Human health risks associated to trace elements and metals in commercial fish from the Brazilian Amazon.

Fish constitutes the main protein source for the Amazonian population. However, the impact of different anthropogenic activities on trace element and metal accumulation in fish and their risks for human health at a regional scale remain largely unexplored. Here we assessed exposure levels of 10 trace elements and metals (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, Pb, and Hg) in 56 samples belonging to 11 different species of fish from the Brazilian Amazon. We studied the relationship between exposure levels, fish origin, and fish feeding habits, and assessed toxicological and carcinogenic risks for the Amazonian population. No significant correlation was found between sampling site and exposure levels to the studied elements, but a significant difference was found between the accumulation of some metals and the position of the fish species in the food chain. The concentrations of Cr and Hg in fish flesh were found to exceed the Brazilian limits for human consumption. This study shows that current fish consumption patterns can lead to estimated daily intakes of Hg, As and Cr that exceed the oral reference dose, thus posing a toxicological concern. Furthermore, carcinogenic risks may be expected due to the continued exposure to Cr and As. The results of this study show that the consumption of wild caught fish in the Amazon region should be controlled. Moreover, continued monitoring of trace element and metal contamination in fish and on the health of the Amazonian population is recommended, particularly for riverine and indigenous communities.

Contamination by microplastics and sorbed organic pollutants in the surface waters of the Tietê River, São Paulo-SP, Brazil.

Microplastics (MPs) are particles between 1 µm and 5 mm in size, originating mainly from poor solid waste and effluent management, that can reach water bodies from various sources. In freshwater environments, the occurrence, distribution, and characterization of this new class of pollutants are still little explored, especially in Brazil. The aim of this study was to assess the occurrence of MPs, as well as the presence and concentration of polychlorinated biphenyls (PCBs) sorbed to these particles in the surface waters of the Tietê River - SP. Surface water samples were collected in duplicate during the dry and wet seasons. The identification and characterization of the MPs was carried out through visual inspection and the chemical identity of the particles was verified using Fourier transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR). For the analysis of PCBs adsorbed to the MPs, the sample extracts were analyzed by gas chromatography coupled with mass spectrometry (GC-MS). The MPs were found in concentrations ranging from 6.67 to 1530 particles m-3, with a predominance of the polymers polyethylene (PE, with 58.17 %) and polypropylene (PP, with 23.53 %). The main morphological categories identified were fragments (56.63 %), fibers (28.42 %), and transparent films (13.06 %). Higher abundances of PCBs were observed in the lower size range, between 0.106 and 0.35 mm. The total concentrations of PCBs in MPs ranged from 20.53 to 133.12 ng g-1. The results obtained here are relevant for understanding the dynamics and level of contamination of MPs and organic pollutants sorbed to these particles in the Tietê River, as well as helping with mitigation measures for the restoration and preservation of this ecosystem.

Temperature and land use change are associated with Rana temporaria reproductive success and phenology.

Chemical pollution, land cover change, and climate change have all been established as important drivers of amphibian reproductive success and phenology. However, little is known about the relative impacts of these anthropogenic stressors, nor how they may interact to alter amphibian population dynamics. Addressing this gap in our knowledge is important, as it allows us to identify and prioritise the most needed conservation actions. Here, we use long-term datasets to investigate landscape-scale drivers of variation in the reproductive success and phenology of UK Common frog (Rana temporaria) populations. Consistent with predictions, we found that increasing mean temperatures resulted in earlier initialisation of spawning, and earlier hatching, but these relationships were not consistent across all sites. Lower temperatures were also linked to increased spawn mortality. However, temperature increases were also strongly correlated with increases in urban area, arable area, and nitrate levels in the vicinity of spawning grounds. As with spawning and hatching, there was marked spatial variation in spawn mortality trends, where some sites exhibited steady increases over time in the proportion of dead or diseased spawn. These findings support previous work linking warming temperatures to shifts in timing of amphibian breeding, but also highlight the importance of assessing the effect of land use change and pollution on wild amphibian populations. These results have implications for our understanding of the response of wild amphibian populations to climate change, and the management of human-dominated landscapes for declining wildlife populations.

Cellular uptake of multi-walled carbon nanotubes is associated to genotoxic and teratogenic effects towards the freshwater diatom Nitzschia linearis.

