Otto Moog | University of Natural Resources and Life Sciences, Vienna (BOKU) (original) (raw)
Papers by Otto Moog
Nepal Journal of Science and Technology, 2003
Although stream poisoning by local herbs 1ike Lyonia ovalifolia, Juglans regia and Euphorbia royl... more Although stream poisoning by local herbs 1ike Lyonia ovalifolia, Juglans regia and Euphorbia royleana is a common fishing practice in many parts of Nepal, the effects of this practice on the environment are more or less unknown. Quantitative study of the benthic invertebrate fauna in a middle sized mid hill stream of Nepal indicated that herb poisoning caused substantial reduction of taxa richness and diversity as well as a significant decrease of the individual and biomass density and composition of macroinvertebrates, irrespective of the systematic afiliation of the fauna. EPT (Ephemeroptera, Plecoptera and Trichoptera), Coleoptera and Diptera were among the most affected groups of macroinvertebrates that have been extirpated up to 95%. Ten core metrics with a significant discriminatory power to detect the herb effects on the benthic fauna have been found. Although this fishing technique mobilises the fine sediment in a significant way that leads to a severe turbidity of the water there were no effects of increased putrescible effects. The assessments based on NEPBIOS-ASPTindicated no change of the saprobic water quality by the disturbance activities. The major impairment to these fauna was narcotisation initiated by poisoning and mechanical disturbances of the river bottom habitats. Both effects lead to lethal effects as well as to an increased drift activity (400%) irrespectively from fauna's natural drifting character. Although only few percent of the standing crop of benthic invertebrates remained in the treated river sections, this type of impairment can be classified as of spatial and temporal importance if the procedure is undertaken within the re-colonisation capacity of the entire benthic fauna.
Verhandlungen, Jun 1, 1991
River Systems, Apr 13, 2000
Quantitative sampling in large, deep rivers is both difficult and cost-intensive. Areas such as s... more Quantitative sampling in large, deep rivers is both difficult and cost-intensive. Areas such as steep banks, deep runs and in high current velocity are often inaccessable and standard methods are difficult to apply. Dredging nets, grabs, corers and air-lift samplers can be used, but they have been developed for research and are usually too expensive for routine monitoring programs. Colonization samplers containing artificial substrate can provide a valid alternative, but nevertheless are mostly too complicated for routine use. To overcome these problems a new colonization sampler based on the Belgian artificial substrate sampler (DE PAUW 1993) was developed and tested for its efficiency were used for the study. At two sites in the Danube near Vienna samples from the colonizing device were compared with samples taken from natural substrates with a Surber-sampler. The sampling method decribed proved to produce reproducible results and is practicable for routine monitoring. The collecting gear consists of inexpensive and readily available materials, sampling can be carried out quickly with few personnel, and handling is easy. Although the Danube-Net-Basket-Sampler seems to display some degree of selectivity, it provides a representative sample of macroinvertebrate fauna with respect to taxonomic composition, individual numbers, and biomass, sufficient for a correct assessment of a given set of metrics used for routine water quality assessment. The colonization samples also support the analysis of functional ecosystem aspects, such as the distribution of functional-feeding guilds and zonation aspects.
Hydrobiologia, Sep 14, 2016
In this paper, a monitoring and modelling concept for ecological optimized harbour dredging and f... more In this paper, a monitoring and modelling concept for ecological optimized harbour dredging and fine sediment disposal in large rivers is presented. According to the concept, first a preliminary assessment should be performed previous to the dredging and dumping procedure to derive knowledge about the current status in hydrodynamics, morphology and instream habitat quality. During the performance of the maintenance work, a high-resolution monitoring program has to be organized to measure flow velocities, the suspended sediment concentrations and the extent of the occurring plume. These data can then be compared with natural suspended sediment conditions and serve as input data for numerical sediment transport modelling. Furthermore, bathymetric surveys and biotic sampling enable the detection of possible effects of dredging and disposal in the postdumping stage. Based on sediment transport modelling approaches, short-to mid-term developments of the sediment plume can be predicted with an additional and final habitat evaluation at the end of the project. This concept was applied and optimized during the maintenance work at the case study winter harbour Linz at the Danube River. The findings of the presented study highlight the necessity of integrated monitoring and modelling approaches for harbour dredging especially in large river systems.
