scholarly journals The Use of Allelochemicals of Aquatic Macrophytes to Suppress the Development of Cyanobacterial “Blooms”

2021 ◽  
Author(s):  
Evgeny Kurashov ◽  
Julia Krylova ◽  
Elena Protopopova
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Aquatic Macrophytes ◽  
Field Experiments ◽  
Water Bodies ◽  
Cyanobacterial Blooms ◽  
Natural Phenomenon ◽  
Anthropogenic Factors ◽  
New Generation ◽  
The Impact

Harmful algal “blooms”, or HABs, is a hazardous natural phenomenon that often occurs under the influence of anthropogenic factors, for example, during the anthropogenic eutrophication of water bodies. An increase in the frequency and duration of cyanobacterial “blooms” carries a number of serious threats, including local and global degradation of water resources and the impact of cyanotoxins. There are various methods of fighting cyanobacterial “blooms” - physical, chemical, the use of bacterial preparations, etc. However, these methods are not effective enough and, most importantly, do not allow effectively solving the problem of suppressing HABs in water bodies without damage to other components of the aquatic ecosystem. Allelopathy is a natural phenomenon for both stimulatory and inhibitory effects of one plant upon another including microorganisms that resolves this problem. Allelochemicals of macrophytes can be considered as natural algaecides and become the basis of a nature-like convergent technology to suppress the development of plankton cyanobacteria and prevent HABs in water bodies. In our work, we used some allelochemicals of aquatic macrophytes to create a combined algicide of the new generation for suppressing the development of cyanobacteria. The effectiveness of suppressing cyanobacterial “blooms” is demonstrated by the example of field experiments with mesocosms and natural phytoplankton.

scholarly journals Harmful Algal Blooms (HABS) along Mexican Coasts

2018 ◽  
Author(s):  
Magnolia Gricel Salcedo-Garduño ◽  
María del Refugio Castañeda-Chávez ◽  
Fabiola Lango-Reynoso ◽  
Itzel Galaviz-Villa
Keyword(s):  
Public Health ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Anthropogenic Factors ◽  
Environment And Public Health ◽  
Negative Effects ◽  
Direct Exposure ◽  
Public Health Strategies ◽  
Toxic Bloom ◽  
The Impact

Harmful algal blooms (HABs) are natural events produced by massive concentration of toxic phytoplankton that can color red, ocher, brown or yellow large extensions of water, its intensity depends on the different species of phytoplankton involved in the proliferation. The spreading of these formations involves an interaction of biological, chemical, meteorological and anthropogenic factors. Several species with potential toxicity have been reported along Mexican coasts, such as Gymnodinium catenatum, Karenia brevis, Pyrodinium bahamense var. compressum. The toxic bloom not only causes an impact during the event, it produces negative effects afterward, such as accumulating deposits of organic matter, alterations of benthic community structure and composition, species presence/absence, and bioaccumulation of toxins in organisms such as bivalve molluscs mainly. Poisoning may occur by consuming contaminated seafood or by direct exposure to aerosols of the toxins, which can provoke diarrhea or even death. Due to the impact of this type of event on the economy, environment and public health, strategies for monitoring, prevention, and systematic mitigation have been implemented for the evaluation of HAB effects. The aim of this review was to determine the state-of-the art of HAB, their reports and effects on the environment and public health in Mexico.

Анализ «Методики разработки нормативов допустимых сбросов веществ и микроорганизмов в водные объекты для водопользователей» в общем контексте водоохранного законодательства (в порядке обсуждения)

2020 ◽  
Author(s):  
I. Saakian ◽  
Aleksandr, Grigor’ev ◽  
E. Kravets ◽  
E. Rudakov ◽  
A. Faddeev ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Bodies ◽  
Anthropogenic Factors ◽  
Water Protection ◽  
Best Available Technologies ◽  
Process Indicators ◽  
Water Users ◽  
Quality Of Water ◽  
Protection Legislation ◽  
The Impact

