Application of Aquatic Insects (Ephemeroptera, Plecoptera And Trichoptera) In Water Quality Assessment of Malaysian Headwater

Chromosome-scale genome assemblies of Himalopsyche anomala and Eubasilissa splendida (Insecta: Trichoptera)

Trichoptera is one of the most evolutionarily successful aquatic insect lineages and is highly valued value in adaptive evolution research. This study presents the chromosome-level genome assemblies of Himalopsyche anomala and Eubasilissa splendida achieved using PacBio, Illumina, and Hi-C sequencing. For H. anomala and E. splendida, assembly sizes were 663.43 and 859.28 Mb, with scaffold N50 lengths of 28.44 and 31.17 Mb, respectively. In H. anomala and E. splendida, we anchored 24 and 29 pseudochromosomes, and identified 11,469 and 10,554 protein-coding genes, respectively. The high-quality genomes of H. anomala and E. splendida provide critical genomic resources for understanding the evolution and ecology of Trichoptera and performing comparative genomics analyses.

Pesticide pollution associations with riverine invertebrate communities in England

Globally freshwater biodiversity has experienced major decline and chemical pollutants are believed to have played a significant role in this decline, but this has not been well quantified for most riverine invertebrate populations. Here we applied a biogeographically independent trait-based bioindicator, SPEARpesticides across sites across five regions (Northern, Midlands and Western, Anglian, Southeast, and Southwest) in England to investigate for associations specifically between pesticide use/pollution and riverine invertebrate communities over a 55-year period (1965-2019). Both spatially and temporally post-1990, the Anglian and Thames regions consistently showed the lowest SPEARpesticides scores, illustrating the presence of fewer pesticide sensitive species. The Anglian region had the highest pesticide use compared to all other regions from 1990 to 2018 and there were negative relationships between the level of pesticide/insecticide use and the regional SPEARpesticides score. Biochemical Oxygen Demand and ammonia, as measures of general water quality, were also negatively correlated with the SPEARpesticides scores across the regions, but these factors were not the driver for the lower SPEARpesticides scores seen in the Anglian region. Based on SPEARpesticides scores, riverine invertebrate communities in England have been most impacted in the Anglian region and we evidence chronic insecticide exposure is likely a significant factor in shaping the status of those invertebrate communities.

Decline of insects and arachnids driven by nutrient enrichment: A meta-analysis

Recent studies have documented global declines in insects and their relatives, but the exact mechanisms explaining these patterns are not fully understood. A potential driver underlying arthropod population declines is increases in anthropogenic inputs of nitrogen (N) and phosphorus (P). Here, we synthesize the effects of N, P, and combined N + P enrichment on the abundance of hexapods (insects and collembola) and arachnids from 901 experiments reported in 84 studies. We found that N and combined N + P enrichment caused significant decreases in the abundance of these groups overall. While arthropod responses to nutrient enrichment across aquatic and terrestrial habitats and in temperate as well as tropical climatic zones differed in magnitude, our results suggest that arthropods are decreasing similarly in response to nitrogen and phosphorus enrichment. Further, despite previously shown differences in the nutrient demands of different insect metamorphosis groups, we found consistent negative effects of N + P enrichment on all groups. Our results also showed that the negative effects of nutrient additions are stronger for aquatic insects that are considered more sensitive to changes in physical-chemical parameters in their environments, Ephemeroptera, Plecoptera, and Trichoptera (EPT), compared with other aquatic insects. In addition, N + P enrichment reduced the abundance of above-ground and below-ground arthropods, suggesting that a similar mechanism driving arthropod community change is acting on both groups. These findings suggest that changes in elemental cycles are a potential cause of the ongoing global decline of arthropods and underscore the serious effects of nutrient enrichment on ecological systems.

