726 results on '"HABs"'
Search Results
202. Assessment of emerging biotoxins (pinnatoxin G and spirolides) at Europe's first marine reserve: Lough Hyne.
- Author
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McCarthy, Moira, Bane, Vaishali, García-Altares, María, van Pelt, Frank N.A.M., Furey, Ambrose, and O'Halloran, John
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MARINE toxins , *RISK assessment , *MARINE parks & reserves , *IMINES , *ADSORPTION (Chemistry) - Abstract
Active and passive sampling methods were employed over a four-month period, at a site off the South-West coast of Ireland, to characterise the occurrence of cyclic imines in the water column. The marine toxins 13-desmethyl-SPXC, 20-methyl SPXG toxins and pinnatoxin G were detected using active sampling from Diaion HP-20 resin. Seven water depths were sampled to determine stratification of the toxins in the water column using Solid Phase Adsorption and Toxin Tracking (SPATT). Both 13-desmethyl-SPXC and pinnatoxin G were detected using two different resin types; Diaion HP-20 and Amberlite XAD761. HP-20 proved more effective at accumulating the toxins, with a higher percentage of positive samples and a higher ratio of toxin adsorbed relative to XAD761. No temporal variation in toxin-quantities was detected, indicating that there was no change in density of causative algal species in the water column. Pinnatoxin G was detected more frequently from surface to 30 m depth, with a similar pattern observed for 13-desmethyl-SPXC occurrence using XAD761. No difference in the occurrence of 13-desmethyl-SPXC was observed between depths using HP-20 resin. This is the first reported incidence of pinnatoxin G in Irish waters and highlights cyclic imines as emerging toxins in European waters. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
203. Environmental influences on the seasonal distribution of Vibrio parahaemolyticus in the Pacific Northwest of the USA.
- Author
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Paranjpye, Rohinee N., Nilsson, William B., Lierman, Martin, Hilborn, Elizabeth D., George, Barbara J., Quanlin Li, Bill, Brian D., Trainer, Vera L., Strom, Mark S., and Sandifer, Paul A.
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VIBRIO parahaemolyticus , *ALGAL blooms , *DIATOMS , *DINOFLAGELLATES , *CHLOROPHYLL - Abstract
Populations of Vibrio parahaemolyticus in the environment can be influenced by numerous factors. We assessed the correlation of total (tl+) and potentially virulent (tdh+) V. parahaemolyticus in water with three harmful algal bloom (HAB) genera (Pseudo-nitzschia, Alexandrium and Dinophysis), the abundance of diatoms and dinoflagellates, chlorophyll-a and temperature, salinity and macronutrients at five sites in Washington State from 2008-2009. The variability in V. parahaemolyticus density was explained predominantly by strong seasonal trends where maximum densities occurred in June, 2 months prior to the highest seasonal water temperature. In spite of large geographic differences in temperature, salinity and nutrients, there was little evidence of corresponding differences in V. parahaemolyticus density. In addition, there was no evident relationship between V. parahaemolyticus and indices of HAB genera, perhaps due to a lack of significant HAB events during the sampling period. The only nutrient significantly associated with V. parahaemolyticus density after accounting for the seasonal trend was silicate. This negative relationship may be caused by a shift in cell wall structure for some diatom species to a chitinous substrate preferred by V. parahaemolyticus. Results from our study differ from those in other regions corroborating previous findings that environmental factors that trigger vibrio and HAB events may differ depending on geographic locations. Therefore caution should be used when applying results from one region to another. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
204. Gambierdiscus species exhibit different epiphytic behaviors toward a variety of macroalgal hosts.
- Author
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Rains, Lacey K. and Parsons, Michael L.
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DINOFLAGELLATES , *SEAFOOD poisoning , *HOSTS (Biology) , *CIGUATERA poisoning , *FOOD chains , *HERBIVORES - Abstract
Ciguatera fish poisoning is a common form of seafood poisoning caused by toxins (ciguatoxins) that accumulate in demersal (reef) food webs. The precursors of ciguatoxins are produced by dinoflagellates of the genus Gambierdiscus , and enter the food web via herbivory and detritivory. The Gambierdiscus genus was recently revised and new research on the physiology and ecology of the revised species is needed. While it has been demonstrated that Gambierdiscus spp. are predominately epiphytic, the variability in epiphytic behavior among the various Gambierdiscus species is not known. Five Gambierdiscus species isolated from the Greater Caribbean Region were the focus of this study ( G. belizeanus , G. caribaeus , G. carolinianus , G. carpenteri , and G. yasumotoi ). Cells of Gambierdiscus were grown in wells with algae fragments from eight different macroalgal host genera ( Acanthophora , Caulerpa , Dasya , Derbesia , Dictyota , Laurencia , Polysiphonia , and Ulva ) where the epiphytic behavior and growth of the different Gambierdiscus species were monitored over 29 days. The results of this experiment demonstrate that epiphytic behavior (growth and attachment) differs among the Gambierdiscus species toward the various macroalgal hosts. Results tended to be specific to Gambierdiscus – host pairings with few commonalities in the way a particular Gambierdiscus species interacted across hosts or how the various Gambierdiscus species responded to a particular host. The Gambierdiscus – host pairings that resulted in the highest growth and attachment combinations were examined in terms of known cellular toxicity and host palatability to determine which pairings could represent the most likely vectors for the transfer of ciguatoxins (or precursors) into the demersal food web. Two pairings, Gambierdiscus belizeanus – Polysiphonia and G. belizeanus – Dictyota , best met these criteria, providing a hypothetical approach to better focus sampling and monitoring efforts on such potential vectors in the benthic environment. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
205. Biosecurity monitoring of Harmful Algal Bloom (HAB) species in Western Australian waters: first confirmed record of Alexandrium catenella (Dinophyceae).
- Author
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Dias, P. Joana, Muñoz, Julieta, Huisman, John M., and McDonald, Justin I.
- Subjects
MONITORING of algal blooms ,BIOSECURITY ,ALEXANDRIUM catenella ,NONINDIGENOUS pests ,SEAFOOD industry ,HEALTH impact assessment ,PREVENTION - Abstract
The Australian National System for the Prevention and Management of Introduced Marine Pest Incursions has identified seven Harmful Algal Bloom (HAB) toxic dinoflagellate species as target species of concern. Alexandrium minutum Halim, 1960, and Alexandrium cf. tamarense (Lebour) Balech, 1995, are currently known to occur in south-western estuaries and coastal waters but with no documented impact on the seafood industry or human health. Monitoring of these species is challenging, time-consuming, expensive, and often relies on traditional morphotaxonomy. This reports the first confirmed detection of another HAB species, Alexandrium catenella (Whedon and Kofoid) Balech, 1995, in Western Australia (WA), using both microscopic and molecular methods. The confirmed detection of A. catenella (A. pacificum Group IV genotype) in WA hopefully will motivate discussion about better monitoring and control of toxic HAB species. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
206. HIGH ALTITUDE BALLOONS FOR SPECIAL OPERATIONS FORCES: SUPPLEMENTING SPACE WITH STRATOSPHERIC SOLUTIONS
- Author
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Blanken, Leo J., Lan, Wenschel D., Defense Analysis (DA), Space Systems Academic Group (SP), Hansen, James E., Blanken, Leo J., Lan, Wenschel D., Defense Analysis (DA), Space Systems Academic Group (SP), and Hansen, James E.
- Abstract
The U.S. military depends on space-based technology for communication, remote sensing, and position, navigation, and timing (PNT). Changing international dynamics in Great Power Competition, specifically the increase in antisatellite testing and development, threaten the space-based capabilities military forces utilize, including Special Operations Forces. In 2006, the Department of Defense developed the Operationally Responsive Space initiative which focused on decreasing the requisite time to place military satellites in orbit following asset loss; however, there is still no way to rapidly reconstitute space-based capabilities that have been compromised. As the space domain becomes increasingly contested, high altitude balloons (HABs) can offer a quick and efficient method to bridge the time gap between the loss of a space asset and its replacement. However, HABs require modularity to improve the time efficiency of payload integration. The purpose of this study is to develop a modular HAB bus, termed the Bento Box, designed to operate independently or integrated in a fixed-wing marsupial vehicle for precision recovery. The integration of three payloads into the Bento Box demonstrates the modularity of the structure, one of which is a software defined radio reconfigured as a bent-pipe communications payload to relay video transmission signals. The study concludes with a field test of the HAB-suspended Bento Box for beyond line-of-sight video relay between maneuver elements., Outstanding Thesis, Lieutenant, United States Navy, Approved for public release. Distribution is unlimited.
- Published
- 2021
207. Polyketide synthase genes and molecular trade-offs in the ichthyotoxic species Prymnesium parvum
- Author
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Anestis, Konstantinos, Kohli, Gurjeet Singh, Wohlrab, Sylke, Varga, Elisabeth, Larsen, Thomas Ostenfeld, Hansen, Per Juel, John, Uwe, Anestis, Konstantinos, Kohli, Gurjeet Singh, Wohlrab, Sylke, Varga, Elisabeth, Larsen, Thomas Ostenfeld, Hansen, Per Juel, and John, Uwe
- Abstract
Prymnesium parvum is a bloom forming haptophyte that has been responsible for numerous fish kill events across the world. The toxicity of P. parvum has been attributed to the production of large polyketide compounds, collectively called prymnesins, which based on their structure can be divided into A-, B- and C-type. The polyketide chemical nature of prymnesins indicates the potential involvement of polyketide synthases (PKSs) in their biosynthesis. However, little is known about the presence of PKSs in P. parvum as well as the potential molecular trade-offs of toxin biosynthesis. In the current study, we generated and analyzed the transcriptomes of nine P. parvum strains that produce different toxin types and have various cellular toxin contents. Numerous type I PKSs, ranging from 37 to 109, were found among the strains. Larger modular type I PKSs were mainly retrieved from strains with high cellular toxin levels and eight consensus transcripts were present in all nine strains. Gene expression variance analysis revealed potential molecular trade-offs associated with cellular toxin quantity, showing that basic metabolic processes seem to correlate negatively with cellular toxin content. These findings point towards the presence of metabolic costs for maintaining high cellular toxin quantity. The detailed analysis of PKSs in P. parvum is the first step towards better understanding the molecular basis of the biosynthesis of prymnesins and contributes to the development of molecular tools for efficient monitoring of future blooms.
- Published
- 2021
208. Paralytic and Amnesic Shellfish Toxins Impacts on Seabirds, Analyses and Management
- Author
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Ben-Gigirey, Begoña, Soliño, Lucía, Bravo, Isabel, Rodríguez Hernández, Francisco José, Casero, María V. M., Ben-Gigirey, Begoña, Soliño, Lucía, Bravo, Isabel, Rodríguez Hernández, Francisco José, and Casero, María V. M.
