The sediment akinete bank links past and future blooms of Nostocales in a shallow lake

2020 ◽  
Author(s):  
Lilen Yema ◽  
Inés O'farrell ◽  
Paula de Tezanos Pinto
Keyword(s):  
Shallow Lake ◽  
Morphological Analysis ◽  
Water Quality Management ◽  
Sufficient Conditions ◽  
Good Method ◽  
Abundant Species ◽  
Phosphorus Concentration ◽  
Cyanobacteria Blooms ◽  
Germination Experiment ◽  
Positive Effect

Abstract In this paper we analyzed how well the akinete bank in the sediments from a shallow lake reflected past blooms of planktonic Nostocales (cyanobacteria), the akinete bank’s potential for reflecting future blooms and whether different nutrient scenarios affect germination and recruitment using a laboratory experiment. Most species found in the plankton were also found in the akinete bank and in the germination experiment. Based on their shape, the most abundant viable akinetes in the sediments potentially corresponded to some of the species forming intense blooms in previous years, and coincided with the most abundant species in a 3-week germination experiment. The effects of nutrients on germination and recruitment were only observed in the early phase of the life cycle (Day 7), where nitrogen-sufficient conditions enhanced germination, while phosphorus concentration had a positive effect on the number of heterocytes. Combined approaches of morphological analysis and experimental germination seem a good method for assessing the past diversity of Nostocales and allowing predictions of the diversity of potential future blooms in shallow lakes and as a tool for water quality management, especially in water bodies lacking information on previous cyanobacteria blooms.

scholarly journals Nutrient Loading, Temperature and Heat Wave Effects on Nutrients, Oxygen and Metabolism in Shallow Lake Mesocosms Pre-Adapted for 11 Years

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 127
Author(s):  
Erik Jeppesen ◽  
Joachim Audet ◽  
Thomas A. Davidson ◽  
Érika M. Neif ◽  
Yu Cao ◽  
...  
Keyword(s):  
Heat Wave ◽  
Shallow Lake ◽  
Nutrient Loading ◽  
Global Changes ◽  
Significant Positive Effect ◽  
Mixed Effect ◽  
Chl A ◽  
Nutrient Loadings ◽  
Positive Effect ◽  
Oxygen Concentrations

Global changes (e.g., warming and population growth) affect nutrient loadings and temperatures, but global warming also results in more frequent extreme events, such as heat waves. Using data from the world’s longest-running shallow lake experimental mesocosm facility, we studied the effects of different levels of nutrient loadings combined with varying temperatures, which also included a simulated 1-month summer heat wave (HW), on nutrient and oxygen concentrations, gross ecosystem primary production (GPP), ecosystem respiration (ER), net ecosystem production (NEP) and bacterioplankton production (BACPR). The mesocosms had two nutrient levels (high (HN) and low (LN)) combined with three different temperatures according to the IPCC 2007 warming scenarios (unheated, A2 and A2 + 50%) that were applied for 11 years prior to the present experiment. The simulated HW consisted of 5 °C extra temperature increases only in the A2 and A2 + 50% treatments applied from 1 July to 1 August 2014. Linear mixed effect modeling revealed a strong effect of nutrient treatment on the concentration of chlorophyll a (Chl-a), on various forms of phosphorus and nitrogen as well as on oxygen concentration and oxygen percentage (24 h means). Applying the full dataset, we also found a significant positive effect of nutrient loading on GPP, ER, NEP and BACPR, and of temperature on ER and BACPR. The HW had a significant positive effect on GPP and ER. When dividing the data into LN and HN, temperature also had a significant positive effect on Chl-a in LN and on orthophosphate in HN. Linear mixed models revealed differential effects of nutrients, Chl-a and macrophyte abundance (PVI) on the metabolism variables, with PVI being particularly important in the LN mesocosms. All metabolism variables also responded strongly to a cooling-low irradiance event in the middle of the HW, resulting in a severe drop in oxygen concentrations, not least in the HN heated mesocosms. Our results demonstrate strong effects of nutrients as well as an overall rapid response in oxygen metabolism and BACPR to changes in temperature, including HWs, making them sensitive ecosystem indicators of climate warming.

Spatial variability and temporal dynamics of cyanobacteria blooms and water quality parameters in Missisquoi Bay (Lake Champlain)

2019 ◽  
Vol 19 (5) ◽  
pp. 1500-1506 ◽  
Author(s):  
I. Melendez-Pastor ◽  
E. M. Isenstein ◽  
J. Navarro-Pedreño ◽  
M-H. Park
Keyword(s):  
Total Phosphorus ◽  
Temporal Dynamics ◽  
Secchi Depth ◽  
Spatial Association ◽  
Phosphorus Concentration ◽  
Lake Champlain ◽  
Total Phosphorus Concentration ◽  
Cyanobacteria Bloom ◽  
Explanatory Variables ◽  
Cyanobacteria Blooms

