scholarly journals Paralytic and Amnesic Shellfish Toxins Impacts on Seabirds, Analyses and Management

Toxins ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 454
Author(s):  
Begoña Ben-Gigirey ◽  
Lucía Soliño ◽  
Isabel Bravo ◽  
Francisco Rodríguez ◽  
María V. M. Casero

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.

2021 ◽  
Vol 9 (3) ◽  
pp. 293
Author(s):  
Mauro Corriere ◽  
Lucía Soliño ◽  
Pedro Reis Costa

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


2021 ◽  
Author(s):  
Yu Ting Zhang ◽  
Shanshan SONG ◽  
Bin ZHANG ◽  
Yang ZHANG ◽  
Miao TIAN ◽  
...  

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


2021 ◽  
Vol 8 ◽  
Author(s):  
María del Carmen Jiménez-Quiroz ◽  
Francisco Javier Barrón-Barraza ◽  
Rafael Cervantes-Duarte ◽  
René Funes-Rodríguez

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


2016 ◽  
Author(s):  
Bruno Dias Duarte Fragoso ◽  
John David Icely ◽  
Nancy Odour ◽  
Gerald Moore ◽  
João Magalhães Neto ◽  
...  

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


Toxins ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 344
Author(s):  
Mariana I. C. Raposo ◽  
Maria Teresa S. R. Gomes ◽  
Maria João Botelho ◽  
Alisa Rudnitskaya

Paralytic shellfish toxins (PSTs) are a group of toxins that cause paralytic shellfish poisoning through blockage of voltage-gated sodium channels. PSTs are produced by prokaryotic freshwater cyanobacteria and eukaryotic marine dinoflagellates. Proliferation of toxic algae species can lead to harmful algal blooms, during which seafood accumulate high levels of PSTs, posing a health threat to consumers. The existence of PST-transforming enzymes was first remarked due to the divergence of PST profiles and concentrations between contaminated bivalves and toxigenic organisms. Later, several enzymes involved in PST transformation, synthesis and elimination have been identified. The knowledge of PST-transforming enzymes is necessary for understanding the processes of toxin accumulation and depuration in mollusk bivalves. Furthermore, PST-transforming enzymes facilitate the obtainment of pure analogues of toxins as in natural sources they are present in a mixture. Pure compounds are of interest for the development of drug candidates and as analytical reference materials. PST-transforming enzymes can also be employed for the development of analytical tools for toxin detection. This review summarizes the PST-transforming enzymes identified so far in living organisms from bacteria to humans, with special emphasis on bivalves, cyanobacteria and dinoflagellates, and discusses enzymes’ biological functions and potential practical applications.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11186
Author(s):  
Lyall Bellquist ◽  
Vienna Saccomanno ◽  
Brice X. Semmens ◽  
Mary Gleason ◽  
Jono Wilson

Commercial, recreational, and indigenous fisheries are critical to coastal economies and communities in the United States. For over three decades, the federal government has formally recognized the impact of fishery disasters via federal declarations. Despite these impacts, national syntheses of the dynamics, impacts, and causes of fishery disasters are lacking. We developed a nationwide Federal Fishery Disaster database using National Oceanic and Atmospheric Administration (NOAA) fishery disaster declarations and fishery revenue data. From 1989-2020, there were 71 federally approved fishery disasters (eleven are pending), which spanned every federal fisheries management region and coastal state in the country. To date, we estimate fishery disasters resulted in $2B (2019 USD) in Congressional allocations, and an additional, conservative estimate of $3.2B (2019 USD) in direct revenue loss. Despite this scale of impact, the disaster assistance process is largely ad hoc and lacks sufficient detail to properly assess allocation fairness and benefit. Nonetheless, fishery disasters increased in frequency over time, and the causes of disasters included a broad range of anthropogenic and environmental factors, with a recent shift to disasters now almost exclusively caused by extreme environmental events (e.g., marine heatwaves, hurricanes, and harmful algal blooms). Nationwide, 84.5% of fishery disasters were either partially or entirely attributed to extreme environmental events. As climate change drives higher rates of such extreme events, and as natural disaster assistance requests reach an all-time high, the federal system for fisheries disaster declaration and mitigation must evolve in order to effectively protect both fisheries sustainability and societal benefit.


Author(s):  
Magnolia Gricel Salcedo-Garduño ◽  
María del Refugio Castañeda-Chávez ◽  
Fabiola Lango-Reynoso ◽  
Itzel Galaviz-Villa

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


2015 ◽  
Vol 282 (1798) ◽  
pp. 20141268 ◽  
Author(s):  
Uwe John ◽  
Urban Tillmann ◽  
Jennifer Hülskötter ◽  
Tilman J. Alpermann ◽  
Sylke Wohlrab ◽  
...  

Dinoflagellates are a major cause of harmful algal blooms (HABs), with consequences for coastal marine ecosystem functioning and services. Alexandrium fundyense (previously Alexandrium tamarense ) is one of the most abundant and widespread toxigenic species in the temperate Northern and Southern Hemisphere and produces paralytic shellfish poisoning toxins as well as lytic allelochemical substances. These bioactive compounds may support the success of A. fundyense and its ability to form blooms. Here we investigate the impact of grazing on monoclonal and mixed set-ups of highly (Alex2) and moderately (Alex4) allelochemically active A. fundyense strains and a non-allelochemically active conspecific (Alex5) by the heterotrophic dinoflagellate Polykrikos kofoidii . While Alex4 and particularly Alex5 were strongly grazed by P. kofoidii when offered alone, both strains grew well in the mixed assemblages (Alex4 + Alex5 and Alex2 + Alex5). Hence, the allelochemical active strains facilitated growth of the non-active strain by protecting the population as a whole against grazing. Based on our results, we argue that facilitation among clonal lineages within a species may partly explain the high genotypic and phenotypic diversity of Alexandrium populations. Populations of Alexandrium may comprise multiple cooperative traits that act in concert with intraspecific facilitation, and hence promote the success of this notorious HAB species.


Author(s):  
Erik Simões ◽  
Renato Campos Vieira ◽  
Mathias Alberto Schramm ◽  
Danielle Ferraz Mello ◽  
Vitor De Almeida Pontinha ◽  
...  

Blooms of the harmful alga Dinophysis acuminata, which produces okadaic acid (OA), are becoming recurrent in Santa Catarina coast, where most of the shellfish marine farms in Brazil are located. We evaluated the impact of D. acuminata blooms on various haemato-immunological parameters and on tissue integrity of cultivated oysters (Crassostrea gigas) and mussels (Perna perna). Animals were sampled during two natural algal blooms, one at Praia Alegre (PA: 2950 cells l−1) and the other at Praia de Zimbros (PZ: 4150 cells l−1). Control animals were sampled at the same sites, 30 days after the end of the bloom. The assayed parameters were: total (THC) and differential (DHC) haemocyte counts, percentage of apoptotic haemocytes (AH), phenoloxidase activity (PO), agglutinating titre (AT) and total protein concentration in haemolymph (PC). Histological analyses were carried out in oysters from PZ. The results showed that some immune parameters were modulated during the toxic blooms, but not in a consistent manner, especially in mussels that accumulated more OA (10×) than oysters. For example, mussel THC decreased significantly (54%) during the bloom at PA, whereas it augmented markedly (64%) at PZ. PO activity was significantly altered by the algal blooms in both bivalve species, while PC increased significantly (66%) only in mussels from PZ bloom. The other parameters (DHC, AH and AT) did not vary in both bivalve species. Histological analyses showed an intense haemocytic infiltration throughout the oyster digestive epithelium, particularly into the stomach lumen during the algal bloom.


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