Ephemeroptera, Plecoptera, Trichoptera Research Articles

Quantification of large-spatial scale and in-stream factors affecting the structure of benthic macroinvertebrate communities in mountain streams

Habitat diversity plays a crucial role in shaping the structure and distribution of benthic macroinvertebrate communities. However, few studies have investigated the concurrent effects of such drivers operating at different spatial scales in mountain streams. Here, we assessed which environmental factors at different spatial scales, related to stream/river type and substrate, influence the diversity of benthic macroinvertebrate assemblages in mountain streams and rivers. Within the framework of the aquatic investigations of the Biodiversity Monitoring South Tyrol (BMS) – a newly-established, regional-based, long-term biodiversity monitoring program – benthic macroinvertebrates and a set of environmental factors describing water quality, stream/river hydromorphology and in-stream habitat characteristics were collected and analysed. The variation in total density, taxonomic richness, Shannon evenness and % Ephemeroptera–Plecoptera–Trichoptera taxa of stream benthic macroinvertebrates was assessed at multi-scale habitat levels, in 48 sampling sites across the mountainous region of the Autonomous Province of Bolzano/Bozen (Italy). The effects of stream/river type, substrates and different environmental factors on community composition of benthic macroinvertebrates were quantified, using a stepfoward Redundancy Analysis (RDA) and generalized additive models (GAMs). In addition, we performed an Indicator Value analysis to detect taxa that were significantly associated with a specific substrate and/or stream/river type. Overall, we observed significant differences in benthic biological metrics among both stream/river and substrate types. We also found at least one indicator taxa for each stream/river type, with environmental factors acting at reach and large-spatial scale – temperature, stream channel stability, elevation – being the key drivers in shaping macroinvertebrate distribution patterns in the analysed mountain rivers. While significant differences in macroinvertebrate community structures were found among substrates, the influence of stream/river type conditions was particularly evident. Apart from ranking environmental variables worth including in a long-term aquatic biodiversity monitoring program in mountain areas, our study provides a baseline for practical applications. For instance, depending on the desired outcome of habitat heterogeneity restoration, it can suggest the optimal scale (landscape vs. reach vs. patch) for prioritizing in-field interventions.

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.

How do different modalities of land use practices impact the environmental features and macroinvertebrates? An assessment of mountain streams from Patagonia, Argentina

Agricultural intensification is a significant process, transforming the land and modifying stream water quality and biodiversity. Land-use practices are associated with substantial changes in vegetation structure, significant inputs of nutrients, erosion, and increased sedimentation, all of which profoundly impact aquatic biota and ecosystem functioning. The effect of different agricultural practices (horticulture, extensive and intensive livestock) on stream water quality was compared in terms of physicochemical features, bacteria, habitat condition, riparian ecosystem, and macroinvertebrate variables in a temperate rural landscape (Patagonia). The main objective was to identify which variables related to land use were determinants in the configuration of biotic communities. Significantly higher values in water temperature, conductivity, nutrients, and bacteria were found at intensively developed sites than at reference ones. The quality of the habitat and the riparian ecosystem had been profoundly modified. A multidimensional scaling analysis revealed that macroinvertebrate assemblages also differed among land use categories, with the variables: total phosphorous, total nitrogen, bacteria (E. coli, mesophilic and total coliforms), water temperature, and oxygen having the highest predictive power. Macroinvertebrate metrics (richness of EPT (Ephemeroptera+Plecoptera+Trichoptera), Plecoptera, shredders and scrapers, and the percentage of scrapers and collectors) proved appropriate bioindicators for discriminating intensive land use impacts and highlighted a trend of biodiversity loss. Plecoptera richness, a taxa group with a high level of endemism, responded significantly to habitat condition degradation. These results confirm that the intensification of land use leads to increased nutrient levels and suppressed aquatic-terrestrial interactions involved in the provision of allochthonous detrital input, shade, and habitat structure for larval stages and adults. The Habitat Condition Index appears to be a useful tool for rapid stream assessment and providing early warnings. Several ecological services are threatened in these Patagonian agroecosystems. Restoring riverbank heterogeneity and improving management practices that ameliorate nutrient and sediment inputs are crucial to enhance biodiversity.

