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[Objective]To understand the structural characteristics of the plankton community and its key environmental impact factors in the rivers of Muli mining area, and to provide data support and reference basis for the management and protection of water resources in the mining area. [Method]Collection and analysis of water and plankton in the rivers (Duosuo and Mori) that surround the opencast mine in the town of Muli. [Result]6 Phylum (21 species) of phytoplankton and 2 Phylum (15 species) of zooplankton were collected in the Dosuo River and 6 Phylum (19 species) of phytoplankton and 2 Phylum (9 species) of zooplankton were collected in the Mori River. In both rivers diatoms, green algae and protozoa were the dominant species, and the density and biomass of plankton were quantitatively higher upstream and lower downstream. The Shannon-Wiener, Margalef and Pielou indices for phytoplankton and zooplankton in Duosuo River are 1. 64 and 0. 58, 0. 86 and 0. 33, 0. 69 and 0. 42, respectively;the Shannon-Wiener, Margalef and Pielou indices for phytoplankton and zooplankton in Mori River are 1. 86 and 0. 21, 0. 87 and 0. 24, 0. 79 and 0. 36. Water temperature, pH, and nitrogen nutrients were identified as the main environmental factors affecting the structure of the planktonic communities in the Dosso and Mojito Rivers by redundancy analysis (RDA) and correlation analysis. [Conclusion]The ecological protection of water in the Muli mining area should focus on nutrient pollution and strengthen the control of non-point source pollution caused by overgrazing. [ABSTRACT FROM AUTHOR]

Aquatic macrophytes serve as shelter and a direct source of food for invertebrates, in addition to indirectly providing items such as algae, detritus, and microorganisms. Thus, aquatic macrophytes act as habitat structuring elements, requiring a distinction between habitat complexity (physical formations such as fractal dimensions, density and biomass) and habitat heterogeneity (diversity of these structures). Here we explore the effects of habitat complexity and habitat heterogeneity on the invertebrate community.We collected macrophytes and invertebrates from 28 sampling sites along a 13.7‐km stretch of the Baía River in Brazil, and examined specific groups (insects, microcrustaceans, and other invertebrates). Environmental variables in the sites were also measured. We aimed to explore the effects of habitat complexity (measured by macrophyte biomass) and habitat heterogeneity (evaluated through macrophyte functional diversity) on the richness and abundance of invertebrates.We found that overall invertebrate richness was positively influenced solely by habitat heterogeneity. For invertebrate abundance, intermediate habitat complexity had more invertebrates, while habitat heterogeneity had a positive impact. Environmental variables influenced only the abundance. For specific groups, insect richness was positively influenced by habitat heterogeneity, while insect abundance decreased with high complexity and increased with high heterogeneity. Microcrustacean abundance was positively influenced by habitat complexity. Richness and abundance of other invertebrates was positively influenced by habitat heterogeneity.Invertebrates prefer macrophyte stands with intermediate complexity and high heterogeneity. Abundance is linked to structural complexity and heterogeneity, while species richness is more strongly associated with heterogeneity. Furthermore, the impact of these factors varies among invertebrate groups.These findings emphasise the importance of integrating a broad range of metrics, such as macrophyte biomass and functional diversity, to gain a thorough understanding of invertebrate community dynamics in future studies. Additionally, our study demonstrates that preserving macrophyte stands with high heterogeneity significantly enhances the diversity of associated invertebrate species. [ABSTRACT FROM AUTHOR]

Flavor, especially odor, is one of the most concerning food qualities for producers and consumers. The odor of E. sinensis is a vital quality indicator and highly variable in species, diets, regions and harvest seasons. These differences could diminish consumer acceptance and reduce the economic returns to the farmer. Until now, 168 volatile compounds have been identified in E. sinensis, of which 42 are shared to five edible parts, and the hepatopancreas has 22 specific compounds. The 30 aroma-active compounds may interact to form odor profiles. Volatile compounds are mainly derived from Phosphatidylethanolamine (PE) and free fatty acids (FFA) by a series of biochemical reactions such as thermal degradation, secondary degradation, molecular rearrangement, and Maillard reaction. The odor of crab has a close relationship with agriculture. Once harvested, the crab also produces odors during processing and storage, which could be controlled by consumers. This work provides information that could support the development of innovative aquaculture strategies to satisfy the needs of the consumer market. [ABSTRACT FROM AUTHOR]

Fish skin acts as the first immune barrier against pathogens from external environments. Recently, fish skin immunity research has gradually become a hot topic in aquaculture disease control. Interestingly, the skin can do air-breathing in some bimodal respiration fish. However, there is no comprehensive understanding of these two functions. In this study, the skin regeneration of loach (Paramisgurnus dabryanus) was investigated through morphological and histological observations. Then, original skins (OS) and the regenerated skins (RS) when their capillaries were the most abundant during healing, were collected for transcriptomic analysis. 285,899,386 clean reads with a total length of 42.34 Gb were obtained. A total of 1282 differentially expressed genes (DEGs) were detected, including 1030 DEGs up-regulated and 252 DEGs down-regulated in the comparison of RS vs. OS. Fc gamma R-mediated phagocytosis (containing gelsolin (Gsn)), chemokine signaling pathway (containing C--C motif chemokine ligand 28 (Ccl28)), and B cell receptor signaling pathway (containing CD80 molecule (Cd81)) were closely related to skin immune response of the loach. PI3K-Akt signaling pathway [containing fibronectin 1 (Fn1) and lysyl oxidase-like 2b (Loxl2b)], TGF-beta signaling pathway [containing thrombospondin 1 (Thbs1)], ECM-receptor interaction [containing integrin alpha 7 (Itga7), Itgb8, Itgb10 and Itgb5], and dilated cardiomyopathy [containing laminin subunit alpha1 (Lama1)] were closely associated with skin air-breathing of the loach. This study is conducive to explore the molecular mechanisms of skin immune response during its regeneration and air-breathing of bimodal respiration fish. This study will benefit for the aquaculture of P. dabryanus and its related species. [ABSTRACT FROM AUTHOR]

Marine aquaculture is currently the fastest-growing seafood industry globally, offering a potential solution to overfishing problems, while enhancing food security and income generation. South Sulawesi, a province in Indonesia, is rich in aquaculture resources, one of which is lobster. The two commonly used aquaculture systems are the floating-net cage (KJA) and fixed-net cage (KJD). The growing market demand and rising lobster prices pose a threat to resource sustainability due to overexploitation. This is issue have to be addressed to achieve sustainable fishery development. Sustainability is the primary focus on global fishery development. According to the United Nations, sustainable development encompasses three dimensions: the economy, social and ecology. Therefore, sustainable fishery, particularly aquaculture, relies on obtaining significant benefits while minimizing environmental damage. Hence, this study aimed to analyze the sustainability level of the pearl lobster (Panulirus ornatus) aquaculture in South Sulawesi, based on the provided background information. The study included a sample of 62 farmers. The sample selection involved the use of the stratified sampling method, with 51 farmers from (KJA) and 11 farmers from (KJD). The sustainability analysis, conducted through assessment of based farmers' perceptions, served as the analytical method. The findings revealed that pearl lobster (Panulirus ornatus) aquaculture has a medium level of sustainability. Employing Integrated Multi Tropic Aquaculture (IMTA) and Regional Integrated Multi Tropic Aquaculture (RIMTA) techniques is a recommended sustainability level. [ABSTRACT FROM AUTHOR]

