Aquatic Insect Species Richness Research Articles

Aquatic insect biodiversity, water quality variables, and microplastics in the living weir freshwater ecosystem

Most Thai rivers have not yet reached "good" ecological status. Furthermore, the scientific community is deeply concerned about the existence and abundance of microplastics (MPs) in freshwater. The live weirs' river health status was assessed using water quality and a variety of aquatic insect species. The research was conducted along Khlong-La, which was compared in the absence (R1, R2) and presence of living weirs (LWs) (M71, M62, M4, and M2). In 2023, aquatic insects and water samples were gathered during two months: January (rainy season) and July (dry season). The results revealed that the six sampling sites had similar physical and chemical properties, with the exception of total dissolved solids, which varied significantly. A total of 658 aquatic insects from 25 families and 6 orders were identified. The Hydropsychidae dominated the aquatic insect fauna at the LWs locations, followed by Chironomidae, Naucoridae, and Caenidae. Ten genera were discovered at the reference site (R1), whereas 16, 21, 24, and 19 were discovered at LWs (M71, M62, M4, M2), and 16 at the reference site (R2). The results of CCA ordination revealed that the most important factors influencing aquatic insect diversity were dissolved oxygen, water temperature, pH, electrical conductivity, and ammonia nitrogen. This study suggests that because of their significant responses to environmental factors, the species richness of aquatic insects may indicate the conservation value of habitats. The BMWPTHAI score was 41, 51, 57, 58, 73, 54, and the ASPTTHAI score was 5.12, 5.10, 5.18, 5.27, 4.86, and 5.40, respectively. Shannon-Weiner diversity index (Hʼ) values were 2.059, 2.461, 2.839, 2.777, and 2.587, respectively. The results showed that the water quality was average. The physicochemical data, as well as the BMWP and ASPT, revealed that the water at the living well was slightly polluted. Furthermore, larger MPs (>500 µm) were found in the largest concentrations, in the shape of fibers, and primarily in the color violet.

Assessing impacts of sulfur deposition on aquatic ecosystems: A decision support system for the Southern Appalachians

AbstractWith climate change and ongoing impacts from human development and resource extraction, US federal land management agencies are acutely concerned with managing for healthy aquatic ecosystems in the Southern Appalachian Mountain (SAM) Region. Here, we describe development of a spatial decision support application to assess the biological and ecological impacts of atmospheric S and N deposition on aquatic ecosystems of the region. We first summarize foundational published work to predict continuous maps of surface water acid neutralizing capacity (ANC) and soil base cation weathering (BCw). We use the predicted ANC and BCw maps to estimate steady‐state critical loads (CLs) of atmospheric S and N deposition. We included estimated CLs of atmospheric N to get a complete picture of CLs and potential exceedances. We then present a logic‐based decision support model for assessing effects of S and N deposition based on statistically modeled stream ANC and CL exceedance. The model is easily modified for continuous monitoring of CL exceedance patterns as new S and N deposition and ANC data become available. We present mapped model results for the SAM study area and an important subset of the region, the Great Smoky Mountains National Park. ANC modeling results revealed that predicted acid sensitivity was spatially variable, with areas of relatively low stream ANC (<50 μeq · L−1) and soil BCw (<50 meq · m−2 · year−1) predominantly found in certain critical areas. Within the Great Smoky Mountains National Park, evidence for S CL exceedance based on an ANC criterion of 50 μeq · L−1 was strong at locations where ambient S deposition was at least two times the CL. We also predicted likely impacts of CL exceedances on aquatic insect species richness and native fish abundance. Responses for insect species richness and fish impact showed variability similar to CL exceedance, with increasing impact positively correlated with elevation. Finally, we discuss ways that the decision support system can be used to prioritize management across the region.