- Abstract
Marine biotoxins have been frequently implicated in morbidity and mortality events in numerous species of birds worldwide. Nevertheless, their effects on seabirds have often been overlooked and the associated ecological impact has not been extensively studied. On top of that, the number of published studies confirming by analyses the presence of marine biotoxins from harmful algal blooms (HABs) in seabirds, although having increased in recent years, is still quite low. This review compiles information on studies evidencing the impact of HAB toxins on marine birds, with a special focus on the effects of paralytic and amnesic shellfish toxins (PSTs and ASTs). It is mainly centered on studies in which the presence of PSTs and/or ASTs in seabird samples was demonstrated through analyses. The analytical techniques commonly employed, the tissues selected and the adjustments done in protocols for processing seabird matrixes are summarized. Other topics covered include the role of different vectors in the seabird intoxications, information on clinical signs in birds affected by PSTs and ASTs, and multifactorial causes which could aggravate the syndromes. Close collaboration between seabird experts and marine biotoxins researchers is needed to identify and report the potential involvement of HABs and their toxins in the mortality events. Future studies on the PSTs and ASTs pharmacodynamics, together with the establishment of lethal doses in various seabird species, are also necessary. These studies would aid in the selection of the target organs for toxins analyses and in the postmortem intoxication diagnoses
- Published
- 2021
209. Automatization of Harmful Algal Bloom early warning services: an example in Galicia (NW Spain)
- Author
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González-Nuevo, Gonzalo, García-García, Luz, Ruiz-Villarreal, Manuel, González-Nuevo, Gonzalo, García-García, Luz, and Ruiz-Villarreal, Manuel
- Published
- 2021
210. Listado de especies de fitoplancton en la bahía de Tumaco, Pacífico colombiano
- Author
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Hoyos Acuña, Jesús Javier, Quintana, Humberto Luis, Bermudez Rivas, Christian, Molina Triana, Andrés Felipe, Albeiro Castrillón, Fredy, Parada Gutiérrez, Jenny Lisbeth, Hoyos Acuña, Jesús Javier, Quintana, Humberto Luis, Bermudez Rivas, Christian, Molina Triana, Andrés Felipe, Albeiro Castrillón, Fredy, and Parada Gutiérrez, Jenny Lisbeth
- Abstract
An updated list of phytoplankton species in Tumaco Bay is presented, generated from available literature from 1979 to 2019 and oceanographic campaigns conducted by the Laboratory of the Pacific Oceanographic and Hydrographic Research Center (CCCP) of the Directorate General Maritime (DIMAR). A total of 400 species comprised in eight divisions are recorded: Cyanophyta, Chlorophyta, Charophyta, Euglenophyta, Haptophyta, Ochorophyta, Bacillariophyta and Dinophyta, two subdivisions, 12 classes, 14 subclasses, 53 orders, 93 families, and 146 genera. Diatoms constituted the most diverse taxa, followed by dinoflagellates; some representatives of cyanobacteria were identified at the generic level. Four genera and five morphospecies represent desmidias, while only two species represent silicoflagellates. The flagellates, euglenas, and chlorophyta are represented by one genus and one morphospecies. The genera with the highest number of species were: Chaetoceros (30), Tripos(29), Protoperidinium(24), Nitzschia (15), Rhizosolenia(12) and Coscinodiscus(10). From the samples analyzed in the laboratory, a total of 152 species were recorded, 39 of which were recorded for the first time in Tumaco Bay. Species were identified according to their habitat and Harmful Algal Bloom (HAB) forming species were, Se presenta un listado actualizado de las especies de fitoplancton de la bahía de Tumaco, generado a partir de la literatura disponible desde 1979 hasta 2019 y campañas oceanográficas realizadas por el Laboratorio del Centro de Investigaciones Oceanográficas e Hidrográficas del Pacífico (CCCP) de la Dirección General Marítima (DIMAR). Se registran un total de 400 especies comprendidas en ocho divisiones: Cyanophyta, Chrorophyta, Charophyta, Euglenophyta, Haptophyta, Ochorophyta, Bacillariophyta y Dinophyta, dos subdivisiones, 12 clases, 14 subclases, 53 órdenes, 93 familias y 146 géneros. Las diatomeas constituyeron el taxa más diverso, seguido de los dinoflagelados; algunos representantes de las cianobacterias fueron identificados a nivel genérico. Cuatro géneros y cinco morfoespecies representan a las desmidias, mientras que, solo dos especies a los silicoflagelados. Los flagelados, euglenas y clorofitas son representados por un género y una morfoespecie. Los géneros con mayor número de especies fueron: Chaetoceros (30), Tripos (29), Protoperidinium (24), Nitzschia (15), Rhizosolenia (12) y Coscinodiscus (10). De las muestras analizadas en el laboratorio, se registran un total de 152 especies de las cuales 39 registradas por primera vez en la bahía de Tumaco. Se identificaron las especies según su hábitat y se determinaron las formadoras de Florecimientos Algales Nocivos (FAN).
- Published
- 2021
211. HIGH ALTITUDE BALLOONS FOR SPECIAL OPERATIONS FORCES: SUPPLEMENTING SPACE WITH STRATOSPHERIC SOLUTIONS
- Author
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Hansen, James E., Blanken, Leo J., Lan, Wenschel D., and Defense Analysis (DA), Space Systems Academic Group (SP)
- Subjects
HABs ,position ,Special Operations Forces ,space systems ,PNT ,unmanned systems ,navigation ,and timing ,high altitude balloons ,over-the-horizon communications - Abstract
The U.S. military depends on space-based technology for communication, remote sensing, and position, navigation, and timing (PNT). Changing international dynamics in Great Power Competition, specifically the increase in antisatellite testing and development, threaten the space-based capabilities military forces utilize, including Special Operations Forces. In 2006, the Department of Defense developed the Operationally Responsive Space initiative which focused on decreasing the requisite time to place military satellites in orbit following asset loss; however, there is still no way to rapidly reconstitute space-based capabilities that have been compromised. As the space domain becomes increasingly contested, high altitude balloons (HABs) can offer a quick and efficient method to bridge the time gap between the loss of a space asset and its replacement. However, HABs require modularity to improve the time efficiency of payload integration. The purpose of this study is to develop a modular HAB bus, termed the Bento Box, designed to operate independently or integrated in a fixed-wing marsupial vehicle for precision recovery. The integration of three payloads into the Bento Box demonstrates the modularity of the structure, one of which is a software defined radio reconfigured as a bent-pipe communications payload to relay video transmission signals. The study concludes with a field test of the HAB-suspended Bento Box for beyond line-of-sight video relay between maneuver elements. Outstanding Thesis Lieutenant, United States Navy Approved for public release. Distribution is unlimited.
- Published
- 2021
212. Proliferaciones de Pseudo-nitzschia spp. (Bacillariophyceae) y otras especies del microplancton en la Bahía de Mazatlán, México
- Author
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Samuel Gómez-Aguirre, Sergio Licea, and Samuel Gómez
- Subjects
PANs ,proliferaciones ,Pseudo-nitzschia ,Mazatlán ,México ,HABs ,blooms ,Mexico ,Biology (General) ,QH301-705.5 - Abstract
Observaciones previas sobre el microplancton de la Bahía de Mazatlán, en el otoño de 1996, revelaron la existencia de altas densidades de Pseudo-nitzschia spp. Este mismo fenómeno se encontró en noviembre 1998 y un mes después se había desplazado al sur de la Bahía de Mazatlán, mientras que por esas mismas fechas, en California, EUA, se registraban accidentes de envenenamiento de mamíferos marinos, accidentes que en el noroeste de México se aprecian entre enero y marzo. Mensualmente se recolectaron muestras de agua superficial (< 0.5 m) y subsuperficial (10 m), de noviembre 1998 a enero 1999 y cada semana, entre febrero 1999 y mayo 2000; las muestras fueron analizadas por la técnica de Utermöhl a 400X. La cuantificación del microplancton presentó un amplio pulso invernal y otro menor en verano de cada ciclo anual. Con el empleo de microscopio electrónico (MEB y MET), se reconocieron cuatro especies de Pseudo-nitzschia y una más en estudio reciente. Las densidades de Pseudo-nitzschia fueron, en orden de importancia: 760 céls ml-1 (7 dic.1999), 610 (6 dic.1998), 335 (12 jul.1999), 198 (1º. feb. 1999), 170 (6 nov.1998), 123 (17 mar.1999), 108 (11 ago.1999). Otras especies de diatomeas (Thalassiosira spp., Asterionellopsis glacialis, Chaetoceros spp., Skeletonema costatum), dinoflagelados (Prorocentrum spp., Scripsiella trochoideda) y ciliados (Myrionecta rubra), manifestaron proliferaciones altas durante el período de este estudioObservations on microplankton in the autumn of 1996 revealed the existence of high densities of Pseudo-nitzschia spp. A similar phenomenon was found in November 1998 and November 1999 and a month later it shifted to the southern Mazatlán Bay while in California, USA, incidents of the poisoning of sea mammals were being recorded; this also happened on the Mexican Pacific coasts from January to March. Water samples collected at surface (
- Published
- 2004
213. ENSO phenomenon and toxic red tides in Mexico
- Author
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José Luis Ochoa
- Subjects
“Red tides” ,harmful algal blooms ,HABs ,marine biotoxins ,toxic phytoplankton ,El Niño ,Geophysics. Cosmic physics ,QC801-809 - Abstract
El Niño provides a partial explanation of the spectrum of marine biotoxins (red tides) on the coast of Mexico. Over 500 human poisoning cases with 20 fatalities in the last 25 years, and mass mortalities of fish, sea birds, marine mammals, and marine turtles have been documented. However, the eventual effect of El Niño on the incidence, frequency and severity of harmful microalgal blooms is uncertain. Because of geographical position and socioeconomical conditions, the impact of harmful microalgal blooms in Mexico will be severe, and a study of red tides is justified.
- Published
- 2003
214. Harmful Algal Bloom in Iligan Bay, Southern Philippines
- Author
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Helen J Vicente, Ruth D. Gaid, Henry E. Dejarme, Elnor C. Roa, and Rhodora V. Azanza
- Subjects
HABs ,discoloration ,Cochlodinium sp. ,fish kill ,Favella sp. ,Science ,Science (General) ,Q1-390 - Abstract
We report the first occurrence of harmful algal bloom (HAB) caused by a non-toxic dinoflagellate, Cochlodinium sp. in Philippine waters, particularly, in Kalangahan Pt.-Manticao Pt., Iligan Bay on March 13-18, 2002. Two patches of Cochlodinium sp. bloom, associated with fish kills in Kalangahan Pt.-Mantacao Pt., Iligan Bay, caused localized water discoloration from the usual ocean blue to rusty brown or reddish brown to blackish. The first patch, located near fish-aggregating device (FAD) areas, spanned 2 km wide, while the second patch, located near a fish corral, spanned 500m wide. These patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches occupied the water column from surface to 5 m depth, but a thick mat formed at 0.5 m to surface. Patches decreased as the bloom began to decline. The observed dead demersal and pelagic fishes coincided with highest bloom density of 3.1 x 104 to 3.8 x 104 cells ml-1 of Cochlodinium. Dissected gills and stomach contents of fishes killed in HAB-affected areas did not reveal any indication of clogging of gills by Cochlodinium sp. Fishes covered by the “shading effect” of Cochlodinium bloom may have suffered anoxia or asphyxation due to oxygen depletion. No poisoning of people who consumed the dead fishes was reported. Laboratory analyses revealed lower DO values, 2.4 to 0.5 mg L-1from 2400 to 0600Hr; 14N:1P ratio; air-water temperature ranged from 28-29°C; pH 7.89-8.29; and salinity, 33-35°/oo. Favella sp., a tintinnid grazer of dinoflagellate was developing in the area at the termination of the Cochlodinium bloom on March 18.
- Published
- 2002
215. Thermotaxic diel vertical migration of the harmful dinoflagellate Cochlodinium (Margalefidinium) polykrikoides: Combined field and laboratory studies.