The Yangtze River is the mother river of China. To promote the aquatic ecosystem protection of the great river, the Project of Yangtze Fisheries Resources and Environment Investigation (2017-2021) supported by the Ministry of Agriculture and Rural Affairs, P. R. China carried out by 24 institutes and universities that located in the Yangtze River basin surveys the status of (1) fish species composition and spatial distribution, (2) current fish abundance, (3) endangered fishes, (4) Yangtze finless porpoise, (5) aquatic eco-environments, (6) water-level fluctuation areas, (7) capture fisheries and recreational fisheries of the Yangtze River mainstream and 10 of its main tributaries, including Yalong River, Heng River, Min River (including Dadu River), Chishui River, Tuo River, Jialing River, Wu River, Han River, Dongting Lake and Poyang Lake. The results showed that there were 443 fish species (belonging to 163 genus, 37 families, and 18 orders) before 2017, but only 323 fish species (including 15 new recorded exotic species) were recorded in the project of 2017-2021. Among them, Cyprinus carpio, Carassius auratus, Hypophthalmichthys molitrix, Pelteobagrus fulvidraco, Coilia brachygnathus, Silurus asotus, Saurogobio dabryi, Ctenopharyngodon idellus, Pelteobagrus nitidus, Hemiculter leucisculus, Siniperca chuatsi, Coreius heterodon, Culter alburnus, Parabramis pekinensis, and Aristichthys nobilis were the dominant species across the whole Yangtze River system. It is estimated that there were 886 million individuals weighing 124.8 million kg, merely equivalent to 27.3% of the resources in 1950s, 30.9% of the resources in 1960s, or 58.7% of the resources in 1980s. In the new list of protected fishes that recorded in the Yangtze River system, only 15 of 29 were collected in this project of 2017-2021. Psephurus gladius has been affirmed to be Extinct by International Union for Conservation of Nature (IUCN). The wild individuals of Tenualosa reevesii and Luciobrama macrocephalus have disappeared for many years and maybe have been extinct already. Acipenser dabryanus has been affirmed to be Extinct in the Wild by IUCN. The natural propagations of A. sinensis, Myxocyprinus asiaticus and Trachidermus fasciatus have been interrupted for many years. The populations of Yangtze finless porpoise in the Yangtze River mainstream, Dongting Lake and Poyang Lake have steadily rising sizes and expanding distributions in 2017-2021. Parts of them migrate from one region to another with the seasons, which would result in the fluctuation of Yangtze finless porpoise population within some regions. The conventional indicators of water quality in the Yangtze River system were good and conformed to the water quality criteria of fishery in 2017-2021. In the last 40 years, the maximum surface water area in the Yangtze River basin extended to approximately 63,360 km2, the minimum surface water area covered approximately 26,396 km2, and the seasonal water-level fluctuation areas occupied approximately 36,964 km2. Compared with 1984-2000 period, the 2001-2020 period witnessed an overall decreasing trend in the frequency of surface water occurrence within about 25,869 km2 of aquatic areas. From 1984 to 2000 period to 2001-2020 period, permanent surface water has decreased by nearly 8,750 km2. In 2017, the fishermen were mainly 40-60 years old and their educational levels were mainly lower than junior high school. In 2017, most anglers were older than 40 and used hand rod and/or sea rod. Their average catch of each time was mainly less than 1 kg. Results suggested that the fishing ban in key waters of the Yangtze River basin is not only an ecological project of aquatic ecosystem conservation, but also a livelihood project for the fisherman to embrace industrial transformation and improve their living conditions. After the implementation of the fishing ban, the fisheries resources would gradually recover, and the Yangtze finless porpoise population size would also see a steady increase. However, the endangered species would remain threatened for a long time. The degraded waterbodies and water-level fluctuation areas would be the key restrictive factors for future aquatic ecosystem recovery in the Yangtze River basin. Since this survey was carried out before the fishing ban, the current results could provide a baseline for future evaluation of the effect of the Yangtze River fishing ban. [ABSTRACT FROM AUTHOR]

The worldwide pesticide marketplace was approximate 85 billion dollars in 2019, growing at a geometric progression rate of 4.2% from 2015, and by 2023 it is projected to grow at a rate of 11.5% to approximately 130.7 billion dollars. Pesticides' uniqueness is defined by the distinctiveness of their chemistry and their relationship with the environment. Pesticide mobility and bioavailability in water bodies are determined by their desorption and absorption processes from soil particles. Waterbodies are severely affected with the build-up of these poisonous impurities with its imbalance in pH and accumulation of heavy metals, which adversely distress the aquatic ecology in the waterbodies. Pesticides are not only damaging to the ecology of the waterbodies; it is also consequentially harmful to humans. It causes gastrointestinal disorders, cardiac and respiratory issues, and even affects the biotic molecules and organs subsequently leading to acute and/or chronic illnesses. This article reviews 200 scientific literatures for existence of pesticides in drinking water and the various remediation technologies available for the treatment to render the water potable. Upon review of more than 20 technologies, suggestions have been made for the best probable technologies for water with presence of pesticide. [ABSTRACT FROM AUTHOR]

Understanding how the causal feedback between phytoplankton and environmental drivers controlling the chlorophyll a (Chl a, as a proxy of phytoplankton biomass)–nutrient relationships are modulated under different ecosystem conditions is a major challenge in aquatic ecology. Using an empirical dynamic model (convergent cross mapping) on a 20‐yr dataset on 20 Danish lakes, we quantified hypothesized causal feedback networks for each lake and related them to lake system properties (e.g., mean water depth, nutrient concentrations and extent of reduction, climate warming) vs. the Chl a–nutrient relationship (estimated from generalized least square models). The results showed prevalent causal feedback across the studied lakes, which demonstrated clear patterns for the tested ecosystem variations. Weaker causal feedbacks were found in deeper lakes and lakes with larger warming trends, while stronger causal feedbacks appeared in lakes experiencing greater reductions of TP (total phosphorus) and TN (total nitrogen). Moreover, these causal feedbacks showed a strong and positive coupled pattern. Most of the causal feedbacks worked as enhancement loops, which promote the sensitivity of phytoplankton to TP, not least in shallow lakes with a high TP reduction, and as regulatory loops, which force a shift in the Chl a–TN relationship from a more negative slope in lakes experiencing a high nutrient reduction and weak warming to a positive slope in lakes with low nutrient reduction and stronger warming. Our findings suggest a mechanistic explanation of how internal feedbacks regulate the Chl a–nutrient relationships across a broad gradient of nutrient reductions, climate warming, and lake morphologies. [ABSTRACT FROM AUTHOR]

Skin microbiomes provide vital functions, yet knowledge about the drivers and processes structuring their species assemblages is limited—especially for non‐model organisms. In this study, fish skin microbiome was assessed by high throughput sequencing of amplicon sequence variants from metabarcoding of V3–V4 regions in the 16S rRNA gene on fish hosts subjected to the following experimental manipulations: (i) translocation between fresh and brackish water habitats to investigate the role of environment; (ii) treatment with an antibacterial disinfectant to reboot the microbiome and investigate community assembly and priority effects; and (iii) maintained alone or in pairs to study the role of social environment and inter‐host dispersal of microbes. The results revealed that fish skin microbiomes harbour a highly dynamic microbial composition that was distinct from bacterioplankton communities in the ambient water. Microbiome composition first diverged as an effect of translocation to either the brackish or freshwater habitat. When the freshwater individuals were translocated back to brackish water, their microbiome composition converged towards the fish microbiomes in the brackish habitat. In summary, external environmental conditions and individual‐specific factors jointly determined the community composition dynamics, whereas inter‐host dispersal had negligible effects. The dynamics of the microbiome composition was seemingly non‐affected by reboot treatment, pointing towards high resilience to disturbance. The results emphasised the role of inter‐individual variability for the unexplained variation found in many host‐microbiome systems, although the mechanistic underpinnings remain to be identified. [ABSTRACT FROM AUTHOR]

The platypus (Ornithorhynchus anatinus) is a semi-aquatic monotreme that occupies a high trophic position in the freshwater ecosystems of eastern mainland Australia and Tasmania. Platypuses are continuously exposed to anthropogenic contaminants including perfluorooctane sulfonate (PFOS). This study examined PFOS concentrations in the livers of deceased platypuses (eight wild; one captive) that were opportunistically collected across NSW over a two- and a half-year period. There was a large variation in PFOS concentrations, ranging from < 1 µg/kg to 1200 µg/kg. This study presents the first report of PFOS contamination in platypuses, revealing their PFOS levels are broadly similar to those found in river otters (Lutra canadensis) and lower than those in American mink (Mustela vison), both which occupy similar ecological niches in freshwater systems. This study raises concerns about the impact of PFOS on platypus health. [ABSTRACT FROM AUTHOR]

