Macroinvertebrate Biodiversity Research Articles

Spatial distribution of benthic taxonomic and functional diversity in the Yellow River Basin: From ecological processes to associated determinant factors

One of the fundamental objectives in ecology is to investigate the ecological processes and associated factors governing the abundance and spatial distribution patterns of biodiversity. However, the reaction of biological communities to environmental degradation remains relatively unknown, even for ecologically crucial communities like macroinvertebrates in aquatic ecosystems. Here, we sampled 117 locations to quantify relative contributions of geographical and environmental factors, including water quality, land use, climate, and hydrological factors, to determine the absolute and relative compositions of macroinvertebrate communities and their spatial distribution in the Yellow River Basin (YRB), the sixth-longest river system on Earth. We assessed relative roles of species sorting and dispersal in determining macroinvertebrate community structure along YRB. Our results demonstrated that alpha and beta diversity indices showed an increase from the up- to low-reaches of YRB. The middle and low-reaches exhibited elevated species diversity and both regions exhibited relatively stable community compositions. The biodiversity of macroinvertebrates was influenced by a combination of geographical factors and environmental variables, with environmental factors predominantly serving as the principal determinants. Results of multiple linear regression and variance decomposition showed that the effect of environmental factors was approximately three times greater than that of spatial factors. These findings provide support for the hypothesis that species sorting, driven by environmental gradients, plays a significant role in shaping the community structure of macroinvertebrates in running water ecosystems at the basin scales. Moreover, the factors contributing to substantial shifts in biodiversity across different segments of YRB indicate that distinct river sections have been influenced by varying stressors, with downstream areas being more susceptible to the impacts of water pollution and urbanization resulting from human activities.

Land use and river-lake connectivity: Biodiversity determinants of lake ecosystems

Lake ecosystems confront escalating challenges to their stability and resilience, most intuitively leading to biodiversity loss, necessitating effective preservation strategies to safeguard aquatic environments. However, the complexity of ecological processes governing lake biodiversity under multi-stressor interactions remains an ongoing concern, primarily due to insufficient long-term bioindicator data, particularly concerning macroinvertebrate biodiversity. Here we utilize a unique, continuous, and in situ biomonitoring dataset spanning from 2011 to 2019 to investigate the spatio-temporal variation of macroinvertebrate communities. We assess the impact of four crucial environmental parameters on Lake Dongting and Lake Taihu, i.e., water quality, hydrology, climate change, and land use. These two systems are representative of lakes with Yangtze-connected and disconnected subtropical floodplains in China. We find an alarming trend of declining taxonomic and functional diversities among macroinvertebrate communities despite improvements in water quality. Primary contributing factors to this decline include persistent anthropogenic pressures, particularly alterations in human land use around the lakes, including intensified nutrient loads and reduced habitat heterogeneity. Notably, river-lake connectivity is pivotal in shaping differential responses to multiple stressors. Our results highlight a strong correlation between biodiversity alterations and land use within a 2–5 km radius and 0.05–2.5 km from the shorelines of Lakes Dongting and Taihu, respectively. These findings highlight the importance of implementing land buffer zones with specific spatial scales to enhance taxonomic and functional diversity, securing essential ecosystem services and enhancing the resilience of crucial lake ecosystems.

Climate warming shifts riverine macroinvertebrate communities to be more sensitive to chemical pollutants.

