Biodiversity patterns of free-living marine nematodes in a tropical bay: Cienfuegos, Caribbean Sea

Spatial and temporal biodiversity patterns of free-living marine nematodes were studied in Cienfuegos Bay, a tropical semi-enclosed basin in the Caribbean Sea. Taxonomic (to species level) and functional (biological trait) approaches were applied for describing the assemblage structure and relating it to abiotic environment based on a sampling scheme in six subtidal stations and three months. Biological trait approach added relevant information to species pattern regarding relationships between diversity patterns and the abiotic environment. The most common morphotypes were deposit feeding nematodes, with colonising abilities of 2–3 (in a scale from 1 to 5), tail conical cylindrical or filiforme and body slender; and their abundance were correlated with depth, organic matter and silt/clay fraction. In spite of a high turnover of species, functional diversity of assemblages did not change notably in space and time. A result probably due to sampling of the habitat pool of species and to low heterogeneity of the studied muddy bottoms. Chemical pollution (organic enrichment and heavy metals) and hydrodynamic regime possibly drove the biodiversity patterns. Spatial distribution of assemblages support the existence of two well differentiated basins inside the bay, the northern basin more polluted than the southern one. The low hydrodynamic regime would determine a poor dispersion of nematodes resulting in high spatial variance in the assemblage structure; and also the associated hypoxic conditions and pollutants in sediments can explain the dominance of tolerant nematode species such as Daptonema oxycerca, Sabatieria pulchra, Terschellingia gourbaultae, and Terschellingia longicaudata. A comparison of spatial– temporal patterns of biodiversity between Cienfuegos Bay and other semi-enclosed bays in temperate regions suggests several similarities: nematode assemblages are strongly influenced by anthropogenic disturbance, temporal trends are weak or overridden by spatial ones, and few cosmopolitan genera/ species tolerant to pollution and hypoxic conditions are dominant

Clave dicotómica para la identificación preliminar de las especies de "Gambierdiscus" y "Fukuyoa" reportadas en la región del Caribe

Los géneros de dinoflagelados bentónicos Gambierdiscus y Fukuyoa están entre los agentes causales de la ciguatera, intoxicación causada por el consumo de invertebrados y peces contaminados con ciguatoxinas. Debido a las similitudes morfológicas que presentan las especies pertenecientes a estos géneros, su identificación requiere del uso combinado de técnicas de microscopía y moleculares. Sin embargo, estas metodologías son poco accesibles para muchos países con limitados recursos económicos, donde lo más común es disponer en la práctica de la microscopía óptica. Este trabajo propone una clave dicotómica para la identificación preliminar de las especies de Gambierdiscus y Fukuyoa reportadas en la región del Caribe, utilizando caracteres morfológicos visibles al microscopio óptico convencional. La clave propuesta permite emplear un número limitado de caracteres morfológicos lo cual fue posible al incluir pocas especies en el análisis.   Recibido: 15.09.2022 Aceptado: 06.06.2023 Editor: Liliana Gómez Lun

Ciguatoxin occurrence in food-web components of a Cuban Coral Reef Ecosystem: Risk-assessment implications

In Cuba, ciguatera poisoning associated with fish consumption is the most commonly occurring non-bacterial seafood-borne illness. Risk management through fish market regulation has existed in Cuba for decades and consists of bans on selected species above a certain weight; however, the actual occurrence of ciguatoxins (CTXs) in seafood has never been verified. From this food safety risk management perspective, a study site locally known to be at risk for ciguatera was selected. Analysis of the epiphytic dinoflagellate community identified the microalga Gambierdiscus. Gambierdiscus species included six of the seven species known to be present in Cuba (G. caribaeus, G. belizeanus, G. carpenteri, G. carolinianus, G. silvae, and F. ruetzleri). CTX-like activity in invertebrates, herbivorous and carnivorous fishes were analyzed with a radioligand receptor-binding assay and, for selected samples, with the N2A cell cytotoxicity assay. CTX activity was found in 80% of the organisms sampled, with toxin values ranging from 2 to 8 ng CTX3C equivalents g−1 tissue. Data analysis further confirmed CTXs trophic magnification. This study constitutes the first finding of CTX-like activity in marine organisms in Cuba and in herbivorous fish in the Caribbean. Elucidating the structure–activity relationship and toxicology of CTX from the Caribbean is needed before conclusions may be drawn about risk exposure in Cuba and the wider Caribbean.info:eu-repo/semantics/publishedVersio

Ciguatoxin Occurrence in Food-Web Components of a Cuban Coral Reef Ecosystem: Risk-Assessment Implications