Aquatic Insects as Bio-Indicators of Water Quality – A Study on Sungai Kawal, Johor National Park of Endau-Rompin, Peninsular Malaysia

Biological indicator species or bio-indicators are sensitive to specific environmental factors so that changes in their environment will be reflected by their incidence or abundance. In fact, aquatic insects of freshwater river and stream ecosystems have been widely used as bio-indicators to examine the species-habitat relationship with regard to the water quality of the habitat. Therefore, this study attempted to determine species richness of aquatic insects in Sungai Kawal, Johor National Park of Endau-Rompin (TNJER), Mersing, Johor, Malaysia; to identify traditional knowledge (TK) used by Jakun tribe in Kampung Peta, TNJER for maintaining rivers and streams at good level; and then to correlate the relationship between the scientific perspective and TK perspective. Aquatic insects were collected and sampled by using kick sampling technique and D-framed net. Throughout the study, a total of 618 individuals consisting of 23 families belonging to seven orders of aquatic insects were reported. The documentation of TK was done by interviewing 10 total respondents of the Jakun tribe in Kampung Peta. Physical features of Sungai Kawal were also recorded during sampling. The correlation between the scientific perspective and TK perspective regarding how the ecosystem maintenance by the Jakun tribe has contributed to an excellent habitat for the aquatic insects to breed and multiply. The number of species recorded indicated the good status of water quality of Sungai Kawal based on science and then supported by TK of the Jakun tribe of Kampung Peta. Furthermore, the findings also suggested a good correlation between the scientific perspective and TK perspective, and the significant contribution of TK of the Jakun tribe to the management of natural resources.

Caddisflies (Trichoptera, Insecta)as Bioindicator of Water Quality Assessment in a Small Stream in Northern Thailand

The influence of environmental variables and the potential as bioindicators of larval stages of the species of Trichoptera were evaluated in a small stream in northern Thailand from January to November 2017. A total of 1,191 individual caddisfly larvae belonging to 7 families and 13 genus were found. The larvae of the family Glossosomatidae were the most abundant, followed by Hydropsychidae and Calamoceratidae. The genus Glossosoma, Hydromanicusand Hydropsyche were the most abundant genus in this study. Results of the CCA ordination showed that total dissolved solids, electrical conductivity, and water temperature were the most important factors affecting the abundance and diversity of caddisfly larvae. Changes in the caddisfly larvae may indicate changes in physicochemical factors owing to urbanization or other anthropogenic. The results showed that the order Trichoptera, identified to the species or genus level, can potentially be used to assess environmental water quality status in freshwater ecosystems. This study suggested that species richness of aquatic insects may indicate the conservation value of the habitats because of their significant responses to environmental factors.

Determining drivers of dragonfly diversity patterns and the implications for conservation in South Africa

Knowing where species occur is essential for conservation planning. In South Africa, regional climatic variation is subject to effects of oceanic current systems, which in turn, determine species diversity patterns. We hypothesize that regional climates and topography are important drivers of aquatic insect species richness, endemism, and assemblage composition, and expect strong assemblage-turnover boundaries to be concurrent with topographical features. We also expected that current conservation networks do not represent aquatic insect species richness and endemism. We used generalized linear mixed models and generalized dissimilarity models to determine drivers of South African dragonfly (Odonata) species richness and assemblage-turnover, as well as to investigate the extent of assemblage-turnover boundaries. We found that climate gradients were significant drivers, and found significant variation in assemblages between sub-regions. Turnover boundaries were gradual but concurrent with topographical features and/or areas with spatial changes in sub-regional climate. Modern-day climate and topography partially explained dragonfly diversity patterns, but other local factors and past geological events likely both contribute to current dragonfly diversity patterns. The existing conservation network in South Africa represents areas of high dragonfly species richness and endemism. We recommend additional conservation efforts in areas outside of protected areas with high species richness and endemism levels, but importantly also in areas with high assemblage-turnover rates to ensure protection of as many species as possible. We also propose further searches in areas with high endemism and high assemblage-turnover for possible discovery of unknown species, and further searches in under-represented areas to improve distribution data for known species.

Fluctuating pond water levels and aquatic insect persistence in a drought-prone Mediterranean-type climate

In dry areas, natural and artificial ponds experience frequent water level fluctuation, affecting conditions for some aquatic and amphibiotic taxa. Water beetles, bugs, and dragonflies make up much of pond diversity, and are responsive to changes in environmental conditions. Using a drought-prone pondscape within the Greater Cape Floristic Region biodiversity hotspot, we determine (1) the relative extent to which species richness, abundance, and composition are affected by pond water level fluctuation, (2) the effects of environmental variables and vegetation characteristics relative to fluctuating water levels, and (3) make recommendations to improve pondscape conservation. We found that the degree of fluctuation had a significant effect on beetle species richness, but had no significant effect on the other focal taxa. Water temperature, pH, and conductivity, and vegetation cover and composition were drivers of aquatic insect species richness, abundances, and assemblage structures. Habitat heterogeneity supported rich aquatic insect assemblages. We recommend that a range of ponds with various degrees of water level fluctuation should be maintained, along with naturally diverse marginal vegetation. Such a dynamic pondscape can contribute greatly towards maintenance of local and regional aquatic insect diversity in drought-prone regions and should be considered as a main focus in conservation efforts.