The increase in industrial production of multi-walled carbon nanotubes (MWCNTs) raises concerns about their potential adverse effects associated to environmental releases, especially in aquatic environments where they are likely to accumulate. This study focuses on the environmental impact of MWCNTs, specifically on a benthic freshwater diatom (Nitzschia linearis), which plays a major role in the primary production of water bodies. The obtained results indicate that exposure to MWCNTs in the presence of natural organic matter (NOM) inhibits diatom's growth in a dose-dependent manner after 72 h of exposure. Interestingly, the photosystem II quantum yield (PSIIQY) in diatoms remains unaffected even after exposure to MWCNTs at 10 mg/L. After 48 h of exposure, MWCNTs are found to bind preferentially to extracellular polymeric substances (EPS) produced by diatoms, which could decrease their toxicity by limiting their interaction with this organism. However, measurement of genotoxicity and teratogenicity in diatoms exposed to MWCNTs revealed that the exposure to MWCNTs increased the occurrence of cells with micronuclei and abnormal frustules. Microscopy analyses including two-photon excitation microscopy (TPEM) revealed the internalization of MWCNTs. Investigations of the diatom's frustule structure using Scanning electron microscopy (SEM) indicated that the presence of pore structures constitutes a pathway allowing MWCNTs uptake. The presence in the diatom's cytoplasm of MWCNTs might possibly induce disturbances of the cellular components, leading to the observed genotoxic and teratogenic effects. In view of previous studies, this work underscores the need for further studies on the interaction between nanomaterials and different diatom species, given the species-specific nature of the interactions.

Sensitivity of Alabama Freshwater Gastropod Species to Nickel Exposure.

Snails are effective bioindicators due to their prolific distribution, high level of endemism, and capacity to accumulate contaminants. Freshwater snails have unique ecological niches which are imperiled by land-use change and the introduction of hazardous chemicals. To assess how environmental alterations affect gastropods, lab-based studies are needed to characterize the toxicity of specific stressors. This can help guide policy decisions and remediation efforts. The aim of this research was to characterize acute toxicity of nickel (Ni) on endemic snails (Somatogyrus georgianus [Walker, 1904], Elimia cahawbensis [Lea, 1861], and Elimia spp.) and measure the accumulation of Ni and mineral elements including calcium (Ca), magnesium, potassium, and sodium (Na). Snails were exposed to six concentrations (25-800 µg/L) of Ni for 96 h. Among the studied snail species, E. cahawbensis was the most sensitive to Ni, with the lowest lethal concentration where 50% of the organisms died (LC50) at 88.88 µg/L Ni after 96 h. The LC50 at 96 h for S. georgianus was 167.78 µg/L Ni, and 393.13 µg/L Ni for Elimia spp. Except for Elimia spp., mortality of the other two snail species corresponded to the whole-body uptake of Ni. Nickel exposure also influenced Ca and Na uptake for Elimia spp. All three endemic species are potential candidate species for evaluating localized effects of human activities, and the present study provides a first step in characterizing how snails would be affected by environmental alterations. More research could further characterize potential effects of other human stressors on these endemic snail species. Future research into subindividual responses and routes of exposure can further elucidate variations in species sensitivity. Environ Toxicol Chem 2024;00:1-11. © 2024 SETAC. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Quantifying regulatory limits for multiple stressors in an open and transparent way.

Biodiversity is confronted globally by multiple stressors. Environmental policies must regulate these stressors to achieve targets, but how should that be done when the outcomes of limits on one stressor are contingent on other stressors, about which there is imperfect knowledge? Deriving regulatory frameworks that incorporate these contingencies is an emerging challenge at the science-policy interface. To be fit for implementation, these frameworks need to facilitate the inherently sociopolitical process of policy implementation and account transparently for uncertainty, such that practitioners and other stakeholders can more realistically anticipate the range of potential outcomes to policy. We developed an approach to quantify stressor limits that explicitly accounts for multistressor contingencies. Using an invertebrate data set collected over 30 years throughout New Zealand, we combined ecological and ecotoxicological models to predict biodiversity loss as a function of one stressor, treating multistressor contingencies as a form of uncertainty about the outcomes of limits on that stressor. We transparently accounted for that uncertainty by presenting regulatory limits as bands bounded between optimistic and pessimistic views that practitioners may have about the local context within which limits are applied. In addition to transparently accounting for uncertainties, our framework also leaves room for practitioners to build stakeholder consensus when refining limits to suit different local contexts. A criticism of this open, transparent approach is that it creates too much scope for choosing limits that are lenient on polluters, paralyzing on-the-ground management of multiple stressors, but we demonstrate that this is not necessarily the case.