Influence of water color and catchment lake cover on stream macroinvertebrate communities: Ecological insights into browning effects

Browning of streams due to increased export of dissolved organic carbon (DOC) and iron has been observed in vast areas of the northern hemisphere with likely adverse ecological effects. Lake basins in stream catchments can moderate DOC export and influence stream communities, which complicates understanding of the effects of DOC. In this study, we explored the independent and interactive effects of water color (proxy for DOC and iron) and catchment lake cover on benthic macroinvertebrate communities in 94 medium-sized boreal forest streams. We first investigated the role of lake basins and other catchment characteristics in controlling water color. We then studied the effects of water color and catchment lake cover on macroinvertebrate community composition, biodiversity, and functional feeding traits. Water color correlated negatively with catchment lake cover, whereas the correlation with peatland cover and drainage intensity was positive. PERMANOVA and GLS analyses indicated that both color and catchment lake cover had a distinct independent effect on invertebrate community composition and community attributes, without significant interactions. Color had an independent negative effect on EPT (Ephemeroptera, Plecoptera, Trichoptera) taxa richness irrespective of lake cover. Increasing water color had negative effect on relative abundance of grazer, but no significant effect on shredder trait, while lake cover had a negative effect on both of the traits. Lake cover exhibited a negative influence on collector-gatherers, and a positive effect on filter feeders, while the predators were positively affected by both factors. The results highlight that water color influences the community structure of boreal stream ecosystems, and the effects are similar regardless of catchment lake cover. Mitigation measures should be emphasized, aimed at reducing DOC and iron runoff, in land use planning and river basin management.

Significant improvement in freshwater invertebrate biodiversity in all types of English rivers over the past 30 years

There remains a persistent concern that freshwater biodiversity is in decline and being threatened by pollution. As the UK, and particularly England, is a densely populated nation with rivers of modest dilution capacity, this location is very suitable to examine how freshwater biodiversity has responded to human pressures over the past 30 years. A long-term dataset of 223,325 freshwater macroinvertebrate records from 1989 to 2018 for England was retrieved and examined. A sub-set of approximately 200 sites per English Region (1515 sites in total with 62,514 samples), with the longest and most consistent records were matched with predicted wastewater exposure, upstream land cover and terrain characteristics (latitude, altitude, slope gradient and flow discharge). To understand changes in macroinvertebrate diversity and sensitivity with respect to these parameters, the biotic indices of (i) overall family richness, (ii) Ephemeroptera, Plecoptera, Trichoptera (EPT) family richness, and (iii) the Biological Monitoring Working Party (BMWP) scores of NTAXA (number of scoring taxa) and (iv) ASPT (average score per taxon) were selected. A review of how close the BMWP scores come to those expected at minimally impacted reference sites was included. For all latitudes, altitudes, channel slope, river size, wastewater exposure levels, and differing proportions of upstream woodland, seminatural, arable and urban land cover, all diversity or sensitivity indices examined improved over this period, although this improvement has slowed in some cases post 2003. Mean overall family richness has increased from 15 to 25 family groups, a 66 % improvement. The improvement in mean EPT family richness (3 to 10 families, >300 % improvement), which are considered to be particularly sensitive to pollution, implies macroinvertebrate diversity has benefited from a national improvement in critical components of water quality.

Assessing physical habitat structure and biological condition in eastern Amazonia stream sites

The advance of agricultural frontiers and industrialization in Amazonia has increased natural resource deterioration, resulting in degraded physical habitat structure and reduced local aquatic biodiversity. We evaluated the relative sensitivities of the Biological Monitoring Working Party (BMWP) and Average Score Per Taxon (ASPT) biotic indexes based on EPT (Ephemeroptera, Plecoptera, Trichoptera) versus EPT taxa richness, EPT abundance, and Shannon-Wiener EPT diversity for evaluating anthropogenic impacts on Amazonian streams. We expected that EPT-BMWP and EPT-ASPT would be more sensitive in detecting environmental changes on stream biota than the other measures. We sampled 32 stream sites in eastern Amazonia distributed along an environmental gradient resulting from different land use intensities. All the biological metrics except EPT-ASPT were significantly responsive to anthropogenic pressures; however, EPT taxa richness was slightly more responsive.