Aquatic insects decline in abundance and occupy low‐quality artificial habitats to survive hydrological droughts

Abstract Hydrological extremes have negative impacts on natural, agricultural, and urban landscapes and place substantial ecological pressure on freshwater habitats. However, the role of artificial freshwater habitats during hydrological drought is poorly understood. Insects make up much of total aquatic fauna and lend themselves to understanding how drought impacts freshwater ecosystems. Using the Greater Cape Floristic Region as an example of a drought‐prone area, we determined the effects of a severe drought on a subset of insects occupying lentic habitats in terms of their species richness, diversity, and assemblage composition. Here, we: (1) calculated the percentage change in average precipitation between a record dry season and the last consistently wet decade; (2) identified the environmental variables driving aquatic insect species richness, diversity and composition; (3) identified the environmental differences between natural ponds and artificial reservoirs; (4) determined whether artificial reservoirs act as suitable habitats for focal taxa during drought; and (5) compared these results to other, pre‐drought studies. Environmental variables related to water chemistry and physical characteristics were drivers of species richness, diversity, and composition, yet vegetation cover remained a major driver. In terms of marginal vegetation cover, most artificial reservoirs did not resemble natural ponds, yet overall 38.4% of sampled aquatic insect species were shared between natural ponds and artificial reservoirs. We found some rare endemic species in artificial reservoirs that had never before been recorded in this habitat during wet years. When our drought findings were compared to earlier, wet years, species richness did not change significantly, although abundance was much lower during the drought year. We postulate that historically, these aquatic insects, which have been through many ecological filters such as drought, must have sought low‐quality habitats to survive water stress periods. Artificial reservoirs, being novel landscape features, cannot fully replace natural ponds, but enable some aquatic insects to survive drought. Artificial reservoirs can be attractive habitats to aquatic insects when they resemble natural ponds, with specific reference to their marginal vegetation characteristics.

Effects of Wood Density on Aquatic Insect Communities in a Cuban Montane Rainforest Stream.

We tested whether hardness or different wood carbon densities, considered as the concentration of carbon structural compounds, influence functional feeding groups and species richness of aquatic insects in a tropical stream. We expected that harder woods would harbor aquatic insect communities with species richness and functional food group profile different from softwoods. We also expected that collector-gatherers and collector-filterers will be more abundant in softwood because harder woods are less substrate suitable for biofilm production. Aquatic insects associated with the following plants were analyzed: Gomidesia lindeniana with high-density, Psychotria grandis with medium-density, and Meriania leucantha with low-density wood. Diptera and Ephemeroptera were the most abundant groups sampled in the woods. Psychotria grandis shows higher concentrations of lignin, cellulose, and hemicellulose, followed by G. lindeniana and M. leucantha. Breakdown rates are different among plant species with M. leucantha having four times highest breakdown rates and on average three more species in the species richness value. We did not find significant differences in the composition of insect species associated with the plants. We found evidence that the richness and functional organization of aquatic insect communities were mostly related to the breakdown rates and lignin amount of the woods. Plants that decompose faster on average have three more species and two more insect functional groups. Our findings suggest that the loss of high carbon density trees in tropical forests can affect aquatic biodiversity.