Cuantificación abierta y transparente de los límites regulatorios para varios estresantes Resumen La biodiversidad enfrenta a múltiples estresantes en todo el mundo. Las políticas ambientales deben regularlos para alcanzar los objetivos fijados, pero ¿cómo hacerlo cuando los resultados de la limitación de un estresante dependen de otros factores, de los que se conoce muy poco? La elaboración de marcos reguladores que incorporen estas contingencias es un reto emergente en la interfaz ciencia­política. Para aplicar estos marcos, se debe facilitar el proceso sociopolítico inherente a la aplicación de políticas y tener en cuenta de forma transparente la incertidumbre, de modo que los profesionales y otras partes interesadas puedan anticipar de forma más realista la variedad de posibles resultados de las políticas. Desarrollamos un método para cuantificar los límites de los estresantes que considera explícitamente las contingencias de múltiples factores. Usamos un conjunto de datos sobre invertebrados recolectados durante 30 años en toda Nueva Zelanda. Después combinamos modelos ecológicos y eco­toxicológicos para predecir la pérdida de biodiversidad en función de un estresante y tratamos las contingencias de múltiples estresantes como una forma de incertidumbre sobre los resultados de los límites de ese mismo estresante. Explicamos esa incertidumbre de forma transparente con los límites normativos como bandas delimitadas entre las opiniones optimistas y pesimistas que los profesionales pueden tener sobre el contexto local en el que se aplican los límites. Además de hacer lo anterior, nuestro marco también deja margen para que los profesionales lleguen a un consenso con las partes interesadas a la hora de perfeccionar los límites para adaptarlos a los distintos contextos locales. Una crítica a este enfoque abierto y transparente crea demasiado margen para elegir límites indulgentes con los contaminadores, paralizando la gestión sobre el terreno de múltiples estresantes, pero demostramos que no es necesariamente así.

Forgotten fish habitats: Developing a conceptual framework for evaluating intermittent waterways and flood channels as native fish habitats: Insights from two freshwater catchments in Australia.

The ability to correctly identify Potential Key Fish Habitats (PKFH) before undertaking development assessments or stream restoration projects is a critical step for determining appropriate management interventions and offset strategies to minimize damage to all life stages of fish. However, there are no rapid, low-cost tools that can be universally utilised to identify PKFH in perennial streams and ephemeral streams in particular. We propose a conceptual framework for developing a rapid field appraisal based on a range of physical fish habitat-supporting features. Four steps are involved in developing the framework: 1) understand fish habitat features using published literature and sub-set model selection using actual data, 2) collect field data, 3) develop the conceptual framework, and 4) classify sites. We tested eight fish habitat-supporting features in the assessment and proposed a decision tree that guided the rapid appraisals at 104 ephemeral sites in southeast Australia. Out of 104 sites, 86% were identified as PKFH, 10% as likely key fish habitats and 4% as unlikely key fish habitats. The rapid field appraisal is cost-effective, simple to implement and does not require expert knowledge of fish habitats. Despite some limitations in the conceptual framework, this appraisal has great potential as a screening technique for PKFH in freshwater streams, particularly ephemeral streams in Australia and other overseas jurisdictions.

Water availability and biological interactions shape amphibian abundance and diversity in Mediterranean temporary rivers.

Amphibians, the most threatened vertebrates globally, face risks due to climate change, habitat loss, and fragmentation. Their sensitivity to environmental changes highlights their importance as ecological indicators. Temporary rivers, influenced by geological, climatic, and anthropogenic factors, play a critical role in shaping biodiversity and community structure. Some species of amphibians may be adapted to these temporary waters, a fact reflected in their life cycles and various biological traits. However, to develop effective conservation strategies for amphibians, it is essential to address the knowledge gaps surrounding the complex interactions between biological dynamics and fluvial habitat conditions. In this study, we investigated how trophic interactions between amphibians and other aquatic organisms (diatoms, macroinvertebrates, and fish), coupled with environmental factors (water availability and riparian structure), can affect amphibian abundance and diversity in temporary rivers. The study was conducted in a Mediterranean river network located in Sant Llorenç del Munt i l'Obac Natural Park (Catalonia, Spain). Our expectations were that habitats suitable for egg deposition, lacking predators (e.g. tadpole-predators and fish), and abundant in food sources would likely support higher amphibian abundance and diversity. However, water availability was identified as a crucial factor shaping abundance and diversity in the studied amphibian communities, even if it correlated with fish presence, and especially impacting amphibian species usually linked to permanent water bodies. Concerning biotic interactions, while our results suggested that amphibian populations in temporary rivers are more dependent on top-down than bottom-up interactions, the presence of aquatic predators was not as conclusive as expected, suggesting that in temporary rivers the fish-avoiding amphibian species can survive using microhabitats or breeding opportunities linked to natural river dynamics. Overall, our findings highlight the importance of considering multi-trophic interactions, hydroperiod and habitat heterogeneity in temporary river ecosystems for effective amphibian conservation.