TINJAUAN KUALITAS SUNGAI BENGKENANG BERDASARKAN FISIKA KIMIA PERAIRAN DAN KOMUNITAS MAKROINVERTEBRATA

This research aims to determine the quality of Bengkenang River based on the physicochemical factors and macroinvertebrates community. The measuring of physicochemical parameters was carried out at three stations, namely Sukarami Village, Durian Seginim, and Padang Burnai with two periods for each station: April 2019 following the peak of the rainy season and September 2019 following the peak of the dry season. The physicochemical factors were analyzed descriptively, while macroinvertebrates community were analyzed as the indices of Shannon-Wiener diversity index (H’), Ephemeroptera-Plecoptera-Trichoptera (EPT), and Family Biotic (FBI). The temperature, dissolved oxygen, degree of acidity, and total dissolved solids of this river in each station were in the normal range. This study found 611 individuals of macroinvertebrates that were divided into 21 species (21 families; 4 phyla; 5 classes). The highest species abundance was Epeourus aculeatus, 22.42% of the total sample. The H’ index from up- to downstteram were 1.79; 2.03; 1.80 respectively, indicating the Bengkenang River is slightly to moderately degraded. The total number of EPT individuals was 305, with mostly found at the downstream and dominated by Heptaginidae (Ephemeroptera). The FBI values were 3.81; 4.18; and 4.33 showed that the quality of the water is “very good”. Based on this physico-chemical factors, H’, EPT, and FBI data, it can be concluded the Bengkenang River is in a good quality.

Bioindicadores de calidad hídrica con diferente cobertura ribereña en la microcuenca Guapara, Ecuador

Agricultural activities produce changes in the margins of the stream banks, causing disturbances in water quality, and in the assemblage of aquatic insect communities. The objective of this research is to evaluate the changes in the structure and composition of the aquatic macroinvertebrate community, and physicochemical variables in relation to the land use of the Guapara river, Cotopaxi province, Ecuador. Samplings were conducted during the rainy season (December to February 2018-2019) in three streams with different riparian cover: agricultural, native forest, and forest plantations, where samples of aquatic insects and physicochemical parameters were collected in situ. A total of 461 aquatic insects corresponding to 7 orders and 25 families were collected. In general, the highest abundance in order and family was presented by Ephemeroptera with 34 %, and Leptophlebiidae with 21 % respectively. According to the Ephemeroptera, Plecoptera Trichoptera (EPT) index, the highest ecological condition was found in streams with native forest cover, and forest plantations respectively, and decreased in the stream with agricultural cover; while BMWP-Cr indicated water contamination in the three streams. Hydrobiosidae (Trichoptera) were associated with high turbidity values; while Gerridae (Hemiptera) were associated with high dissolved oxygen concentrations; in addition, Ptilodactylidae (Coleoptera) preferred the Q1-CA, and Q3-CF conditions, while Leptophlebiidae (Ephemeroptera) were associated with the stream of native forest. A negative influence of agricultural activity on the physicochemical parameters of the water and on the structure of the aquatic insect community assemblage was evidenced.

Aquatic macroinvertebrate trophic guilds, functional feeding groups, and water quality of an andean urban river

In the Anthropocene, man has imposed his activities above the natural processes of ecosystems. Rivers have undergone major changes associated with urban centers, so monitoring them is important to determine their status and suitability to provide environmental services. Studies applying the community ecology approach, such as energy flow in aquatic macroinvertebrate assemblages, may be appropriate to determine their status and functioning. This study characterized an Andean river that runs across the city of Ayacucho (Peru). Water physicochemical parameters and biotic quality indices were used and compared with the abundance of trophic guild components and functional feeding groups to demonstrate that the latter are at least equally suitable to estimate water quality. The river section studied ranged from 2640 to 2900 m a.s.l. and was monitored in the wet and dry seasons. Six monitoring stations were established according to the extent of the influence of the urban center. Water physicochemical variables and macroinvertebrate abundances were determined. A Surber net was used for multihabitat sampling; macroinvertebrates were identified to genus level (in most cases) and counted to estimate relative abundances. Trophic guilds (detritivore, predator, herbivore) were formed using the genus data from identification according to the information available in Argentina, Colombia, Ecuador, Bolivia, and Peru. Functional feeding groups were set based on the classification of families. The sensitivity of trophic metrics was assessed by relating them to environmental variables and the Andean Biotic Index (ABI), the Biological Monitoring Working Party adapted for Colombia (BMWP/Col.), and the Ephemeroptera, Plecoptera, Trichoptera (EPT) indices. Environmental variables and biotic indices increased significantly in the most impacted stations, where the abundance of most taxa decreased. The components of trophic guilds and functional groups varied, and those feeding on fine particles increased in sites with a higher urban impact. The metrics based on trophic characteristics were highly correlated with the BMWP/Col and ABI indices. Therefore, these indices can be used to estimate river water quality and provide information on its functioning.