Effects of management intensity, function and vegetation on the biodiversity in urban ponds

Ponds are important elements of green areas in cities that help counteract the negative consequences of urbanization, by providing important habitats for biodiversity in cities and being essential nodes in the overall landscape-scale habitat network. However, there is relatively little knowledge about the impacts of pond management intensity, function and environmental variables on urban pond biodiversity. In this study we addressed this gap by investigating which factors were correlated with the level of biodiversity in urban ponds, indicated by species richness of aquatic insects, in Stockholm, Sweden. Our study did not confirm any direct link between the perceived intensity of management or function of ponds and overall biodiversity. However, it seems that management can influence particular groups of species indirectly, since we found that Trichoptera richness (Caddisflies) was highest at intermediate management intensity. We suggest that this is caused by management of vegetation, as the amount of floating and emergent vegetation was significantly correlated with both the overall species richness and the richness of Trichoptera (Caddisflies). This relationship was non-linear, since ponds with an intermediate coverage of vegetation had the highest richness. Interestingly, the amount of vegetation in the pond was significantly affected by pond function and pond management. The overall species richness and richness of Trichoptera were also positively correlated with pond size. Since we found that the pattern of relations between species richness and environmental variables differed between the insect groups we suggest that it will be difficult to provide overall design and management recommendations for ponds in urban green areas. Therefore, it is recommended that to provide high aquatic diversity of species in urban areas one should aim at promoting high diversity of different types of ponds with differing management and environmental factors that shape them.

Aquatic Insects from the Caatinga: checklists and diversity assessments of Ubajara (Ceará State) and Sete Cidades (Piauí State) National Parks, Northeastern Brazil.

BackgroundDiversity and distribution of Neotropical aquatic insects is still poorly known, with many species to be recorded and many others to be described, due to the small number of taxonomists and sparse faunistic studies. This knowledge is especially poor in the Caatinga Domain in Northeastern Brazil, even though, this region may have played an important historical role in the spatial evolution of faunas of forested areas in northern South America.New informationAquatic insect checklists of 96 species from Parque Nacional de Ubajara (Ceará State, Brazil) and 112 species from Parque Nacional de Sete Cidades (Piauí State, Brazil) are presented, representing the following taxa: Elmidae, Epimetopidae, Hydrophilidae, and Torridincolidae (Coleoptera), Hemerodromiinae (Diptera: Empididae), Ephemeroptera, Gerromorpha and Nepomorpha (Hemiptera), Odonata, Plecoptera, and Trichoptera. Because of the scarce number of biological inventories in Northeastern Brazil, several new distributional records (of species, genera, and families) for Brazil, Northeastern Brazil, and Ceará and Piauí states are provided. In addition, several undescribed species were detected, being 26 from Ubajara and 20 from Sete Cidades. Results represent a significant increase to the known fauna of these states, ranging from 13%-70% increase for Ceará and 41% to 91% increase for Piauí. Although both parks are relatively close to each other and within the Caatinga domain, their aquatic fauna display a very high complementarity (89% species), possibly due to structural differences of water bodies sampled in each park. Rarefaction curves based on quantitative light trap samples suggest a much higher expected species richness of aquatic insects at Sete Cidades than at Ubajara National Park. Discussion on biogeographical affinities of this sample of the Caatinga fauna is provided.

Changes in species richness of aquatic insects in a newly constructed biotope

Changes in species richness of aquatic insects in a newly constructed biotope

고도에 따른 제주 습지 수서곤충의 종풍부성 변화 : Rapoport 법칙의 검정

The effect of altitude and latitude on biodiversity (or species richness) has been a topic of great interest for many biogeographers for a long time. This study was conducted to examine the dynamics of species richness of aquatic insects along the altitudinal gradient in 24 wetlands on Mt. Halla, Jeju and test the Rapoport`s rule. The species richness of aquatic insects monotonically decreased with increasing altitude, showing a significant inverse correlation (r

Development of Biological Diversity in Farmland Ponds

ABSTRACT To describe the rate of pond diversity development and how the age of ponds affects diversity of plants, amphibians, and aquatic insects, eight recently created artificial ponds (four young ponds created in the year 2003 and four new ponds created in the year 2007) were compared to four reference ponds. For each pond, we recorded the presence of plants and the abundance of amphibians and aquatic insects in plots of 0.25 m2 along two orthogonal transects. Data were analyzed using rarefaction technique, permutation tests for multivariate analysis of variance (PERMANOVA), and rank-abundance diagrams. The new and young ponds showed lower plant and aquatic insect species richness than the reference ponds, and the communities showed gradual changes over time in all three taxa Amphibians, which were absent from new ponds, reached the same species richness as in reference ponds five years after pond creation. PERMANOVA wormed on presence/absence data showed no significant differences in community composition for aquatic insects and amphibians among pond age but showed significant differences among ponds belonging to, the same age classes for all taxa studied.