- Author
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Lim, Young Kyun, Kim, Jin Ho, Ro, Hyejoo, and Baek, Seung Ho
- Subjects
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FISH kills , *MARINE heatwaves , *FIELD research , *THERMAL stresses , *TEMPERATURE effect , *WATER temperature - Abstract
• Cochlodinium polykrikoides exhibited limited diel vertical migration (DVM) behavior to avoid thermal stress during marine heatwave conditions. • C. polykrikoides exhibited an efficient DVM pattern based on thermotaxis under temperature difference between surface and bottom water by changing migration velocity. • We suggest that the thermotaxic DVM is an important ecological strategy used by C. polykrikoides to optimize environmental conditions for growth. The harmful dinoflagellate Cochlodinium polykrikoides , a species that causes mass mortality of farmed fish, uses diel vertical migration (DVM) as an ecological strategy. In summer 2018, a bloom of C. polykrikoides occurred on the southern coast of Korea when the surface water temperature exceeded 29 °C, as a result of a marine heatwave. To understand the effect of high temperature conditions on the DVM of C. polykrikoides , vertical profiles of environmental variables and the occurrence of the dinoflagellate were investigated through a 48 h field survey. In addition, a thermally stratified environment (6–12 °C difference between the surface and bottom layers) was established in a laboratory study to investigate the effect of temperature difference between water layers on the DVM of C. polykrikoides. In the field, most of the C. polykrikoides population was at a depth of 3–6 m during the day, where the water temperature was significantly lower (p < 0.01; Chi square = 57.98; Kruskal–Wallis test) than in the surface layer (0 m), and only the water temperature at 0 m was not correlated with weighted mean depth of C. polykrikoides , suggesting the usage of DVM to avoid high temperature stress. According to our field and laboratory results, there was a trend of greater DVM velocity by thermotaxis when moving from "unfavorable" water temperature (30 °C hot and 12 °C cold) to "favorable" water temperature for growth (optimal 24 °C) of C. polykrikoides. Our findings suggest that thermotaxic DVM is an important ecological strategy used by C. polykrikoides to optimize environmental conditions for growth through vertical positioning and changing migration velocity. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
216. Gaging Downstream Transport of Cyanobacteria in the Raritan River Basin
- Author
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Clonan, Kyle R.
- Subjects
- Cyanobacteria, Harmful Algae Blooms, HABs, drinking water, Earth Sciences, Environmental Sciences, Cyanobacteria--New Jersey--Raritan River Watershed
- Abstract
Cyanobacteria dominated Harmful Algal Blooms (HABs) have the potential to release toxic compounds harmful to human health. Few studies have examined the potential for cyanobacteria travelling from lacustrine HAB sources through fluvial systems used for potable water supply. The Raritan Basin Water Supply Complex (RBWSC) sources potable water for several utilities serving more than 1.5 million people in central New Jersey. The RBWSC features three lentic waterbodies with persistent HABs; discharges from these waterbodies all reach the downstream drinking water intakes. The objectives of this study were to 1) review the persistence of cyanobacteria during fluvial transport from upstream, cyanobacteria-dominated lakes and reservoirs to downstream drinking water intakes in the RBWSC, and 2) find which physiological parameters influence the downstream transport of cyanobacteria. This study found cyanobacteria persistence downstream was primarily influenced by discharge, with periods of higher discharge resulting in greater persistence of cyanobacteria travelling downstream. Factors frequently associated with lentic cyanobacteria growth—such as higher concentrations of nitrogen and phosphorous, warm water temperatures, and lower turbidity—did not show evidence of aiding lotic cyanobacteria travel. It is unclear why some cyanobacteria genera showed greater persistence than others. Drinking water managers in the RBWSC should know that an increased, but diluted, amount of cyanobacteria may reach their intakes during periods of increased discharge. Downstream transport of cyanobacteria from HABs should be investigated on a sitespecific basis, as transport mechanisms, impoundments, trappings, and phytoplankton composition are specific to each water basin.
- Published
- 2022
217. Editorial: Physiology and molecular biology of aquatic cyanobacteria
- Author
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George S Bullerjahn and Anton F Post
- Subjects
Cyanobacteria ,Nitrogen Fixation ,Prochlorococcus ,Synechococcus ,HABs ,Microbiology ,QR1-502 - Published
- 2014
- Full Text
- View/download PDF
218. Morphological and molecular characterization of Gambierdiscus caribaeus (Dinophyceae), with a confirmation of its occurrence in the Colombian Caribbean Tayrona National Natural Park
- Author
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Edgar Arteaga-Sogamoso, Francisco Rodríguez, and José Ernesto Mancera-Pineda
- Subjects
0106 biological sciences ,HABs ,Gambierdiscus caribaeus ,Ciguatoxin ,Zoology ,Plant Science ,Aquatic Science ,01 natural sciences ,Intraspecific competition ,03 medical and health sciences ,Genus ,Centro Oceanográfico de Vigo ,Medio Marino ,Ecology, Evolution, Behavior and Systematics ,030304 developmental biology ,Caribbean ,0303 health sciences ,biology ,010604 marine biology & hydrobiology ,Dinoflagellate ,biology.organism_classification ,Colombian ,Seagrass ,Thalassia testudinum ,benthic dinoflagellates ,Dinophyceae - Abstract
Dinoflagellates in the genus Gambierdiscus are known to produce potent neurotoxins known as ciguatoxins. These toxins vector through the food web and can reach sufficiently high levels to cause ciguatera fish poisoning (CFP). In many regions of the Caribbean, little is known about the occurrence of CFP-causing species or the incidence of CFP, despite its apparent regional increase over the last few decades. Given the intraspecific variability in content and potencies of these toxins among Gambierdiscus species, the precise identification of local species of this genus is crucial. In this study we confirm the presence of the epibenthic dinoflagellate Gambierdiscus caribaeus in the Colombian continental Caribbean. Cells were collected in seagrass beds of Thalassia testudinum in Bonito Gordo, a site located on the western side of Bahía Concha, Tayrona National Natural Park, near the city of Santa Marta, Colombia. Subsequently, a single strain of Gambierdiscus could be established for further identification. Morphological (light and scanning electron microscopy), and molecular results (partial LSU and ITS rDNA sequencing) were consistent with the original description of G. caribaeus, as well as with the morphological characteristics shown by other authors in organisms obtained near the sampling area., SI
- Published
- 2021
219. Retention and fate of groundwater-borne nitrogen in a coastal bay (Kinvara Bay, Western Ireland) during summer.
- Author
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Rocha, C., Wilson, J., Scholten, J., and Schubert, M.
- Subjects
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GROUNDWATER , *SUMMER , *NITROGEN cycle , *PHYTOPLANKTON , *EUTROPHICATION - Abstract
The magnitude of submarine groundwater discharge (SGD) and its contribution to nitrogen biogeochemistry in a small embayment in the Western Coast of Ireland subject to occasional hypoxia were investigated during summer. Time series (24 h) of Rn, NO, NO, NH, dissolved reactive silicate (DRSi) and salinity (June 2010, July and September 2011 and July 2013), total dissolved phosphorus (TDP) (September 2011 and July 2013) and dissolved organic nitrogen (DON) (July 2013) were measured at the mouth of the bay and coupled with relevant sediment-water fluxes and input loadings to derive nutrient budgets. In-situ activity ratios of the naturally occurring radium isotopes Ra and Ra were employed in parallel to the freshwater fraction method to determine the timescale of freshwater retention in the system. Based on Rn mass balances (n = 4), the mean groundwater (±SE) discharge into Kinvara Bay was 10.4 ± 6.3×10 m days, delivering average loads of 376 ± 67 kg Si day (as DRSi), 1.6 ± 0.2 kg P day (as TDP) and ~280 kg N day of dissolved nitrogen (272 ± 49 DIN, essentially as NO, and 8.2 ± 1.6 DON), which correspond to ~98.8, 49.1 and ~93.5 % of total allochthonous nutrient inputs respectively. Expressed on an areal basis and annual scale the exogenous N summer loading of Kinvara is equivalent to 25.9 g N m year. Our biogeochemical budgets indicate that tight benthic-pelagic coupling contributes to the very high retention levels of N within the bay with subtidal sediments acting as a link in the internal N cycle via DNRA, while ~18 % of the exogenous N load is removed by benthic denitrification. Rapid cycling of DON into bioavailable forms of N within the timescale of freshwater retention in the system (~7 days) contributes ~50 % to local biological N fixation. Nutrient availability ratios are N:P ~173 and Si:P ~503, indicating that primary production is P-limited while the carbon yield (~3.01 × 10 mol C day, or ~0.313 kg C m year) suggests the bay is eutrophic during the summer. SGD-borne Nitrogen loading is therefore the major driver of eutrophication in Kinvara Bay. Our biogeochemical characterization is consistent with the observed phytoplankton community composition and species succession and justifies the local observation of HAB's. In addition, the relative magnitude of DNRA-promoted N retention compared to N removal by denitrification, coupled with seasonal hypoxia, suggests that the system is advanced in the chronological sequence of eutrophication effects on shallow coastal systems. [ABSTRACT FROM AUTHOR]
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- 2015
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220. Evolution of the MIDTAL microarray: the adaption and testing of oligonucleotide 18S and 28S rDNA probes and evaluation of subsequent microarray generations with Prymnesium spp. cultures and field samples.
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McCoy, Gary, Touzet, Nicolas, Fleming, Gerard, and Raine, Robin
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PRYMNESIUM parvum ,TOXIC algae ,PHYTOPLANKTON ,OLIGONUCLEOTIDE arrays ,RECOMBINANT DNA ,IN situ hybridization ,SEAWATER - Abstract
The toxic microalgal species Prymnesium parvum and Prymnesium polylepis are responsible for numerous fish kills causing economic stress on the aquaculture industry and, through the consumption of contaminated shellfish, can potentially impact on human health. Monitoring of toxic phytoplankton is traditionally carried out by light microscopy. However, molecular methods of identification and quantification are becoming more common place. This study documents the optimisation of the novel Microarrays for the Detection of Toxic Algae (MIDTAL) microarray from its initial stages to the final commercial version now available from Microbia Environnement (France). Existing oligonucleotide probes used in whole-cell fluorescent in situ hybridisation (FISH) for Prymnesium species from higher group probes to species-level probes were adapted and tested on the first-generation microarray. The combination and interaction of numerous other probes specific for a whole range of phytoplankton taxa also spotted on the chip surface caused high cross reactivity, resulting in false-positive results on the microarray. The probe sequences were extended for the subsequent second-generation microarray, and further adaptations of the hybridisation protocol and incubation temperatures significantly reduced false-positive readings from the first to the second-generation chip, thereby increasing the specificity of the MIDTAL microarray. Additional refinement of the subsequent third-generation microarray protocols with the addition of a poly-T amino linker to the 5′ end of each probe further enhanced the microarray performance but also highlighted the importance of optimising RNA labelling efficiency when testing with natural seawater samples from Killary Harbour, Ireland. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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221. Diagnosing domoic acid toxicosis in the California sea lion ( Zalophus californianus) using behavioral criteria: A novel approach.
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Wittmaack, Christiana, Lahvis, Garet P., Keith, Edward O., and Self-Sullivan, Caryn
- Abstract
Domoic acid toxicosis in the California sea lion ( Zalophus californianus) is difficult to diagnose using presence of toxin alone because the duration of domoic acid presence in blood and urine is generally less than 48 hr following exposure. Because domoic acid toxicosis is often suggested by presentation of behavioral abnormalities, we asked whether assessment of behavior might be useful for diagnostic purposes. We developed an ethogram to categorize behavioral data collected via continuous focal animal sampling. In total, 169 subjects were observed at a rehabilitation center. Sea lions with domoic acid toxicosis displayed head weaving ( P < 0.0001) and muscle fasciculations ( P < 0.01) significantly more often than animals in a comparison group. Dragging hind flippers and swift scanning were observed exclusively in animals from the domoic acid toxicosis group. The data show that behavioral diagnostic criteria can be effective in the diagnosis of domoic acid toxicosis in the California sea lion. Zoo Biol. 34:314-320, 2015. © 2015 Wiley Periodicals Inc. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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222. Potential applications of nuisance microalgae blooms.