Spatio-temporal Effects of Anthropogenic Disturbances on Macroinvertebrates in Subukia River, Kenya

Anthropogenic disturbances modify river habitat conditions and influence the distribution of biotic communities. However, the effect of anthropogenic disturbances on macroinvertebrates is unknown for the Subukia River, despite its importance as a source of water for the local people and a habitat for organisms. This study was conducted to evaluate the effect of study site locality and seasonal variability on macroinvertebrate characteristics in the Subukia River. Nine study sites were chosen to correspond with livestock watering and human activities such as laundry washing, water abstraction, cultivation, dumping of solid wastes, settlements along the riparian zone and clearance of riparian vegetation. Mean invertebrate abundance, Shannon-Wiener diversity index, a Multimetric index, Taxa richness, Ephemeroptera, Plecoptera, Trichoptera (EPT) abundance and richness and Dominance index were determined. The results of the study showed that study site locality had a significant effect on Taxa richness (p=0.003), EPT abundance (p = 0.003) and richness (p=0.02), Shannon-Wiener diversity (p=0.003) and Multimetric index (p=0.003). Seasonal variability only had a significant effect on Taxa richness (p=0.01). In conclusion, most macroinvertebrate characteristics are influenced by anthropogenic disturbances and are less influenced by seasonal variability.

DNA‐based assessment of environmental degradation in an unknown fauna: The freshwater macroinvertebrates of the Indo‐Burmese hotspot

Abstract New methods are required for biomonitoring of poorly known tropical ecosystems, but biological assessments of environmental status are limited by insufficient information on taxonomy, composition and ecology of local communities. The current work applies DNA‐based assessment to establish the impact of various types of anthropogenic disturbances on the freshwater macroinvertebrates in an understudied biodiversity hotspot in South Asia, an area that attracts increasing attention for the loss of aquatic ecosystems. We sampled 16 river systems in the Chittagong Hill Tracts region of Bangladesh and characterised habitat intactness based on a set of 14 environmental parameters associated with habitat quality and human activities. Whole‐community metabarcoding was used to investigate the distribution of hypothetical species‐level clusters (Operational Taxonomic Units, OTUs) across sites of different impacts. We found >900 DNA clusters of insects, decapods and molluscs, dominated by Diptera, which revealed significant variation (p < 0.001) in richness across sites. The presumed sensitive Ephemeroptera‐Plecoptera–Trichoptera (EPT) represented 15.6% of total OTU richness. The type and strength of anthropogenic stressors varied greatly across streams but did not affect total OTU diversity. In contrast, EPT richness decreased by ~50% in response to habitat degradation. Partial‐network analysis revealed 26 OTUs that may serve as potential indicators for either good or poor ecological status. Overall, our results document high diversity, local endemicity and pronounced responses to disturbance in these largely unexplored but threatened habitats. Synthesis and applications. The proposed methodology combines local habitat surveys across sites of various degrees of disturbance with species‐level metabarcoding, as a model for biological evaluation of water bodies in poorly known and inaccessible places across the world. Implemented here for the Indo‐Burmese hotspot, the approach will have great value for applied conservation management as a step towards building a biomonitoring system in this region where currently little is known about the taxonomy, diversity and endemicity in both intact and disturbed ecosystems.

Macroinvertebrate assemblages in mountain tributaries of glacial-fed and rain-fed rivers in eastern Nepal