Predicting the species richness of aquatic insects in streams using a limited number of environmental variables

Artificial neural networks were used to predict the species richness of 4 major orders of aquatic insects (Ephemeroptera, Plecoptera, Trichoptera, and Coleoptera, i.e., EPTC) at a site, using a limited number of environmental variables. EPTC richness was recorded in the Adour–Garonne stream system (France), at 155 unstressed sampling sites, which were characterized using 4 environmental variables: elevation, stream order, distance from the source, and maximum water temperature. The EPTC and environmental data were first computed with the Self-Organizing Map (SOM) algorithm. Then, using the k-means algorithm, clusters were detected on the map and the sampling sites were classified separately for each variable and for EPTC richness. Four clusters could be identified on the SOM map, according to the 4 environmental variables, and this classification was chiefly related to stream order and elevation (i.e., the longitudinal location of sampling sites within a stream system). Similarly, 4 subsets were derived from the SOM according to a gradient of EPTC richness. There was also a high coincidence between observed (field data) and calculated (predicted from the output neurons of the SOM) species richness in each taxonomic group. Species richness relationships between Ephemeroptera, Trichoptera, and Coleoptera for both observed and predicted data were highly significant. However, correlation coefficients among species richness of Plecoptera and the other groups were low. Last, a multilayer perceptron neural network, trained using the backpropagation algorithm, was used to predict EPTC richness (output) using the 4 above-mentioned environmental variables (input). The model showed high predictability (r = 0.91 and r = 0.61 for training and test data sets, respectively), and a sensitivity analysis revealed that elevation and stream order contributed the most among the 4 input variables. Prediction of species richness using a limited number of environmental variables is, thus, a valuable tool for the assessment of disturbance in a given area. The degree to which human activities have altered EPTC richness can be determined by knowing what the EPTC richness should be under undisturbed conditions in a given area.

Applications of artificial neural networks for patterning and predicting aquatic insect species richness in running waters

Two artificial neural networks (ANNs), unsupervised and supervised learning algorithms, were applied to suggest practical approaches for the analysis of ecological data. Four major aquatic insect orders (Ephemeroptera, Plecoptera, Trichoptera, and Coleoptera, i.e. EPTC), and four environmental variables (elevation, stream order, distance from the source, and water temperature) were used to implement the models. The data were collected and measured at 155 sampling sites on streams of the Adour–Garonne drainage basin (South-western France). The modelling procedure was carried out following two steps. First, a self-organizing map (SOM), an unsupervised ANN, was applied to classify sampling sites using EPTC richness. Second, a backpropagation algorithm (BP), a supervised ANN, was applied to predict EPTC richness using a set of four environmental variables. The trained SOM classified sampling sites according to a gradient of EPTC richness, and the groups obtained corresponded to geographic regions of the drainage basin and characteristics of their environmental variables. The SOM showed its convenience to analyze relationships among sampling sites, biological attributes, and environmental variables. After accounting for the relationships in data sets, the BP used to predict the EPTC richness with a set of four environmental variables showed a high accuracy ( r=0.91 and r=0.61 for training and test data sets respectively). The prediction of EPTC richness is thus a valuable tool to assess disturbances in given areas: by knowing what the EPTC richness should be, we can determine the degree to which disturbances have altered it. The results suggested that methodologies successively using two different neural networks are helpful to understand ecological data through ordination first, and then to predict target variables.

Biological Monitoring: The Dilemma of Data Analysis

Biological Monitoring: The Dilemma of Data Analysis

Effects of exported seston on aquatic insect faunal similarity and species richness in lake outlet streams in Montana, USA

The quantity of seston exported from a lake affected the qualitative composition and species richness of aquatic insects in 13 lake outlet streams in northwestern Montana. Mean values for chlorophyll and particulate organic carbon in lake effluent waters ranged from 0.5 to 2.7 and 80 to 601 mg m-3, respectively. Correlations between a detrended correspondence analysis of faunal similarities in outlet streams and measures of organic export from the lake indicated that distributional patterns were primarily dependent upon the general trophic status of the lakes. A comparison of faunal assemblages at stream stations located at the outlet and 100 m downstream demonstrated that species composition at the two stations was more similar in productive systems.