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Kim, Jang, Kottuparambil, Sreejith, Moh, Sang, Lee, Taek, Kim, Youn-Jung, Rhee, Jae-Sung, Choi, Eun-Mi, Kim, Byung, Yu, Yong, Yarish, Charles, and Han, Taejun
- Abstract
Algal blooms have become a major concern in coastal areas and the great lakes of the world. Because of their various consequences for aquatic ecosystems and resources, algal blooms are called 'harmful algal blooms' (HABs). HABs often become severely detrimental when they involve one or more toxin-producing microalgae of various taxonomic origins. The accumulation of algal biomass also has deleterious effects on the ecological status of water. However, appropriate management strategies can allow the beneficial utilization of these events by consuming the biomass feedstock in the production of valuable biocommodities, including biofuels, functional food ingredients, UV-absorbing compounds, pharmaceutical products, etc. However, if the algal biomass can be harvested prior to the onset of their death phase, nutrients (carbon, nitrogen, and phosphorus) can also be removed from the ecosystem by harvesting the algal blooms. Great progress has been made in the last decade in monitoring and predicting HABs, and a demand is emerging for persuasive postevent management policies that focus on the potential utilization of these blooms as natural renewable bioresources. This review summarizes various potential applications of nuisance algal blooms and the need for scientific research into their economic and industrial potential. Major algal products with great ecological and economic significance and their contemporary global utilization are analyzed. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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223. Detection and effects of harmful algal toxins in Scottish harbour seals and potential links to population decline.
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Jensen, Silje-Kristin, Lacaze, Jean-Pierre, Hermann, Guillaume, Kershaw, Joanna, Brownlow, Andrew, Turner, Andrew, and Hall, Ailsa
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- *
ALGAL toxins , *HARBOR seal , *SAXITOXIN , *DOMOIC acid , *IMMUNOLOGICAL adjuvants - Abstract
Over the past 15 years or so, several Scottish harbour seal ( Phoca vitulina ) populations have declined in abundance and several factors have been considered as possible causes, including toxins from harmful algae. Here we explore whether a link could be established between two groups of toxins, domoic acid (DA) and saxitoxins (STXs), and the decline in the harbour seal populations in Scotland. We document the first evidence that harbour seals are exposed to both DA and STXs from consuming contaminated fish. Both groups of toxins were found in urine and faeces sampled from live captured (n = 162) and stranded animals (n = 23) and in faecal samples collected from seal haul-out sites (n = 214) between 2008 and 2013. The proportion of positive samples and the toxins levels measured in the excreta were significantly higher in areas where harbour seal abundance is in decline. There is also evidence that DA has immunomodulatory effects in harbour seals, including lymphocytopenia and monocytosis. Scottish harbour seals are exposed to DA and STXs through contaminated prey at potentially lethal levels and with this evidence we suggest that exposure to these toxins are likely to be important factors driving the harbour seal decline in some regions of Scotland. [ABSTRACT FROM AUTHOR]
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- 2015
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224. Domoic acid assimilation in copepods by consuming organic polymers and Pseudo-nitzschia from experiments conducted using water samples collected in northern Gulf of Mexico in 2017 and 2018.
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Marquez Jr., Israel A., Maiti, Kanchan, Krause, Jeffrey W, Marquez Jr., Israel A., Maiti, Kanchan, and Krause, Jeffrey W
- Abstract
Dataset: Field domoic acid and copepods, Domoic acid assimilation in copepods by consuming organic polymers and Pseudo-nitzschia. Results from experiments designed to investigate the contribution of organic polymers and Pseudo-nitzschia to domoic acid trophic transfer. Water samples were collected in the northern Gulf of Mexico in 2017 and 2018. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/808413, NSF Division of Ocean Sciences (NSF OCE) OCE-1558957, U.S. Food and Drug Administration (FDA) 5U19FD005923-04
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- 2020
225. First Report of Paralytic Shellfish Toxins in Marine Invertebrates and Fish in Spain
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Ben-Gigirey, Begoña, Rossignoli, A.E., Riobó, Pilar, Rodríguez Hernández, Francisco José, Ben-Gigirey, Begoña, Rossignoli, A.E., Riobó, Pilar, and Rodríguez Hernández, Francisco José
- Abstract
A paralytic shellfish poisoning (PSP) episode developed in summer 2018 in the Rías Baixas (Galicia, NW Spain). The outbreak was associated with an unprecedentedly intense and long-lasting harmful algal bloom (HAB) (~one month) caused by the dinoflagellate Alexandrium minutum. Paralytic shellfish toxins (PSTs) were analyzed in extracts of 45 A. minutum strains isolated from the bloom by high-performance liquid chromatography with post-column oxidation and fluorescence detection (HPLC-PCOX-FLD). PSTs were also evaluated in tissues from marine fauna (invertebrates and fish) collected during the episode and in dolphin samples. The analysis of 45 A. minutum strains revealed a toxic profile including GTX1, GTX2, GTX3 and GTX4 toxins. With regard to the marine fauna samples, the highest PSTs levels were quantified in bivalve mollusks, but the toxins were also found in mullets, mackerels, starfish, squids and ascidians. This study reveals the potential accumulation of PSTs in marine invertebrates other than shellfish that could act as vectors in the trophic chain or pose a risk for human consumption. To our knowledge, this is the first time that PSTs are reported in ascidians and starfish from Spain. Moreover, it is the first time that evidence of PSTs in squids is described in Europe.
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- 2020
226. Colors d’aigua
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Agencia Estatal de Investigación (España), Berdalet, Elisa, Agencia Estatal de Investigación (España), and Berdalet, Elisa
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[EN] A great diversity of pigments allow photosynthetic organisms to capture light energy to conduct photosynthesis. Pigments are a fingerprint of the evolutionary history of these organisms through successive endosymbioses and mutations, as well as a taxonomic classification tool. In this paper, the main groups of microscopic photosynthetic organisms found in aquatic habitats – microalgae and cyanobacteria – are briefly presented, with a specific mention of their pigment composition. These organisms form the basis of microbial food webs and they are fundamental for life on our planet. In some specific cases, however, the proliferation of certain organisms has negative effects on humans and the environment. These events are referred to as “harmful algal blooms” (HABs), which are often visible because the water takes on the colour of the photosynthetic pigments – the colour of the algae, [CAT] Els organismes fotosintètics capten l’energia de la llum gràcies a una gran diversitat de pigments els quals, alhora, són reflex de la història evolutiva a partir d’endosimbiosis i mutacions successives. Els pigments són també una eina de classificació taxonòmica. En aquest document es presenten breument els grups principals d’organismes fotosintètics microscòpics, microalgues i cianobacteris que trobem en els hàbitats aquàtics, indicant en particular els pigments que els caracteritzen. Aquests organismes constitueixen la base de les xarxes tròfiques microbianes i són fonamentals per a la vida al planeta. Tanmateix, en alguns casos concrets, les proliferacions de certs organismes comporten efectes negatius a les persones i el medi ambient. Es tracta de les proliferacions algals nocives o harmful algal blooms (HAB), les quals sovint es fan visibles perquè l’aigua pren el color dels pigments fotosintètics, el color de l’alga
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- 2020
227. Description of two new coexisting parasitoids of blooming dinoflagellates in the Baltic sea: Parvilucifera catillosa sp. nov. and Parvilucifera sp. (Perkinsea, Alveolata)
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Academy of Finland, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Alacid, Elisabet, Reñé, Albert, Gallisai, Rachele, Paloheimo, Aurora, Garcés, Esther, Kremp, Anke, Academy of Finland, Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Alacid, Elisabet, Reñé, Albert, Gallisai, Rachele, Paloheimo, Aurora, Garcés, Esther, and Kremp, Anke
- Abstract
Perkinsea are a group of intracellular protist parasites that inhabit all types of aquatic environments and cause significant population declines of a wide variety of hosts. However, the diversity of this lineage is mostly represented by environmental rDNA sequences. Complete descriptions of Perkinsea that infect marine dinoflagellates have increased in recent literature due to the identification, isolation and culturing of representatives during bloom events, contributing to expand the knowledge on the diversity and ecology of the group. Shallow coastal areas in the Baltic Sea suffer seasonal dinoflagellate blooms. In summer 2016, two parasitoids were isolated during a Kryptoperidinium foliaceum bloom in the Baltic Sea. Morphological features and sequences of the small and large subunit of the ribosomal DNA gene revealed these two parasitoids were new species that belong to the genus Parvilucifera. This is the first time that Parvilucifera infections are reported in the Inner Baltic Sea. The first species, Parvilucifera sp. has some morphological and phylogenetic features in common with P. sinerae and P. corolla, although its ultrastructure could not be studied and the formal description could not be done. The second new species, named Parvilucifera catillosa, has several distinct morphological features in its zoospores (e.g. the presence of a rostrum), and in the shape and size of the apertures in the sporangium stage, which are larger and more protuberant than in the other species of the genus. Infections observed in the field and cross-infection experiments determined that the host range of both Parvilucifera species was restricted to dinoflagellates, each one showing a different host preference. The coexistence in the same environment by the two closely related parasitoids with very similar life cycles suggests that their niche separation is the preferred host
- Published
- 2020
228. Assessing risks and mitigating impacts of harmful algal blooms on mariculture and marine fisheries
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European Commission, Agencia Estatal de Investigación (España), Brown, Andrew Ross, Lilley, Martin K. S., Shutler, Jamie, Lowe, Chris, Artioli, Yuri, Torres, Ricardo, Berdalet, Elisa, Tyler, Charles R., European Commission, Agencia Estatal de Investigación (España), Brown, Andrew Ross, Lilley, Martin K. S., Shutler, Jamie, Lowe, Chris, Artioli, Yuri, Torres, Ricardo, Berdalet, Elisa, and Tyler, Charles R.
- Abstract
Aquaculture is the fastest growing food sector globally and protein provisioning from aquaculture now exceeds that from wild capture fisheries. There is clear potential for the further expansion of marine aquaculture (mariculture), but there are associated risks. Some naturally occurring algae can proliferate under certain environmental conditions, causing deoxygenation of seawater, or releasing toxic compounds (phycotoxins), which can harm wild and cultured finfish and shellfish, and also human consumers. The impacts of these so-called harmful algal blooms (HABs) amount to approximately 8 $billion/yr globally, due to mass mortalities in finfish, harvesting bans preventing the sale of shellfish that have accumulated unsafe levels of HAB phycotoxins and unavoided human health costs. Here, we provide a critical review and analysis of HAB impacts on mariculture (and wild capture fisheries) and recommend research to identify ways to minimise their impacts to the industry. We examine causal factors for HAB development in inshore versus offshore locations and consider how mariculture itself, in its various forms, may exacerbate or mitigate HAB risk. From a management perspective, there is considerable scope for strategic siting of offshore mariculture and holistic Environmental Approaches for Aquaculture, such as offsetting nutrient outputs from finfish farming, via the co-location of extractive shellfish and macroalgae. Such pre-emptive, ecosystem-based approaches are preferable to reactive physical, chemical or microbiological control measures aiming to remove or neutralise HABs and their phycotxins. To facilitate mariculture expansion and long-term sustainability, it is also essential to evaluate HAB risk in conjunction with climate change
- Published
- 2020
229. Chemical Ecology of the Benthic Dinoflagellate Genus Ostreopsis: Review of Progress and Future Directions
- Author
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Agence Nationale de la Recherche (France), European Commission, Intergovernmental Oceanographic Commission of UNESCO, Agencia Estatal de Investigación (España), Pavaux, Anne-Sophie, Berdalet, Elisa, Lemée, Rodolphe, Agence Nationale de la Recherche (France), European Commission, Intergovernmental Oceanographic Commission of UNESCO, Agencia Estatal de Investigación (España), Pavaux, Anne-Sophie, Berdalet, Elisa, and Lemée, Rodolphe
- Abstract
The genus Ostreopsis includes some species that produce high biomass blooms and/or synthesize toxic compounds that can be transferred through the marine food webs or aerosolized causing ecological, human health and socio-economic impacts. Ostreopsis species are increasing their biogeographic distribution from tropical to more temperate waters and causing recurrent blooms in certain coastal areas, thus constituting an emerging concern worldwide. The proliferation capacity of Ostreopsis is due to a complex and poorly understood combination of multiple factors, and may be a paradigm of chemical ecology reviewed here. A first section summarizes the basic knowledge on the different Ostreopsis species, the toxins they produce and the described foodborne and airborne effects of Ostreopsis toxins on humans. Secondly, direct and indirect interactions between Ostreopsis species and their environment are reviewed. Mucopolysaccharide substances produced by the cells to attach to different substrates appear to be a key element on the chemical ecology and requires further study. However, this research is challenged by technical limitations to conduct ecologically realistic and harmonized studies where organisms can be in direct contact with Ostreopsis cells, their mucus and/or the released extracellular toxic compounds. Understanding the transfer mechanisms of these substances within the food web, potentially affecting humans is critical and requires further study with new analytical tools. Still, the progress in knowledge achieved in the last years, combined with experimental and field studies using cutting edge methods will facilitate to address the open questions on the chemical ecology of Ostreopsis and understand its bloom dynamics now, and under future climate and anthropogenic change scenarios