While river macroinvertebrates are the most widely used form of bioindicators, their baseline information, although crucial, is scarce in Nepal. The main objective of this study was to assess the macroinvertebrate assemblages in mountain tributaries of the glacial-fed Tamor and rain-fed Kamala rivers. A total of eight sites were sampled during March 2015 (Spring), November 2015 (Autumn), January 2016 (Winter), and May 2016 (Summer). Altogether, 49 Families of macroinvertebrates belonging to 15 Orders were identified with 39 Families and 12 Orders in Tamor’s tributaries, and 33 Families and 10 Orders in Kamala’s tributaries. Non-metric multi-dimensional scaling (NMDS) revealed different assemblages between the two river systems. The most dominant Order in the Tamor was Ephemeroptera and it was Trichoptera in the Kamala. EPT (Ephemeroptera Plecoptera Trichoptera) assemblages were the most abundant in all four seasons for both the river systems and higher % EPT in Tamor’s tributaries indicate better water quality than in the Kamala tributaries. Typical cold water adapted Families such as Rhyacophilidae and Stenopsychidae were observed in Tamor’s tributaries whereas in Kamala’s tributaries, warm water adapted Families like Naididae and Thiaridae were found, reflecting a difference in the abiotic variables such as temperature, dissolved oxygen attributed to each of the catchments. This baseline data can serve as the foundation for further bioassessment including those of climate change impacts on aquatic biodiversity.

Çoruh Nehir Havzası (Türkiye) su kalitesi’nin bazı biyotik indeksler kullanılarak belirlenmesi

In this study, it was aimed to evaluate the water quality of the Çoruh Basin using BMWP (Biological Monitoring Working Party) index, ASPT (Average Score Per Taxon) index, Shannon-Wiener Diversity Index, EPT (Ephemeroptera Plecoptera Trichoptera taxa), EP (Ephemeroptera Plecoptera taxa) index scores and benthic macroinvertebrates. The benthic macroinvertebrates were collected from 54 stations at the Çoruh basin between 2014-2016 years. Standard hand net (D-frame net) and Ekman-Birge grab were used as sampling tools. As a result of the diagnoses, a total of 7246 individuals belonging to Insecta, Crustacea, Mollusca, Oligochaeta and Plathyhelminthes were obtained. It was determined that the most dominant group was Insecta and the rarest group was Plathyhelminthes. It was observed that the BMWP score ranged between 5 and 94, and the lowest and highest number of families detected in the stations were 1 and 18, respectively. It was determined that the Shannon Wiener diversity index value was between 0.54-2.20, therefore the basin streams generally showed moderate pollution. The results of BMWP index show that the basin streams had mostly show 3rd and 4th class water quality and also biodiversity decreases with the deterioration of the riverbed or exposure to pollution.

Predicting the biodiversity hotspots of macrozoobenthos in the Yangtze river basin

Identifying the biodiversity hotspots could enrich our understanding for biodiversity conservation. The Yangtze River Basin (YRB) is seriously threatened by multiple stressors leading to rapid biodiversity declines, thus urgently requires an integrated biodiversity conservation. Based on field samplings and the literatures, we described the macrozoobenthos compositions in different reaches and water bodies. We then predicted suitable habitat areas for the main groups, and linked those distributions with key environmental variables. Finally, we analyzed biodiversity hotspots (BHs) of macrozoobenthos and compared them with BHs of large aquatic animals (including fishes, Waterfowls, Yangtze finless porpoise, etc.), and discussed the applicability of selecting macrozoobenthos as biodiversity surrogate for biodiversity conservation. A total of 1033 taxa were recorded. From the upper to lower of YRB, genera number of Oligochaeta and Mollusca increased, of EPT (Ephemeroptera, Plecoptera, Trichoptera) decreased, and of Chironomidae barely changed. In different water bodies, genera number of Oligochaeta, Mollusca, Chironomidae are the highest in lakes of the mid-lower YRB, while that of EPT are the highest in tributaries. Key environmental variables were water body types, elevation and max temperature of the warmest month. The total BHs areas of macrozoobenthos and large aquatic animals in the upper, and mid­lower YRB were 3.54 × 105 km2 and 2.95 × 105 km2, 2.95 × 105 km2 and 1.70 × 105 km2, respectively. The overlapping BHs were 2.0 × 105 km2 and 1.1 × 105 km2, respectively. The BHs of macrozoobenthos had a wider range, and included most BHs of large aquatic animals. Meanwhile, BHs of macrozoobenthos could indicate some habitats those were difficult to cover by selecting large aquatic animals as conservation targets, e.g., seasonal streams and water bodies that suffered from human disturbances. Based on these results, we argue that macrozoobenthos is a good biodiversity surrogate for biodiversity conservation.