Mangroves are implemented as nature‐based solutions (NbS) for coastal protection, climate change mitigation (carbon sequestration) and other services. They play a core role in providing benefits for biodiversity, livelihoods and human well‐being. Ecological research has informed the use of mangroves as NbS, but failure of NbS projects has often been due to misconceptions about mangrove ecology and the limited use of the wide range of ecological knowledge available. Enhanced knowledge of the spatial and temporal variation in ecological processes, and differentiation among mangrove tree species and assemblages (including fauna and microbial communities) in the provision of ecosystem functions and services, will support successful use of mangroves as NbS. Knowledge of mangrove responses to the interacting pressures of climate change and human uses of the coastal zone will support resilient NbS projects. Synthesis. The success of mangroves as NbS can be improved with increased incorporation of knowledge of the ecology of mangrove plants, animals and microbes and by sharing and co‐producing knowledge within mangrove societies. [ABSTRACT FROM AUTHOR]

The development of hydroelectric projects has adversely affected the reproductive activities of downstream fish species. To facilitate the natural reproduction of fish and restore spawning grounds post‐dam construction, it is imperative to explore the ecological factors crucial for their reproduction. Currently, various research methods with different advantages and limitations are employed for this purpose. Using identified spawning locations and periods as clues, we quantitatively investigate the flow velocity, water depth, water temperature, and riverbed substrate required for spawning. The results are validated using habitat simulation methods, aiming to establish a more scientific approach to explore ecological factors affecting fish reproduction. This study provides a more scientific, systematic, and detailed report on the ecological factors required for the spawning of Gymnocypris eckloni: flow velocity ranging from 0.19 to 0.97 m/s, water depth from 0.28 to 1.12 m, water temperature between 11.4 and 15.2°C, and predominantly gravel substrate. The reliability of the results was verified in another spawning ground, with good verification results. This research provides crucial data for the bio‐mimetic reproductive technology of Gymnocypris eckloni and the restoration of spawning grounds for natural fish reproduction post‐dam construction. It addresses the lack of suitable ecological factor data for protective fish species in the upper reaches of the Yellow River. The method exhibits strong scientific, accurate, and implementable characteristics. [ABSTRACT FROM AUTHOR]

Carrion ecology, i.e. the decomposition and recycling of dead animals, has traditionally been neglected as a key process in ecosystem functioning. Similarly, despite the large threats that inland aquatic ecosystems (hereafter, aquatic ecosystems) face, the scientific literature is still largely biased towards terrestrial ecosystems. However, there has been an increasing number of studies on carrion ecology in aquatic ecosystems in the last two decades, highlighting their key role in nutrient recirculation and disease control. Thus, a global assessment of the ecological role of scavengers and carrion in aquatic ecosystems is timely. Here, we systematically reviewed scientific articles on carrion ecology in aquatic ecosystems to describe current knowledge, identify research gaps, and promote future studies that will deepen our understanding in this field. We found 206 relevant studies, which were highly biased towards North America, especially in lotic ecosystems, covering short time periods, and overlooking seasonality, a crucial factor in scavenging dynamics. Despite the low number of studies on scavenger assemblages, we recorded 55 orders of invertebrates from 179 families, with Diptera and Coleoptera being the most frequent orders. For vertebrates, we recorded 114 species from 40 families, with birds and mammals being the most common. Our results emphasise the significance of scavengers in stabilising food webs and facilitating nutrient cycling within aquatic ecosystems. Studies were strongly biased towards the assessment of the ecosystem effects of carrion, particularly of salmon carcasses in North America. The second most common research topic was the foraging ecology of vertebrates, which was mostly evaluated through sporadic observations of carrion in the diet. Articles assessing scavenger assemblages were scarce, and only a limited number of these studies evaluated carrion consumption patterns, which serve as a proxy for the role of scavengers in the ecosystem. The ecological functions performed by carrion and scavengers in aquatic ecosystems were diverse. The main ecological functions were carrion as food source and the role of scavengers in nutrient cycling, which appeared in 52.4% (N = 108) and 46.1% (N = 95) of publications, respectively. Ecosystem threats associated with carrion ecology were also identified, the most common being water eutrophication and carrion as source of pathogens (2.4%; N = 5 each). Regarding the effects of carrion on ecosystems, we found studies spanning all ecosystem components (N = 85), from soil or the water column to terrestrial vertebrates, with a particular focus on aquatic invertebrates and fish. Most of these articles found positive effects of carrion on ecosystems (e.g. higher species richness, abundance or fitness; 84.7%; N = 72), while a minority found negative effects, changes in community composition, or even no effects. Enhancing our understanding of scavengers and carrion in aquatic ecosystems is crucial to assessing their current and future roles amidst global change, mainly for water–land nutrient transport, due to changes in the amount and speed of nutrient movement, and for disease control and impact mitigation, due to the predicted increase in occurrence and magnitude of mortality events in aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Hydra is known for its natural occurrence, anatomical simplicity, intricate physiology, regenerative capacity, and ease of maintenance and manipulation in laboratory environments. It has proven to be a valuable model organism in various disciplines. Its applications range from developmental biology, stem cell research, animal physiology to environmental toxicology including ecotoxicology. The sensitivity of Hydra to a variety of environmental stressors and chemical agents such as metals, nanomaterials, and toxic organic compounds provides valuable insights into physiological mechanisms affected by environmental stressors and pollution, and Hydra can be of great use in environmental monitoring. Furthermore, since green Hydra lives in a symbiotic relationship with unicellular photoautotrophic algae, it is a suitable model organism for symbiosis research. Recently, it has become a popular model in holobiont research. The adaptability and importance of Hydra also extends to aquatic science and aquatic ecology, particularly in the context of monitoring and water pollution. Since the 1980s, Hydra has been increasingly used in various fields of research and has established itself as an important versatile model organism in numerous scientific studies. Hydra also represents an outstanding model in the fields of education and STEM. Hydra continues to be an important model in the 21st century, contributing significantly to our understanding of the biology of water and advancing freshwater research, and possibly finding its way to regenerative medicine and tumor pathobiology research. [ABSTRACT FROM AUTHOR]

Despite making up one of the most ecologically diverse groups of living birds, comprising soaring, diving and giant flightless taxa, the evolutionary relationships and ecological evolution of Anseriformes (waterfowl) remain unresolved. Although Anseriformes have a comparatively rich, global Cretaceous and Paleogene fossil record, morphological datasets for this group that include extinct taxa report conflicting relationships for all known extinct taxa. Correct placement of extinct taxa is necessary to understand whether ancestral anseriform feeding ecology was more terrestrial or one of a set of diverse aquatic ecologies and to better understand avian evolution around the K-T boundary. Here, we present a new morphological dataset for Anseriformes that includes more extant and extinct taxa than any previous anseriform-focused dataset and describe a new anseriform species from the early Eocene Green River Formation of North America. The new taxon has a mediolaterally narrow bill which is rarely found in previously described anseriform fossils. The matrix created to assess the placement of this taxon comprises 41 taxa and 719 discrete morphological characters describing skeletal morphology, musculature, syringeal morphology, ecology, and behavior. We additionally combine the morphological dataset with published sequences using Bayesian methods and perform ancestral state reconstruction for select morphological, ecological and behavioral characters. We recover the new Eocene taxon as the sister taxon to (Anseranatidae+Anatidae) across all analyses, and find that the new taxon represents a novel ecology within known Anseriformes and the Green River taxa. Results provide insight into avian evolution during and following the K-Pg mass extinction and indicate that Anseriformes were likely ancestrally aquatic herbivores with rhamphothecal lamellae.. [ABSTRACT FROM AUTHOR]

