain are main sources of Fe(II) (up to 0.9 nmol L−1) in light penetrated surface waters. Indication for organic Fe(II) complexation resulting in prolonged residence times in oxygenated water was observed. Surface dwelling heterocystous cyanobacteria where mainly responsible for Fe(II) consumption in comparison to other phytoplankton. The significant Fe(II) concentrations in surface waters apparently play a major role in cyanobacterial bloom development in the Baltic Sea and are a major contributor to the Fe requirements of diazotrophs. Second, Fe(II) concentrations up to 1.44 nmol L−1 were observed at water depths below the euphotic zone, but above the oxic anoxic interface. Finally, all Fe(III) is reduced to Fe(II) in anoxic deep water. However, only a fraction thereof is present as ferrous ions (up to 28 nmol L−1) and was detected by the CL-FIA method applied. Despite their high concentrations, it is unlikely that ferrous ions originating from sub-oxic waters could be a temporary source of bioavailable iron to the euphotic zone since mixed layer depths after strong wind events are not deep enough in summer time.

Extreme winds in a WRF downscaling for the SAM-22 CORDEX domain for the 1979-2018 Historical Period

2021 ◽  
Author(s):  
Natalia Pillar da Silva ◽  
Rosmeri Porfírio da Rocha ◽  
Natália Machado Crespo ◽  
Ricardo de Camargo ◽  
Jose Antonio Moreira Lima ◽  
...  
Keyword(s):  
Wind Speed ◽  
Oil And Gas ◽  
Offshore Structures ◽  
Horizontal Resolution ◽  
Historical Period ◽  
Climate Projections ◽  
Wind Speeds ◽  
Extreme Wind ◽  
Wind Events ◽  
Extreme Winds

<p>This study aims to evaluate how extreme winds (above the 95th percentile) are represented in a downscaling using the regional model WRF over the CORDEX South American domain in an approximate 25 km (0.22 degrees) horizontal resolution, along with CFSR as input. The main focus of the analysis resides over the coastal Brazilian region, given a large number of offshore structures from oil and gas industries subject to impact by severe events. Model results are compared with a reanalysis product (ERA5),  estimates from satellites product (Cross-Calibrated Multi-Platform Wind Speed), and available buoy data (Brazilian National Buoy Project). Downscaling results from WRF show an underestimation of maximum and extreme wind speeds over the region when compared to all references, along with overestimation in the continental areas. This directly impacts results for extreme value estimation for a larger return period and severity evaluation of extreme wind events in future climate projections. To address this, a correction procedure based on the linear relationship between severe wind from satellite and model results is applied. After linearly corrected, the extreme and maximum wind speed values increase and errors in the representation of severe events are reduced in the downscaling results.</p>

scholarly journals Rapid adaptation of harmful cyanobacteria to rising CO2

2016 ◽  
Vol 113 (33) ◽  
pp. 9315-9320 ◽  
Author(s):  
Giovanni Sandrini ◽  
Xing Ji ◽  
Jolanda M. H. Verspagen ◽  
Robert P. Tann ◽  
Pieter C. Slot ◽  
...  
Keyword(s):  
Cyanobacterial Bloom ◽  
Eutrophic Lake ◽  
Cyanobacterial Blooms ◽  
High Flux ◽  
Flux Rate ◽  
Eutrophic Lakes ◽  
Field Evidence ◽  
Evolutionary Changes ◽  
Lakes And Reservoirs ◽  
Harmful Cyanobacterial Blooms

Rising atmospheric CO2 concentrations are likely to affect many ecosystems worldwide. However, to what extent elevated CO2 will induce evolutionary changes in photosynthetic organisms is still a major open question. Here, we show rapid microevolutionary adaptation of a harmful cyanobacterium to changes in inorganic carbon (Ci) availability. We studied the cyanobacterium Microcystis, a notorious genus that can develop toxic cyanobacterial blooms in many eutrophic lakes and reservoirs worldwide. Microcystis displays genetic variation in the Ci uptake systems BicA and SbtA, where BicA has a low affinity for bicarbonate but high flux rate, and SbtA has a high affinity but low flux rate. Our laboratory competition experiments show that bicA + sbtA genotypes were favored by natural selection at low CO2 levels, but were partially replaced by the bicA genotype at elevated CO2. Similarly, in a eutrophic lake, bicA + sbtA strains were dominant when Ci concentrations were depleted during a dense cyanobacterial bloom, but were replaced by strains with only the high-flux bicA gene when Ci concentrations increased later in the season. Hence, our results provide both laboratory and field evidence that increasing carbon concentrations induce rapid adaptive changes in the genotype composition of harmful cyanobacterial blooms.

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