Identifying and prioritizing aquatic habitats for conservation in a poorly studied region

Setting conservation priorities is an important step when resources are finite. Indeveloping countries such as Iraq, information about aquatic habitats is quite limited and prioritizing such habitats for conservation requires a multidisciplinary approach to utilize available types of data efficiently. We divided aquatic ecosystems of the Kurdistan Region of northern Iraq into 76 planning units. Next, we compiled mayfly, stonefly, and caddisfly (Insecta: Ephemeroptera-Plecoptera-Trichoptera (EPT)) data for 33 of them; these units were ranked for EPT conservation using a combination of indices. We selected the subset of units with the highest priority for EPT conservation and considered them to represent samples of healthy aquatic habitats in the region; we used these units, along with various landscape predictor variables, in correlative distribution modeling for healthy aquatic habitats across the entire region. Our approach resulted in identifying one lake and 23 riverine units as healthy aquatic habitats of conservation priority in the region. Our research shows that in developing countries where knowledge about aquatic habitats and species is minimal, conservation studies can still be conducted using water quality bioindicators along with a combination of conservation indices and spatial modeling.

Development of a multimetric index for assessing the ecological integrity of some selected rivers and streams in the north-eastern part of Lake Tana sub-basin, Ethiopia

A multimetric index was developed using benthic macroinvertebrates to assess the ecological health of selected rivers and streams in the north-eastern part of Lake Tana subbasin, Ethiopia. One-time extensive sampling was carried out during the post-rainy season (November–December) of 2016. Macroinvertebrates were collected using a Surber sampler and a D-frame net at twenty sites. Based on the measured physico-chemical variables, sampling sites were clustered into references (n = 8) and test sites (n = 4). Approximately thirty potential candidate metrics were tested, and five metrics were selected as core metrics: number of Ephemeroptera Plecoptera Trichoptera taxa, percentage of Ephemeroptera individuals, percentage of EPT individuals, percentage that were shredders, and the percentage that were filter-feeders. These metrics were scored on a continuous scale from 0 to 10. To develop Lake Tana subbasin multimetric index (LTSBMI), scores were added and scaled to produce a score from 0 to 100. The final index was divided into five water quality classes: 'very good', 'good', 'fair', 'poor' and 'very poor'. The LTSBMI was effective in discriminating sites with different levels of impacts, but should be checked to other localities. The current LTSBMI could be used for ecosystem health assessment and monitoring in different Aftropical river systems with similar agroecology.

Effects of effluent discharges from a cement factory on the ecology of macroinvertebrates in an Afrotropical river.

Cement factory waste water impacts on the ecology of macroinvertebrate assemblages of the Oinyi River, North Central area of Nigeria, were evaluated bi-monthly for 1 year as part of a study to understand the effects of pollution processes in the lotic system that may initiate the development of policy and improved regulation. Three sampling stations, each 100 m long, were selected along 11-km stretch of the river. Station 1, located upstream of the discharge point from the cement factory plant; station 2, immediately downstream of the effluent discharge point; and station 3, 4 km downstream, were sampled. The waste water from the cement effluent factory impacted negatively on the water chemistry by elevating the levels of some heavy metals (Mn, Zn, Cu, and Ni), and other physicochemical parameters such as turbidity, chemical oxygen demand (COD), conductivity, and total suspended solid. A total of 81 macroinvertebrate taxa combined were recorded from the river. The community structure, diversity, and abundance depicted distinct variation between the effluent-impacted site, and the upstream station as the most sensitive macroinvertebrate taxa such as Neoperla and Cheumatopsyche species was completely missing from the effluent-impacted site. The preponderance of some dipteran taxa (Tanypus sp., Eristalis tenax, Simulum sp., Empis sp., and Atherix sp.) and drastic reduction in the Ephemeroptera-Plecoptera-Trichoptera (EPT) organisms in the impacted station is an indication that the chemical components of the cement effluent waste water were lethal to some aquatic forms. Extrapolations from canonical correspondence analysis (CCA) results revealed that turbidity, conductivity, BOD, orthophosphate-phosphorus, and heavy metals were strongly associated with the impacted station. Generally, the community structure of station 1 was more diverse with more sensitive taxa, different from those of stations 2 and 3, which were prone to intense human activities. The need for careful consideration of the water quality and indicator organisms is important for restoration of this river.

Response of benthic macroinvertebrates to dam removal in the restoration of the Boardman River, Michigan, USA.