First record of metazoan parasites of hybrids between the genera Colossoma and Piaractus in natural environments.

The practice of hybridization is carried out globally in fish farms. Here, we present the first record of the parasitic fauna of hybrids among genus Colossoma and Piaractus in natural environments. We identified a total of 48 hybrids, nine F1 hybrids (nuclear DNA from both species present in the cross) and 38 advanced hybrids (nuclear DNA from one species), both from crosses between Piaractus brachypomus and Piaractus mesopotamicus, and one F1 "tambacu" corresponding to cross between Colossoma macropomum and Piaractus mesopotamicus. This is the first record of Anacanthorus penilabiatus, Anacanthorus toledoensis, Mymarothecium viatorum, Mymarothecium ianwhittington, Haementeria sp., Dadaytrema oxycephala, Rondonia rondoni, and Echinorhynchus gomesi parasitizing hybrids collected in a natural environment. With this, we expand knowledge about the diversity of fish and parasites in the upper Paraná River and warn about the risk that fish escapes can cause in the basin.

Bending the curve of global freshwater biodiversity loss: what are the prospects?

Freshwater biodiversity conservation has received substantial attention in the scientific literature and is finally being recognized in policy frameworks such as the Global Biodiversity Framework and its associated targets for 2030. This is important progress. Nonetheless, freshwater species continue to be confronted with high levels of imperilment and widespread ecosystem degradation. An Emergency Recovery Plan (ERP) proposed in 2020 comprises six measures intended to "bend the curve" of freshwater biodiversity loss, if they are widely adopted and adequately supported. We review evidence suggesting that the combined intensity of persistent and emerging threats to freshwater biodiversity has become so serious that current and projected efforts to preserve, protect and restore inland-water ecosystems may be insufficient to avert substantial biodiversity losses in the coming decades. In particular, climate change, with its complex and harmful impacts, will frustrate attempts to prevent biodiversity losses from freshwater ecosystems already affected by multiple threats. Interactions among these threats will limit recovery of populations and exacerbate declines resulting in local or even global extinctions, especially among low-viability populations in degraded or fragmented ecosystems. In addition to impediments represented by climate change, we identify several other areas where the absolute scarcity of fresh water, inadequate scientific information or predictive capacity, and a widespread failure to mitigate anthropogenic stressors, are liable to set limits on the recovery of freshwater biodiversity. Implementation of the ERP rapidly and at scale through many widely dispersed local actions focused on regions of high freshwater biodiversity and intense threat, together with an intensification of ex-situ conservation efforts, will be necessary to preserve native freshwater biodiversity during an increasingly uncertain climatic future in which poorly understood, emergent and interacting threats have become more influential. But implementation of the ERP must be accompanied by measures that will improve water, energy and food security for humans - without further compromising the condition of freshwater ecosystems. Unfortunately, the inadequate political implementation of policies to arrest widely recognized environmental challenges such as climate change do not inspire confidence about the possible success of the ERP. In many parts of the world, the Anthropocene future seems certain to include extended periods with an absolute scarcity of uncontaminated surface runoff that will inevitably be appropriated by humans. Unless there is a step-change in societal awareness of - and commitment to - the conservation of freshwater biodiversity, together with necessary actions to arrest climate change, implementation of established methods for protecting freshwater biodiversity may not bend the curve enough to prevent continued ecosystem degradation and species loss.

Evaluating the Effects of Diet on the Sensitivity of Hyalella azteca to an "Eco-friendly" Deicing Agent.