In Cuba, ciguatera poisoning associated with fish consumption is the most commonly occurring non-bacterial seafood-borne illness. Risk management through fish market regulation has existed in Cuba for decades and consists of bans on selected species above a certain weight; however, the actual occurrence of ciguatoxins (CTXs) in seafood has never been verified. From this food safety risk management perspective, a study site locally known to be at risk for ciguatera was selected. Analysis of the epiphytic dinoflagellate community identified the microalga Gambierdiscus. Gambierdiscus species included six of the seven species known to be present in Cuba (G. caribaeus, G. belizeanus, G. carpenteri, G. carolinianus, G. silvae, and F. ruetzleri). CTX-like activity in invertebrates, herbivorous and carnivorous fishes were analyzed with a radioligand receptor-binding assay and, for selected samples, with the N2A cell cytotoxicity assay. CTX activity was found in 80% of the organisms sampled, with toxin values ranging from 2 to 8 ng CTX3C equivalents g−1 tissue. Data analysis further confirmed CTXs trophic magnification. This study constitutes the first finding of CTX-like activity in marine organisms in Cuba and in herbivorous fish in the Caribbean. Elucidating the structure–activity relationship and toxicology of CTX from the Caribbean is needed before conclusions may be drawn about risk exposure in Cuba and the wider Caribbean

Variaciones espaciales y temporales de las comunidades de la meiofauna en la bahía de Cie, Cubanfuegos

The community structure of meiofauna was studied in 16 subtidal sampling stations and in four months in Cienfuegos Bay, Cuba for describing their patterns of distribution, as well as their possible causes. Silt/clay (S/C) and organic matter (OM) contents in sediment were positively correlated, and their changes were related to spatial variation of sedimentary environment across stations. The narrow range of interstitial salinity suggests a slight effect on meiofauna even when changes of surficial salinity occurred. Density and number of taxa changed among dry and wet seasons plausibly as a response to hypoxic conditions due to water stratification in the wet season. Negative relationships were recorded among S/C and OM with meiofaunal densities possibly due to restrictive effects of accumulation and oxidation of organic matter. Physical disturbance appears to be a main process affecting meiofauna in some shallow stations subjected to strong waving and tidal currents. No any single ecological factor explains the large spatial variability of meiofaunal communities in the whole bay; a combination of several processes like distribution of primary production, stratification/mixing of the water column and physical disturbance probably is occurring in the bay.Se estudió la estructura de la comunidad de la meiofauna en 16 estaciones submareales y en cuatro meses, en la bahía de Cienfuegos, Cuba, para describir sus patrones de distribución así como sus posibles causas. Los contenidos de limo/arcilla (S/C) y materia orgánica (OM) en los sedimentos estuvieron positivamente correlacionados y sus cambios se relacionaron con la variación espacial del ambiente sedimentario a través de las estaciones. El restringido intervalo de salinidad intersticial sugiere un efecto pequeño sobre la meiofauna aún cuando ocurrieron cambios en la salinidad superficial. La densidad y el número de taxa cambiaron entre la estaciones seca y húmeda como respuesta a las condiciones hipóxicas causadas por la estratificación del agua en la estación húmeda. Se determinaron relaciones negativas entre los contenidos de limo/arcilla y materia orgánica con las densidades de la meiofauna, debido posiblemente a los efectos restrictivos causados por la acumulación y oxidación de la materia orgánica. El disturbio físico parece ser un proceso principal que afecta a la meiofauna en algunas estaciones someras sujetas a fuerte oleaje y corrientes de marea. Ningún factor ecológico por sí solo explica la gran variabilidad espacial de las comunidades de la meiofauna en la bahía; probablemente una combinación de varios procesos como la distribución de la producción primaria, la estratificación/mezcla de la columna de agua y el disturbio físico está ocurriendo en la bahía

Sistema integrado de vigilância e gestão de florações de algas nocivas na província de Cienfuegos, Cuba