Выполнен анализ действующей редакции Методики разработки нормативов допустимых сбросов веществ и микроорганизмов в водные объекты для водопользователей , утвержденной приказом Минприроды России от 17 декабря 2007 г. 333, на предмет непротиворечивости и соответствия нормам водоохранного законодательства. Выявлена неопределенность применения Методики в условиях воздействия на качество воды природных и антропогенных факторов, не зависящих от конкретного водопользователя. Положения Методики противоречат принципам нормирования воздействия на водные объекты на основе наилучших доступных технологий, что было показано на примерах утвержденных технологических показателей содержания загрязняющих веществ в сточных водах различных отраслей промышленности. Анализ системы нормирования допустимых воздействий на водные объекты и географической дифференциации нормативов качества воды в пределах Российской Федерации вместе с системой целевых показателей качества воды также показал несоответствие Методики основным принципам водоохранного законодательства.The analysis of the current edition of the Methods of developing standards for permissible discharges of substances and microorganisms into water bodies for water users , approved by the Order of the Ministry of Natural Resources of Russia dated December 17, 2007 No. 333 for consilience and compliance with the regulations of the water protection legislation, is carried out. Uncertainty of the application of the Methods in the conditions of the impact of natural and anthropogenic factors that are independent of a specific water user on the quality of water has been identified. The provisions of the Methods contradict the principles of regulating the impact on water bodies based on the best available technologies shown on the examples of approved process indicators of the concentrations of various industrial pollutants in wastewater. An analysis of the system of regulating the permissible impact on water bodies and the geographical differentiation of water quality standards within the boundaries of the Russian Federation, together with the system of water quality targets, also showed that the Methods do not comply with the basic principles of the water protection legislation.

scholarly journals Effects of the Marine Biotoxins Okadaic Acid and Dinophysistoxins on Fish

2021 ◽  
Vol 9 (3) ◽  
pp. 293
Author(s):  
Mauro Corriere ◽  
Lucía Soliño ◽  
Pedro Reis Costa
Keyword(s):  
Okadaic Acid ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Current Knowledge ◽  
Global Climate ◽  
Scientific Evidence ◽  
Shellfish Poisoning ◽  
Morphological Alterations ◽  
The Impact ◽  
Dsp Toxins

Natural high proliferations of toxin-producing microorganisms in marine and freshwater environments result in dreadful consequences at the socioeconomically and environmental level due to water and seafood contamination. Monitoring programs and scientific evidence point to harmful algal blooms (HABs) increasing in frequency and intensity as a result of global climate alterations. Among marine toxins, the okadaic acid (OA) and the related dinophysistoxins (DTX) are the most frequently reported in EU waters, mainly in shellfish species. These toxins are responsible for human syndrome diarrhetic shellfish poisoning (DSP). Fish, like other marine species, are also exposed to HABs and their toxins. However, reduced attention has been given to exposure, accumulation, and effects on fish of DSP toxins, such as OA. The present review intends to summarize the current knowledge of the impact of DSP toxins and to identify the main issues needing further research. From data reviewed in this work, it is clear that exposure of fish to DSP toxins causes a range of negative effects, from behavioral and morphological alterations to death. However, there is still much to be investigated about the ecological and food safety risks related to contamination of fish with DSP toxins.

scholarly journals A Review of Nontraditional Biomanipulation

2008 ◽  
Vol 8 ◽  
pp. 1184-1196 ◽  
Author(s):  
Xia Zhang ◽  
Ping Xie ◽  
Xiaoping Huang
Keyword(s):  
Algal Blooms ◽  
Algal Species ◽  
Planktivorous Fish ◽  
Bighead Carp ◽  
Cyanobacterial Blooms ◽  
Management Tool ◽  
Nutrient Concentrations ◽  
Effective Management ◽  
Nuisance Algae ◽  
The Impact