Andean glaciers are losing mass rapidly but a centennial‐scale context to those rates is lacking. Here we show the extent of >5,500 glaciers during the Little Ice Age chronozone (LIA; c. 1,400 to c. 1,850) and compute an overall area change of −25% from then to year 2000 at an average rate of −36.5 km2 yr−1 or −0.11% yr−1. Glaciers in the Tropical Andes (Peru, Bolivia) have depleted the most; median −56% of LIA area, and the fastest; median −0.16% yr−1. Up to 10 × acceleration in glacier area loss has occurred in Tropical mountain sub‐regions comparing LIA to 2,000 rates to post‐2000 rates. Regional climate controls inter‐regional variability, whereas local factors affect intra‐region glacier response time. Analyzing glacier area change by river basins and by protected areas leads us to suggest that conservation and environmental management strategies should be re‐visited as proglacial areas expand. Plain Language Summary: Andean glaciers are melting fast but how that rate compares in a longer‐term context is unknown. In this study we mapped the extent of >5,500 glaciers during the Little Ice Age, which was the last major glacial advance culminating about c. 150 years ago. We analyzed the change in glacier size and computed overall area change of −25% from the LIA to year 2000 at a rate of −36.5 km2 per year or −0.11% per year. Glaciers within Peru and Bolivia have shrunk the most by median −56% of LIA area, and the fastest by median −0.16% per year. We discuss that these glaciers are depleting and retreating due to climate change but that response is compounded by glacier size, shape and terminus environment effects. As glaciers melt they reveal proglacial landscapes that tend to be highly unstable, impacting water resources, natural hazards and terrestrial and aquatic ecology. Key Points: Little Ice Age (LIA) chronozone extent of >5,500 glaciers mapped from geomorphological evidenceOverall glacier area change of −25% to year 2000 at a rate of −36.5 km2 yr−1 or −0.11% yr−1Up to 10 × acceleration in glacier area loss for Tropical sub‐regions comparing LIA to 2,000 with post‐2000 rates [ABSTRACT FROM AUTHOR]

Aquatic birds are notable among the global avifauna for living in environments exposed to large amounts of light. Despite growing evidence that visual adaptations to light underly the ecology and evolution of the avian tree of life, no comprehensive comparative analysis of visual acuity as approximated by eyes size exists for the global aquatic avifauna. Here, I use Stanley Ritland's unpublished dataset of measurements for axial length collected from museum specimens to explore the ecology and evolution of eye size variation for half of the aquatic avifauna (N = 464 species). After correcting for body mass allometry and incorporating phylogenetic relationships, aquatic species had significantly smaller eyes compared to terrestrial species. Furthermore, species using hyperopic foraging manoeuvres, exhibiting carnivorous and insectivorous diets, and displaying nocturnal behaviour had larger eyes. Plunge‐divers (e.g. boobies and tropic birds) and stalkers (e.g. herons) had the largest relative eye sizes, especially species identifying prey at higher altitudes or longer distances. Underwater pursuit‐divers foraging at greater depths had larger eyes, likely due to the dramatic attenuation of light in the deep ocean. Overall, residual eye size was phylogenetically conserved (l = 0.94), with phylogeny alone explaining 62% of residual eye size variation. Collectively, these results suggest that the relatively bright environments found in aquatic ecosystems negate the adaptive benefits of costly metabolic investments associated with developing and maintaining larger eyes, while also reducing the potential occurrence of disability glare. Strong correlations between eye size and foraging ecology in different aquatic environments corroborate similar comparative studies of terrestrial birds and underscore the central role that vision has played in driving the ecology and evolution of the global avifauna. [ABSTRACT FROM AUTHOR]

Maintaining the health of coastal aquaculture ecosystems is crucial for sustainable development. Therefore, establishing a specific ecosystem health assessment index system for aquaculture bays is paramount. This system allows for the evaluation of the health status of these bays and aids in the planning and restoration of fishery habitats. Utilizing the well-known "Pressure-State- Response" framework, a comprehensive evaluation index system with 14 indicators was developed. Additionally, the analytic hierarchy process and entropy weight methods were employed to assess the ecosystem health of Sansha Bay, a representative aquaculture bay in Fujian Province, China. The results revealed variations in health status across four zones in 2020, categorized as "good" or "excellent". However, the security index was more spatially distributed and classified from "fair" to "safety". Key indicators critical to sustaining the health of the aquaculture bay ecosystem included the regional environmental risk index, the proportion of industrial discharge outlets, the zooplankton species diversity index, the phytoplankton species diversity index, the molar ratio of phosphorus to nitrogen, and the size of nature reserves. According to the assessments of ecosystem health and ecological security, vigorous endeavors in aquatic ecology are paramount to ensure the enduring sustainability of aquaculture, with a specific emphasis on Zoning 1 and Zoning 4. These findings not only enhance and expand the methods for assessing the health of aquaculture bay ecosystems but also provide a scientific basis for the conservation of fishery habitats and the green, high-quality development of the aquaculture industry in Sansha Bay. [ABSTRACT FROM AUTHOR]

We used an extensive multispecies dataset to examine how C and N stable isotope ratios (δ13C and δ15N) of aquatic consumers varied with body size in populations of northern lakes. Ontogenetic variation in tissue δ13C and δ15N was evident in a diversity of aquatic consumers. Relationships with body size tended to be stronger and more consistently positive for δ15N, and more variable in nature for δ13C. Among-population variation in ontogenetic slopes was greater for δ13C than for δ15N for most biota examined. Relationships between δ13C and δ15N and body size were still significant even after accounting for variation owing to tissue C:N and body condition. Ontogenetic variation was more strongly linked to age than body size in some fishes, particularly for δ15N, but age effects, inferred from growth rate, also accounted for variation in δ13C and δ15N beyond body size effects; δ13C tended to be positively related and δ15N tended to be negatively related to growth rate. There was only limited evidence of concordance in ontogenetic slopes between co-habiting pairs of species, suggesting that the factors driving ontogenetic variation in stable isotope ratios may be largely species- or population-specific. However, ontogenetic slopes of individual taxa were related to various lake habitat features representing climate, ecosystem size, and water clarity. The proportion of isotopic niche space attributable to ontogenetic variation can be substantial and this has implications for applying and interpreting isotopic niche metrics. Our study provides the broadest and most comprehensive analysis of ontogenetic variation in isotopic compositions of freshwater consumers to date and our results underscore the need to account for this variation in the analysis of freshwater food webs. [ABSTRACT FROM AUTHOR]

Particulate organic matter (POM) is an important energy source for aquatic consumers, understanding its origin and composition is essential for understanding the energetic dynamics of aquatic environments. The aim of this study was to analyze the relationship between POM and phytoplankton (isotopic values and chlorophyll concentration) and abiotic variables during dry and rainy seasons. Sampling was conducted in rivers and lagoons in the floodplain of the Upper Paraná River. We found a greater difference in δ13C values of POM between sampling points than between seasons, indicating that the composition of regional sources influences the composition of POM more than dry and rainy seasons. In addition, the concentration of chlorophyll during the dry season was positively correlated with δ13C values during that rainy period. Additionally, we found a relationship between factors limiting the growth of phytoplankton and δ13C values of POM, such as phosphate ions, indicating that variables that regulate phytoplankton growth tend to influence the composition of POM in river floodplains. Therefore, maintaining the variables that regulate the phytoplankton community is of fundamental importance for the composition of POM, an important energy source in aquatic environments. [ABSTRACT FROM AUTHOR]

The increasing global concern regarding plastic pollution has prompted the research into the consequences of microplastics (MPs) on aquatic ecosystems. Fairy shrimp Branchinella kugenumaensis are freshwater planktonic organisms that have existed for 250 million years. This study aimed to uncover the harmful effects of MPs, with a particular focus on their size variations (0.1, 1, and 5 µm), on the fairy shrimp. We focused on how MPs could significantly affect the survival and growth of fairy shrimp. Notably, larger MPs, especially those measuring 5 µm, caused higher mortality rates and hindered the growth compared to smaller ones. The impact of MPs continued even subsequent to depuration in clean water. The accumulation of MPs within the intestines of fairy shrimp resulted in intestinal blockages, disrupted excretory functions, and harmed intestinal epithelial cells. Examinations at the histological, cellular, and molecular levels showed that exposure to MPs triggered necroptosis in intestinal cells, accompanied by alterations in pathways related to transcription, translation, digestion, energy metabolism, and neurological functions. Furthermore, the effects of MPs on gene expression and pathways varied based on particle size, with larger MPs having a more significant effect and causing a strong response in xenobiotic biodegradation and metabolism pathways. We suggest that the increasing severity of MPs pollution could pose a significant threat to the survival of fairy shrimp. This study provided vital insights into the complex relationship between microplastics and aquatic organisms, and highlighted the urgent need to address the potential devastating impact of plastic pollution on freshwater ecosystems. Additionally, due to their rapid growth, strong reproductive capacity, sensitivity, and ease of cultivation, fairy shrimp hold the potential candidate to serve as a model organism for studying the effects of MPs and other pollutants on freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Diatoms are widely dispersed single-celled eukaryotic microalgal species inhabiting every kind of aquatic ecosystem. Identification and isolation of diatoms have been the need of the hour for the sustainable development of environmental goals. The current study focuses on the isolation of various diatoms from the southern coastal region of Dhanushkodi, Rameshwaram and Mandapam in the Ramanathapuram district of Tamil Nadu, India, and their identification using scanning electron microscopy (SEM). The species were determined based on the girdle, striae, valves, and other crucial terms present on the frustules and identified as pennate diatoms Navicula sp., Amphora sp., and Gomphonema sp., respectively. The identified species were cultured in artificial saltwater that had been enhanced with a modified f/2-Si media composition. In addition to enhancing the local flora, the identified strains represent the diatoms diversity along India's southern coast. [ABSTRACT FROM AUTHOR]