- Published
- 2020
230. Anthropogenic nutrients and harmful algae in coastal waters.
- Author
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Davidson, Keith, Gowen, Richard J., Harrison, Paul J., Fleming, Lora E., Hoagland, Porter, and Moschonas, Grigorios
- Subjects
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ALGAL blooms , *NUTRIENT pollution of water , *TOXIC algae , *HEALTH risk assessment , *MARINE pollution , *MONITORING of algal blooms , *HYDRODYNAMICS , *ECONOMICS , *PREVENTION - Abstract
Harmful algal blooms (HABs) are thought to be increasing in coastal waters worldwide. Anthropogenic nutrient enrichment has been proposed as a principal causative factor of this increase through elevated inorganic and/or organic nutrient concentrations and modified nutrient ratios. We assess: 1) the level of understanding of the link between the amount, form and ratio of anthropogenic nutrients and HABs; 2) the evidence for a link between anthropogenically generated HABs and negative impacts on human health; and 3) the economic implications of anthropogenic nutrient/HAB interactions. We demonstrate that an anthropogenic nutrient-HAB link is far from universal, and where it has been demonstrated, it is most frequently associated with high biomass rather than low biomass (biotoxin producing) HABs. While organic nutrients have been shown to support the growth of a range of HAB species, insufficient evidence exists to clearly establish if these nutrients specifically promote the growth of harmful species in preference to benign ones, or if/how they influence toxicity of harmful species. We conclude that the role of anthropogenic nutrients in promoting HABs is site-specific, with hydrodynamic processes often determining whether blooms occur. We also find a lack of evidence of widespread significant adverse health impacts from anthropogenic nutrient-generated HABs, although this may be partly due to a lack of human/animal health and HAB monitoring. Detailed economic evaluation and cost/benefit analysis of the impact of anthropogenically generated HABs, or nutrient reduction schemes to alleviate them, is also frequently lacking. [ABSTRACT FROM AUTHOR]
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- 2014
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231. A SPATIAL APPROACH OF THE ENVIRONMENTAL FACTORS CONTROLLING PLANKTON COMMUNITIES IN THE DANUBE DELTA.
- Author
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Alina, DUMITRACHE, Larisa, FLORESCU, Laura, PARPALĂ, Cristina, SANDU, and Mirela, MOLDOVEANU
- Subjects
- *
PLANKTON , *ALGAL blooms , *LIGHT intensity , *GREEN algae , *MACROPHYTES , *CYANOBACTERIA , *EUTROPHICATION - Abstract
The Danube Delta represents an open socio-ecological system of international importance. The services provided by this environmental complex to human society are endangered. The aim of this study was to understand the driving mechanisms triggering harmful algal blooms, in the context of environmental changes and their consequences for food webs. The cyanobacterial blooms are triggered by a combination of abiotic factors: nutrient content, increasing temperatures, light intensity. The bloom risk increases by removing natural competitors (green algae, macrophytes), by affecting the natural grazers which control the algal growth. The results of our investigations carried out in 26 ecosystems belonging to the 4 lake complexes (Roşu-Puiu, Matiţa-Merhei, Gorgova-Uzlina, Şontea-Fortuna) indicated a higher frequency of cyanobacterial blooms in late summer or early fall. The quantification of algal community performed in situ with a field fluorometer (Fluoroprobe III, bbe Moldaenke, DE) indicated that 4 major algal groups were present in all the lakes: Chlorophyta, Bacillariophyta, Cryptophyta, Cyanobacteria. The structural parameters fluctuated in a wide range. The complex most affected by the algal blooms was Roşu - Puiu. The results of multiple regression analysis evidenced a strong relationship between Cyanobacteria and TP (p<0.001) and marginally with NO3 and PO4. The light and TP were significant factors that influenced the Chlorophyceae development. The phytoplankton biomass, expressed as chlorophyll a content, was explained by the TP (89%, p<0.001). The zooplankton analysis of the samples collected in spring evidenced 95 taxa, Rotifera (44 sp.), Ciliata (21 gen), Cladocera (18 sp.) and Copepoda (6 sp.). The minimum value of zooplankton abundance was in Gorgostel (1.67 ind L-1) and maximum values in Roşu (29.93 ind L-1). An analysis of the similarity degree highlighted a 50% resemblance among the following lakes that belongs to Matiţa-Merhei complex: Dracului, Lung, Babina, Rădăcinoasele. Future analyses will focus on the cyanobacteria effects on food web. [ABSTRACT FROM AUTHOR]
- Published
- 2014
232. Monitoring toxic Ostreopsis cf. ovata in recreational waters using a qPCR based assay.
- Author
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Casabianca, Silvia, Perini, Federico, Casabianca, Anna, Battocchi, Cecilia, Giussani, Valentina, Chiantore, Mariachiara, and Penna, Antonella
- Subjects
DINOFLAGELLATE blooms ,BENTHIC ecology ,RECREATION areas ,WATER quality ,AQUACULTURE ,BIOLOGICAL assay ,ENVIRONMENTAL standards - Abstract
Ostreopsis sp. is a toxic marine benthic dinoflagellate that causes high biomass blooms, posing a threat to human health, marine biota and aquaculture activities, and negatively impacting coastal seawater quality. Species-specific identification and enumeration is fundamental because it can allow the implementation of all the necessary preventive measures to properly manage Ostreopsis spp. bloom events in recreational waters and aquaculture farms. The aim of this study was to apply a rapid and sensitive qPCR method to quantify Ostreopsis cf. ovata abundance in environmental samples collected from Mediterranean coastal sites and to develop site-specific environmental standard curves. Similar PCR efficiencies of plasmid and environmental standard curves allowed us to estimate the LSU rDNA copy number per cell. Moreover, we assessed the effectiveness of mitochondrial COI and cob genes as alternative molecular markers to ribosomal genes in qPCR assays for Ostreopsis spp. quantification. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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233. Aquaculture in coastal urbanized areas : a comparative review of the challenges posed by Harmful Algal Blooms
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Federico M. Lauro, Guillaume Drillet, Aurore Trottet, Christaline George, Asian School of the Environment, DHI Water & Environment(s) Pte Ltd, Singapore, SGS Testing & Control Services Singapore Pte Ltd, Singapore, and Singapore Centre for Environmental Life Sciences and Engineering (SCELSE)
- Subjects
HABs ,2019-20 coronavirus outbreak ,Environmental Engineering ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Science ,0208 environmental biotechnology ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Algal bloom ,Global population ,Aquaculture ,Environmental protection ,Urbanization ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Water Science and Technology ,Food security ,business.industry ,digestive, oral, and skin physiology ,Pollution ,Sustainable food production ,020801 environmental engineering ,Geography ,business - Abstract
Increasing global population has resulted in increased urbanization of coastal areas across the globe. Such an increase generates many challenges for sustainable food production and food security. The development of aquaculture has proven to be an extremely good option to ensure food security (uninterrupted supply and good quality of food) by many countries, especially those with urban areas affected by space limitations such as Singapore. However, the implementation of aquaculture is not without its challenges and impacts to the environment, with Harmful Algal Blooms (HABs) being one of the major concerns in coastal waters. In this review we analyze the development of the aquaculture industry with respect to HABs in Singapore and compare it to similar urban areas such as Hong Kong (SAR China), Salalah (Oman), Cape Town (South Africa), Valencia (Spain), Rotterdam (The Netherlands), Tampa bay (USA), Vancouver (Canada), and Sydney (Australia). Along with HABs, the abovementioned urban areas face different challenges in sustainably increasing their aquaculture production with respect to the economy and geography. This review further assesses the different production and monitoring strategies that have been implemented to counter these challenges while sustainably increasing production. The ongoing COVID-19 pandemic has affected the world with lockdowns and border closures resulting in logistical difficulties in seafood trade which has further accentuated the dependencies on food import. We conclude that the challenges faced by urban areas for sustainable achievement of food security through development of the aquaculture industry can be effectively managed through proper planning, management and collaboration of knowledge/skills on an international level. National Research Foundation (NRF) Published version This study was supported by the National Research Foundation, Prime’s Minister’s Office, Singapore under its Marine Science Research and Development Programme (Award No. MSRDP-P13) and NRF-NERC-SEAP-2020 grant call, “Understanding the Impact of Plastic Pollution on Marine Ecosystems in South East Asia (South East Asia Plastics (SEAP)” (Award No. SEAP-2020-0003).
- Published
- 2021
234. Cyanobacterial blooms in oligotrophic lakes: Shifting the high‐nutrient paradigm
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Julio Alberto Alegre Stelzer, Ana M. Morales-Williams, Cayelan C. Carey, Kiyoko Yokota, Rebecca L. North, Karen S. Atkins, Peter D. F. Isles, Kaitlin L. Reinl, Lisette N. de Senerpont Domis, Jason J. Venkiteswaran, Lars G. Rudstam, Theodore D. Harris, Bastiaan Willem Ibelings, Justin D. Brookes, Jorrit Mesman, Qing Zhan, and Aquatic Ecology (AqE)
- Subjects
0106 biological sciences ,HABs ,010504 meteorology & atmospheric sciences ,Aquatic Science ,cyanobacterial blooms ,01 natural sciences ,Cyanobacterial blooms ,Oligotrophic ,Nutrient ,nutrients ,ddc:550 ,Climate change ,14. Life underwater ,0105 earth and related environmental sciences ,Trophic level ,Ekologi ,Ecology ,010604 marine biology & hydrobiology ,Plan_S-Compliant_NO ,Nutrients ,6. Clean water ,Physiological Adaptations ,climate change ,oligotrophic ,13. Climate action ,international ,Environmental science ,Eutrophication ,Freshwater systems - Abstract
1. Freshwater cyanobacterial blooms have become ubiquitous, posing major threats to ecological and public health. 2. Decades of research have focused on understanding drivers of these blooms with a primary focus on eutrophic systems; however, cyanobacterial blooms also occur in oligotrophic systems, but have received far less attention, resulting in a gap in our understanding of cyanobacterial blooms overall. 3. In this review, we explore evidence of cyanobacterial blooms in oligotrophic freshwater systems and provide explanations for those occurrences. 4. We show that through their unique physiological adaptations, cyanobacteria are able to thrive under a wide range of environmental conditions, including low-nutrient waterbodies. 5. We contend that to fully understand cyanobacterial blooms, and thereby mitigate and manage them, we must expand our inquiries to consider systems along the trophic gradient, and not solely focus on eutrophic systems, thus shifting the high-nutrient paradigm to a trophic-gradient paradigm.