The aim of this review is to identify problems, find general patterns, and extract recommendations for successful management using nontraditional biomanipulation to improve water quality. There are many obstacles that prevent traditional biomanipulation from achieving expectations: expending largely to remove planktivorous fish, reduction of external and internal phosphorus, and macrophyte re-establishment. Grazing pressure from large zooplankton is decoupled in hypereutrophic waters where cyanobacterial blooms flourish. The original idea of biomanipulation (increased zooplankton grazing rate as a tool for controlling nuisance algae) is not the only means of controlling nuisance algae via biotic manipulations. Stocking phytoplanktivorous fish may be considered to be a nontraditional method; however, it can be an effective management tool to control nuisance algal blooms in tropical lakes that are highly productive and unmanageable to reduce nutrient concentrations to low levels.Although small enclosures increase spatial overlap between predators and prey, leading to overestimates of the impact of predation, microcosm and whole-lake experiments have revealed similar community responses to major factors that regulate lake communities, such as nutrients and planktivorous fish. Both enclosure experiments and large-scale observations revealed that the initial phytoplankton community composition greatly impacted the success of biomanipulation. Long-term observations in Lake Donghu and Lake Qiandaohu have documented that silver carp (Hypophthalmichthys molitrix) and bighead carp (H. nobilis) (two filter-feeding planktivorous species commonly used in management) can suppress Microcystis blooms efficiently. The introduction of silver and bighead carp could be an effective management technique in eutrophic systems that lack macrozooplankton. We confirmed that nontraditional biomanipulation is only appropriate if the primary aim is to reduce nuisance blooms of large algal species, which cannot be controlled effectively by large herbivorous zooplankton. Alternatively, this type of biomanipulation did not work efficiently in less eutrophic systems where nanophytoplankton dominated.

scholarly journals Comparison of Short-Term Toxicity of 14 Common Phycotoxins (Alone and in Combination) To The Survival of Brine Shrimp Artemia Salina

2021 ◽  
Author(s):  
Yu Ting Zhang ◽  
Shanshan SONG ◽  
Bin ZHANG ◽  
Yang ZHANG ◽  
Miao TIAN ◽  
...  
Keyword(s):  
Ecological Risk ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Algal Species ◽  
Natural Populations ◽  
Marine Ecosystems ◽  
Artemia Salina ◽  
Marine Organisms ◽  
Short Term ◽  
The Impact

Abstract Toxic harmful algal blooms (HABs) can cause deleterious effects in marine organisms, threatening the stability of marine ecosystems. It is well known that different strains, natural populations and growth conditions of the same toxic algal species may lead to different amount of phycotoxin production and the ensuing toxicity. To fully assess the ecological risk of toxic HABs, it is of great importance to investigate the toxic effects of phycotoxins in marine organisms. In this study, the short-term toxicity of 14 common phycotoxins (alone and in combination) in the marine zooplankton Artemia salina was investigated. On the basis of 48 h LC50, the order of toxicity in A. salina was AZA3 (with a LC50 of 0.0203 µg/ml)＞AZA2 (0.0273 µg/ml) ＞PTX2 (0.0396 µg/ml)＞DTX1 (0.0819 µg/ml)＞AZA1 (0.106 µg/ml)＞ SPX1 (0.144 µg/ml)＞YTX (0.172 µg/ml)＞dcSTX (0.668 µg/ml)＞OA (0.728 µg/ml)＞STX (1.042 µg/ml)＞GYM (1.069 µg/ml)＞PbTx3 (1.239 µg/ml)＞hYTX (1.799 µg/ml)＞PbTx2 (2.415 µg/ml). For the binary exposure, additive effects of OA and DTX1, DTX1 and hYTX; antagonistic effects of OA and PTX2, OA and STX; and synergetic effects of DTX1 and STX, DTX1 and YTX, DTX1 and PTX2, PTX2 and hYTX on the mortality of A. salina were observed. These results provide valuable toxicological data for assessing the impact of phycotoxins on marine planktonic species and highlight the potential ecological risk of toxic HABs in marine ecosystems.

scholarly journals Environmental Considerations for the Management of the Bivalve Fisheries of Bahía Magdalena (Mexico), a Coastal Lagoon at the Southern End of the California Current

2021 ◽  
Vol 8 ◽  
Author(s):  
María del Carmen Jiménez-Quiroz ◽  
Francisco Javier Barrón-Barraza ◽  
Rafael Cervantes-Duarte ◽  
René Funes-Rodríguez
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Large Scale ◽  
Environmental Variability ◽  
Southern Oscillation ◽  
Warming Trend ◽  
Regional Warming ◽  
Biological Variables ◽  
The Impact ◽  
Bahia Magdalena