Freshwaters are highly threatened ecosystems that are vulnerable to chemical pollution and climate change. Freshwater taxa vary in their sensitivity to chemicals and changes in species composition can potentially affect the sensitivity of assemblages to chemical exposure. Here we explore the potential consequences of future climate change on the composition and sensitivity of freshwater macroinvertebrate assemblages to chemical stressors using the UK as a case study. Macroinvertebrate assemblages under end of century (2080-2100) and baseline (1980-2000) climate conditions were predicted for 608 UK sites for four climate scenarios corresponding to mean temperature changes of 1.28 to 3.78°C. Freshwater macroinvertebrate toxicity data were collated for 19 chemicals and the hierarchical species sensitivity distribution model was used to predict the sensitivity of untested taxa using relatedness within a Bayesian approach. All four future climate scenarios shifted assemblage compositions, increasing the prevalence of Mollusca, Crustacea and Oligochaeta species, and the insect taxa of Odonata, Chironomidae, and Baetidae species. Contrastingly, decreases were projected for Plecoptera, Ephemeroptera (except for Baetidae) and Coleoptera species. Shifts in taxonomic composition were associated with changes in the percentage of species at risk from chemical exposure. For the 3.78°C climate scenario, 76% of all assemblages became more sensitive to chemicals and for 18 of the 19 chemicals, the percentage of species at risk increased. Climate warming-induced increases in sensitivity were greatest for assemblages exposed to metals and were dependent on baseline assemblage composition, which varied spatially. Climate warming is predicted to result in changes in the use, environmental exposure and toxicity of chemicals. Here we show that, even in the absence of these climate-chemical interactions, shifts in species composition due to climate warming will increase chemical risk and that the impact of chemical pollution on freshwater macroinvertebrate biodiversity may double or quadruple by the end of the 21st century.

The impacts of different seasons on macroinvertebrate community structure and functional diversity in the Jingui River, China

Species diversity and functional diversity indices reflect the variations of community structure and their responses to environmental stress. This study clarifies the biodiversity of macroinvertebrates in the Jingui River of Shenzhen and their response to the aquatic environment across different seasons. Utilizing ten functional traits, we conducted a seasonal survey at ten sampling points to examine changes in macroinvertebrate species and functional diversity, along with their relationships with environmental variables in the JGR. The results of the study demonstrated that the species and functional diversity of macroinvertebrates were significantly affected by season. Redundancy analysis indicated that water velocity, hydrogen ion concentration, turbidity, water depth, and total nitrogen were the most important factors for macroinvertebrate functional diversity. Moreover, structural equation modeling demonstrated that seasonal variations in total nitrogen, ammonia nitrogen, nitrate nitrogen, conductivity, water velocity, and hydrogen ion concentration directly or indirectly impacted the species diversity and functional diversity of macroinvertebrates. This study provides valuable information into the seasonal variation characteristics of macroinvertebrate communities, contributing to a more comprehensive understanding of biodiversity crucial for maintaining river ecosystem functioning and stability.

Freshwater macroinvertebrates along the Nigeria-Cameroon border enhance the conservation value of the lower Guinea forest biodiversity hotspot

In Nigeria and tropical Africa, the bias towards the protection of natural sites on account of terrestrial biodiversity or their resultant ecosystem services has led to a considerably low number of freshwater conservation studies in the region. To close this gap, six lotic freshwater systems in three different natural sites (Obudu Mountains, Agbokim Waterfalls, and Cross River National Park) along the Cameroon border of Nigeria were evaluated for the biodiversity of macroinvertebrates and some aspects of water quality in December 2021 and March 2022. Among other macroinvertebrate-related indices, the community conservation index (CCI), which considers the presence of threatened, rare, and notable species, was used for the conservation evaluation of the freshwater systems. The Ephemeroptera-Plecoptera-Trichoptera (EPT) species were notably rich at the sites, with over 12 species each at the Afundu Stream, Kwa River, Cataract Stream, and Agbokim River. All of the sites had a very high conservation value, according to the CCI, which was greater than 20. Some Obudu sites (Grotto and Becheve streams), despite having fewer EPT taxa, had higher CCI than the Kwa or Agbokim River. This was due to the presence of the endangered damselflies (Africocypha centripunctata and Allocnemis vicki) at the Obudu sites and a rare mayfly species in Nigeria (Tricorythus tinctus), which was reported at Agbokim and Kwa Rivers. The presence of a notable damselfly genus (Pentaphlebia) at the Afundu stream of the Obudu Mountains also raises some hope that the critically endangered damselfly (Pentaphlebia gamblesi), whose adult was last seen in 1973, could still be alive at the site. Canonical Correspondence Analysis revealed that the proportion of scrapers had a strong association with high BOD and EC in Agbokim River, while the Becheve and Grotto streams which had high vegetal cover was positively associated with shredders. Also, increasing DO in Afundu Stream, Kwa River and Cataract Stream was positively associated with EPT richness. This study revealed that more freshwater ecological studies need to be conducted at isolated natural sites and protected areas in Africa. Findings from such studies have implications for preserving freshwater ecosystems of high conservation value from the various threats that characterize the Anthropocene.

