Aquatic Ecology最新文献

This paper touched on the issue of microfibre as it is gaining worldwide attention within the academic and industrial environment. The study was done using secondary data sourced from the SCOPUS platform and Google Scholar. The study reviewed the concept of microfibre, its sources, effects, and management following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The review brought to light that microfibre is a confusing concept as different practitioners relate to it differently. Also, the common sources of microfibre put forth by various studies include the textile industry, laundering processes, and wastewater treatment plants. However, there are notable differences in emphasis and scope across studies, and there are contrasting perspectives regarding the magnitude and significance of certain sources. While there is a consensus among researchers regarding the detrimental impacts of microfibres on aquatic ecosystems and biota, the specific mechanisms and severity of these effects vary considerably. The studies reviewed agreed on the urgency of addressing microfibre pollution; there is, however, a diversity of perspectives on mitigation strategies reflecting the complex and multifaceted nature of the issue. The study recommended research gaps that have been silent, but are necessary to tackle the problem of microfibre pollution.

A key component of conservation biology is understanding how community composition responds to environmental conditions, including stressors (e.g., eutrophication). However, this is complicated by the accompanying shifts in taxa co-occurrence due to taxa interactions (e.g., competition, predation). Thus, we need to consider both taxa co-occurrence and abiotic conditions simultaneously to understand the relative influence of these factors on community composition. In this study, we aimed to elucidate the relative role of water quality and taxa co-occurrence in determining phytoplankton, zooplankton, and macroinvertebrate communities in a set of lakes varying in trophic status from oligotrophic to meso-eutrophic. We built joint species distribution models (JSDMs) using a generalized linear latent variable modelling approach to isolate the influence of abiotic variables and taxa co-occurrence for each level of the food web. We found that water quality explained most of the variation in community composition for all groups, especially for zooplankton (78%) and macroinvertebrate (62%) communities. Additionally, total phosphorus was a significant driver of many taxa in these groups. These findings indicate a strong “bottom-up” control of the lower aquatic food web in these lakes and signify an important role of phosphorus across a distinct trophic gradient. Overall, we demonstrate the effectiveness of JSDMs for determining the relative impacts of abiotic variables on community composition which can provide key insights for lake management.

The red swamp crayfish Procambarus clarkii is widely used as a model organism for studying aquatic ecosystems, with various behavioral assessment methods developed for this purpose. However, up to now, the assessment still lack of improvement, slow, and low throughput. Thus, this study aimed to investigate multiple behaviors of several color variants of this species by using deep learning approach tools with fully automation. In natural and artificial habitats, P. clarkii occurs in multiple color morphs, including white (W), blue (B), and red (R), which are also popular in the aquarium trade. This study optimized multiple deep learning tools: UMATracker, Idtracker.ai, and DeepLabCut to assess innate color preferences, circadian rhythms, and agonistic behaviors respectively in P. clarkii. With this optimized setup, we compared the behaviors of W, B, and R color variant. It displayed that B exhibited more pronounced behaviors compared to the W and R variants. In circadian rhythm activity, the B morph displayed a significantly higher average velocity than other color variants during both day and night cycles. In terms of color preference, no significant differences were found among the R, B, and W variants. Additionally, R, B, and W showed similar agonistic behaviors, displaying aggression in various ways, such as spreading claws and bracing against opponents. By integrating these machine and deep learning tools we can retrieve faster and reliable results.

Underwater noise is a common form of environmental pollution, but its effects on fish physiology have not been clarified. In this work, the hybrid sturgeon, which has physiological similarities to Chinese sturgeon (Acipenser sinensis), was chosen to investigate the effects of noise on sturgeon physiology and predict its potential impact on Chinese sturgeon. The fish were exposed to 145 ± 5 dB noise, which is comparable to the noise levels near the natural habitat of sturgeons, for 48 h, followed by a 48-h noise-free period to allow for recovery. Blood physiological parameters of juvenile sturgeons were measured at 0, 24, 48, and 96 h. After 48 h of noise exposure, significant changes were observed in biochemical markers: alkaline phosphatase (ALP) and superoxide dismutase (SOD) increased significantly, while aspartate transaminase (AST), lactate dehydrogenase (LDH), and gamma-glutamyl transferase (GGT) decreased. Hormonal markers showed marked increases in epinephrine (EPI) and cortisol levels. Metabolic markers also exhibited changes, including significant increases in glucose, uric acid (UA), and blood urea nitrogen (BUN). Following 48 h of noise removal, EPI, glucose, UA, BUN, and LDH levels remained significantly elevated, with a significant decrease in alanine transaminase (ALT). This study reveals that noise stress can adversely affect the immune functions of hybrid sturgeons and disrupt their hormone secretion. Furthermore, these effects do not reverse within a short period (48 h). By using blood biomarkers, this study provides valuable data for assessing the environmental impact of underwater noise and offers theoretical guidance for sturgeon aquaculture and conservation.