This study presents an overview of bivalve assemblages in Bahia Magdalena (BM, México) and the possible impact of environmental variability on these populations, constantly stressed by fishing. This lagoon is responsible for a high proportion of harvest of regional bivalves. First, we list the bivalve species reported in public biogeographic databases. Based on eight commercially exploited species, we described the composition of the bivalve assemblage and its biological characteristics, the history of fishery, and environmental variability in the marine area adjacent to the lagoon (1970–2019) and the habitat of bivalves (2002–2020). Sources of data were public databases and published literature. The enlisted species (n = 184) belong to six orders, and most are small and infaunal, but the structure of the assemblage is unknown. The fisheries began at different times and focused on the most valuable resources. Almost all harvest of bivalves had wide variations because of intensive fishing and a weak regulation frame. After 2015, the main resources were the Pacific wing-oyster (a new resource since 2017) and the geoduck clam due to the declining abundance of other resources (e.g., pen shells, Pacific calico scallop). There was a warming trend in the region since the 1970's, but the strongest El Niño-Southern Oscillation (ENSO) phases caused the most notable changes before 2013; after that year, a combination of large-scale phenomena increased the temperature significantly. The trend of chlorophyll-a abundance negatively correlated with temperature, but there was an almost constant supply of particulate organic matter in the interior of Bahia Magdalena (BM). After 2015, the quality of lagoon water gradually deteriorated, and in 2017 and 2019, harmful algal blooms developed, but the impact was not fully assessed. The challenges faced by the fishery are multiple (institutional weakness and regional warming); however, permanent monitoring programs of environmental conditions and critical biological variables should be implemented to design scenarios that allow fishery sustainability.

scholarly journals Quantifying Scales of Spatial Variability of Cyanobacteria in a Large, Eutrophic Lake Using Multiplatform Remote Sensing Tools

2021 ◽  
Vol 9 ◽  
Author(s):  
Samantha L. Sharp ◽  
Alexander L. Forrest ◽  
Keith Bouma-Gregson ◽  
Yufang Jin ◽  
Alicia Cortés ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Spatial Variability ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Temporal Dynamics ◽  
Eutrophic Lake ◽  
Hyperspectral Data ◽  
Cyanobacterial Blooms ◽  
Satellite Monitoring ◽  
Sampling Effort

Harmful algal blooms of cyanobacteria are increasing in magnitude and frequency globally, degrading inland and coastal aquatic ecosystems and adversely affecting public health. Efforts to understand the structure and natural variability of these blooms range from point sampling methods to a wide array of remote sensing tools. This study aims to provide a comprehensive view of cyanobacterial blooms in Clear Lake, California — a shallow, polymictic, naturally eutrophic lake with a long record of episodic cyanobacteria blooms. To understand the spatial heterogeneity and temporal dynamics of cyanobacterial blooms, we evaluated a satellite remote sensing tool for estimating coarse cyanobacteria distribution with coincident, in situ measurements at varying scales and resolutions. The Cyanobacteria Index (CI) remote sensing algorithm was used to estimate cyanobacterial abundance in the top portion of the water column from data acquired from the Ocean and Land Color Instrument (OLCI) sensor on the Sentinel-3a satellite. We collected hyperspectral data from a handheld spectroradiometer; discrete 1 m integrated surface samples for chlorophyll-a and phycocyanin; multispectral imagery from small Unmanned Aerial System (sUAS) flights (∼12 cm resolution); Autonomous Underwater Vehicle (AUV) measurements of chlorophyll-a, turbidity, and colored dissolved organic matter (∼10 cm horizontal spacing, 1 m below the water surface); and meteorological forcing and lake temperature data to provide context to our cyanobacteria measurements. A semivariogram analysis of the high resolution AUV and sUAS data found the Critical Scale of Variability for cyanobacterial blooms to range from 70 to 175 m, which is finer than what is resolvable by the satellite data. We thus observed high spatial variability within each 300 m satellite pixel. Finally, we used the field spectroscopy data to evaluate the accuracy of both the original and revised CI algorithm. We found the revised CI algorithm was not effective in estimating cyanobacterial abundance for our study site. Satellite-based remote sensing tools are vital to researchers and water managers as they provide consistent, high-coverage data at a low cost and sampling effort. The findings of this research support continued development and refinement of remote sensing tools, which are essential for satellite monitoring of harmful algal blooms in lakes and reservoirs.