Salting of roadways contaminates local waterways via snowmelt and precipitation runoff, eliciting various toxicological impacts on aquatic ecosystems. Recently, "eco-friendly" deicing alternatives have been introduced in hopes of mitigating environmental impacts of deicing agents, while maintaining human safety. These "eco-friendly" alternatives may pose their own set of environmental concerns that require further study. While the potential toxicity of road salts has been evaluated for various aquatic species, the environmental factors that may influence this toxicity are less understood; and for emerging deicing alternatives, there is a lack of literature documenting these potential implications. For aquatic organisms, the highest exposure to road salts may coincide with reduced food availability, namely during the winter months. The present study evaluates the effect of a conditioning diet on the sensitivity of adult Hyalella azteca to an "eco-friendly"-labeled beet deicer (Snow Joe MELT Beet-IT). Various conditioning diets were examined, including TetraMinTM, TetraMin and diatom (Thalassiosira weissflogii) combinations, and TetraMin and conditioned Acer sacharum leaves. For each diet type, 48- and 96-h water-only toxicity bioassays were conducted with adult H. azteca. These results were compared to organisms which experienced a 96-h starvation period prior to exposure and culture organisms. Diet types representing excess quality and quantity of food significantly decreased the toxicity of beet deicer to the organisms. However, starvation likely increases the toxicity of road salts to H. azteca. Therefore, the quantity and quality of food available to H. azteca may influence their sensitivity to deicing agents. Environ Toxicol Chem 2024;00:1-8. © 2024 SETAC.

Draft genome sequences of three Planktothrix rubescens strains cultivated from a eutrophic lake in Norwalk, Ohio (USA).

Draft genomes were generated for three filamentous toxin-producing cyanobacterial strains cultivated from aquatic sources in Ohio sequenced by NovaSeq S4. Here, we report the classification and genome statistics of Planktothrix rubescens PR221, PR222, and PR223.

Use of consumer insights to inform behavior change interventions aimed at illegal pet turtle trade in China.

Illegal poaching and overexploitation for the international pet trade are among the greatest threats to freshwater turtles in Southeast Asia. Expanding consumer research in China is crucial to filling knowledge gaps about the scale and structure of illegal trade and developing audience-targeted and relevant interventions that may reduce demand for illegal turtles as pets. We applied mixed methods to provide a detailed understanding of the consumer side of the illegal pet turtle trade in China. We conducted 30 interviews with key stakeholders and online surveys (n = 2456) of turtle keepers via community forums. From these, we identified 3 core consumer groups based on their prior turtle-keeping experience, species exposure, and potential for future purchases. We conducted a thematic qualitative analysis of concepts related to the capability, opportunity, motivation, and behavior (COM-B) model to determine the factors influencing the illegal pet turtle trade and to identify barriers to illegal purchases. Specifically, we identified purchasers' capabilities, opportunities, and motivations in the context of legality, enforcement risk, captive breeding, and impacts on wild population. We developed consumer journey maps (i.e., visual representations of customer's experiences throughout their buying journey) for core consumer groups. These maps illustrate the sequential behaviors and processes that consumers undertake when purchasing turtles, from initial exposure to sourcing, keeping, and providing a new home. Key factors influencing illegal purchases included convenient purchase channels, misguided cognition and motivations for pet keeping, and weak law enforcement. Effective interventions included messages focusing on shifting cognition and beliefs, increasing legal risk perception, and emphasizing stringent law enforcement, primarily delivered through online channels. Our results underscore the necessity for adaptable, audience-tailored interventions to reduce consumer demand for illegal wildlife products. The mixed-methods approach, combining quantitative and qualitative data, provided a comprehensive understanding of the target behavior and can inform the development of effective intervention strategies.