The larvae of caddisfly species (Insecta, Trichoptera) in northern Thai streams and their relationships to environmental variables

There have been few systematic studies on Trichoptera larvae in Thailand. The larval stages of the endemic species remain mostly unknown. Continued work on describing the larval stages of species will improve the precision of water quality monitoring metrics and enable ecological studies of species. This paper describes the unknown larvae of Hydropsyche pallipenne Banks 1938 and Hydropsyche askalaphos Malicky & Chantaramongkol 2000, with their identities deduced from the fact that both the larvae described here and identifiable adult specimens were sampled at the same location. Also, the effects of environmental variables on the distribution of caddisfly larvae in northern Thai streams were investigated. In total, 41 taxa from seven streams were identified, representing twenty-four genera and thirteen families. The Hydropsychidae were the most numerous family collected, accounting for 1,487 specimens (54%). Trichopteran abundance (for Triaenodes sp., Marilia sumatrana, Amphipsyche meridiana, Hydropsyche askalaphos, Leptocerus sp., Ganonema sp., Chimarra cf. akkaorum, Cheumatopsyche cf. dubitans, Macrostemum sp., and Leptocerus sp.) is influenced by environmental factors such as water temperature, dissolved oxygen, total dissolved solids, ammonia nitrogen, nitrate nitrogen, and pH. Because of their significant responses to environmental fluctuations, the caddisfly assemblage proved useful in identifying variations in water quality conditions in northern Thai streams.  

DNA barcoding unveils a high diversity of caddisflies (Trichoptera) in the Mount Halimun Salak National Park (West Java; Indonesia)

Background

Trichoptera are one of the most diverse groups of freshwater insects worldwide and one of the main bioindicators for freshwater quality. However, in many areas, caddisflies remain understudied due to lack of taxonomic expertise. Meanwhile, globally increasing anthropogenic stress on freshwater streams also threatens Trichoptera diversity.

Methods

To assess the Trichoptera diversity of the area within and around the Mount Halimun Salak National Park (MHSNP or Taman Nasional Gunung Halimun Salak) in West Java (Indonesia), we conducted a molecular-morphological study on Trichoptera diversity using larvae from a benthic survey and adults from hand-netting. In addition to morphological identification, we applied four different molecular taxon delimitation approaches (Generalized Mixed Yule Coalescent, Bayesian Poisson Tree Processes, Automatic Barcode Gap Discovery and Assemble Species by Automatic Partitioning) based on DNA barcoding of Cytochrome-C-Oxidase I (COI).

Results

The molecular delimitation detected 72 to 81 Operational Taxonomic Units (OTU). Only five OTUs could be identified to species level by comparing sequences against the BOLD database using BLAST, and four more to the genus level. Adults and larvae could be successfully associated in 18 cases across six families. The high diversity of Trichoptera in this area highlights their potential as bioindicators for water quality assessment.

Conclusions

This study provides an example of how molecular approaches can benefit the exploration of hidden diversity in unexplored areas and can be a valuable tool to link life stages. However, our study also highlights the need to improve DNA barcode reference libraries of Trichoptera for the Oriental region.

Characterisation of Macroinvertebrate Communities in Maritsa River (South Bulgaria)—Relation to Different Environmental Factors and Ecological Status Assessment

A survey of the macrozoobenthos communities in the Maritsa River (South Bulgaria) was carried out in the summer of 2021. Benthic samples were collected and physicochemical parameters (water temperature, pH, conductivity, dissolved oxygen and nutrients) were measured at 15 sites located on the main river and its tributary system. The studied sites belonged to different river types and characterised the diversity of the ecological conditions—from unaffected to anthropogenically influenced river stretches. In addition, data from a study conducted in the summer of 2020 were used to analyse species–factor interactions in the river ecosystems and to assess the bio-indicative potential of the aquatic invertebrates. The dynamics of the taxonomic composition and abundance of the macrozoobenthos were analysed in relation to environmental factors. The physicochemical conditions of the water environment changed during the period of high water, which led to a reduction in the composition of the macrozoobenthos. Plecoptera and Trichoptera decreased in richness and abundance downstream and under human impacts. Ephemeroptera and Chironomidae were permanently present along the whole river. Oligochaeta increased in the lower river reaches and at sites with a greater amount of organic matter. The ecological status determined by the macrozoobenthos varied from high (site 1) to good, moderate and bad (site 13) at the studied sites.

