scholarly journals Protected Freshwater Ecosystem with Incessant Cyanobacterial Blooming Awaiting a Resolution

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 129 ◽  
Author(s):  
Nada Tokodi ◽  
Damjana Drobac Backović ◽  
Jelena Lujić ◽  
Ilija Šćekić ◽  
Snežana Simić ◽  
...  

For 50 years persistent cyanobacterial blooms have been observed in Lake Ludoš (Serbia), a wetland area of international significance listed as a Ramsar site. Cyanobacteria and cyanotoxins can affect many organisms, including valuable flora and fauna, such as rare and endangered bird species living or visiting the lake. The aim was to carry out monitoring, estimate the current status of the lake, and discuss potential resolutions. Results obtained showed: (a) the poor chemical state of the lake; (b) the presence of potentially toxic (genera Dolichospermum, Microcystis, Planktothrix, Chroococcus, Oscillatoria, Woronichinia and dominant species Limnothrix redekei and Pseudanabaena limnetica) and invasive cyanobacterial species Raphidiopsis raciborskii; (c) the detection of microcystin (MC) and saxitoxin (STX) coding genes in biomass samples; (d) the detection of several microcystin variants (MC-LR, MC-dmLR, MC-RR, MC-dmRR, MC-LF) in water samples; (e) histopathological alterations in fish liver, kidney and gills. The potential health risk to all organisms in the ecosystem and the ecosystem itself is thus still real and present. Although there is still no resolution in sight, urgent remediation measures are needed to alleviate the incessant cyanobacterial problem in Lake Ludoš to break this ecosystem out of the perpetual state of limbo in which it has been trapped for quite some time.

2001 ◽  
Vol 1 (2) ◽  
pp. 237-246 ◽  
Author(s):  
M. Tarczyńska ◽  
Z. Romanowska-Duda ◽  
T. Jurczak ◽  
M. Zalewski

Eutrophication of reservoirs used for drinking water supplies is a very common problem, particularly in lowland reservoirs. Long water retention time (60-120 days) favours cyanobacterial bloom occurrence in Sulejów Reservoir, Poland. The localisation of the water intake in a bay exposed to north-east winds favoured the Microcystis bloom accumulation, which formed a 0.5 m thick dense scum for the first time in September 1999. Cyanobacterial hepatotoxins can pose a potential health problem because the presence of about 0.8 μg/l microcystins was detected in drinking water during three series of analysis. An investigation of the efficiency of each stage of water treatment processes in the elimination of microcystins showed that pre-chlorination, coagulation, and rapid sand filtration were ineffective in removing microcystins from water. Significant elimination was observed after ozonation and chlorination. The concentration of microcystins in bloom material was between 12 to 860 μg/g dry weight of phytoplankton biomass. Management strategies for reservoirs should consider the important role of ecohydrological processes, which are often very easy to regulate, and which can be useful for bio-manipulation of the water ecosystem.


2015 ◽  
Vol 41 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Dominik Szczukocki ◽  
Radosław Dałkowski ◽  
Barbara Krawczyk ◽  
Renata Juszczak ◽  
Luiza Kubisiak-Banaszkiewicz ◽  
...  

Abstract Cyanobacterial blooms occur frequently in artificial lakes, especially in water reservoirs with small retention exposition to anthropopressure. The abundant occurrence of cyanobacteria is accompanied by danger of oxygen imbalance in the aquatic environment and the secretion of toxins that are possible threat to human health and life. Cyanobacterial cell growth depends on a number of physical (temperature, light exposure), chemical (pH, concentration of compounds containing nitrogen and phosphorus) and biological (the presence of other organisms) factors. This paper presents the results of the analysis of water from reservoirs located in southern Wielkopolska region (Pokrzywnica-Szałe, Gołuchów and Piaski-Szczygliczka). Some important physico-chemical parameters of water samples taken from investigated reservoirs as well as cyanotoxins concentration were determined. Furthermore, the cyanobacterial species were identified. There was also an attempt made to correlate the water parameters with the cyanobacteria development and cyanotoxins production. On the basis of the results obtained in the analyzed season, it can be concluded that water from Pokrzywnica and Gołuchów reservoirs was rich in nutrients, hence the intense cyanobacterial blooms and cyanotoxins in water were observed


Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2583
Author(s):  
Elisabeth Vardaka ◽  
Konstantinos Ar. Kormas

Cyanobacterial blooms have become a frequent phenomenon in freshwaters worldwide; they are a widely known indicator of eutrophication and water quality deterioration. Information and knowledge contributing towards the evaluation of the ecological status of freshwaters, particularly since many are used for recreation, drinking water, and aquaculture, is valuable. This Special Issue, entitled “Advancing Knowledge on Cyanobacterial Blooms in Freshwaters”, includes 11 research papers that will focus on the use of complementary approaches, from the most recently developed molecular-based methods to more classical approaches and experimental and mathematical modelling regarding the factors (abiotic and/or biotic) that control the diversity of not only the key bloom-forming cyanobacterial species, but also their interactions with other biota, either in freshwater systems or their adjacent habitats, and their role in preventing and/or promoting cyanobacterial growth and toxin production.