Assessing biodiversity and regulatory ecosystem services in urban water bodies which serve as aqua-Nature-based Solutions

In sight of a growing urban population and intensified extreme weather events, cities must integrate in their urban planning elements to both reduce their impact (i.e., air and water pollution, degradation of habitats, loss of biodiversity) and increase their resilience to climate change. In contrast to engineering solutions, which normally not only fail to adequately address these issues but often also exacerbate them, Nature-based Solutions are an efficient strategy which can help cities become more sustainable. Aqua-Nature-based Solutions (aNBS) tackle water-related hazards by enhancing water regulation and mitigating flood and drought impacts. However, under a warming climate, aNBS are expected to often dry-out, changing biodiversity and the ecosystem services they support. The aim of this study is to compare the biodiversity of temporarily and permanently wet urban waterbodies which function as aNBS. We selected two pond complexes with different hydroperiod (i.e., different duration, amplitude and frequency of inundation) and studied the riparian vegetation and aquatic macroinvertebrate biodiversity. The Multimetric Macroinvertebrate Index of Flanders was used to determine the macroinvertebrate biodiversity and to assess water quality of the ponds. Using water stable isotopes and piezometers, the hydrological dynamics were studied in order to identify the water regulating ecosystem services these ponds deliver. The results showed that the selected pond complexes have a high plant biodiversity, particularly in temporary ponds. Water quality ranged from moderate to poor and macroinvertebrate biodiversity tended to be greater in permanent ponds. Plant and macroinvertebrate alien species were also found in the aNBS. Regarding water regulating ecosystem services, the pond complexes enhanced infiltration and groundwater recharge, providing resilience to both flooding and drought. Our findings corroborate previous studies on the need of diversifying urban ponds’ hydroperiod to support biodiversity. Thus, integrating well-designed aNBS into urban planning might be a way to make cities more resilient to water climate-related hazards while enhancing biodiversity.

Analysis of Water Quality Assessment in Narmada River and Bio-diversity of Littoral Benthic Macro-invertebrates at Barwani (Rajghat)

River Narmada is one of the 13 prominent rivers of India, which covers 98,797 sq km of total water-shed area. Narmada is considered to be the lifeline of Madhya Pradesh and most important west flowing river of India.The monitoring of water quality of Narmada River was carried out for One year August 2011 to July 2012. Barwani sampling stations were selected at downstream of Narmada River. The water samples collected were analyzed, as per standard methods parameters such as pH, Turbidity were measured in-situ. Raised values of physico-chemical parameters indicate the pollution of riverine ecosystem due to domestic wastes,municipal sewage, industrial effluent from Security Paper Mill (SPM) and agricultural run-off that influence the water quality directly or indirectly. Statistical analysis carried out through correlation method and also evaluates Average values (AV), Standard Deviation (SD), Standard Variance (SV),Standard Error (SE) and 95% Confidence Limit (CL) to assess the pollution load assessment. The results revealed that most of the water samples were below or out of limited; according to the WHO, BIS standards. Macroinvertebrates are an important component of river ecosystems and are a link in the transfer of material and energy from producers to top level consumers and also act as excellent bioindicators

Macroinvertebrate Spatial Diversity Patterns of Shore Habitats in Italian High-Altitude Natural and Permanent Lakes and Ponds