- Published
- 2021
235. Growth and Nutrient Uptake Characteristics of Heterosigma akashiwo (Raphidophyceae) under Nitrogen and Phosphorus Concentrations in the East China Sea
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Anqiang Yang, Xiaoshuang Li, Richard G. J. Bellerby, and Wang Yanna
- Subjects
HABs ,Geography, Planning and Development ,chemistry.chemical_element ,Aquatic Science ,Biochemistry ,Algal bloom ,chemistry.chemical_compound ,Nutrient ,Nitrate ,nutrients ,Phytoplankton ,TD201-500 ,Water Science and Technology ,biology ,Water supply for domestic and industrial purposes ,Phosphorus ,Hydraulic engineering ,biology.organism_classification ,Phosphate ,chemistry ,Heterosigma akashiwo ,Environmental chemistry ,phytoplankton ,Environmental science ,growth rate ,Eutrophication ,TC1-978 - Abstract
Heterosigma akashiwo is classified as a harmful algal bloom (HAB) species that frequently occurs in eutrophic coastal waters and results in the contamination and mortality of fish and shellfish. The growth of H. akashiwo in four phosphate and nitrate concentration scenarios, representing the observed nutrient concentration ranges in the East China Sea (ECS), was evaluated to further understand the effect of nutrient concentrations on H. akashiwo blooms. The specific growth rate in the exponential growth phase (µ′) and the maximum cell density were lower (17–21% and 41%, respectively) under low phosphorus concentration scenarios, compared to the rates observed under high phosphorus concentration scenarios. The cellular nitrogen-to-phosphorus ratios of H. akashiwo were influenced by the initially supplied N:P ratio and the allocation strategy employed. Phosphorus concentration had a greater influence on the total growth of H. akashiwo than nitrate did, within the natural nutrient conditions of the ECS. These results could serve as a reference for coastal water management and marine ecological management and may be useful for further studies on the simulation and prediction of H. akashiwo blooms, particularly in the ECS.
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- 2021
236. Description of two new coexisting parasitoids of blooming dinoflagellates in the Baltic sea: Parvilucifera catillosa sp. nov. and Parvilucifera sp. (Perkinsea, Alveolata)
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R. Gallisai, Aurora Paloheimo, Anke Kremp, Albert Reñé, Elisabet Alacid, Esther Garcés, Academy of Finland, Ministerio de Ciencia, Innovación y Universidades (España), and Agencia Estatal de Investigación (España)
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0106 biological sciences ,HABs ,Parvilucifera ,Lineage (evolution) ,Population ,Zoology ,Plant Science ,010501 environmental sciences ,Aquatic Science ,medicine.disease_cause ,DNA, Ribosomal ,01 natural sciences ,medicine ,Animals ,Perkinsea ,14. Life underwater ,education ,Ribosomal DNA ,Phylogeny ,0105 earth and related environmental sciences ,Life Cycle Stages ,education.field_of_study ,biology ,010604 marine biology & hydrobiology ,fungi ,Dinoflagellate ,Niche differentiation ,Protist ,biology.organism_classification ,Parasite ,Alveolata ,Ultrastructure ,Host range ,Dinoflagellida ,Specificity - Abstract
15 pages, 9 figures, 2 tables, supplementary materials https://doi.org/10.1016/j.hal.2020.101944, Perkinsea are a group of intracellular protist parasites that inhabit all types of aquatic environments and cause significant population declines of a wide variety of hosts. However, the diversity of this lineage is mostly represented by environmental rDNA sequences. Complete descriptions of Perkinsea that infect marine dinoflagellates have increased in recent literature due to the identification, isolation and culturing of representatives during bloom events, contributing to expand the knowledge on the diversity and ecology of the group. Shallow coastal areas in the Baltic Sea suffer seasonal dinoflagellate blooms. In summer 2016, two parasitoids were isolated during a Kryptoperidinium foliaceum bloom in the Baltic Sea. Morphological features and sequences of the small and large subunit of the ribosomal DNA gene revealed these two parasitoids were new species that belong to the genus Parvilucifera. This is the first time that Parvilucifera infections are reported in the Inner Baltic Sea. The first species, Parvilucifera sp. has some morphological and phylogenetic features in common with P. sinerae and P. corolla, although its ultrastructure could not be studied and the formal description could not be done. The second new species, named Parvilucifera catillosa, has several distinct morphological features in its zoospores (e.g. the presence of a rostrum), and in the shape and size of the apertures in the sporangium stage, which are larger and more protuberant than in the other species of the genus. Infections observed in the field and cross-infection experiments determined that the host range of both Parvilucifera species was restricted to dinoflagellates, each one showing a different host preference. The coexistence in the same environment by the two closely related parasitoids with very similar life cycles suggests that their niche separation is the preferred host, This study was supported by the Academy of Finland, grant 251564 to A.K. E. G and A.R. were supported by MINECO COPAS “Understanding top-down control in coastal bloom-forming protists” (CTM2017-86121-R). Phytoplankton cultures were provided by the culture collection of the Finnish Environment Institute (SYKE), With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)
- Published
- 2020
237. First Report of Paralytic Shellfish Toxins in Marine Invertebrates and Fish in Spain
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Pilar Riobó, Begoña Ben-Gigirey, Araceli E. Rossignoli, and Francisco Rodríguez
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0106 biological sciences ,HABs ,marine invertebrates ,Alexandrium minutum ,Dolphins ,Health, Toxicology and Mutagenesis ,Starfish ,lcsh:Medicine ,Zoology ,Toxicology ,paralytic shellfish toxins ,01 natural sciences ,Algal bloom ,non-traditional vectors ,Centro Oceanográfico de Vigo ,medicine ,Animals ,Shellfish Poisoning ,northwest Iberian Peninsula ,Medio Marino ,Paralytic shellfish poisoning ,PSTs ,Shellfish ,Invertebrate ,PSP ,fish ,biology ,communication ,010604 marine biology & hydrobiology ,lcsh:R ,010401 analytical chemistry ,Fishes ,Dinoflagellate ,Marine invertebrates ,Ría de Vigo ,biology.organism_classification ,medicine.disease ,invertebrates ,biological poisons ,0104 chemical sciences ,Shellfish poisoning ,shellfish ,Spain ,Dinoflagellida ,Marine Toxins ,Biological Monitoring - Abstract
A paralytic shellfish poisoning (PSP) episode developed in summer 2018 in the Rías Baixas (Galicia, NW Spain). The outbreak was associated with an unprecedentedly intense and long-lasting harmful algal bloom (HAB) (~one month) caused by the dinoflagellate Alexandrium minutum. Paralytic shellfish toxins (PSTs) were analyzed in extracts of 45 A. minutum strains isolated from the bloom by high-performance liquid chromatography with post-column oxidation and fluorescence detection (HPLC-PCOX-FLD). PSTs were also evaluated in tissues from marine fauna (invertebrates and fish) collected during the episode and in dolphin samples. The analysis of 45 A. minutum strains revealed a toxic profile including GTX1, GTX2, GTX3 and GTX4 toxins. With regard to the marine fauna samples, the highest PSTs levels were quantified in bivalve mollusks, but the toxins were also found in mullets, mackerels, starfish, squids and ascidians. This study reveals the potential accumulation of PSTs in marine invertebrates other than shellfish that could act as vectors in the trophic chain or pose a risk for human consumption. To our knowledge, this is the first time that PSTs are reported in ascidians and starfish from Spain. Moreover, it is the first time that evidence of PSTs in squids is described in Europe., SI
- Published
- 2020
238. The study of fluorescence features of microalgae from the genus Pseudo-nitzschia and the possibility of their detection in water.
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Alexander, Popik, Evgeniy, Gamayunov, Sergey, Voznesenskiy, Zhanna, Markina, and Tatiana, Orlova
- Abstract
This article presents the fluorescent characteristics of eight microalgae cultures of the genus Pseudo-nitzschia. We show that the normalized fluorescence temperature curves of the studied Pseudo-nitzschia cultures are very similar. Due to this similarity, the authors obtained the "passport" characteristic, averaged on the measured characteristics, which with high accuracy approximates the fluorescence temperature curves of each studied species of Pseudo-nitzschia algae. The similarity indexes between the fluorescence temperature curves of each test sample and the passport curve were obtained using the modernized cosine method. The authors introduce the concept of the scaling factor α, which allows for achieving a reliable determination of the presence/absence of Pseudo-nitzschia microalgae both in monoculture samples and in samples from two cultures. The article shows the possibility of determining Pseudo-nitzschia microalgae in a mixture of two cultures with 10% content. • Fluorescence of all strains Pseudo-nitzschia in our work has a similar character. • We can determine Pseudo-nitzschia by fluorescence and the modernized cosine method. • In mixtures, we determine the relative content more than 10% of Pseudo-nitzschia. [ABSTRACT FROM AUTHOR]
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- 2022
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239. Application of passive (SPATT) and active sampling methods in the profiling and monitoring of marine biotoxins.
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McCarthy, Moira, van Pelt, Frank N. A. M., Bane, Vaishali, O'Halloran, John, and Furey, Ambrose
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SAMPLING (Process) , *MARINE toxins , *SORBENTS , *AQUATIC ecology , *SEAFOOD poisoning , *PHYTOPLANKTON , *BIOACCUMULATION - Abstract
Solid phase adsorbent and toxin tracking (SPATT) enables temporally and spatially integrated monitoring of biotoxins in aquatic environments. Monitoring using two adsorbent resins was performed over a four-month period at Lough Hyne Marine Reserve, Ireland. A range of Diarhettic Shellfish Poisoning (DSP) toxins were detected from SPATT extracts throughout the study period. The majority of biotoxins were detected in the top 20-30 m of the water column and a spike in toxin accumulation was measured during August 2010. Phytoplankton analysis confirmed the presence of toxin-producing species Dinophysis acuta and Dinophysis acuminata during the bloom. SPATT has the potential to provide useful information on phycotoxin distribution in the water column; enabling evidence-based decisions regarding appropriate depths for obtaining phytoplankton and shellfish samples in marine biotoxin monitoring programmes. Active sampling was performed continuously over 7-days and high quantities of toxins were successfully accumulated in the HP-20 resin, okadaic acid (~13 mg), dinophysis toxin-2 (~29 mg), pectenotoxin-2 (~20 mg) and pectenotoxin-2-seco acid (~6 mg) proving this an effective method for accumulating DSP toxins from the marine environment. The method has potential application as a tool for assessing toxin profiles at proposed shellfish harvesting sites. [ABSTRACT FROM AUTHOR]
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- 2014
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240. An overview of historical harmful algae blooms outbreaks in the Arabian Seas.
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Al Shehhi, Maryam R., Gherboudj, Imen, and Ghedira, Hosni
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ALGAL blooms ,DISEASE outbreaks ,NOXIOUS weeds ,PHYTOPLANKTON ,DRINKING water ,WATER quality ,SALINE water conversion - Abstract
Harmful algae blooms (HABs), often composed of oceanic plants called phytoplankton, are potentially harmful to the marine life, water quality, human health, and desalination plants, a chief source of potable water in the Arabian Gulf. The last decade has seen a noticeable increase in the frequency of HAB outbreaks in the Arabian Seas. This increase is mainly caused by the unprecedented economic growth in the region. The increased human activities in the region have added more stress to the marine environment and contributed to the changes observed in the properties of the marine ecosystem: high temperature and salinity, high evaporation rates, limited freshwater inflow, shallow nature, pollution. However, very few studies that cover the HAB outbreaks, causes, impacts and biological characteristics over the region have been published. This work presents a comprehensive overview of historical HAB outbreaks recorded in the region, and investigate their causes and impact, and seasonal variability. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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241. Large-scale bloom of Akashiwo sanguinea in the Northern California current system in 2009.