Morphological and molecular characterisation of the Popijač's Yellow Sally, Isoperlapopijaci sp. nov., a new stenoendemic stonefly species from Croatia (Plecoptera, Perlodidae)

A new species of the Yellow Sally genus (Isoperla Banks, 1906) is described, based on morphological (males and females adults, larval and egg) and molecular (the barcode region of the cytochrome c oxidase subunit I gene (COI)) features. Popijač’s Yellow Sally, I.popijaci Hlebec & Sivec, sp. nov. inhabits two karstic sources of the Krasulja rivulet in Croatia. Male and female of the new species are characterised by colouration patterns of the head and pronotum; the dimensions of the female subgenital plate; the medial penial armature and oval-shaped egg without collar and anchor. The larvae differ from their congeners by the uniquely coloured head and pronotum. Based on morphological characteristics I.popijacisp. nov. belongs to the I.tripartita species group. Phylogenetic and taxonomic relationships were reconstructed using three methods of phylogenetic inference and three species delimitation methods. As I.popijacisp. nov. occurs at a narrow area of the Krasulja rivulet in Krbava field, the study puts emphasis on the conservation and hotspot importance of the temporary rivers in the Dinaric karst. Furthermore, the study accentuates the necessity for further research on the genetic diversity of Plecoptera in Croatia.

Seasonal consumption of terrestrial prey by a threatened stream fish is influenced by riparian vegetation

The consumption of terrestrial prey by fishes highlights the functional value of terrestrial habitats, but such consumption is not well documented for many small-bodied species. We determined the diet and consumption of terrestrial prey by a threatened fish, silver shiner Notropis photogenis, using stomach content and stable isotope analyses to better understand the functional role of riparian habitat for the species. Results indicate silver shiner is a generalist drift feeder that consumes a wide range of aquatic and terrestrial prey. Both stomach content and stable isotope analyses indicated that terrestrial prey was commonly exploited and that terrestrial prey consumption was both seasonally and spatially variable. Based on stomach contents, the contribution of terrestrial prey was (average ± SD) 41.53 ± 32.35% in fall and 20.45 ± 20.45% in summer; based on stable isotopes it was 35.24 ± 4.41% in fall and 39.88 ± 12.34% in summer. During fall, when bankside terrestrial invertebrates were more abundant, silver shiner stomachs contained significantly more terrestrial prey in reaches where riparian vegetation cover was highest, indicating that intact riparian cover may facilitate access to high-quality prey. The consumption of terrestrial prey may be particularly important in fall, as it may promote increased growth and survival leading to more successful overwintering. Our findings suggest that terrestrial subsidies are ecologically valuable for silver shiner and that the protection of reaches with intact riparian habitats would likely improve conservation and recovery efforts by helping ensure access to key prey resources.

Evaluating the Pressure and Loss Behavior in Water Pipes Using Smart Mathematical Modelling

Due to the constant need to enhance water supply sources, water operators are searching for solutions to maintain water quality through leakage protection. The capability to monitor the day-to-day water supply management is one of the most significant operational challenges for water companies. These companies are looking for ways to predict how to improve their supply operations in order to remain competitive, given the rising demand. This work focuses on the mathematical modeling of water flow and losses through leak openings in the smart pipe system. The research introduces smart mathematical models that water companies may use to predict water flow, losses, and performance, thereby allowing issues and challenges to be effectively managed. So far, most of the modeling work in water operations has been based on empirical data rather than mathematically described process relationships, which is addressed in this study. Moreover, partial submersion had a power relationship, but a total immersion was more likely to have a linear power relationship. It was discovered in the experiment that the laminar flows had Reynolds numbers smaller than 2000. However, when testing with transitional flows, Reynolds numbers were in the range of 2000 to 4000. Furthermore, tests with turbulent flow revealed that the Reynolds number was more than 4000. Consequently, the main loss in a 30 mm diameter pipe was 0.25 m, whereas it was 0.01 m in a 20 mm diameter pipe. However, the fitting pipe had a minor loss of 0.005 m, whereas the bending pipe had a loss of 0.015 m. Consequently, mathematical models are required to describe, forecast, and regulate the complex relationships between water flow and losses, which is a concept that water supply companies are familiar with. Therefore, these models can assist in designing and operating water processes, allowing for improved day-to-day performance management.