A comparative analysis of environmental conditions between Alpine and Apennine lakes/ponds which represent different faces of European mountain regions was conducted. The data set was created on the basis of previous works carried out by national and international institutions including biological, physical–chemical, geographic, and precipitation data from 27 lakes/ponds placed at altitudes ranging from 2334 ± 294 m a.s.l. (in the Alps) and 1541 ± 154 m a.s.l. (in the Apennines), with mean maximum depths of about 5.5 ± 4.6 m. A specific focus was dedicated to chironomids as outstanding sentinels for local and global changes in habitat conditions. Species richness and Taxonomic Distinctness Indices were applied to lakes/ponds macroinvertebrates to highlight differences in the biodiversity of the two areas. Subsequently, associations between descriptors of the mountain region climate, lithology, water chemistry, lake morphology, geography, macroinvertebrate assemblage richness, and distinctness were examined through Principal Component Analysis, Analysis of Variance, and Non-metric Multi-dimensional Scaling. Results showed strong positive correlations between mean annual precipitation and temperature with lake macroinvertebrate biodiversity as a whole and with chironomid in particular. Thus, these shore habitats face a threat under climate change conditions (impacting thermal and precipitation regimes). These results are also central in showing that even small ecosystems are important sources of biodiversity for the lower altitudes, stressing the urgency of including them within targeted monitoring and action plans to preserve their peculiar habitat, flora, and fauna.

Assessing the Impact of Anthropic Pressures on Aquatic Macroinvertebrates: A Functional Trait Approach in the Irtysh River Watershed.

Little is known about how changes in the biodiversity and functional traits of macroinvertebrates in rivers respond to the responses of anthropic pressures and their driving factors. Macroinvertebrates were sampled at 17 sites in the Irtysh River Basin and classified macroinvertebrates into 10 traits and 38 categories between May and August 2022. Then, we performed R-mode linked to Q-mode (RLQ) analysis and calculated functional richness, evenness, divergence, and Rao's quadratic entropy (RaoQ) for each site and community-weighted means for each trait category. Our results indicated that there were pronounced alterations in species variability in the urban region. Functional divergence indicated fierce competition among species and considerable niche overlap in the urban region. Functional evenness indicated that species abundance distribution and interspecific functional distance were not uniform in the urban region. Functional richness indicated that the urban region was the strongest region in terms of niche occupation, resource utilization, and buffering capacity for environmental fluctuations. Rao's quadratic entropy showed that the trait difference of macroinvertebrates was the largest in all regions, which was caused by the gradient environmental difference. Research has revealed that urbanization significantly influences the evolutionary trajectory of macroinvertebrate fauna, culminating in an upsurge in pollution-tolerant species and a convergence of functional traits. We recommend strengthening the control of urban and industrial pollution and wise planning and management of land and water resources to mitigate the impact of anthropogenic destruction on habitat fragmentation in the Irtysh River Basin.

Seasonal variability of lotic macroinvertebrate communities at the habitat scale demonstrates the value of discriminating fine sediment fractions in ecological assessments.

Despite lotic systems demonstrating high levels of seasonal and spatial variability, most research and biomonitoring practices do not consider seasonality when interpreting results and are typically focused at the meso-scale (combined pool/riffle samples) rather than considering habitat patch dynamics. We therefore sought to determine if the sampling season (spring, summer and autumn) influenced observed macroinvertebrate biodiversity, structure and function at the habitat unit scale (determined by substrate composition), and if this in turn influenced the assessment of fine sediment (sand and silt) pressures. We found that biodiversity supported at the habitat level was not seasonally consistent with the contribution of nestedness and turnover in structuring communities varying seasonally. Habitat differences in community composition were evident for taxonomic communities regardless of the season but were not seasonally consistent for functional communities, and, notably, season explained a greater amount of variance in functional community composition than the habitat unit. Macroinvertebrate biodiversity supported by silt habitats demonstrated strong seasonal differences and communities were functionally comparable to sand habitats in spring and to gravel habitats in autumn. Sand communities were impoverished compared to other habitats regardless of the season. Silt habitats demonstrated a strong increase in Ephemeroptera, Plecoptera and Trichoptera (EPT) taxa and functional richness from spring into autumn, while vegetation habitats displayed a peak in EPT abundance in summer. Only silt and sand habitats demonstrated temporal variability in functional evenness suggesting that these habitats are different in terms of their resource partitioning and productivity over time compared to other habitats. Gravel and vegetation habitats appeared to be more stable over time with functional richness and evenness remaining consistent. To accurately evaluate the influence of fine sediment on lotic ecosystems, it is imperative that routine biomonitoring and scientific research discriminate between sand and silt fractions, given they support different biodiversity, particularly during summer and autumn months.