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White, Angelicque E., Watkins-Brandt, Katie S., McKibben, S. Morgaine, Wood, A. Michelle, Hunter, Matthew, Forster, Zach, Xiuning Du, and Peterson, William T.
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- *
DINOFLAGELLATE blooms , *SEA bird mortality , *WATER currents , *PLANKTON - Abstract
Significant seabird mortality on the Oregon (OR) and Washington (WA) coast in 2009 has been attributed to a massive bloom of the dinoflagellate Akashiwo sanguinea (K. Hirasaka) G. Hansen & Ø. Moestrup. Initial, albeit limited, observations suggested this bloom began in WA and reached OR waters through southward transport. Here, we explore a combination of remote sensing products and an exceptional latitudinal dataset of plankton counts collected in the surfzone and offshore in OR and WA coastal waters. Records of satellite ocean color for this period support the new finding that blooms were concurrent in OR and WA waters, with no evidence for latitudinal propagation as had been previously suggested. Plankton analyses further indicate that there was a rapid and synchronized increase of A. sanguinea between late August and mid-September of 2009 along wide swaths of the OR and WA coasts. Bloom onset occurred during a prolonged quiescent and warm period in late August-early September, near the end of the March-October upwelling phase. An upwelling event in October likely contributed to foam production through vertical mixing of A. sanguinea rich waters. Bloom intensity peaked earlier and at higher levels in WA waters as compared to OR with cell concentrations exceeding 1.5 × 106 cells L-1 (WA) and ~350,000 cells L-1 (OR). In OR samples, A. sanguinea cells comprised upwards of 90% of dinoflagellate cell counts and ~30% of total phytoplankton cells. At some locations, A. sanguinea persisted well into November-December of 2009, during which time satellite sea surface temperature records indicated anomalously warm surface waters (up to ~5 °C greater than climatological means). Taken together, the data reveal a HAB event of a magnitude unprecedented in over a decade of observations. We hypothesize that these blooms originated from either a cryptic cyst bed and/or a pelagic seed bank of viable vegetative cells. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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242. An Adaptive Model to Monitor Chlorophyll-a in Inland Waters in Southern Quebec Using Downscaled MODIS Imagery.
- Author
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El-Alem, Anas, Chokmani, Karem, Laurion, Isabelle, and El-Adlouni, Sallah E.
- Subjects
- *
CHLOROPHYLL , *CHLOROPLAST pigments , *PHOTOSYNTHETIC pigments , *PHOTOSYNTHESIS , *TETRAPYRROLES - Abstract
The purpose of this study is to assess the performance of an adaptive model (AM) in estimating chlorophyll-a concentration (Chl-a) in optically complex inland waters. Chl-a modeling using remote sensing data is usually based on a single model that generally follows an exponential function. The estimates produced by such models are relatively accurate at high Chl-a concentrations, but accuracy drops at low concentrations. Our objective was to develop an approach combining spectral response classification and three semi-empirical algorithms. The AM discriminates between three blooming classes (waters poorly, moderately, and highly loaded in Chl-a), with discrimination thresholds set using the classification and regression tree (CART) technique. The calibration of three specific estimators for each class was achieved using a multivariate stepwise regression. Compared to published models (Floating Algae Index, Kahru model, and APProach by ELimination) using the same data set, the AM provided better Chl-a concentration estimates (R2 of 0.96, relative RMSE of 23%, relative Bias of -2%, and a relative NASH criterion of 0.9). Moreover, the AM achieved an overall success rate of 67% in the estimation of blooming classes (corresponding to low, moderate, and high Chl-a concentration classes). This was done using an independent data set collected from 22 inland water bodies for the period 2007-2010 and for which the only information available was the blooming class. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
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243. Categorizing the severity of paralytic shellfish poisoning outbreaks in the Gulf of Maine for forecasting and management.
- Author
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Kleindinst, Judith L., Anderson, Donald M., McGillicuddy, Dennis J., Stumpf, Richard P., Fisher, Kathleen M., Couture, Darcie A., Michael Hickey, J., and Nash, Christopher
- Subjects
- *
PARALYTIC shellfish poisoning , *ALGAL blooms , *ALEXANDRIUM , *ECOLOGICAL forecasting , *MICROBIAL cysts , *ENVIRONMENTAL management - Abstract
Abstract: Development of forecasting systems for harmful algal blooms (HABs) has been a long-standing research and management goal. Significant progress has been made in the Gulf of Maine, where seasonal bloom forecasts are now being issued annually using Alexandrium fundyense cyst abundance maps and a population dynamics model developed for that organism. Thus far, these forecasts have used terms such as “significant”, “moderately large” or “moderate” to convey the extent of forecasted paralytic shellfish poisoning (PSP) outbreaks. In this study, historical shellfish harvesting closure data along the coast of the Gulf of Maine were used to derive a series of bloom severity levels that are analogous to those used to define major storms like hurricanes or tornados. Thirty-four years of PSP-related shellfish closure data for Maine, Massachusetts and New Hampshire were collected and mapped to depict the extent of coastline closure in each year. Due to fractal considerations, different methods were explored for measuring length of coastline closed. Ultimately, a simple procedure was developed using arbitrary straight-line segments to represent specific sections of the coastline. This method was consistently applied to each year’s PSP toxicity closure map to calculate the total length of coastline closed. Maps were then clustered together statistically to yield distinct groups of years with similar characteristics. A series of categories or levels was defined (“Level 1: Limited”, “Level 2: Moderate”, and “Level 3: Extensive”) each with an associated range of expected coastline closed, which can now be used instead of vague descriptors in future forecasts. This will provide scientifically consistent and simply defined information to the public as well as resource managers who make decisions on the basis of the forecasts. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
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244. Understanding interannual, decadal level variability in paralytic shellfish poisoning toxicity in the Gulf of Maine: The HAB Index.
- Author
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Anderson, Donald M., Couture, Darcie A., Kleindinst, Judith L., Keafer, Bruce A., McGillicuddy, Jr., Dennis J., Martin, Jennifer L., Richlen, Mindy L., Hickey, J. Michael, and Solow, Andrew R.
- Subjects
- *
PARALYTIC shellfish poisoning , *TOXICOLOGY of poisonous fishes , *ALGAL blooms , *ALEXANDRIUM , *MICROBIAL cysts - Abstract
Abstract: A major goal in harmful algal bloom (HAB) research has been to identify mechanisms underlying interannual variability in bloom magnitude and impact. Here the focus is on variability in Alexandrium fundyense blooms and paralytic shellfish poisoning (PSP) toxicity in Maine, USA, over 34 years (1978–2011). The Maine coastline was divided into two regions – eastern and western Maine, and within those two regions, three measures of PSP toxicity (the percent of stations showing detectable toxicity over the year, the cumulative amount of toxicity per station measured in all shellfish (mussel) samples during that year, and the duration of measurable toxicity) were examined for each year in the time series. These metrics were combined into a simple HAB Index that provides a single measure of annual toxin severity across each region. The three toxin metrics, as well as the HAB Index that integrates them, reveal significant variability in overall toxicity between individual years as well as long-term, decadal patterns or regimes. Based on different conceptual models of the system, we considered three trend formulations to characterize the long-term patterns in the Index – a three-phase (mean-shift) model, a linear two-phase model, and a pulse-decline model. The first represents a “regime shift” or multiple equilibria formulation as might occur with alternating periods of sustained high and low cyst abundance or favorable and unfavorable growth conditions, the second depicts a scenario of more gradual transitions in cyst abundance or growth conditions of vegetative cells, and the third characterizes a ”sawtooth” pattern in which upward shifts in toxicity are associated with major cyst recruitment events, followed by a gradual but continuous decline until the next pulse. The fitted models were compared using both residual sum of squares and Akaike's Information Criterion. There were some differences between model fits, but none consistently gave a better fit than the others. This statistical underpinning can guide efforts to identify physical and/or biological mechanisms underlying the patterns revealed by the HAB Index. Although A. fundyense cyst survey data (limited to 9 years) do not span the entire interval of the shellfish toxicity records, this analysis leads us to hypothesize that major changes in the abundance of A. fundyense cysts may be a primary factor contributing to the decadal trends in shellfish toxicity in this region. The HAB Index approach taken here is simple but represents a novel and potentially useful tool for resource managers in many areas of the world subject to toxic HABs. [Copyright &y& Elsevier]
- Published
- 2014
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245. Distribution, abundance and diversity of Gambierdiscus spp. from a ciguatera-endemic area in Marakei, Republic of Kiribati.
- Author
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Xu, Yixiao, Richlen, Mindy L., Morton, Steve L., Mak, Yim Ling, Chan, Leo Lai, Tekiau, Aranteiti, and Anderson, Donald M.
- Subjects
- *
DINOFLAGELLATES , *PHYTOGEOGRAPHY , *ALGAL genetics , *CIGUATERA poisoning , *TOXICOLOGY of poisonous fishes - Abstract
Highlights: [•] Genetic and morphological analysis identified three Gambierdiscus species and three previously unreported ribotypes from Marakei, Republic of Kiribati. [•] All Gambierdiscus isolates tested exhibited low or moderate ciguatoxin-like content. [•] Gambierdiscus distribution patterns corresponded with previous patterns of fish toxicity. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
246. Seasonal dynamics of Alexandrium tamarense and occurrence of paralytic shellfish poisoning toxins in bivalves in Nanji Islands, East China Sea.
- Author
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Tao Jiang, Yixiao Xu, Yang Li, Tianjiu Jiang, Feng Wu, and Fan Zhang
- Abstract
A monitoring program for seasonal dynamics of A. tamarense and paralytic shellfish poisoning toxins (PSTs) in bivalves was carried out from April 2006 to March 2007 in Nanji Islands, East China Sea. Low abundances of A. tamarense (fewer than 4.0 x 10² cells L
-1 ) were first observed on 15 April 2006. During middle May, blooms of A. tamarense were documented, with the mean density of 3.8 x 10³ cells L-1 and 0.75 x 10³ cells L-1 , corresponding to surface and bottom water columns, respectively. Environmental conditions of temperature range 18-20°C and salinity range 29.5-31 coincided with a high abundance of A. tamarense in the region, and the bloom collapse was likely to be a response to P limitation. Toxin concentrations in cultured Patinopecten yessoensis, Mytilus galloprovincialis and wild Mytilus coruscus during A. tamarense blooms ranged from 68.9 to 96.3 µg STXeq per 100 g flesh. Toxin profiles were similar among bivalve shellfish samples, dominated by C1 and C2 in 51.4-64.6 mol% of toxins, with an average of 60.6 mol%, followed by GTX5, GTX1-GTX4, dcGTX2 and dcGTX3. However, from January to March 2007, lower toxin concentrations, 18.9-40.8 µg STXeq per 100 g were found only in the wild Oyster sp., comprising GTX4, GTX5 and GTX1. Dynamics of Alexandrium tamarense and the factors that influence its blooms, as well as the relationship between A. tamarense and paralytic shellfish poisoning toxins (PSTs) in shellfish, have only been rarely studied in the East China Sea. This investigation showed that nutrient concentrations and temperature played important roles in determining the amplitude of A. tamarense blooms and an increase in cell numbers of A. tamarense coincided with the detection of PSTs in shellfish. This research provides a basis for the establishment of effective toxin-monitoring strategies. [ABSTRACT FROM AUTHOR]- Published
- 2014
- Full Text
- View/download PDF
247. Evidence of a Transgenerationally Developed Microcystin Toxin Tolerance in Daphnia magna
- Author
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Knight, Alexis and Sibley, Paul
- Subjects
HABs ,Microcystins ,Daphnia ,Cyanotoxins ,fungi ,polycyclic compounds ,Toxins ,Adaptation ,Cyanobacteria ,Tolerance - Abstract
The increased severity of harmful algal blooms (HABs) has diminished aquatic ecosystem health globally. Primary producers are adversely affected by microcystin toxins released during HABs and commonly experience fitness and survival reductions. To assess the effects of multigenerational microcystin exposure, five generations of Daphnia magna were exposed and observed for changes in survival, reproduction, and growth. Microcystins significantly reduced adult sizes, but maternal exposure increased reproduction in re-exposed offspring, indicating development of microcystin tolerance through maternal transfer. Varying exposure showed that frequency impacts tolerance, with multiple exposures positively correlating with reproductive output, and absence of exposure leading to tolerance loss. Concurrent exposure to non-toxic M. aeruginosa confirmed microcystins as the likely sole negative effect source and resulted in increased growth and reproduction in D. magna. This research provides important insights into long-term tolerance dynamics of microcystin exposed D. magna and the nature of future HAB impacts on zooplankton communities.