The document is a report of the February 2024 ESA Council Meeting, held on Zoom. The meeting began with introductions and a welcome from Emilie Graves and Catherine O'Riordan. President Shahid Naeem discussed the new Council format and strategic planning efforts. President-elect Stephanie Hampton presented a draft of a new strategic plan, which was discussed in breakout rooms focusing on equity and inclusion, community building, and operational excellence. Updates were given on ESA publications and funding opportunities. The creation of new ESA sections for Climate Adaptation and Coastal & Marine Ecology was approved. Recommendations for standardizing governance and activities were presented, and the meeting concluded with information on the next Speaker-Elect and closing remarks. [Extracted from the article]

Protist plankton can be divided into three main groups: phytoplankton, zooplankton, and mixoplankton. In situ methods for studying phytoplankton and zooplankton are relatively straightforward since they generally target chlorophyll/photosynthesis or grazing activity, while the integration of both processes within a single cell makes mixoplankton inherently challenging to study. As a result, we understand less about mixoplankton physiology and their role in food webs, biogeochemical cycling, and ecosystems compared to phytoplankton and zooplankton. In this paper, we posit that by merging conventional techniques, such as microscopy and physiological data, with innovative methods like in situ single-cell sorting and omics datasets, in conjunction with a diverse array of modeling approaches ranging from singlecell modeling to comprehensive Earth system models, we can propel mixoplankton research into the forefront of aquatic ecology. We present eight crucial research questions pertaining to mixoplankton and mixotrophy, and briefly outline a combination of existing methods and models that can be used to address each question. Our intent is to encourage more interdisciplinary research on mixoplankton, thereby expanding the scope of data acquisition and knowledge accumulation for this understudied yet critical component of aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Eco‐evolutionary experiments are typically conducted in semi‐unnatural controlled settings, such as mesocosms; yet inferences about how evolution and ecology interact in the real world would surely benefit from experiments in natural uncontrolled settings. Opportunities for such experiments are rare but do arise in the context of restoration ecology—where different "types" of a given species can be introduced into different "replicate" locations. Designing such experiments requires wrestling with consequential questions. (Q1) Which specific "types" of a focal species should be introduced to the restoration location? (Q2) How many sources of each type should be used—and should they be mixed together? (Q3) Which specific source populations should be used? (Q4) Which type(s) or population(s) should be introduced into which restoration sites? We recently grappled with these questions when designing an eco‐evolutionary experiment with threespine stickleback (Gasterosteus aculeatus) introduced into nine small lakes and ponds on the Kenai Peninsula in Alaska that required restoration. After considering the options at length, we decided to use benthic versus limnetic ecotypes (Q1) to create a mixed group of colonists from four source populations of each ecotype (Q2), where ecotypes were identified based on trophic morphology (Q3), and were then introduced into nine restoration lakes scaled by lake size (Q4). We hope that outlining the alternatives and resulting choices will make the rationales clear for future studies leveraging our experiment, while also proving useful for investigators considering similar experiments in the future. [ABSTRACT FROM AUTHOR]

Cyanobacterial blooms (CBs) present significant challenges to Chinese mitten crab (CMC) culture, posing hazards to the aquatic microbial ecology. However, the current focus on the microbial ecological changes within the CMC culture system under the influence of CBs is somewhat insufficient. There's an urgent need to analyze the microbial ecosystem of the CMC culture system under CBs. This study employed 16S rRNA gene amplicon sequencing to investigate the dynamics of the environmental microbial community in both the rice-crab co-culture (RC) and crab monoculture (CM) models. The results revealed that cyanobacteria reached high levels in the CM water in July, while they began to increase in the RC water in August. Notably, OTU147 (uncultured bacterium g_Planktothrix NIVA-CYA 15), identified as the dominant taxon associated with CBs, showed a significant linear relationship with TP, NO2 --N, and the N:P ratio. TP, TN, NO2 --N, and CODMn had a more pronounced impact on the structure of bacterial communities and cyanobacterial taxa in the water. The bacterial community structure involved in carbon metabolism displayed temporal succession in the water. The co-occurrence network of the bacterial community primarily consisted of Chloroflexi, Proteobacteria, and Firnicutes in the sediment, and Actinobacteria, Proteobacteria, Chloroflexi, and Bacteroidota in the water. In contrast, the co-occurrence network included different peripheral species in the sediment and water. Keystone species were predominantly represented by OTU22 (uncultured actinobacterium g_ hgcI clade) and OTU12 (uncultured Opitutae bacterium g_ norank) in the RC water, and by OTU25 (uncultured bacterium g_ Limnohabitans) in the CM water. TP, TN, NO2 --N, and CODMn were identified as the primary environmental factors influencing these keystone taxa within the culture water. In conclusion, this study on the microbial ecology of the CMC culture system under the influence of CBs provides valuable insights that can be instrumental in subsequent management efforts. [ABSTRACT FROM AUTHOR]

Lumajang is one of the regency in East Java Province that has various types of freshwater ecosystems and have great potential as habitats for various insects, especially dragonflies. Dragonflies are insects that mostly live aquatically, so their existence is highly dependent on the condition of aquatic ecosystems. This study aims to compare the composition and diversity of dragonfly species in various habitat types in Lumajang. The study was conducted in lentic and lotic ecosystems in Lumajang. The method used was the Visual Encounter Survey (VES) technique adapted from the sweeping net. The data analysis used to determine differences in dragonfly species composition was the Bray-Curtis similarity analysis, while diversity analysis was conducted using the Shannon-Wiener index. This study recorded 29 species from seven families, including seven endemic dragonfly species found only on several islands in Indonesia. In the analysis of the Shannon-Wiener diversity index, the results show that in all research locations have a value of H'= 1.07-2.11, where the Rice Field habitat is the location with the highest value among other locations, with a value of H' = 2.11. The similarity analysis of dragonfly species composition using Bray Curtis similarity showed that it was divided into three groups. The composition of dragonflies found in several habitats in Lumajang is different, which can be influenced by many factors such as site elevation, habitat type (lentic or lotic), and habitat condition, as well as several other factors such as microclimate and vegetation (related to food availability). [ABSTRACT FROM AUTHOR]

This comprehensive review explores the escalating challenge of nutrient enrichment in aquatic ecosystems, spotlighting the dire ecological threats posed by harmful algal blooms (HABs) and excessive particulate organic matter (POM). Investigating recent advancements in water treatment technologies and management strategies, the study emphasizes the critical need for a multifaceted approach that incorporates physical, chemical, and biological methods to effectively address these issues. By conducting detailed comparative analyses across diverse aquatic environments, it highlights the complexities of mitigating HABs and underscores the importance of environment-specific strategies. The paper advocates for sustainable, innovative solutions and international cooperation to enhance global water quality and ecosystem health. It calls for ongoing advancement, regular monitoring, and comprehensive research to adapt to emerging challenges, thus ensuring the preservation of aquatic biodiversity and the protection of communities reliant on these vital resources. The necessity of integrating technological innovation, ecological understanding, and global cooperation to safeguard aquatic ecosystems for future generations is paramount. [ABSTRACT FROM AUTHOR]