Conservation of temporary streams: The relevance of spatiotemporal variation in beta diversity

Abstract Temporary streams are affected by increasing human alterations, and this situation is expected to worsen under global change. Understanding biodiversity trends and the contribution of sites and species to β‐diversity is of high importance in establishing conservation priorities at a regional scale. This paper focuses on aquatic macroinvertebrate biodiversity in temporary streams on the island of Mallorca, using a space–time framework. Differences in α‐diversity, spatial–temporal fluctuations of β‐diversity, local contribution to β‐diversity (LCBD) and species contribution to β‐diversity (SCBD) were examined. Data analysis shows that only the space–time approach to β‐diversity can capture the full variation of macroinvertebrate composition in temporary streams. This confirmed our hypothesis that β‐diversity patterns are better explained by incorporating the temporal dimension to the space–time approach. Regarding β‐diversity components, species replacement components always dominate over richness difference. These results imply that β‐diversity variability is mainly caused by differences in species composition, while the relative difference in richness among sites has a minor role. Consequently, the optimal conservation strategy requires the protection of several undisturbed sites. Although the LCBD analysis did not detect any keystone sites, it helped to identify those sites that should be prioritized for restoration efforts (sites with high LCBD values and low α‐diversity). We also concluded that SCBD analysis should be interpreted carefully, as rare endemic species had low SCBD values. This study demonstrated the need for incorporating temporal variability in the analysis of biodiversity patterns in highly dynamic ecosystems, such as temporary streams. It also revealed the urgency of preserving a spatial network of temporary streams under non‐impaired conditions that can act as dispersal point sources to other streams for biodiversity conservation. These insights are relevant for Mallorca and other Mediterranean islands, and for the protection of temporary rivers elsewhere.

Effect of Anthropogenic Pressure on the Biodiversity of Benthic Macroinvertebrates in Some Urban Rivers (Yaoundé)

In Cameroon, the environmental profile is increasingly marked by anarchic urbanisation, which is strongly illustrated by the discharge of waste into the aquatic environment, leading to pollution. Indeed, the tributaries of the Mfoundi and Mefou river basins have nowadays become dumping grounds and receptacles for all kinds of waste, leading to the degradation of water quality and a reduction in biodiversity. This study aims to evaluate the effect of anthropogenic pressure on the biodiversity of benthic macroinvertebrates in three rivers of the Mfoundi basin (Ebogo, Abiergue, and Ako’o). For this purpose, some physicochemical parameters were measured according to standard methods, and benthic macroinvertebrates were collected according to the multihabitat approach. To this end, the physicochemical analyses revealed that the waters of these different streams are slightly basic and poorly oxygenated, with a saturation rate of 9.725 ± 11.74% and significant organic pollution. Biologically, a total of 5793 benthic macroinvertebrates divided into three phyla, eight orders, and more than thirty families were collected, with a population dominated by the order of insects and a low level of diversity dominated by pollutant organisms such as the Chironomidae, Lumbriculidae, and Physidae, which are saprobionts and saprophilous organisms. A redundancy analysis indicated that the main groups of benthic macroinvertebrates obtained were related to the gradients of the physicochemical parameters measured. The Shannon–Weaver diversity and Piélou equitability indexes showed the low diversity of the organisms within the different courses and their low equipartition, mainly due to the saprobiont and saprophilous groups that dominate the population. The exogenous inputs due to the increase in the population of the city of Yaoundé, which dumps its waste into the waterways, have major repercussions on the quality of the water and the population that abounds in this environment, particularly the benthic macroinvertebrates, which are an important link in the monitoring of water quality.