Uso de las percepciones del consumidor para guiar las intervenciones de cambio conductual enfocadas en el mercado ilegal de tortugas en China Resumen La caza furtiva y la sobreexplotación por el comercio internacional de mascotas son algunas de las mayores amenazas para las tortugas de agua dulce del sudeste asiático. Es esencial conocer más sobre los consumidores en China para llenar los vacíos en el conocimiento sobre la escala y la estructura del comercio ilegal y desarrollar intervenciones pertinentes y dirigidas al público que puedan reducir la demanda de tortugas como mascotas ilegales. Aplicamos métodos mixtos para conocer en detalle la percepción del consumidor del comercio ilegal de tortugas como mascotas en China. Realizamos 30 entrevistas a actores clave y encuestas en línea (n=2456) a cuidadores de tortugas a través de foros comunitarios. A partir de ellas, identificamos tres grupos principales de consumidores en función de su experiencia previa en la cría de tortugas, su exposición a las especies y su potencial para futuras compras. Realizamos un análisis cualitativo temático de conceptos relacionados con el modelo de capacidad, oportunidad, motivación y comportamiento (COM­B) para determinar los factores que influyen en el comercio ilegal de tortugas e identificar las barreras para las compras ilegales. En concreto, identificamos las capacidades, oportunidades y motivaciones de los compradores en el contexto de la legalidad, el riesgo de aplicación de la ley, la cría en cautiverio y el impacto sobre la población silvestre. Elaboramos mapas de viaje del consumidor (representaciones visuales de las experiencias del cliente a lo largo de su compra) para los principales grupos de consumidores. Estos mapas ilustran los comportamientos y procesos secuenciales que llevan a cabo los consumidores cuando compran tortugas, desde la exposición inicial hasta la adquisición, el mantenimiento y la asignación de un nuevo hogar. Entre los factores clave que influyen en las compras ilegales se encuentran la conveniencia de los canales de compra, los conocimientos y motivaciones erróneos para mantener mascotas y la debilidad de la aplicación de la ley. Las intervenciones eficaces incluyeron mensajes centrados en cambiar los conocimientos y las creencias, aumentar la percepción del riesgo legal y hacer hincapié en la aplicación rigurosa de la ley, principalmente a través de canales virtuales. Nuestros resultados destacan la necesidad de intervenciones adaptables y adaptadas al público para reducir la demanda de productos ilegales de fauna silvestre por parte de los consumidores. El enfoque de métodos mixtos, que combina datos cuantitativos y cualitativos, proporcionó una comprensión exhaustiva del comportamiento objetivo y puede servir de base para el desarrollo de estrategias de intervención eficaces.

Global invasion and biosecurity risk from the online trade in ornamental crayfish.

Trade in undomesticated ornamental animals has rapidly expanded beyond brick-and-mortar retail stores to now include growing numbers of internet marketplaces. The growing volume, diversity, and origins of invasive non-native species in trade challenge already weak national biosecurity policies. Despite widespread focus on vertebrates, many knowledge gaps exist regarding the online global trade of ornamental invertebrates. We conducted the first global assessment of the online trade in and associated invasion risk of freshwater crayfishes, which are increasingly popular aquarium animals. We systematically examined e-commerce marketplaces in multiple languages, scrapping information that included species identity, price, quantity, and shipping designation from each crayfish listing. Next, we combined geographic pathways of shipping associated with online trade (introduction risk) and environmental suitability modeling (establishment risk) to estimate global risk of non-native crayfish invasion risk. We identified hundreds of online marketplaces and thousands of sale listings in 33 countries (5 continents) involving 60 species and representing a selling value of ∼US$1.5 million. Invasion risk of non-native crayfish in trade was widespread, with geographic hotspots coinciding with both elevated opportunities for introduction (greater shipping offerings) and establishment. Precise characterization of the online species trade is fundamental to support new and reformed biosecurity policies, build industry partnerships, and design educational campaigns to prevent species invasions through trade. We found that the taxonomy, geography, and economics of the global online ornamental crayfish trade are vast and require greater attention.

Invasión global y riesgos de bioseguridad a partir del mercado virtual de langostinos de ornato Resumen El comercio de animales ornamentales silvestres se ha expandido rápidamente más allá de las tiendas minoristas para incluir un número creciente de tiendas en línea. El creciente volumen, diversidad y origen de las especies no nativas invasoras en el comercio suponen un reto para las ya débiles políticas nacionales de bioseguridad. A pesar de la gran atención que se presta a los vertebrados, existen muchos vacíos en el conocimiento sobre el comercio mundial en línea de invertebrados ornamentales. Realizamos la primera evaluación mundial del comercio virtual de langostinos de agua dulce, animales de ornato cada vez más populares, y el riesgo de invasión asociado. Analizamos sistemáticamente los mercados de comercio electrónico en varios idiomas, recopilando información que incluía la identidad de las especies, el precio, la cantidad y la designación de envío de cada listado de langostinos. Después combinamos las vías geográficas de envío asociadas al comercio en línea (riesgo de introducción) y los modelos de idoneidad ambiental (riesgo de establecimiento) para estimar el riesgo global de invasión de los langostinos no nativos. Identificamos cientos de mercados en línea y miles de listados de venta en 33 países (cinco continentes) que afectaban a 60 especies y representaban un valor de venta de ∼1.5 millones de dólares estadunidenses. El riesgo de invasión de langostinos no nativos en el comercio fue extenso, con puntos geográficos críticos que coincidían con elevadas oportunidades de introducción (mayores ofertas de envío) y de establecimiento. La caracterización precisa del comercio virtual de especies es fundamental para respaldar políticas de bioseguridad nuevas y reformadas, establecer alianzas con la industria y diseñar campañas educativas para prevenir las invasiones de especies a través del comercio. Descubrimos que la taxonomía, la geografía y la economía del comercio mundial en línea de langostinos de ornato es amplio y requiere mayor atención.