Fresh, green leaves are increasing as resources in aquatic ecosystems due to more frequent severe spring and summer storms, but research on allochthonous resources typically uses senescent leaves. We examined macroinvertebrate colonization of green leaves of three native deciduous trees (red maple, red oak, and tulip poplar) over two weeks within both a stream and fishless pond. Leaf colonization varied depending on the taxa of leaves and colonizers, submersion time, and the ecosystem examined. Within the stream, the densities of isopods (Lirceus sp.) and snails (mostly the invasive Potamopyrgus antipodarum) did not vary significantly across leaf species. In contrast, mayflies (Tricorythodes sp.) in the stream colonized tulip poplar in greater numbers than red oak leaves, while higher densities of planarians (order Tricladida) occurred within red oak leaves. The numbers of mayflies and snails decreased significantly by the second week, but the densities of isopods and planaria within stream leaf packs were consistent. In contrast, within the pond, significantly more isopods (Caecidotea communis) were collected after the first than after the second week of submersion and in tulip poplar leaves. Clams (Sphaeriidae) in the pond, on the other hand, were more prevalent in the second week but did not discriminate among leaf species. While the number of leeches (mostly Helobdella stagnalis) was consistent across weeks, significantly fewer leeches resided within tulip poplar leaves than within red oak leaves. Our results suggest that there are no consistent colonization-preference rankings of species of fresh leaves across freshwater benthic macroinvertebrate taxa. Even within a functional feeding group (e.g., the two types of isopods and snails, all detritivore-herbivores), there were differences in colonization patterns. Therefore, increased allochthonous inputs of fresh leaf litter due to severe spring- and summer-time storms are likely to promote the populations of various taxa to different extents. [ABSTRACT FROM AUTHOR]

Researchers are increasingly using biologging equipment (e.g., telemetry receivers, temperature loggers) to characterize the ecology of aquatic ecosystems. This equipment is commonly deployed at a wide range of water depths and greatly expands our capacity to remotely monitor aquatic ecosystems; however, equipment retrieval can be a major challenge. Here, we describe a technological solution to this challenge that uses a combination of live imaging sonar and a remotely operated vehicle to efficiently locate and recover equipment across a wide range of conditions (e.g., turbid water, range of water depths). We provide details on our specific equipment setup (total cost < Can$15,000) used for the recovery of acoustic fish tracking receivers moored to the benthos of Stoney Lake, Ontario, Canada. There are some limitations to this approach, which are discussed. With technological advances and increases in affordability of commercially available products, this approach may be widely applicable to recover biologgers from depth. [ABSTRACT FROM AUTHOR]

Morphometry is the process that deals with mathematical analysis and calculations of the various land surface dimensions. In this study, morphometry analysis and changes in riverbeds due to anthropogenic activities have been studied using geospatial techniques for a stretch of the Yamuna river in Delhi. The parametric values related to morphometry, such as low permeability and high surface run-off were determined through Remote Sensing, which is helpful to understand the characteristics of the area. The study reveals that morphometric parameters and land surface properties are closely interrelated and are dependent on each other. Analysis has lightened up that over the year river span has been reduced from 5.15 to 4.23 sq. km and there is a trend of reduction and alteration of the channel in upcoming days. The morphometric conditions also indicate a concern of flood during monsoon. This study also focuses on the adverse effects of anthropogenic activities on the Yamuna riverbed morphology. There is a need for restriction on haphazard human activities, effective planning and management for sustainable development of the Yamuna riverbed in Delhi. The study suggests further research on aquatic ecology, water quality, and life expectancy of the river due to immense anthropogenic pressure. [ABSTRACT FROM AUTHOR]

The present study provides new insight into the key aspects of the early formative period of the ecosystem concept in aquatic ecology. Raymond Lindeman's trophodynamics is known to be a starting point for the development of the modern concept of ecosystem. The trophodynamic approach in ecology was proposed by Lindeman in his widely cited paper of 1942. Lindeman's views are analyzed in comparison with the contemporary production studies in aquatic ecology. It is shown that a similar theoretical system has been proposed in the USSR at the end of the 1930s by Georgiy G. Vinberg. He introduced the concept of biotic balance based on the wide appraisal of the dark and light bottles method. The study shows that both Lindeman's trophodynamics and Vinberg's concept of biotic balance relied on an energy-based approach in considering the wholeness of a water body. The two scientists, however, differed in several important aspects concerning the interpretation of the role of living organisms. The holistic interpretation of ecosystem by Lindeman and Vinberg can be seen as part of the dilemma between physicalism and organicism. At the same time, the main emphasis in the concepts of both Vinberg and Lindemann was on the primary production component, a feature that was common to the first holistic systems in production hydrobiology (e.g., E. Naumann's regional limnology). It is clear that modern problems of aquatic ecology should be addressed from the perspective of the organismocentric understanding of the ecosystem, but undoubtedly at the new level of development of this view. [ABSTRACT FROM AUTHOR]

Much of the ecological discourse surrounding the polarising theropod Spinosaurus has centred on qualitative discussions. Using a quantitative multivariate data analytical approach on size-adjusted linear measurements of the skull, we examine patterns in skull shape across a range of sauropsid clades and three ecological realms (terrestrial, semi-aquatic, and aquatic). We utilise cluster analyses to identify emergent properties of the data which associate properties of skull shape with ecological realm occupancy. Results revealed terrestrial ecologies to be significantly distinct from both semi- and fully aquatic ecologies, the latter two were not significantly different. Spinosaurids (including Spinosaurus) plotted away from theropods in morphospace and close to both marine taxa and wading birds. The position of nares and the degree of rostral elongation had the greatest effect on categorisation. Comparisons of supervised (k-means) and unsupervised clustering demonstrated categorising taxa into three groups (ecological realms) was inappropriate and suggested instead that cluster division is based on morphological adaptations to feeding on aquatic versus terrestrial food items. The relative position of the nares in longirostrine taxa is associated with which skull bones are elongated. Rostral elongation is observed by either elongating the maxilla and the premaxilla or by elongating the maxilla only. This results in the nares positioned towards the orbits or towards the anterior end of the rostrum respectively, with implications on available feeding methods. Spinosaurids, especially Spinosaurus, show elongation in the maxilla-premaxilla complex, achieving similar functional outcomes to elongation of the premaxilla seen in birds, particularly large-bodied piscivorous taxa. Such a skull construction would bolster "stand-and-wait" predation of aquatic prey to a greater extent than serving other proposed feeding methods. [ABSTRACT FROM AUTHOR]

Macrophytes not only integrate environmental conditions but also reflect the trophic state of the aquatic environment through several metrics. The lack of knowledge on the biology and ecology of aquatic plants in Moroccan rivers makes it very difficult to establish a comprehensive and effective national metric for assessing the trophic state of rivers. Indeed, the use of one of the European methods, which have been the subject of geographical intercalibration projects across different countries, particularly those in the Mediterranean region, proves necessary. Given Morocco's geographic location within the Mediterranean Basin, Macrophyte Biological Index for Rivers (IBMR) was chosen as a method to assess Moroccan running waters. Furthermore, it allowed answering a number of questions about the usage of biological metrics based on macrophytic communities throughout Morocco. The obtained results showed that the IBMR can provide an indication of the overall trophic state of the watercourse, but with well-defined conditions, namely stable hydrological conditions with a significant richness in contributing pollution-sensitive species. Although this macrophyte index showed correlations with the parameters responsible for eutrophication phenomena, it remained less effective in the face of the downgrading parameter. Thus, the particular context of Moroccan watercourses, namely the watercourses of the Upper Oum Er-rbia basin, and the major pitfall that still lies in the knowledge of the ecology of plant groups in Moroccan running waters, can pose a problem in the application of the IBMR index, especially with regard to ubiquitous species that dominate the downstream sites of the studied rivers. [ABSTRACT FROM AUTHOR]