Hydrobiologia, Feb 1, 2015
This study presents the development of a multimetric index using benthic macroinvertebrates (BMI)... more This study presents the development of a multimetric index using benthic macroinvertebrates (BMI) to assess the ecological health of highland rivers in Ethiopia. BMI were collected from 22 reference and 82 impaired sites determined based on hydro-morphological, land use, and physical and chemical criteria. Of 75 potential metrics tested to integrate the multimetric index, only nine core metrics were selected based on their abilities to distinguish reference and impaired sites, strength of correlation with pertinent environmental parameters, and their independence from other metrics. The metrics retained in the multimetric index were total number of taxa, EPT-BH [ 1sp (Ephemeroptera, Plecoptera, and Trichoptera taxa where Baetidae and Hydropsychidae taxa are considered if they consist more than one taxon), % Oligochaeta and Red Chironomidae, % COPTE (Coleoptera, Odonata, Plecoptera, Trichoptera, and Ephemeroptera), % EPT-BCH (EPT without Baetidae, Caenidae, and Hydropsychidae), ASPT-SASS (Average South African Scoring System Per Taxa), FBI (Family Biotic Index), % shredders, and % collector gathering. The final index derived from these metrics was divided into five river quality class (high, good, moderate, poor, and bad). A validation procedure showed that the index is stable along different hydrological conditions and sensitive to the current range of anthropogenic disturbances in Ethiopian highland rivers.
Regulated rivers, May 1, 1993
The effects of intermittent power generation on the fish fauna and benthic invertebrates of sever... more The effects of intermittent power generation on the fish fauna and benthic invertebrates of several Austrian rivers have been investigated quantitatively. In contrast to the more or less local adverse effects of impoundments or stream channelization, artificial flow fluctuations generally disturb a long section of a given river. Within all the river sections investigated, a breakdown of the benthic invertebrate biomass of between 75 and 95% was observed within the first few kilometres of river length. A reduction of between 40 and 60% of biomass compared with undisturbed areas could be detected within the following 20–40 km. The reduction of the fish fauna is within the same order of magnitude and correlates well with the amplitude of the flow fluctuations. Several reasons for the breakdown are summarized and proposals for the minimization of these detrimental effects of artificial short‐term fluctuations are given.
Verhandlungen, Sep 1, 2001
CRC Press eBooks, Sep 3, 2008
The Hindu Kush-Himalayan (HKH) region is covering some 3500 km over eight countries from Afghanis... more The Hindu Kush-Himalayan (HKH) region is covering some 3500 km over eight countries from Afghanistan in the west to Myanmar in the east. This region is world's youngest mountain range offering highest altitudinal variation on Earth with extreme climatic contrasts. Despite such unique features, very less is known in terms of taxonomic knowledge of aquatic macroinvertebrates from this region. This paper introduces 8097 macroinvertebrate taxa.