Ecological effect of a small dam on the macroinvertebrate assemblage and water quality of Koga River, Northwest Ethiopia

There has been an increasing effort to construct dams across rivers to control the flow of the streams and secure water storage, and river damming has become one of the most prominent human impacts on the freshwater ecosystem. Nonetheless, the effect of river damming on the river ecosystem is only partially understood in Ethiopia. This study is aimed to assess the ecological effect of small dams on macroinvertebrate assemblages and the water quality of the Koga River ecosystem. A total of 15 sites; five from upstream, five from the dam, and five from downstream of the Koga River was sampled for macroinvertebrates and water quality parameters. The sampling was done from September to November 2016. A total of 40 families of macroinvertebrates were recorded, among which Coenagrionidae, Belostomatidae, Naucoridae, and Physidae were the most abundant. The biodiversity of macroinvertebrates was significantly higher in the downstream location of Koga Dam, where there was an attenuated sediment load to the river. Among the functional feeding groups, the percentage of filterer-collectors was higher in the upstream locations, whereas scraper families were higher in the downstream locations of the dam. Vegetation cover, turbidity, and pH were identified as the most important water quality factors delineating the pattern of macroinvertebrate community structure in the river system. Turbidity and orthophosphate concentrations were higher in the upstream sampling locations. The average sediment layer thickness was higher on the upstream side of the dam. The results suggest that sediment adversely affects the macroinvertebrate assemblage. Higher concentrations of sediment and phosphate were noted in the upstream location of the dam. The water quality (turbidity and nutrient concentrations) of the stream was affected by River Damming by influencing the sediment and nutrient dynamics of the river. Therefore, planning and implementation of an integrated watershed and dam management system are suggested to prolong the useful lifespan of the dam and sustain its ecological integrity.

Density declines, richness increases, and composition shifts in stream macroinvertebrates

Documenting trends of stream macroinvertebrate biodiversity is challenging because biomonitoring often has limited spatial, temporal, and taxonomic scopes. We analyzed biodiversity and composition of assemblages of >500 genera, spanning 27 years, and 6131 stream sites across forested, grassland, urban, and agricultural land uses throughout the United States. In this dataset, macroinvertebrate density declined by 11% and richness increased by 12.2%, and insect density and richness declined by 23.3 and 6.8%, respectively, over 27 years. In addition, differences in richness and composition between urban and agricultural versus forested and grassland streams have increased over time. Urban and agricultural streams lost the few disturbance-sensitive taxa they once had and gained disturbance-tolerant taxa. These results suggest that current efforts to protect and restore streams are not sufficient to mitigate anthropogenic effects.

Outflows from lakes as ecotones - stable conditions maintain macroinvertebrates biodiversity

Outflows from the lakes are rarely considered as an ecotones. The main research direction on invertebrates of lake outflows most often are functional feeding groups, especially filter-feeders as a dominant group in that environment. Our goal was to describe the biodiversity of macroinvertebrates in lake-river ecotones in lowlands of Central Europe, found the environmental factors that shape the biodiversity of that environment and indicate directions for further biodiversity conservation. 40 outflows from lakes with different parameters were selected for the research. During the research, 57 taxa were found at the study sites, of which 32 taxa reached a frequency at least 10 %. The Multiple linear regression showed only one significant relationships between fluvial model and biodiversity. Of the components of this model, only depth of the outflow correlated significantly. There was observed significant differences in the Shannon-Wiener index, which was significantly higher in deeper outflows. Depth of the outflow indirectly affects the preservation of the biodiversity of the ecotone, which results from the greater stability of the water conditions in this place. It should be pay special attention to the water conditions of the catchments in order to minimize water level fluctuations and their negative effect on biodiversity in lake-river ecotones.