2017 ◽  
Vol 17 (1) ◽  
pp. 36-41
Author(s):  
Namkhaidorj Sainbileg ◽  
Wang Tong ◽  
Yang Fan ◽  
Yang Guisheng

Species diversity and composition of bird community at South Lake Wetland Park in Hohhot city were investigated from October 2013 to September 2014. In total,64 bird species belonging to 33 families and 14 orders were recorded. There are 36 summer migrant species, 15 resident species, 11 traveling species and 2 winter migrant species found. The habitats of birds were grouped into four types (wetland, woodland, grassland and residential area) according to topography and vegetation types in the survey area.Shannon-Weiner Diversity Index (H`) was 2.9450 in wetland area and 1.0768 in grassland area the highest and the lowest values, respectively. The evenness of bird species was 0.4058 lowest in woodland and 0.7581 highest in residential area. The dominance index of bird species was 0.0733 lowest in the wetland and 0.4319 highest in the woodland, respectively. This paper analyzed the relationship between the main dominant bird species and their habitat characteristics,explained the main reasons for the increased bird species number.


1970 ◽  
pp. 20-34 ◽  
Author(s):  
Imran A Dar ◽  
Mithas A Dar

The main thrust in this research work has been given on the evaluation of current status of Avifauna associated with Shallabug wetland. The main objectives were to evaluate the bird population fluctuation, to determine various threats to waterbirds and their habitats, and to present the remedial measures based on the key issues identified. For the purpose of present investigation, the study area was divided systematically into three study units of 700 m² each. Visual census method was used for the estimation of bird population. Visual counting was made with the help of high power field binocular (SG- 9.2) from respective vantage points. The birds were observed on the monthly basis in 2008 and the fluctuation in bird population was determined in different seasons: summer, autumn and winter.  The observations were made from 5:00 am to 7:00 am (when they come out from their resting place) and 6:00 pm to 7:00 pm (when they approach towards their resting place). The analysis of the results showed that the Shallabug Wetland is particularly important for migratory bird species and marsh land breeding species. The wetland was also found important for long distance migrants as a stopper site for feeding and resting. The bird population showed fluctuation with site differences as well as with changing seasons. Key words: Wetland, Shallabug, Avifauna, Fluctuation, Wetland managementDOI: 10.3126/jowe.v2i1.1853 Journal of Wetlands Ecology, (2009) vol. 2, pp 20-34


1997 ◽  
Vol 54 (8) ◽  
pp. 1736-1742 ◽  
Author(s):  
A K-Y Lam ◽  
E E Prepas

Closed-bottom limnocorrals were placed in a hardwater lake in central Alberta to compare the effect of two alternative approaches to chemical removal of toxic phytoplankton blooms. Reglone A, which lyses phytoplankton cells, and lime-alum, which precipitates intact phytoplankton cells out of the water column were both effective in removing phytoplankton from the water column. Our results were consistent with laboratory studies in that treatment with Reglone A removed phytoplankton (primarily cyanobacteria) blooms with a concomitant increase in dissolved microcystin (exo-MCYST) and phosphorus concentrations in the surrounding water whereas lime-alum treatment did not. Maximum exo-MCYST concentrations in the water phase of the lime-alum treated limnocorrals were 32-fold lower than those recorded in the Reglone-treated limnocorrals. Treatment with lime alone caused a sharp rise in pH (to >10), and the observed increase in exo-MCYST was likely due to pH shock. Exo-MCYST concentration in the Reglone-treated enclosures remained high for the duration of the experiment (>5 days). As microcystin did not partition onto lake sediments in laboratory studies, our limnocorrals results were probably a good indication of microcystin dynamics in lakes. Thus, the use of chemicals such as lime-alum that precipitate out intact phytoplankton cells lessens the potential health risk where microcystins are present.


1999 ◽  
Vol 9 (4) ◽  
pp. 315-331 ◽  
Author(s):  
Peter G. Ryan ◽  
Carlos Bento ◽  
Callan Cohen ◽  
John Graham ◽  
Vincent Parker ◽  
...  