Evaluation of the surface water quality in the Kebir-Rhumel catchment area (northeast Algeria) using biotic indices and physico-chemical analyses

Assessing the water quality of the Kebir-Rhumel watershed by the use of benthic macroinvertebrates and physico-chemical analysis is the aim of this work. Thirteen physicochemical parameters and macroinvertebrates fauna were collected monthly in 15 stations located along the catchment area in the two principal wadis: El Kebir and Rhumel. Canonical correspondence analysis was used to study the relationships between physico-chemical parameters and macroinvertebrates. Biotic indices Biological Monitoring Working Party (BMWP'), Global Biological Normalized Index (IBGN), EPT index (Ephemeroptera, Plecoptera, Trichoptera), and %EPT/Chironomidae, based on benthic macroinvertebrates, have been applied in assessing the biological water quality. According to the results, a majority of the physicochemical parameters measured during the study period show spatial heterogeneity (Kruskal-Wallis, P value < 0.05), indicating that Rhumel wadi is more polluted compared with El Kebir wadi; the NO₂^-, NO₃^-, PO₄^-3, Cl^-, and SM contents are very high consequences of human and industrial anthropogenic actions. Canonical correspondence analysis has shown that the environmental parameters measured during this study influence the dynamics of macroinvertebrates, and the polluo-resistant taxa (Chironomidae) predominate in sites very rich in organic matter with low oxygen conditions. Sensitive taxa have a vulnerability to pollution. The biotic indices used confirm the diagnosis of the physicochemical analysis demonstrating a very degraded quality at Rhumel wadi. The EPT index and %EPT/Chironomidae results are closer to the scores of the BMWP' index.

Influences of environmental parameters and phytoplankton productivity on benthic invertebrates in a tropical oligotrophic lake, northern Malaysia

Studies that associate environmental parameters with aquatic organisms in man-made lakes remain limited by accessibility and interest particularly in many Asian countries. With missed opportunities to monitor environmental transitions at Lake Kenyir, our knowledge of lake transition is restricted to the non-mixing shallow waters only. Triplicate monthly benthic invertebrate samples were collected concurrently with various environmental parameters at three locations (zones A-C) of Kenyir Lake, Malaysia. Our results affirmed that the northeast part of Lake Kenyir is oligotrophic. Abundance of phytoplankton, total suspended solids, phosphate, nitrite and nitrate drive the abundance of various groups of benthic invertebrates. All of these extrinsic variables (except phosphate) negatively influenced the density of Trichoptera and positively influenced (P<0.05) the densities of Polychaeta, Oligochaeta, Bivalvia, Gastropod, Isopoda and Copepod in all zones. Phosphate negatively influenced the density of Trichoptera and positively influenced (P<0.05) the densities of Oligochaeta, Bivalvia and Copepod. Its influences on the Polychaeta, Gastropod and Isopoda densities were zone-specific. Overall, seasons equally influenced the relationships between extrinsic and response variables in all zones. The results of this study are useful to evaluate the lake's environmental quality, in conservation and in similar projects involving environmental handling, monitoring and recovery.

Biological Water Quality Indices Performance Based on Aquatic Insects in Recreational Rivers

Abundance and distribution of aquatic insects respecting to several water chemical parameters from six rivers were studied in order to determine the performance of biological index in monitoring the water quality. A total of 960 individuals of aquatic insects from nine orders were recorded using kick and drag sampling techniques. Lubok Semilang had the greatest number of aquatic insects with 250 individuals, followed by Telaga Tujuh (181 individuals) and Sungai Durian Perangin (171 individuals). EPT (Ephemeroptera, Plecoptera and Trichoptera) order were the most dominant order recorded in all six rivers. Lata Kekabu had more diverse and richer aquatic insect assemblages based on ecological indices compared to the other five rivers. In order to evaluate the water quality of recreational rivers in Malaysia, Family Biotic Index (FBI), Malaysian Family Biotic Index (MFBI) and Biological Monitoring Working Party (BMWP) were used and compared with Water Quality Index (WQI) to determine the water quality at the study areas. Results demonstrated that the biotic indices were more sensitive towards changes in water parameters than the WQI. Among all the biological indices, MFBI was the most suitable index to be adopted in Malaysian river water assessment as it is more reliable in assessing the status of water quality.