Impact of No-Tillage on Soil Invertebrate Communities in the Southern Forest Steppe of West Siberia: Preliminary Research

The aim of our study is to assess changes in soil macroinvertebrate biodiversity when conventional tillage (CT) is replaced by no-tillage (NT) in agroecosystems of the southern part of the West Siberian forest steppe. The research was conducted in the Novosibirsk region at the end of May 2017, May 2018, and in June 2018. The agricultural plots with CT and NT were located close to each other on identical soils, at a distance of about 200 m from the nearest forest shelterbelts. NT technology has been applied on the experimental plot since 2007. Sampling of invertebrates was conducted in two ways, namely soil sampling and pitfall trapping. The majority of basic physicochemical properties of soil were the same or similar between the CT and NT plots. However, depending on the type of tillage, different soil invertebrate communities had already developed in the control (CT) and experimental (NT) plots during this time. The community of the CT plot includes a large number of flying predatory Carabidae species typical of early successional stages (such as Bembidion properans and B. quadrimaculatum, Poecilus spp.) and phytophages, i.e., larvae of Elateridae. The NT plot has significantly higher density and species richness of earthworms (Eisenia nordenskioldi and synanthropic E. fetida in the NT plot versus one individual of E. nordenskioldi in the CT plot). The NT plot has a significantly richer and more abundant assemblage of spiders (especially in spring) and a poor assemblage of insect predators (except for the superdominant ground beetle Poecilus cupreus and the subdominant P. versicolor in summer 2018). Large numbers of larvae of some carabids (e.g., Amara consularis) were found in the NT soil, suggesting that they complete a full life cycle in this habitat.

Ecological characterisation of urban ponds in the Netherlands: a study based on data collected by volunteers

Blue space in the urban environment can positively contribute to public health and well-being. Many urban freshwater systems, however, are exposed to anthropogenic stressors, resulting in deteriorated water quality and biodiversity. Private garden ponds are essential elements of this blue space but little is known about their water quality since they are not monitored by water professionals. The Dutch citizen science initiative Waterdiertjes.nl focusses on biological water quality assessment using macroinvertebrates and launched a campaign to investigate garden ponds in 2021. The campaign yielded macroinvertebrate recordings in 60 garden ponds and limited additional information on dimensions, and presence of water vegetation and fish. Volunteers also investigated 92 public urban ponds in 2021. Combining both data allowed for evaluation of the similarity between both pond types. Analyses were also performed to discover the importance of pond dimensions and presence of aquatic vegetation or fish for the macroinvertebrate biodiversity and water quality. Multivariate analyses showed a considerable overlap in macroinvertebrate community composition between garden and public urban ponds. Results showed high variability in taxon richness, total macroinvertebrate density and water quality scores A significant, nonlinear relation was observed between pond depth and macroinvertebrate taxon richness with the highest richness at a depth of 0.5-1m. Submerged vegetation correlated significantly with taxon richness with little vegetation having the lowest richness. Presence of fish or floating vegetation was not significantly related to taxon richness, total density and water quality scores possibly due to unnatural conditions that underlie in garden ponds. Since water professionals and academic scientists do not monitor garden ponds, citizen science may provide valuable data on water quality and biodiversity in these waters. The present initiative showed that volunteers can successfully monitor understudied ecosystems and gather data on temporal and spatial scales complementary to professional data that lead to new (ecological) insights.

Exploring macroinvertebrate biodiversity in the dynamic southern Balkan stream network of the Vjosa using preservative-based DNA metabarcoding