Graphical abstract

One of the characteristic ducks in Lake Mývatn, Iceland, has been the long-tailed duck (Clangula hyemalis) which was present in large numbers during the early 1900s but declined in numbers during the twentieth century. The long-tailed duck is a circumpolar sea duck, often with longitudinal migratory routes between wintering and breeding sites. In recent decades the species has been in decline throughout its range and it is now classified as vulnerable. In Iceland, the breeding population is 2000–3000 individuals, but the winter population is considerably larger (> 110,000) with wintering birds coming from other areas. To identify the phylogeographic origin of the species in Iceland, for both the breeding and the wintering population, variation in the control region of the mitochondrial DNA (mtDNA) was analyzed and compared with samples obtained from across the species range. Two distinct lineages of the control region were found in Iceland, one of which occurred at high frequency in the Icelandic breeding population. The haplotype lineage found in high frequency in the breeding population in Iceland was absent or in low frequencies elsewhere, except in the Yukon-Kuskokwim Delta, Alaska. The patterns observed in the mitochondria may reflect an overall genetic divergence of the Icelandic breeding population from the other sites studied or alternatively sexual differences in philopatry which may only affect the maternally transmitted markers.

Determining ecological thresholds for natural communities has implications for biodiversity conservation and for identifying reference conditions. Among aquatic communities’ phytoplankton is an important indicator of environmental changes and is highly susceptible to physical, chemical, and biological variations in aquatic ecosystems. This study shows multiple ecological thresholds of the phytoplankton community associated with rainfall, turbidity, water temperature, pH, particulate organic carbon, and total nitrogen, which were key factors influencing the phytoplankton community throughout the hydrological year in Lago Grande do Curuai. Among the six gradients evaluated, five (turbidity, temperature, pH, total nitrogen, and precipitation) influenced the distribution and biovolume of phytoplankton. This influence was associated with multiple points of change in the phytoplankton community along these gradients, phytoplankton species and morphofunctional groups (MBFG). The structure of the phytoplankton community in this system showed great variation throughout the year, as multiple ecological thresholds of the community were detected, which are associated with variations in habitat conditions. The MBFG ecological classification indicated a certain degree of loss of responses, potentially due to the weaker signal and lower amplitude threshold response. In conclusion, both classification methods have the potential to be effective biomonitoring and ecological management tools for this environment.

Temephos is an organophosphorus insecticide used as a common larvicide. Although no studies to our knowledge report the presence of temephos in Mexican waterbodies, the Latin American government still uses the larvicide to control Aedes aegypti and illnesses associated with dengue. Freshwater systems and wastewater treatment plants contain microorganisms such as zooplankton species. Non-target organisms can interact directly with the larvicide due to the application in water producing adverse effects in their populations. Most ecotoxicological assays using zooplankton species are based on previously unexposed populations, discarding multigenerational point of view and in silico methods. In the present study, chronic effects were evaluated through life table demography for Moina macrocopa (0, 0.25, 0.5, 1 µg L^-1) and Ceriodaphnia dubia (0, 0.06, 0.125, 0.25 µg L^-1) exposed to sublethal levels of temephos in the medium for two generations (F0 and F1). Regardless of the concentrations used, temephos produced effects on both cladocerans species in the two generations. Induced maternal effects can be observed in the tolerance of the offspring of M. macrocopa, compared to C. dubia, where the impacts were far greater in the F1 generation. This can be explained due to the interactions of binding sites on arginine kinase, suggesting potential inhibitory effects of temephos on the amino acid.