scholarly journals Nutrient Control to Prevent the Occurrence of Cyanobacterial Blooms in a Eutrophic Lake in Southern Sweden, Used for Drinking Water Supply

2018 ◽  
Author(s):  
Jing Li ◽  
Lars-Anders Hansson ◽  
Kenneth M. Persson
Keyword(s):  
Total Phosphorus ◽  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Cyanobacterial Bloom ◽  
Eutrophic Lake ◽  
N:P Ratio ◽  
Cyanobacterial Blooms ◽  
Southern Sweden ◽  
Dissolved Phosphorus ◽  
Future Work

Control of nutrients, mainly nitrogen (N) and phosphorus (P), plays a significant role in preventing cyanobacterial blooms (harmful algal blooms (HABs)). This study aimed at evaluating changes in the risk of the occurrence of cyanobacterial blooms and advancing the understanding of how N and P affect the growth of cyanobacteria in a eutrophic lake, Lake Vombsjön, in southern Sweden. Statistical analysis was used to demonstrate the pattern of cyanobacterial blooms, that the highest content present in September and the later that algal blooms occur, the more likely it is a cyanobacterial bloom as cyanobacteria became dominating in October and November (90%). Two hypothesises tested in Lake Vombsjön confirmed namely that a high total phosphorus (TP) level correlates with an abundance of cyanobacteria and that low N:P ratio (total nitrogen/total phosphorus < 20) favours the growth of cyanobacteria. To control the growth of cyanobacteria in Lake Vombsjön, the TP level should be kept below 20 µg/L and the N:P ratio be maintained at a level of over 20. The two species Planktothrix agardhii, and Pseudanabaena spp. should be carefully monitored especially in late autumn. Future work should consider any high degree of leakage from the sediment of the dissolved phosphorus available there.

scholarly journals Monitoring approaches for supporting offshore aquaculture management and EU Directives at Sagres, Portugal

2016 ◽  
Author(s):  
Bruno Dias Duarte Fragoso ◽  
John David Icely ◽  
Nancy Odour ◽  
Gerald Moore ◽  
João Magalhães Neto ◽  
...  
Keyword(s):  
Harmful Algal Blooms ◽  
Algal Blooms ◽  
Secchi Depth ◽  
Aquaculture Management ◽  
Additional Water ◽  
Eu Directives ◽  
Routine Sampling ◽  
Offshore Aquaculture ◽  
Maritime Spatial Planning ◽  
The Impact

The increasing development of aquaculture activity in the coast of Sagres, area included in the Parque Natural do Sudoeste Alentejano e Costa Vicentina (PNSACV) SW Portugal, has to comply with regional and national regulations. The development also has to comply with EU directives including: Quality of Shellfish Waters Directive 2006/113/EC (QSWD); Water Framework Directive 2000/60/EC (WFD); Marine Strategy Framework Directive 2008/56/EC (MSFD); Maritime Spatial Planning 2014/89/EU, (MSP). During 2014/2015, a monitoring routine was established to assess the potential impact of aquaculture in the region, as required by the Agência Portuguesa do Ambiente (APA). This involved a weekly sampling routine of water parameters at surface and bottom, including temperature (SST), salinity (Sal), Secchi depth, chlorophyll (Chl), suspended particulate matter (SPM), pH, oxygen (O2) and nutrients. Additional water samples were collected for phytoplankton counts to provide information on the species contributing to Harmful Algal Blooms (HABs). Associated with the routine sampling, innovative approaches to understanding the impact of aquaculture have been undertaken including: use of remote sensing products to provide spatial and temporal data for SST, Sal, Chl, and SPM validated with in situ radiometric data (Satlantic and WISP-3); genomics for HABs and flow cytometry for nanoplankton; a survey of impact on the benthos; determination of nutrient condition in the region through nutrient stoichiometry; automisation of data collection with an oceanographic buoy. Preliminary data from both routine and innovative studies will be presented in relation to aquaculture management and to the requirements of the WFD and the MSFD.

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