Agricultural water serves various functions, including public interest purposes, beyond its primary role in agricultural production. In order to evaluate the various public interest purposes of agricultural water, a quantified study of the effect of agricultural water on river flow, water quality, and aquatic ecosystems is needed. Therefore, this study quantified the impact of agricultural water on the environmental and ecological maintenance function of downstream rivers, taking into account the return flow of agricultural water in rural areas. To this end, first, the effect of agricultural return flow on river maintenance function was evaluated by comparing the return flow quantity calculated using the reservoir supply data with the simulated river flow rate through the SWAT model. Second, the effect of the agricultural return flow on the downstream river environmental ecological function was analyzed using the optimal flow rate results calculated through the PHABSIM model. The lastly, the effect of agricultural water by farming period on the water quality of downstream rivers was analyzed. As a result of the analysis, it was found that the return flow of agricultural water had a large effect on the river flow rate in the case of the non-rainy season, but the optimal ecological flow rate was not satisfied. In the case of river water quality, it was confirmed that the effect of agricultural water (mainly considered as a pollutant) was not significant, except for the drainage duration of rice paddies. Therefore, it can be understood that agricultural water is not only used for the purpose of production but can also have a positive impact on the aquatic ecology of downstream rivers. [ABSTRACT FROM AUTHOR]

Statistical models used in toxicity experiments have been quite useful tools in interpreting the organism's susceptibility, exposure response, amount of tolerable concentration, and function of tolerance time. In order to determine and evaluate the toxic effects of boron on Daphnia pulex (Leydig, 1860), different boron concentrations considered to be tolerable in aquatic ecosystems were tested for D. pulex. Percentage mortality rates at different boron concentrations and probit regression estimates at these concentrations were investigated through the static method. Probit analysis in this study revealed that rising boron concentrations led to mortality, and that finding was statistically significant with P value. These results indicate that the use of episodic boron, which enters the aquatic ecosystem through natural or unnatural means, should be planned due to its potential for stress or toxicity situations on organisms. [ABSTRACT FROM AUTHOR]

Animals rely on olfaction to detect and process invaluable chemical information about their environment. For olfaction to function, chemicals must first be detected, which leads to the activation of signal-transduction pathways at the peripheral olfactory organ. As the olfactory system is in direct contact with the environment, the system is constantly vulnerable to damage by contaminants entering the atmosphere or hydrosphere. Contaminants may have a variety of effects, including disrupting olfactory signals generated during chemical detection, or altering numerous targets along the signal transduction pathway. With any impairment of chemical detection, animals may be unable to rely on olfaction to make correct decisions about their environment and thus their fitness. While other reviews have focussed on olfactory toxicology in general, here we specifically explore how contaminants may affect the signal-transduction pathways at various points and link those changes to olfactory functionality across vertebrates with a focus on fishes. [ABSTRACT FROM AUTHOR]

Occurrence of neurotoxic chemicals in the aquatic environment is on the rise posing a potential threat to aquatic biota including fish. In teleosts, zebrafish has become a popular model organism for toxicological studies and testing strategies. However, over the decade, siluriformes (catfish) are also finding ever increasing application being robust as well as their adaptability to adverse ecological conditions, surgical interventions, and tolerant models for toxicity studies and manipulations. Such information can infer potential effects occurring to other species exposed to neurotoxins in their aquatic environment and predicting potential risks of a chemical for the aquatic ecosystem. The aim of this review is to compare and interpret recent results published concerning neurobehavioral and morphological disturbances caused by toxicants/pollutants providing a holistic view of potential neurotoxic outcomes in catfish. Overall, this review summarizes various effects of toxicants/pollutants in terms of neurotoxicity and neurodegeneration associated with behavioral phenotypes. [ABSTRACT FROM AUTHOR]

The decline in water conditions contributes to the crisis in clean water biodiversity. The interactions between water conditions indicators and the correlations among these variables and taxonomic groupings are intricate in their impact on biodiversity. However, since there are just a few kinds of Internet of Things (IoT) that are accessible to purchase, many chemical and biological measurements still need laboratory studies. The newest progress in Deep Learning and the IoT allows for the use of this method in the real-time surveillance of water quality, therefore contributing to preserving biodiversity. This paper presents a thorough examination of the scientific literature about the water quality factors that have a significant influence on the variety of freshwater ecosystems. It selected the ten most crucial water quality criteria. The connections between the quantifiable and valuable aspects of the IoT are assessed using a Generalized Regression-based Neural Networks (G-RNN) framework and a multi-variational polynomial regression framework. These models depend on historical data from the monitoring of water quality. The projected findings in an urbanized river were validated using a combination of traditional field water testing, in-lab studies, and the created IoT-depend water condition management system. The G-RNN effectively differentiates abnormal increases in variables from typical scenarios. The assessment coefficients for the system for degree 8 are as follows: 0.87, 0.73, 0.89, and 0.79 for N-O3-N, BO-D5, P-O4, and N-H3-N. The suggested methods and prototypes were verified against laboratory findings to assess their efficacy and effectiveness. The general efficacy was deemed suitable, with most forecasting mistakes smaller than 0.3 mg/L. This validation offers valuable insights into IoT methods' usage in pollutants released observation and additional water quality regulating usage, specifically for freshwater biodiversity preservation. [ABSTRACT FROM AUTHOR]

This paper contains information on the records of bottom macroinvertebrates, fish, amphibians, reptiles, birds and mammals collected during a field expedition in the valley of the Shokhdara River (in the vicinity of Khorog) near its mouth and confluence with the Panj River in autumn 2019-- spring 2020. As a result of the study, 3 species of fish (Actinopterigii Cyprinidae -- 2, Nemacheilidae -- 1 were found in the Shokhdara River and 1 additional species was confirmed by local people. Five species of reptiles (Squamata, Colubridae -- 2, Viperidae -- 1, Agamidae -- 1, Gekkonidae -- 1) and 1 species of amphibians (Anura, Bufonidae -- 1) were recorded. Twenty-four taxa of aquatic macroinvertebrates were recorded (89.7 % -- Insecta): Simuliidae -- 35.8 %, Ephemeroptera -- 18.7 %, Chironomidae -- 18 %, Trichoptera -- 10.5 %, Oligochaeta -- 6.5 %, Plecoptera -- 2.8 %, Diptera -- 2.5 %, Gastropoda -- 2.5 %. Nematoda, Turbellaria, Ostracoda, Copepoda, Cyclops spp., Sphaerium spp., Araneida, Acarina, Odonata, Heteroptera, Coleoptera, Neuroptera, Lepidoptera and Megaloptera represented only 2.7 % of the collected specimens of bottom invertebrates. Ninety-nine bird species (48 % of the avifauna of the study area) were recorded during the autumn/spring surveys. Among mammals, rare and internationally protected species such as Asian otter, snow leopard and Himalayan brown bear were confirmed to inhabit the areas adjacent to the surveyed river valley. [ABSTRACT FROM AUTHOR]

Pollution of water bodies with heavy metals can lead to the death of fish and other aquatic organisms, a decrease in biodiversity and a threat to ecosystems, emphasising the importance of preserving the natural environment; pollution of water bodies can have serious economic consequences, in particular, a decrease in profits from fishing, tourism, and other activities related to water use, which requires the development of water management strategies. The purpose of the study was to determine the general trends in the content of heavy metals in the surface waters of the Teteriv River and fattening pond No. 1 of the LLC "SHF INTERRYBHOSP". Water samples were taken at the stream of the Teteriv River (Vidsichne Reservoir) and in the fattening pond No. 1 at a depth of 0.2-0.5 m from the surface for further laboratory analysis of the content of heavy metal ions (HM). The atomic absorption method of analysis was used to study water. Laboratory studies of surface waters in the Teteriv River and pond were performed according to the following indicators: hydrogen index (pH), lead, cadmium, manganese, zinc, and iron content. The results of the study of the content of heavy metals in the Teteriv River are presented, which showed that the content of such heavy metals as: Pb, Cd, Mn, Zn and Fe, in river water, with the exception of iron, exceed the limits of maximum admissible values of water quality indicators for fishery water bodies. Background HM indicators from fattening pond No. 1 did not show an excess of the MAC (maximum admissible concentration). High concentrations of lead, cadmium, manganese, and iron are explained by powerful anthropogenic pollution, the source of which is agricultural and industrial complexes of Zhytomyr Oblast. The results can be used to establish effective monitoring of water quality in reservoirs and develop strategies to reduce pollution in aquatic ecosystems. [ABSTRACT FROM AUTHOR]