Abstract Cyanobacteria bloom events have been associated with eutrophication processes, along with hydrologic and climate factors. Missisquoi Bay is a portion of Lake Champlain (USA–Canada) that is highly eutrophic and prone to cyanobacteria blooms and cyanotoxins. This study assessed the spatial–temporal influence of nutrients, turbidity and temperature in cyanobacteria distributions during a bloom event in the summer of 2006. Correlations, generalized linear models (GLMs), geostatistics and local indications of spatial association (LISA) autocorrelation analysis tested the influence of nutrient and non-nutrient explanatory variables in cyanobacteria biovolume. Total phosphorus exhibited a high direct correlation with cyanobacteria biovolume. The best performing GLMs included total phosphorus, total nitrogen, Secchi depth (as turbidity) and temperature as explanatory variables of cyanobacteria biovolume. Variogram analysis of those variables resulted in a better understanding of the underlying spatial variation process of the cyanobacteria bloom event. The LISA test revealed a moderate but stable autocorrelation between cyanobacteria biovolume and total phosphorus from 180 to 1,000 m of weight distance, suggesting the possibility of up-scaling the current results to coarse-resolution satellite imagery for more frequent monitoring of bloom events. The LISA test also revealed the spatial–temporal dynamic (movement of cyanobacteria scums) of high cyanobacteria blooms with high total phosphorus concentration.

Anabaenopsis morphospecies (Cyanobacteria, Nostocales) from Los Patos shallow lake (Province of Buenos Aires, Argentina)

Phytotaxa ◽  
2016 ◽  
Vol 272 (3) ◽  
pp. 173 ◽  
Author(s):  
ANABELLA AGUILERA ◽  
JIŘĺ KOMÁREK ◽  
RICARDO O. ECHENIQUE
Keyword(s):  
Population Dynamics ◽  
Species Richness ◽  
Shallow Lake ◽  
Algal Blooms ◽  
Buenos Aires ◽  
Morphological Diversity ◽  
Abundant Species ◽  
American Continent ◽  
First Report ◽  
Almost All

The genus Anabaenopsis comprises about 20 morphospecies distributed in plankton of tropical, subtropical and temperate regions during warm periods. The morphological diversity and population dynamics of Anabaenopsis species from one artificial shallow lake from the Province of Buenos Aires, Argentina, was studied during summer 2005 and 2006; and from April 2012 to May 2014. The most common and abundant species were identified as A. elenkinii and A. cf. cunningtonii (first report in Argentina). Anabaenopsis circularis and A. milleri (first report in the American continent and Argentina) were less common, whereas A. nadsonii was rarely observed. Almost all species contributed to algal blooms during warm periods. However, some species were registered even under the lowest temperatures recorded (7.5 °C) and sustained biovolume also during winter (A. milleri, A. elenkinii and A. cf. cunningtonii). These results indicate that some species of the genus are capable of growing at temperatures much lower than 20°C. The species richness noted in this study suggests that there is likely much more diversity remaining on this genus to be reported in Argentina.

scholarly journals A survey of tire-breeding mosquitoes (Diptera: Culicidae) in the Dominican Republic: Considerations about a pressing issue

Biomédica ◽  
2020 ◽  
Vol 40 (3) ◽  
pp. 507-515 ◽  
Author(s):  
Mikel A. González ◽  
María Altagracia Rodríguez-Sosa ◽  
Yohan Enmanuel Vásquez-Bautista ◽  
Elizabeth del Carmen Rosario ◽  
Jesús Confesor Durán-Tiburcio ◽  
...  
Keyword(s):  
Public Health ◽  
Organic Matter ◽  
Dominican Republic ◽  
Abundant Species ◽  
Human Populations ◽  
Immature Stages ◽  
Breeding Sites ◽  
Larval Habitats ◽  
Positive Effect ◽  
Artificial Reservoirs

Introduction: Discarded vehicle tires represent a serious threat both to the environment and to public health as they have the potential to harbor important mosquito (Diptera: Culicidae) vectors.Objective: To assess the importance of used vehicle tires as larval habitats for mosquito fauna that colonize these artificial reservoirs in Jarabacoa, Dominican Republic.Materials and methods: Used tires were sampled with pipettes at specialized tire fitting shops and scattered stockpiles of tires between June and August, 2018.Results: We sampled 396 tires; 57 (Container Index=14.4%) were positive for immature stages and contained 2,400 specimens, 11 species, and four genera (Anopheles, Aedes, Culex, and Toxorhynchites). The most abundant species was Aedes albopictus (42.3%) followed by Aedes aegypti (34.3%), and Culex quinquefasciatus (14.0%) while other species (9.4%) were less abundant. The container index varied significantly among the different tire sizes (χ2=13.4; p≤0.05). The highest infestation levels were found in the largest tires. A low positive correlation (r=0.38, n=396; p≤0.001) between the tire size and the prevalence of immature stages was recorded. The presence of organic matter had an overall positive effect on the infestation levels (U=11,430.0; p≤0.001).Conclusions: These rubber residues, usually located nearby human populations, represent suitable breeding sites for arboviruses vectors such as dengue, chikungunya, Zika, and West Nile.

The Role of Fish Communities in Water Quality Management of a Large Shallow Lake

2003 ◽  
Vol 88 (5) ◽  
pp. 498-507 ◽  
Author(s):  
István Tátrai ◽  
Gábor Paulovits ◽  
Kálmán Mátyás ◽  
János Korponai
Keyword(s):  
Water Quality ◽  
Quality Management ◽  
Shallow Lake ◽  
Water Quality Management ◽  
Fish Communities ◽  
Large Shallow Lake
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