Biological and chemical monitoring of the ecological risks of pesticides in Lake Ziway, Ethiopia

Lake Ziway, a freshwater lake located in Ethiopia, is under the pressure of pesticide and nutrient pollution due to agricultural activity and urbanization. This study has analysed concentrations of insecticides, fungicides and nutrients in water and sediment samples of Lake Ziway taken in the wet and dry season at 13 sites expected to be under different environmental stress and assessed their expected ecological impacts. Malathion, dimethoate, metalaxyl, diazinon, chlorpyrifos, fenitrothion and endosulfan were detected in more than half of the water samples, while diazinon, α-cypermethrin and endosulfan were frequently detected (>25%) in sediment samples. Higher levels of physicochemical parameters were observed at sample locations proximate to agricultural and urban activities. Risk quotients (RQ) and multi-substance Potentially Affected Fraction (msPAF_RA) were calculated to assess the ecological risk of individual and mixture of pesticides, respectively. The majority of the pesticides detected in the water of the lake showed a potential acute risk (RQ > 1), specifically the insecticides chlorpyrifos, λ-cyhalothrin and α-cypermethrin for which high potential acute risks were calculated using a 2nd tier risk assessment. Levels of pesticides in sediment showed low ecological risks. Arthropods and fishes are expected to be highly affected by mixtures of pesticides (msPAF_RA = < 1-80%) detected at locations that are proximate to smallholders' farms, and receive largescale farms' wastewater and at sites where inflow rivers join the lake. Macroinvertebrates based redundancy analysis showed the effectiveness of EPT richness to assess ecological status of the lake. Training for smallholder farmers on pesticides safety and usage, and implementation of improved effluent management mechanisms by floriculture farms are urgently needed intervention measures to reduce the pollution.

Physicochemical and biological status of Aghlagan river, Iran: effects of seasonal changes and point source pollution

Although the macroinvertebrates have been widely used as bio-indicator for river water quality assessment in developed countries, its application is new in Iran and data on the health status of the most ecologically important rivers in Iran is scarce. The present study aimed at monitoring and assessing the ecological quality of Aghlagan river, northwest of Iran, using integrated physicochemical-biological approaches. A total of 14,423 samplings were carried out from the headwater to downstream sites at four stations (S1, 2, 3, 4) by a Surber sampler (30 cm × 30 cm) from June 2018 to April 2019. The results obtained from macroinvertebrate biotic index revealed that the genera of Gammarus (Amphipoda) and Baetis (Ephemeroptera) were the most abundant in all seasons. The PAST software was applied to analyze the diversity indices (Shannon-Weiner diversity, Evenness, and Simpson indices). Based on the cluster analysis, S3 established the least similarity to other stations. The average frequency of each macroinvertebrate species was determined by one-factor analysis of similarities (ANOSIM). In accordance with canonical correspondence analysis (CCA), temperature and phosphate were found as the dominant factors effecting the macroinvertebrate assemblage and distribution. Moreover, the results obtained from the biological indices concluded very good quality of S4 by Helsinhoff and EPT indices and fair quality using BMWP index. The data on the macrobenthos assemblage and dynamics in the Aghlagan river across a hydraulic gradient provided useful information on water management efforts that assist us to find sustainable solutions for the enhanced quality of the river by balancing environmental and human values.

Small Patches of Riparian Woody Vegetation Enhance Biodiversity of Invertebrates

Patches of riparian woody vegetation potentially help mitigate environmental impacts of agriculture and safeguard biodiversity. We investigated the effects of riparian forest on invertebrate diversity in coupled stream-riparian networks using a case study in the Zwalm river basin (Flanders, Belgium). Agriculture is one of the main pressures in the basin and riparian forest is limited to a number of isolated patches. Our 32 study sites comprised nine unshaded “unbuffered” sites which were paired with nine shaded “buffered” sites on the same stream reach, along with five ‘least-disturbed’ sites and nine downstream sites. We sampled water chemistry, habitat characteristics and stream and riparian invertebrates (carabid beetles and spiders) at each site. Three methods were used to quantify riparian attributes at different spatial scales: a visually-assessed qualitative index, quantitative estimates of habitat categories in six rectangular plots (10 × 5 m) and geographic information system (GIS)-derived land cover data. We investigated relationships between invertebrates and riparian attributes at different scales with linear regression and redundancy analyses. Spiders and carabids were most associated with local riparian attributes. In contrast, aquatic macroinvertebrates were strongly influenced by the extent of riparian vegetation in a riparian band upstream (100–300 m). These findings demonstrate the value of quantifying GIS-based metrics of riparian cover over larger spatial scales into assessments of the efficacy of riparian management as a complement to more detailed local scale riparian assessments in situ. Our findings highlight the value of even small patches of riparian vegetation in an otherwise extensively disturbed landscape in supporting biodiversity of both terrestrial and freshwater invertebrates and emphasize the need to consider multiple spatial scales in riparian management strategies which aim to mitigate human impacts on biodiversity in stream-riparian networks.