SummaryWe report the current status of birds at the Namuli Massif, northern Mozambique. Despite being the only known locality for the Namuli Apalis Apalis lynesi and the nominate race of the Dapplethroat Arcanator orostruthus, the mountain is very little known ornithologically. Prior to our survey it had only been visited by an ornithologist in 1932, when Jack Vincent collected in the area for three weeks. During our week-long survey in November-December 1998 we recorded 130 bird species from the Namuli area, including all three globally threatened species reported by Vincent (Thyolo Alethe Alethe choloensis, Dapplethroat and Namuli Apalis). The higher-elevation (>1,500 m) forests are still largely intact, but most of those at lower elevations have been cleared for agriculture. The alethe and apalis are common, occurring in remnant forest patches and secondary scrub as well as pristine forest from 1,160 to 2,000 m. The Dapplethroat is restricted to large, intact forests above 1,500 m, but also is fairly common (up to 2–3 singing males per hectare; greater densities than recorded elsewhere). Red-rumped Swallow Hirundo daurica was recorded for the first time in Mozambique, and was suspected of breeding at 1,400 m. We estimate that some 1,300 ha of pristine forest remains on the main massif between Gurue and Mount Namuli, but this area is being reduced by burning and “subsistence” logging. Approximately 7,000 people currently live in the area east of the main forest. Grazing by goats and pigs on the montane grasslands surrounding the forests is another problem, but the gravest threat is posed by improved road access to the area, which could open the forests to commercial logging. In addition to being the sole locality known for the Namuli Apalis and the nominate race of Dapplethroat, the Namuli forests probably support the largest single populations of Thyolo Alethe and the well-marked belcheri race of Green Barbet. These populations make Namuli arguably the most critical Important Bird Area for Mozambique, and the remaining forests have a high priority for conservation action.


PLoS ONE ◽  
2021 ◽  
Vol 16 (2) ◽  
pp. e0238013
Author(s):  
Takehiro Kazama ◽  
Kazuhide Hayakawa ◽  
Victor S. Kuwahara ◽  
Koichi Shimotori ◽  
Akio Imai ◽  
...  

Direct measurements of gross primary productivity (GPP) in the water column are essential, but can be spatially and temporally restrictive. Fast repetition rate fluorometry (FRRf) is a bio-optical technique based on chlorophyll a (Chl-a) fluorescence that can estimate the electron transport rate (ETRPSII) at photosystem II (PSII) of phytoplankton in real time. However, the derivation of phytoplankton GPP in carbon units from ETRPSII remains challenging because the electron requirement for carbon fixation (Фe,C), which is mechanistically 4 mol e− mol C−1 or above, can vary depending on multiple factors. In addition, FRRf studies are limited in freshwater lakes where phosphorus limitation and cyanobacterial blooms are common. The goal of the present study is to construct a robust Фe,C model for freshwater ecosystems using simultaneous measurements of ETRPSII by FRRf with multi-excitation wavelengths coupled with a traditional carbon fixation rate by the 13C method. The study was conducted in oligotrophic and mesotrophic parts of Lake Biwa from July 2018 to May 2019. The combination of excitation light at 444, 512 and 633 nm correctly estimated ETRPSII of cyanobacteria. The apparent range of Фe,C in the phytoplankton community was 1.1–31.0 mol e− mol C−1 during the study period. A generalised linear model showed that the best fit including 12 physicochemical and biological factors explained 67% of the variance in Фe,C. Among all factors, water temperature was the most significant, while photosynthetically active radiation intensity was not. This study quantifies the in situ FRRf method in a freshwater ecosystem, discusses core issues in the methodology to calculate Фe,C, and assesses the applicability of the method for lake GPP prediction.


2019 ◽  
Vol 18 (06) ◽  
pp. 30-37
Author(s):  
Tam T. Nguyen

Dong Nai biosphere reserve (DNBR) is well known for its high level of biodiversity and of global meaningful ecosystem. The fauna includes 84 species of mammals belonging to 28 families, 10 orders; 407 bird species; 141 reptile and amphibian species; 175 fish species; 2,017 insect species. The fish fauna of DNBR maintains many rare and endangered fish species recorded in the Vietnam red book and international union for conservation of nature red list (IUCN's red list) such as Scleropages formosus and many other rare fish species, such as Morulius chrysophekadion, Chitala ornata, Probarbus jullieni, Cyclocheilichthys enoplos… This study was aimed to identify fish composition distributed in DNBR. After the sampling period (01/2019 to 08/2019), a total of 114 fish species belonging to 11 orders and 28 families were recorded in DNBR. There were 09 species of fish on the list of rare and endangered fish species of Ministry of Agriculture and Rural Development of Vietnam, 3 species (Chitala ornata, Cosmochilus harmandi and Hemibagus filamentus) on the Vietnam red list book; 01 species (Ompok bimaculatus) on the IUCN's red list, 11 exotic species, 78 commercial species and 13 species having potential as aquarium fish. In addition, the study also found the first presence of a species of phallostethid, Phenacostethus smithi in DNBR


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