This article explores the issue of maritime environmental damage and the establishment of liability for such damage. It emphasizes the importance of addressing environmental degradation in maritime regions and assigning responsibility for harmful actions. The article discusses different forms of compensation for environmental damage, including financial compensation for material and physical damage, as well as compensation for non-material damage and damage to livelihoods. It also explores the legal attribution of criminal liability for environmental crimes, both for legal entities and natural persons. The text highlights the importance of accountability and compensation for environmental harm and the need for international cooperation to achieve international environmental security. The Algerian legislation is mentioned as an example of a legal framework that acknowledges the importance of protecting the maritime environment and holding those responsible for causing harm accountable. [Extracted from the article]

The transboundary Irtysh River flows through the territory of three countries. The Irtysh River is subjected to intense anthropogenic impact. In the Kazakhstan part of the Irtysh River basin, there are zones of industrial influence in the cities of Pavlodar and Aksu. Hydroelectric power, ferroalloy plants, and coal pits are located in the territory of these cities. The study of the species composition of phytoplankton is a basic method in bioindication. Phytoplankton plays an essential role in evaluating the ecological status of aquatic ecosystems. The algae flora of the transboundary Irtysh River has not been studied thoroughly enough. Most hydrobiological studies in the Kazakhstan part of the Irtysh River basin were devoted to studying reservoirs. Based on this, the relevance of studying the planktonic communities of the Kazakhstan part of the Irtysh River is increasing. This study aimed to analyze the richness of phytoplankton species in the Kazakh part of the Irtysh River basin. The research was conducted in July 2023 at 27 stations. The selection sites were located on the upper and lower reaches of the Irtysh River. Sections of the Black Irtysh, from the border with the Altai to the confluence with Lake Zaisan, and sections in the Pavlodar region were surveyed. We registered 153 species and subspecies of algae from Heterokontophyta (69), Chlorophyta (61), Cyanobacteria (16), Charophyta (4), Euglenophyta (2), and Dinoflagellata (1) in the phytoplankton. A high level of similarity characterized phytoplankton of most of the surveyed sites. [ABSTRACT FROM AUTHOR]

Ecotoxicological models play a vital role in understanding the inuence of toxicants on population dynamics in contaminated aquatic ecosystems. Traditional differential equation models describing interactions between populations and toxicants typically assume instantaneous population growth, overlooking potential time delays associated with reproductive and maturation processes. In this paper, we introduce two models with time delays to investigate the interaction between a population and a toxicant, where the population growth is governed by a delayed logistic equation. We mainly focus on the stability analysis of the steady states of the models. Our fndings indicate that high toxicant concentrations result in population extinction, whereas moderate toxicant levels can potentially induce bistability, where the population's fate, whether persistence or extinction, depends on the initial densities of the population and toxicant. Furthermore, both our theoretical analysis and numerical simulations demonstrate that the time delay can lead to the destabilization of the coexistence steady states and the appearance of periodic solutions through Hopf bifurcation. [ABSTRACT FROM AUTHOR]

Lakes host a high level of biodiversity, especially in their littoral zone, and provide various ecological and socio‐economic services. Lake ecosystems are impacted by a combination of pressures from different human activities (industry, hydroelectricity, agriculture, recreational activities, domestic and urban uses). Anthropic pressures can lead to alterations and dysfunctions in lakes, particularly in the littoral zone.The 2000 EU Water Framework Directive led to considerable efforts to improve the ecological status of European water bodies. However, in France, measures implemented by lake managers to counteract, limit or suppress anthropogenic impacts are still poorly identified. Moreover, their effects on hydromorphology, physico‐chemistry and biotic communities are often only partially reported (the monitoring being incomplete or heterogeneous, if not missing).This paper proposes a framework to harmonize the monitoring of habitat improvement actions conducted in the littoral zone of lakes. The monitoring method is presented as well as the sampling protocols and techniques set out to survey both the restored and control zones at the European French territory scale.Long‐term monitoring of hydromorphological, biological and physicochemical features is expected to improve our understanding of recolonization mechanisms following restoration. The proposed approach will therefore guide practitioners to identify the best restoration options and ultimately contribute to the conservation of recipient populations and communities. [ABSTRACT FROM AUTHOR]

Background: Due to the multifactorial etiology, tumor manifestation in any vertebrate species may become a critical issue. This topic requires more consideration for species in aquatic ecosystems as an enclosed habitat. In addition, knowledge about oncogenesis in the aquaculture industry enhances the quality of products and its earned benefits. Objectives: This study investigated the tumor lesions, their characteristics, and probable causes, in the most commercially important fish in the southern Caspian Sea: Caspian white fish (Rutilus kutum). Methods: To accomplish this goal, after gross pathology of more than 20 cases, histopathological examinations and electron microscopic assays were employed. Results: The findings confirmed squamous cell carcinoma and squamous cell papilloma in the examined cases. Furthermore, the virus-like particles were clearly observed in the transmission electron microscopy results, indicating the probable viral etiology for these neoplastic lesions in Caspian Kutum. Conclusion: This study is the first to report the tumor prevalence in fish species of the southern Caspian Sea, which could be an alert for the mentioned ecosystem's health and the whole aquaculture industry. [ABSTRACT FROM AUTHOR]

Abstract The development of hydroelectric projects has adversely affected the reproductive activities of downstream fish species. To facilitate the natural reproduction of fish and restore spawning grounds post‐dam construction, it is imperative to explore the ecological factors crucial for their reproduction. Currently, various research methods with different advantages and limitations are employed for this purpose. Using identified spawning locations and periods as clues, we quantitatively investigate the flow velocity, water depth, water temperature, and riverbed substrate required for spawning. The results are validated using habitat simulation methods, aiming to establish a more scientific approach to explore ecological factors affecting fish reproduction. This study provides a more scientific, systematic, and detailed report on the ecological factors required for the spawning of Gymnocypris eckloni: flow velocity ranging from 0.19 to 0.97 m/s, water depth from 0.28 to 1.12 m, water temperature between 11.4 and 15.2°C, and predominantly gravel substrate. The reliability of the results was verified in another spawning ground, with good verification results. This research provides crucial data for the bio‐mimetic reproductive technology of Gymnocypris eckloni and the restoration of spawning grounds for natural fish reproduction post‐dam construction. It addresses the lack of suitable ecological factor data for protective fish species in the upper reaches of the Yellow River. The method exhibits strong scientific, accurate, and implementable characteristics.

At the sediment-water interfaces, filamentous cable bacteria transport electrons from sulfide oxidation along their filaments towards oxygen or nitrate as electron acceptors. These multicellular bacteria belonging to the family Desulfobulbaceae thus form a biogeobattery that mediates redox processes between multiple elements. Cable bacteria were first reported in 2012. In the past years, cable bacteria have been found to be widely distributed across the globe. Their potential in shaping the surface water environments has been extensively studied but is not fully elucidated. In this review, the biogeochemical characteristics, conduction mechanisms, and geographical distribution of cable bacteria, as well as their ecological effects, are systematically reviewed and discussed. Novel insights for understanding and applying the role of cable bacteria in aquatic ecology are summarized.

High-frequency water quality measurements in streams and rivers have expanded in scope and sophistication during the last two decades. Existing technology allows in situ automated measurements of water quality constituents, including both solutes and particulates, at unprecedented frequencies from seconds to subdaily sampling intervals. This detailed chemical information can be combined with measurements of hydrological and biogeochemical processes, bringing new insights into the sources, transport pathways, and transformation processes of solutes and particulates in complex catchments and along the aquatic continuum. Here, we summarize established and emerging high-frequency water quality technologies, outline key high-frequency hydrochemical data sets, and review scientific advances in key focus areas enabled by the rapid development of high-frequency water quality measurements in streams and rivers. Finally, we discuss future directions and challenges for using high-frequency water quality measurements to bridge scientific and management gaps by promoting a holistic understanding of freshwater systems and catchment status, health, and function.