Reliable biodiversity data are crucial for environmental research and management. Unfortunately, data paucity prevails for many regions and organismal groups such as aquatic invertebrates. High-throughput DNA-based identification, in particular DNA metabarcoding, has accelerated biodiversity data generation. However, in the process of metabarcoding, specimens are usually destroyed, precluding later specimen-based analyses. Metabarcoding of DNA released into the preservative ethanol has been proposed as a non-destructive alternative, but proof-of-principle studies have yielded ambiguous results, reporting variance in detection probability for various taxa and methodological biases. In this study, we tested the performance of preservative-based metabarcoding of aquatic invertebrates in comparison to a standard morpho-taxonomic assessment based on samples from one of Europe’s last free-flowing rivers, the Vjosa. Multi-habitat samples were collected at 43 sites in two seasons and stored in ethanol, after fixation in formaldehyde for morpho-taxonomic analyses. Preservative-based DNA metabarcoding detected three times more taxa but failed to detect other taxa found using the standard method. In addition to incomplete reference data and primer bias that likely precluded the detection of specific taxa, preservative-based DNA metabarcoding cannot provide accurate abundance estimates. However, the metabarcoding data revealed distinct small-scale and large-scale community patterns in the Vjosa river network, which were also recovered by quantitative data of the standard approach. Overall, our results indicate that preservative-based metabarcoding provides important biodiversity data, which could be further improved by quantitative validation. The method is robust and reliable, even though samples were taken under harsh field-conditions and stored without cooling. Further, our results emphasise the need for reliable DNA barcoding reference libraries. Building those may be supported by preservative-based metabarcoding that maintains intact vouchers for subsequent specimen-based analyses.

Catching the Drift of Marine Invertebrate Diversity through Digital Repositories—A Case Study of the Mangroves and Seagrasses of Maputo Bay, Mozambique

Mangroves and seagrasses present with high marine macroinvertebrate biodiversity that contributes to their structure and functioning. Macroinvertebrates possess a broad range of functional traits, making them excellent models for biodiversity and available-trait-based studies. This study aimed to characterize the biodiversity of marine macroinvertebrates as two different ecosystems situated along the coastline of Maputo Bay by compiling dispersed data from online databases. Specifically, this study addressed species richness, taxonomic and functional diversity based on two traits (habitat occupation and trophic guild), and the community structure of these traits. Mangroves presented with a higher species richness and taxonomic diversity than seagrasses. The functional diversity of mangroves was mostly explained by the trophic guild trait. In the case of seagrasses, functional diversity was mostly due to differences in habitat occupation in the 20th century, but the trophic guild accounted for this functional diversity from 2000 onwards. The comparison of community compositions between the two ecosystems showed low or no similarity. The use of digital databases revealed some limitations, mostly regarding the sampling methods and individual counts. The trends and data gaps presented in this study can be further used to inform subsequent systematic data acquisition and support the development of future research. A further step that may be taken to improve the use of digital data in future biodiversity studies is to fully incorporate functional traits, abundance and sampling methods into online databases.

Environmental factors are the major drivers of macroinvertebrate assemblage structure in southern Brazilian coastal lakes

AbstractCoastal freshwater lakes are distinctive landscape features in South America, and benthic macroinvertebrates are key to their ecological functioning. Identifying the main factors driving the assemblage structure of benthic macroinvertebrate is thus important for the development of management strategies in these ecosystems. However, studies on the drivers of macroinvertebrate assemblages are scarce in subtropical coastal lakes of the Neotropical region. Here, we evaluated the role of environmental (morphometric and water chemistry variables) and spatial factors in the assemblage structure of benthic macroinvertebrates in 36 coastal freshwater lakes in Brazil from 2008 to 2015. Macroinvertebrate family richness increased with ammonium, pH and water transparency, and decreased with nitrate content (slope ≈1 for all significant variables). Environmental factors explained most of the variation in macroinvertebrate composition (16%) compared to spatial ones (3.4%). In specific, Dugesiidae, Hydrobiidae, Corbiculidae, Sphaeromatidae, Noteridae, Hydropsychidae, Culicidae and Ceratopogonidae predominated in lakes with lower conductivity (<100 μS/cm) and higher water transparency (>1 m). Spatial factors summarized differences in macroinvertebrate assemblages between isolated and connected lakes. Although none of the lakes studied are directly impacted by organic pollution, our results suggest that benthic macroinvertebrate assemblages in subtropical coastal lakes are mostly structured by water chemistry, likely reflecting the major trends in land use along the study region (transition from agriculture to urban areas). We recommend that the conservation of macroinvertebrate biodiversity in southern Brazilian coastal lakes focus on the monitoring of water chemistry factors associated with human‐based land use.