Dam removal is an increasingly important method of stream restoration, but most removal efforts are under-studied in their effects. In order to better understand the effects of such removals on the stream ecosystem, we examined changes in stream macroinvertebrate communities from 2011–2016. Comparisons were focused above, below, and before and after the October 2012 removal of the Brown Bridge Dam on the Boardman River in Michigan (USA), as well as to new channel sites created in its former reservoir (2013–2015). Using linear mixed-effect models on the percent abundance of ecologically sensitive taxa (% Ephemeroptera, Plecoptera, Trichoptera (EPT)), total density of all macroinvertebrates, overall taxa richness, and Functional Feeding Groups, along with multivariate analyses on the community matrix, we examined differences in community composition among sites and years. EPT declined downstream of the dam immediately after dam removal, but recovered in the second year, becoming dominant within 2–4 years. Downstream sites before removal had different community composition than upstream sites and downstream sites after removal (p<0.001), while upstream and downstream sites after removal converged towards similarity. New channel (restored) %EPT, density, and taxa richness were not different from upstream sites in any year following removal, but new channel sites were the most distinct in community composition, possessing multiple indicator taxa characteristic of unique new conditions. The invasive New Zealand mud snail (Potamopyrgus antipodarum) was absent from all sites prior to dam removal, but appeared at low densities in upstream sites in 2013, had spread to all sites by 2015, and showed large increases at all sites by 2016. Managers employing dam removal for stream restoration should include post-removal monitoring for multiple years following removal and conduct risk analysis regarding potential effects on colonization of invasive invertebrate species.

Assessment of Macroinvertebrates as Bioindicators of Water Quality in the Littoral Zone of Lake Mainit, Philippines

Water quality in the lake littoral zone influence habitat complexity. This study determined the relationships of macroinvertebrates in response to water physicochemical parameters in ten littoral zone stations across four municipalities of Lake Mainit Philippines. Macroinvertebrates were collected following the standard protocol for littoral areas with modifications and taxa groupings were assigned based on sensitivity to pollution. Water Quality Index (WQI) from the identified bioindicator species was computed. Results revealed that all physicochemical parameters of the ten sampling stations passed the water quality standard set by DAO 2016, except for the pH and temperature readings of Mansayao and Tagbuyawan. Out of 20, 924 macroinvertebrates collected, 16 species were identified from 13 families. Station Mansayao exhibited higher species diversity (H’=1.98). No EPT (Ephemeroptera, Plecoptera, Trichoptera) species were observed across stations. Most of the macroinvertebrates collected were under Taxa 2 (50%) and Taxa 3 (50%), the presence of which, indicates moderate to poor water quality. The WQIs range from 3.1-3.7, which means the stations have “rather dirty to average” and “dirty water”, except for the San Roque station (WQI=2.5), which showed a polluted water quality. Of the 16 species of macroinvertebrates collected, only ten species showed moderate positive association to pH, dissolve oxygen, temperature and Total Dissolved Solids. Littoral zones of the Lake Mainit still support and harbor a variety of aquatic macroinvertebrates. However, the abundance of pollutiontolerant species indicates a declining water quality due to the influence of anthropogenic activities surrounding the lake.

Cave lithology influencing EPT (Ephemeroptera, Plecoptera, Trichoptera) assemblages and habitat structure in south-eastern Brazil

Knowing how cave lithology influences the benthic macroinvertebrate fauna is important for conservation and management of subterranean aquatic systems. However, those influences are still poorly understood, especially in the Neotropics. This study aimed to understand how cave lithology can influence benthic EPT assemblages by assessing the differences in the EPT genera structure in caves of two distinct lithologies (quartzite and limestone) and determining possible differences in the lithology habitats. To achieve this, hydrochemistry data and biological samples were collected in six allogenic cave streams from the two aforementioned lithologies. Results showed that both the assemblages from different lithologies and within the same lithology are statistically different, thus indicating probable regional influences beyond local ones. Our results also pointed out an effect of lithology on the substrate parameters, which in turn affected the EPT composition. Cave lithology affects water chemical and physical characteristics, thus supporting different EPT assemblages. The results of this study provide a foundation for future investigation on how the lithology can influence the benthic macroinvertebrate fauna and should lead to means of predicting such fauna on the basis of the cave lithology and water chemistry.