Las floraciones algales nocivas pueden tener consecuencias negativas en la salud, economía y diversidad biológica de los ecosistemas marinos. En la provincia de Cienfuegos, ubicada al centro-sur de Cuba, han ocurrido diferentes eventos de estas floraciones en su bahía de igual nombre, con impactos negativos en la salud pública y la economía del país, así como para la localidad. El objetivo de este trabajo fue diseñar e implementar un sistema de vigilancia y gestión de esos eventos para la provincia de Cienfuegos, con vistas a disponer de mecanismos de acción intersectorial bien definidos, ante la aparición de tales microrganismos, basado en los principios del Manejo Integrado de Zonas Costeras. Durante el año 2021, se constató científicamente eventos de floraciones de las algas aludidas, por lo que se desarrolló un taller para el diseño y la propuesta de dicho sistema, utilizando el criterio de especialistas claves en la gestión de los eventos mencionados en el territorio. El sistema de vigilancia y gestión tuvo como principal característica garantizar la integración de los sectores relacionados con la problemática en la provincia. Este sistema fue dividido en cinco etapas: vigilancia, comunicación, activación del sistema, gestión directa y evaluación de impactos. En octubre de 2021, se logró implementarlo con resultados satisfactorios, tras la ocurrencia de una floración del dinoflagelado Vulcanodinium rugosum. Su puesta en práctica contribuyó a mitigar los impactos de las floraciones algales nocivas en diferentes sectores de desarrollo en la provincia de Cienfuegos.Harmful algal blooms can have negative consequences on the health, economy, and biological diversity of marine ecosystems. In the province of Cienfuegos, located in south-central Cuba, different bloom events have occurred in the bay of the same name, with a negative impact on the health and economy of the locality, as well as of the country. The objective of this research project was to design and implement a surveillance and management system of these events in the province of Cienfuegos, with the purpose of having well-defined intersectoral action mechanisms for the occurrence of these microorganisms, based on the principles of Integrated Management of Coastal Zones. During 2021, bloom events of these algae were scientifically confirmed; consequently, a workshop was developed for the design and proposal of this system, using the criteria of key specialists in the management of these events in the territory. The main characteristic of the monitoring and management system was to guarantee the integration of the sectors in the province related to this problem. This system was divided into five stages: surveillance, communication, system activation, direct management, and impact assessment. In October 2021, the system was implemented with satisfactory results after a bloom of the dinoflagellate Vulcanodinium rugosum. The implementation of this system contributed to mitigate the impacts of harmful algal blooms in different development sectors in the province of Cienfuegos.As florações de algas nocivas podem ter consequências negativas na saúde, economia e biodiversidade dos ecossistemas marinhos. Na província de Cienfuegos, localizada no centro-sul de Cuba, diferentes eventos dessas florações ocorreram em sua baía de mesmo nome, com impactos negativos na saúde pública e na economia do país, bem como para a localidade. O objetivo deste trabalho foi desenhar e implementar um sistema de vigilância e gestão desses eventos para a província de Cienfuegos, com vistas a ter mecanismos de ação intersetorial bem definidos, diante do surgimento de tais microrganismos, com base nos princípios da Gestão Integrada da Zona Costeira. Durante o ano de 2021, os eventos de florações de algas referidas foram cientificamente verificados, portanto, foi desenvolvido um workshop para o desenho e a proposta do citado sistema, utilizando os critérios de especialistas-chave na gestão dos eventos mencionados no território. A principal característica do sistema de monitoramento e gestão foi garantir a integração dos setores relacionados ao problema na província. Esse sistema foi dividido em cinco etapas: vigilância, comunicação, ativação do sistema, gestão direta e avaliação de impacto. Em outubro de 2021, foi possível implantá-lo com resultados satisfatórios, após a ocorrência de floração do dinoflagelado Vulcanodinium rugosum. Sua aplicação contribuiu para mitigar os impactos das florações de algas nocivas em diferentes setores de desenvolvimento na província de Cienfuegos

Addressing the Problem of Harmful Algal Blooms in Latin America and the Caribbean- A Regional Network for Early Warning and Response

Harmful algal blooms (HABs) constitute a worldwide problem, affecting aquatic ecosystems, public health and local economies. Supported by the International Atomic Energy Agency since 2009, Latin America and the Caribbean (LAC) countries, including Brazil, Chile, Colombia, Costa Rica, Cuba, Dominican Republic, El Salvador, Guatemala, Haiti, Mexico, Nicaragua, Panama, Uruguay and Venezuela, have integrated a regional network for early warning of HABs and biotoxins in seafood. Technical capacities have been developed at regional level to identify toxic species, evaluate biota toxicity, and to perform retrospective analysis of HAB occurrence. This network involves 58% of the coastal LAC countries, two regional reference centers (in El Salvador and Cuba), 14 well equipped institutions, and 177 professionals trained to contribute to the operation of HAB and biotoxin monitoring programs. All countries from the network have reported planktonic and benthic toxic species, and in selected cases, associated with toxin in biota. Dinocyst abundance analysis in 210Pb-dated sediment cores have shown that some harmful species have been present in the region for at least 100 years ago, and that both coastal water pollution and climate change are important drivers for HAB occurrence. Efforts must be made to enrich the data base records on HAB events occurred in LAC, better understand key environmental variables that control HABs and expand coverage of HAB monitoring to all coastal countries in LAC to promote sustainable development of the region.Organismo Internacional de Energía Atómica/[RLA/7/020]/IAEA/AustriaOrganismo Internacional de Energía Atómica/[RLA/7/022]/IAEA/AustriaOrganismo Internacional de Energía Atómica/[ELS/7/002]/IAEA/AustriaOrganismo Internacional de Energía Atómica/[ELS/7/003]/IAEA/AustriaOrganismo Internacional de Energía Atómica/[ELS/7/005]/IAEA/AustriaOrganismo Internacional de Energía Atómica/[ELS/7/007]/IAEA/AustriaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Estructuras Microscópicas (CIEMIC