Taxonomic and ecological significance of synnema-like structures/acanthophyses produced by Physisporinus (Meripilaceae, Polyporales) species.

Physisporinus, a genus in Polyporales, Basidiomycota, is a versatile fungus that lives as a wood decomposer, a potential pathogen of standing trees, and an orchid mycobiont. We previously reported that some Physisporinus species inhabiting wet wood in aquatic environments such as streams and waterfalls form synnema-like structures (SSs) bearing acanthophyses at their apices, and that they produce acanthophyses on vegetative hyphae when cultured on agar media. In this study, we investigated the acanthophysis-forming ability in Physisporinus and allied genera, and experimentally demonstrated the function of SSs. Phylogenetic analyses and observations of Meripilus, Physisporinus and Rigidoporus cultures showed that all of the strains forming acanthophyses belonged to Physisporinus, whereas strains of Meripilus and Rigidoporus did not produce acanthophyses. These findings suggest that SS/acanthophysis formation is a useful taxonomic character for members of Physisporinus. When Physisporinus strains were cultured under oxygen (O2) concentrations of 5, 10, 20 and 40%, most of those cultured under 20% O2 formed the most acanthophyses. According to these experimental data, the SSs/acanthophyses in Physisporinus were considered to have a respiratory function. Physisporinus probably acquired the SS/acanthophysis-forming ability to adapt to moist and/or aquatic habitats and to decay wet wood in which the O2 concentration is often low.

Faecal source apportionment using molecular methods: A proof of concept using the FEAST algorithm.

Faecal contamination of freshwater and marine environments represents a significant risk for public health, recreational activity and food safety, and tools for evaluating complex multi-source contamination remain largely in the development phase. We evaluated the efficacy of the Fast Expectation Maximization (FEAST) microbial source tracking (MST) algorithm to apportion sources of faecal contamination among four mammalian species of interest in coastal waters in New Zealand. Using 16S ribosomal DNA metabarcoding of faecal samples from cows, fur seals, and sheep, as well as human wastewater, we aimed to differentiate and quantify the contribution of these sources in mixed faecal samples. Multivariate analysis confirmed significant differences in the microbial communities associated with each mammalian source, with specific bacterial classes indicative of different sources. The FEAST algorithm was tested using mixed DNA and mixed faecal samples, and we found that the algorithm correctly assigned the dominant source from all samples, but underestimated the dominant source's proportional contribution. This underestimation suggests the need for further refinement and validation to ensure accurate source apportionment in environmental samples where the faecal signal is likely to be a minor component. Despite these limitations, the findings of our study, in combination with the evidence from others who have tested the FEAST algorithm in environmental settings, indicates that it represents an advance on existing tools for microbial source tracking and may become a useful addition to the toolbox for environmental management.

Hydrographic shifts in coastal waters reflect climate-driven changes in hydrological regimes across Northwestern Patagonia.

Climate-driven changes in freshwater inputs have been shown to affect the structure and function of coastal ecosystems. We evaluated changes in the influence of river runoff on coastal systems of Northwestern Patagonia (NWP) over recent decades (1993-2021) by combined analysis of long-term streamflow time series, hydrological simulation, satellite-derived and reanalysis data on sea surface conditions (temperature, turbidity, and salinity). Significant decreases in minimum streamflow across a zone spanning six major river basins were evident at weekly, monthly, and seasonal scales. These changes have been most pronounced in mixed-regime northern basins (e.g., Puelo River) but appear to be progressing southward to rivers characterised by a nival regime. In the adjacent two-layer inner sea, reduced freshwater input corresponds with a shallower halocline and increased surface temperatures across northern Patagonia. Our results underscore the rapidly evolving influence of rivers on adjacent estuarine and coastal waters in NWP. We highlight the need for cross-ecosystem observation, forecasting, mitigation and adaptation strategies in a changing climate, together with corresponding adaptive basin management of systems that supply runoff to the coastal marine waters.

Assessing ecological responses of exposure to the pyrethroid insecticide lambda-cyhalothrin in sub-tropical freshwater ecosystems.