Intermittent rivers are hydrologically extreme freshwater systems that periodically cease to flow. Such habitats occur worldwide, but they are most common in semi-arid regions of the world, such as the Mediterranean region. Trichoptera are frequently used in biomonitoring programmes worldwide. However, their biodiversity and ecological requirements in intermittent Mediterranean karst habitats are still poorly understood. Here, we provide data on Trichoptera assemblage metrics (taxa richness, diversity and abundance), assemblage structure (trophic structure and stream zonation preference), and their relationship with environmental variables in the lotic phase of four intermittent rivers in the Dinaric karst region of the Mediterranean in the Western Balkans. Due to the extreme hydrological conditions in the studied habitats, Trichoptera showed a low taxa richness (10 taxa). The highest diversity was recorded in rivers with greater habitat heterogeneity. In addition, rivers with higher conductivity and water temperature, and lower water velocity had more diverse assemblages. The trophic structure and stream zonation preferences of Trichoptera were significantly different among the intermittent rivers studied, with the influence of anthropogenic activities evident in certain rivers. However, the variability of Trichopteran assemblages along the course of each intermittent river, was generally low, which could be attributed to the uniform microhabitat composition and physico-chemical water parameters in the studied rivers. The results of this study could provide a valuable background for further research and the development of conservation measures for both Trichoptera and intermittent karst habitats in the Mediterranean.

Our work is based on the assumption of a connection between the development of phytoplankton as chlorophyll a (CHL) and the long-term dynamics of solar activity expressed as sunspot numbers (Wolf numbers, W) by the example of the Rybinsk Reservoir (Upper Volga, Russia). We analyzed the possible relationship between mean for the growing season CHL and W over the period of solar cycles 20–24 (1969–2019), as well as the relationship between CHL in water and bottom sediments with W during the entire cycle 24 (2009–2019). A moderate tendency towards a decrease in CHL with increasing W was revealed for cycles 20 and 22, but for cycle 21 there was no correlation between them at all. A linear increase in CHL with increasing W was detected for cycle 23 and the most distinct for the cycle 24. A close relationship with high positive correlation coefficients equal to 0.74 and 0.70 have been established between W and CHL in water and bottom sediments during cycle 24. For sedimentary pigments, the degree of correlation with W depends on the type of bottom sediments. A reliable connection is typical for deep areas with a high rate of sludge accumulation; in areas with unfavorable conditions for sedimentation, such a relationship has not been identified. It is assumed that the increased correlation between CHL and solar activity in the cycle 24 compared to the previous cycles is due to the anomaly of this cycle, characterized by unprecedentedly low W values.

Over 27 years in Great Salt Lake (GSL: Utah, USA), phytoplankton relative abundances of chlorophytes, diatoms and cyanobacteria varied dramatically (monthly < 10–90% for each). This observed variability within the lake was compared to laboratory experimental results with pure cultures (> > 90%) of several of the most common GSL phytoplankton (chlorophyte–Dunaliella viridis, diatom–Nitzschia epithemioides, cyanobacterium–Euhalothece sp.). Maximum abundances and growth rates were measured across ranges of temperature (10–30 °C), salinity (30–150 ppt) and nutrients (nitrogen: 0.0–0.64 mg/L, silica:17–51 mg/L) observed within GSL. Experimental results indicated the abundance and growth rate of D. viridis increased as salinity and nitrogen increased and decreased as temperature increased. The abundances and growth rates of N. epithemioides and Euhalothece decreased as salinity increased, and increased as temperature and nitrogen increased, and N. epithemioides increased as silica increased. Observed GSL phytoplankton relative abundances responded to environmental conditions as observed in the experiments, but correlations were weak except for chlorophytes, as diatoms and cyanobacteria relative abundances occasionally increased with unfavorable experimental conditions. The weak correlations between laboratory results and GSL observations could be due to the release of diatoms and cyanobacteria from microbialite biofilms in the lake’s benthos with cold stress and high winds, as a 5–10% release can produce diatom and cyanobacteria phytoplankton relative abundances of 24–48%. This suggests a novel potential link between GSL pelagic and benthic zones.