- Published
- 2020
248. Adsorption Strategy for Removal of Harmful Cyanobacterial Species Microcystis aeruginosa Using Chitosan Fiber
- Author
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Sok Kim, Yoon E. Choi, Yun Hwan Park, Ho Seon Kim, and Chulhwan Park
- Subjects
HABs ,Sorbent ,Lysis ,Geography, Planning and Development ,TJ807-830 ,02 engineering and technology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,TD194-195 ,01 natural sciences ,Renewable energy sources ,Chitosan ,chemistry.chemical_compound ,Adsorption ,Harmful cyanobacterial blooms ,Microcystis aeruginosa ,GE1-350 ,Fiber ,0105 earth and related environmental sciences ,Aqueous solution ,biology ,Environmental effects of industries and plants ,Renewable Energy, Sustainability and the Environment ,Biosorption ,021001 nanoscience & nanotechnology ,biology.organism_classification ,Environmental sciences ,chemistry ,Chemical engineering ,0210 nano-technology - Abstract
Microcystis aeruginosa is one of the predominant species responsible for cyanobacterial-harmful algal blooms (Cyano-HABs) in water bodies. Cyano-HABs pose a growing number of serious threats to the environment and public health. Therefore, the demand for developing safe and eco-friendly solutions to control Cyano-HABs is increasing. In the present study, the adsorptive strategy using chitosan was applied to remove M. aeruginosa cells from aqueous phases. Using a simple immobilization process, chitosan could be fabricated as a fiber sorbent (chitosan fiber, CF). By application of CF, almost 89% of cyanobacterial cells were eliminated, as compared to those in the control group. Field emission scanning electron microscopy proved that the M. aeruginosa cells were mainly attached to the surface of the sorbent, which was correlated well with the measurement of the surface area of the fiber. We tested the hypothesis that massive applications of the fabricated CF to control Cyano-HABs might cause environmental damage. However, the manufactured CF displayed negligible toxicity. Moreover, we observed that the release of cyanotoxins and microcystins (MCs), during the removal process using CF, could be efficiently prevented by a firm attachment of the M. aeruginosa cells without cell lysis. Our results suggest the possibility of controlling Cyano-HABs using a fabricated CF as a non-toxic and eco-friendly agent for scaled-up applications.
- Published
- 2020
- Full Text
- View/download PDF
249. Actualisation de l’évaluation des risques liés à la présence de cyanobactéries et leurs toxines dans les eaux destinées à l’alimentation, les eaux de loisirs et les eaux destinées aux activités de pêche professionnelle et de loisir
- Author
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Quiblier, Catherine, Amzil, Zouher, Baurès, Estelle, Banas, Damien, Biré, Ronel, Fessard, Valérie, Gugger, Muriel, Lance, Emilie, Laplace-Treyture, Christophe, Latour, Delphine, Anne-Marie, Levet, Marie, B, Mattei, César, Richard, Benjamin, Brigitte, Vinçon-Leite, Welté, Bénédicte, Arnich, Nathalie, Catastini, Carole, Teyssandier, Marie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France, Université Paris Diderot - Paris 7 (UPD7), Muséum national d'Histoire naturelle (MNHN), École des Hautes Études en Santé Publique [EHESP] (EHESP), Université de Lorraine (UL), Laboratoire de sécurité des aliments de Maisons-Alfort (LSAl), Agence nationale de sécurité sanitaire de l'alimentation, de l'environnement et du travail (ANSES), Laboratoire de Fougères - ANSES, Collection de l'Institut Pasteur (CIP), Institut Pasteur [Paris] (IP)-Université Paris Cité (UPCité), Ecosystèmes aquatiques et changements globaux (UR EABX), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Agence Régionale de Santé de Normandie [Caen] (ARS Normandie), Université d'Angers (UA), Agence Régionale de Santé Bretagne, École des Ponts ParisTech (ENPC), Retraité, Direction de l'Evaluation des Risques (DER), and Anses
- Subjects
HABs ,[SDV.EE]Life Sciences [q-bio]/Ecology, environment ,Microcystins ,Cyanotoxins ,Arbre décisionnel ,Cyanobacteria ,Harmful blue-green algae ,Recreational waters ,Drinking water ,Bloom ,Cyanobactéries ,Activités nautiques ,Prolifération ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Baignade ,Cyanotoxines ,ComputingMilieux_MISCELLANEOUS ,EDCH - Abstract
Les cyanobactéries sont des bactéries photosynthétiques à Gram négatif dont la pigmentation varie du bleu-vert au rouge. Elles sont encore parfois désignées, à tort du point de vue biologique, sous le terme d’algues bleues. Les cyanobactéries se développent dans les milieux terrestres et aquatiques, qu’ils soient saumâtres, marins ou dulçaquicoles. Lorsque les conditions environnementales (température, nutriments) leur sont favorables, elles peuvent alors proliférer de manière massive et rapide (en quelques jours), on parle alors d’efflorescence (ou « bloom » en anglais). Dans certains cas, ces proliférations entraînent un changement de couleur de l’eau, une odeur nauséabonde et/ou leur accumulation à la surface de l’eau. Certaines espèces de cyanobactéries produisent des toxines appelées cyanotoxines qui peuvent présenter des effets néfastes pour la santé humaine et animale. La présence de cyanobactéries est observée de plus en plus fréquemment, sur tous les continents, expliquant la préoccupation internationale croissante au regard des conséquences écologiques, sanitaires et économiques associées.En 1998, le programme EFFLOCYA, initié par les ministères en charge de la santé et de l’environnement, a mis en évidence le fait que la prolifération de cyanobactéries capables de libérer des toxines dans les eaux brutes utilisées pour la production d’eau destinée à la consommation humaine (EDCH) et les eaux de baignades constitue un risque sanitaire émergent.Suite à ces travaux, le ministère chargé de la santé a saisi en 2001 l’Agence française de la sécurité sanitaire des aliments (Afssa) afin d’effectuer une évaluation des risques liés à la présence de cyanobactéries dans les EDCH. Cette demande a été complétée en mars 2004 par une saisine de l’Agence française de sécurité sanitaire de l’environnement et du travail (Afsset) par les ministères chargés de l’environnement et de la santé. L’Afsset devait évaluer les risques sanitaires encourus par les baigneurs et les autres usagers des plans et cours d’eau et proposer des valeurs limites de qualité relatives à la concentration de cellules et/ou toxines dans les eaux de baignade. En juillet 2006, les deux agences ont publié un rapport commun (Afssa – Afsset, 2006) en réponse à ces deux saisines.L’Agence recommandait alors d’acquérir des connaissances sur les toxines et les ressources dans le but de pouvoir évaluer les risques liés aux cyanotoxines. C’est ainsi que depuis la parution de ce rapport, de nombreux résultats d’analyses de cyanotoxines et cyanobactéries dans les ressources utilisées pour produire de l’EDCH, dans les EDCH elles-mêmes et les eaux récréatives ont été colligés par les Agences régionales de santé (ARS).Ces données ont entre autres choses révélé la présence de cyanobactéries susceptibles de produire des cyanotoxines - pour lesquelles il n’existe aucune valeur sanitaire acceptable dans des retenues d’eau destinées à produire de l’EDCH - que ce soit en métropole ou dans les territoires ultramarins, où peu de données sont cependant disponibles. Par ailleurs, malgré les recommandations formulées en 2006, il existe toujours des difficultés et une grande disparité dans la gestion des risques des eaux de baignade contaminées par des cyanobactéries. Pour ces différentes raisons, la Direction Générale de la Santé (DGS) a sollicité l’Anses afin qu’elle actualise son expertise de 2006 à la lumière des nouvelles connaissances disponibles.[Saisine liée n°2015-SA-0206]
- Published
- 2020
250. Satellite Ocean Color Based Harmful Algal Bloom Indicators for Aquaculture Decision Support in the Southern Benguela
- Author
-
Stewart Bernard and Marié E. Smith
- Subjects
HABs ,0106 biological sciences ,lcsh:QH1-199.5 ,010504 meteorology & atmospheric sciences ,Site selection ,Ocean Engineering ,lcsh:General. Including nature conservation, geographical distribution ,Aquatic Science ,Oceanography ,01 natural sciences ,Algal bloom ,ocean color ,remote sensing ,Aquaculture ,Phytoplankton ,lcsh:Science ,0105 earth and related environmental sciences ,Water Science and Technology ,Global and Planetary Change ,biology ,business.industry ,010604 marine biology & hydrobiology ,Dinoflagellate ,Hypoxia (environmental) ,biology.organism_classification ,MERIS ,aquaculture ,Ocean color ,Environmental science ,lcsh:Q ,OLCI ,Bloom ,business - Abstract
The aquaculture industry of southern Africa faces environmental threats from harmful algal blooms (HABs), which have the potential to cause devastating economic losses (Pitcher et al., 2019). Satellite earth observation offers a systematic and cost effective method for operational monitoring of HABs over large areas. Whilst the chlorophyll-a concentration ([Chl-a]) product, often used as a proxy for phytoplankton biomass, can be used to indicate high biomass blooms (elevated biomass against a background signal of 5–10 mgChl m−3), there is a clear need for value-added products that not only alert on bloom presence, but also on the bloom type and persistence. This study demonstrates the identification of different phytoplankton communities that can feasibly be identified in bloom concentrations from space, relevant to the aquaculture industry of South Africa. In terms of water-leaving reflectance, 76 % of the variance in the red and NIR spectral region is significantly positively correlated to phytoplankton abundance, [Chl-a], and the maximum line height (MLH) (defined as the height of the maximum reflectance peak above a baseline between 665 and 753 nm). The MLH is related to dominant phytoplankton types derived from phytoplankton count data, in order to identify thresholds which represent blooms that pose a high hypoxia and/or toxicity risk; whilst 0.0016 < MLH < 0.003 represent low to moderate concern mixed assemblage blooms, MLH > 0.003 has a strong likelihood of indicating high biomass dinoflagellate or Pseudo-nitzschia blooms. These techniques are routinely used by the aquaculture industry in South Africa for decision support and risk mitigation. The high biomass nature of the South African regional waters provide strong assemblage-related spectral variability, which can be exploited with the spectral bands of OLCI and MERIS. Application to these sensors not only ensures future monitoring capability, but also allows the creation of a historical risk climatology that can guide the site selection of industries sensitive to the presence of HABs, such as aquaculture facilities and desalination plants.
- Published
- 2020
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