Pyrethroid insecticides are widely detected in aquatic ecosystems due to their extensive use in agriculture and horticulture, which could pose a potential risk to aquatic non-target organisms. While previous ecotoxicological studies have been conducted mainly with standard tests and local species under temperate conditions, scarce information is available on the effects of pyrethroid insecticides on communities and ecosystems under (sub-)tropical conditions. A single application of lambda-cyhalothrin at concentrations of 0, 9, 30, and 100 ng/L was evaluated in outdoor mesocosms under sub-tropical conditions. Lambda-cyhalothrin was found to dissipate rapidly in the water column, with only 11 % and 7 % of the remaining dose measured at 1 and 3 days after application, respectively. Lambda-cyhalothrin concentrations disappeared considerably faster from the water compartment compared to temperate conditions. Consistent decreases in abundance were observed for Lecane lunaris at the medium and higher treatments (NOEC = 9 ng/L) and at the highest treatment (NOEC = 30 ng/L) for Keratella tropica. On the contrary, two taxa belonging to Cladocera (i.e., Ceriodaphnia sp. and Diaphanosoma sp.) showed the most prominent increase in abundance related to the lambda-cyhalothrin treatments. At the community level, a consistent no observed effect concentrations (NOECs) of 9 ng/L could be calculated for the zooplankton community. A marginal significant overall treatment related effect was observed for the macroinvertebrate community. The results of species sensitivity distribution (SSD) analysis based on results of acute toxicity experiments conducted alongside the mesocosm experiment and obtained from the literature indicated that macroinvertebrates from temperate regions may be generally more sensitive than their counterparts in (sub-)tropical regions. Overall, these findings suggest that environmentally relevant concentrations of the pyrethroid insecticide lambda-cyhalothrin may lead to different ecological outcomes in freshwater ecosystems in the (sub-)tropics relative to temperate regions.

Field and Laboratory Evidence That Chlorpyrifos Exposure Reduced the Population Density of a Freshwater Snail by Increasing Juvenile Mortality.

Pesticides have been frequently detected in global freshwater ecosystems, but attempts to document changes in population dynamics of organisms upon exposure to pesticides, establish a causal relationship between exposure and population effects, and identify the key toxic events within individuals under natural field conditions remain rare. Here, we used a field survey, a reciprocal cross-transplant experiment, and a laboratory toxicity experiment to build a compelling case that exposure to the insecticide chlorpyrifos was responsible for differences in snail (Bellamya aeruginosa) densities in eastern (ELL) and western basins of Liangzi Lake in China. Our field survey and reciprocal cross-transplant experiment revealed significant differences in snail densities, juvenile percentage, survival, and relative telomere length (RTL) in the two basins. The insecticide chlorpyrifos detected in snail tissues was negatively correlated with snail densities, the percentage of juvenile snails, and RTL and had an extremely high risk quotient in ELL. In the laboratory experiment, tissue concentrations of chlorpyrifos detected in ELL were associated with reduced RTL and increased juvenile mortality in B. aeruginosa. These results support the hypothesis that chlorpyrifos exposure in ELL reduced the density of snails by reducing juvenile survival and, consequently, recruitment to the adult population.

Performance analysis of floating bifacial stand-alone photovoltaic module in tropical freshwater systems of Southern Asia: an experimental study.

The optimization of floating bifacial solar panels (FBS PV) in tropical freshwater systems is explored by employing response surface methodology (RSM) and central composite design (CCD). Previous studies have yet to explore the long-term durability, environmental impact, economic viability, and performance of FBS PV systems under various climatic conditions. This study addresses this gap by focusing on panel height, water depth, and tilt angle to improve performance. The quadratic model reveals significant non-linear relationships impacting FBS PV power generation with freshwater cooling. Our models demonstrate high explanatory power, with R-squared values of 0.9831 for output power and 0.9900 for Bi-Facial gain. Experimental validation using conventional white surface (CWS) and proposed freshwater surface (PFS) indicates notable improvements in power generation, achieving a 4.34 to 4.86% gain in bifacial efficiency across various irradiation levels. Under 950 W/m2 irradiation, freshwater cooling achieves a 3.19% higher bifacial gain compared to CWS cooling. Panel temperature analysis shows consistent reductions with freshwater cooling, ranging from 1.43 to 2.72 °C, enhancing overall efficiency and longevity. This research highlights the potential of freshwater cooling in optimizing bifacial solar systems, offering actionable insights for sustainable energy solutions in tropical regions.