Study on the Fauna of Aquatic Insects in Northwestern Iran

Background:

Aquatic insects include groups of arthropods which at least one step of their life happens in water. Some of these insects play an important role in the transmission of various diseases to human and animals. Because there is a little information about the fauna of aquatic insects in Iran, this study was aimed to collect and identify aquatic insects in northwestern Iran.

Methods:

A descriptive cross sectional study was performed in July 2017 in Rivers of three villages of Osku County of East Azerbaijan Province, northwestern Iran. The specimens were collected using different methods including D frame net-collector, standard mosquito dipper, Sweep Netting and plastic pipette. The collected specimens were identified based on the systematic keys of aquatic insects.

Results:

Totally 285 samples were collected. Four orders including Diptera, Hemiptera, Ephemeroptera and Coleoptera were identified. Collected samples belonged to seven families of Tipulidae, Chironomidae, Corixidae, Culicidae, Hydrophilidae, Baetidae and Dytiscidae. The most predominant family was Culicidae belonging to order Diptera. Culiseta longiareolata was the most frequent species collected in the study area.

Conclusion:

Aquatic insects usually play an important role in the food chain of animals and some species of them act as predators and play an important role in the biological control of vectors. Therefore, more studies are required to carry out in the field of aquatic insects.

Trophic responses to aquatic pollution of native and exotic livebearer fishes

The objective of this study was to evaluate if aquatic pollution promote diet shifts in two livebearer fishes (Poeciliidae): an exotic species, the guppy (Poecilia reticulata), and a native livebearer (Phalloceros uai). The study was carried out in a Brazilian basin highly impacted by anthropogenic activities, especially discharge of domestic and industrial sewage from a region with more than five million human inhabitants. To evaluate the trophic ecology of both native and exotic species it was analysed carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotopes of fish tissue, food resources and, sewage. Moreover, stable isotopes analyses were coupled with gut contents of the two species to provide additional information about fish diet. Exotic guppy abundance was high in the most polluted site, where P. reticulata assimilated carbon directly from sewage. The native species was absent in the most polluted site, but presented wider niches than the exotic species in almost all other sites. Gut content analyses indicated high consumption of aquatic insects by both species. However, while the native species consumed a diverse suite of insect taxa, the exotic species consumed mainly Chironomidae larvae. We conclude that aquatic pollution promotes diet shifts in both native and exotic species, with both species changing their trophic niches in a similar way according to the level of degradation of the environment. The ability to directly assimilate sewage, together with its capacity to survive in environments with poor water quality and its reproductive strategy, may favour the establishment of exotic guppies in strongly polluted sites.

Impact of environmental factors on aquatic biodiversity in roadside stormwater ponds

Constructed stormwater ponds mitigate runoff volumes and pollution, and provide other ecosystem services, such as supporting biodiversity, but these services attracted relatively less attention. The impacts of the pollution levels in the water column and sediments, the physical characteristics of ponds, and the presence of amphibians on the macroinvertebrate community composition and biodiversity were explored in twelve stormwater ponds in Norway. Also, the similarities between macroinvertebrate, zooplankton and plant communities were explored. Most of the taxa displayed in the ordination diagram were positively correlated with the pond size and the number of neighbouring ponds, and negatively correlated with the pollution levels in the water column and sediments. However, no statistically significant impacts on the number of taxa and Shannon index were observed. There were low similarities between the macroinvertebrate and zooplankton community compositions as well as between the plant and macroinvertebrate community compositions in the stormwater ponds. We observed a significant positive correlation between the number of plant and of zooplankton taxa, and a weak non-significant positive correlation between the number of plant and of macroinvertebrate taxa. Overall, the explanatory variables had a significant impact on the community composition, but not on the number of taxa nor Shannon index.