![Research paper thumbnail of The vertical distribution of zooplankton in the Goggausee (the influence of algae and Chaoborus flavicans) [Translation from: Carinthia II 166/186 373-385, 1976]](https://attachments.academia-assets.com/112380421/thumbnails/1.jpg)
](
Benthic invertebrates were used as bioindicators to document the effect of restoration measures i... more Benthic invertebrates were used as bioindicators to document the effect of restoration measures in the backwater Alte Donau in Vienna, a former side-arm of the Danube. The study covers four periods of lake management: (1): the mesotrophic year before eutrophication (1987), (2): the 2 years of chemical iron chloride treatment aimed at the phosphate precipitation in the water column and the oxidization of nitrate-treated sediment surface layers (1995–1996), (3): further 3 years of other lake management measures during the restoration period (1995–1999), and (4): an early stage of the re-establishment of underwater vegetation (2000, 2003). Over eight survey years from 1987 to 2003, about 330 benthic invertebrate taxa with three most abundant systematic groups were identified: 37 species of oligochaetes, 23 species of molluscs (18 gastropods and 5 bivalves), and 190 species of the chironomids and other dipterans. The trophic classification index that refers to a habitat quality score by chironomids indicates the year 1987 as mesotrophic (3.46, the index range for mesotrophic conditions is 2.50–3.49). In this year the chironomids and oligochaet species inhabited a variety of diverse habitats ranging from soft sediments (clay and mud), sand, gravel, pebbles and stones to dense stands of macrophytes. The biomonitoring record of 15 mollusc species was significantly higher in this mesotrophic reference year than in any other following survey year. The trophic classification index denotes 1995 as the most eutrophied year. With the restoration and the re-establishment of macrophytes the values of this index decreased but remained higher than during the mesotrophic condition. In the years 1995 and 1996, when the chemical treatment with iron chloride, slaked lime and calcium nitrate was applied and the macrophytes were rare, the biomass of chironomids and oligochaets was particularly low. Among the three important taxonomic groups, i.e. the chironomids, bivalves, and oligochaets, only the first two groups achieved relative biomass dominance. The relative importance of chironomids over oligochaets during these both years of the Riplox-treatment might rather mirror the losses of oligochaets being affected by nitrate exposure than the re-colonization by ‘new’ chironomid species in the sediment. In addition, in particular active filter feeders such as bivalves seemed to adjust well to the muddy sediment environment after chemical treatment. In the following years of the restoration and the early stage of macrophyte re-establishment, oligochaets and bivalves became the dominant groups mainly contributing to the macrozoobenthic biomass, while the biomass of chironomids remained relatively low. Different from the indication by enhanced water transparency and low phytoplankton biomass achieved by restoration measures in 2004, the shift towards a mesotrophic environment seemed to be retarded when assessing Alte Donau by the chironomid habitat quality score index. The main reason why the chironomid assemblage did not follow the other indicators of mesotrophic conditions in 2004 can be seen in the disruption of the sediment (e.g. by sedimentation of precipitation chemicals) and associated loss of underwater habitat structure due to still relatively low macrophyte biomass during the last invertebrate survey. The phytophilic chironomid species still had a low abundance when only about 50% of the macrophyte biomass was recorded if compared with the mesotrophic situation in 1987. Despite the wax and wane of benthic invertebrates described during the eight-year survey, invertebrate biomass is relatively high in the long-term average and thus characterises Alte Donau as a lowland environment along habitats from low- to high altitudes.
Verhandlungen, Dec 1, 2000
International Journal of Speleology
Between 2015 and 2019, the list of Lepidoptera from “cave” habitats (i.e., proper caves, rock she... more Between 2015 and 2019, the list of Lepidoptera from “cave” habitats (i.e., proper caves, rock shelters and artificial subterranean structures) in Austria grew from 17 to 62 species, although the effort of data collection remained nearly constant from the late 1970s onwards. The newly recorded moths and butterflies were resting in caves during daytime in the the warm season, three species were also overwintering there. We observed Catocala elocata at 28 cave inspections, followed by Mormo maura (18), Catocala nupta (7), Peribatodes rhomboidaria, and Euplagia quadripunctaria (6). More than half of the species have been repeatedly observed in caves in Austria or abroad, so their relationship with such sites is apparently not completely random. Since the increase of records in Austria coincided with a considerable rise in the annual number of hot days (maximum temperatures ≥30°C) from 2015 onwards, we interpret the growing inclination of certain Lepidoptera towards daytime sheltering in...
Journal of Environmental Management, 2022
Conserving aquatic resources in the West African Sahel requires water management tools to assess ... more Conserving aquatic resources in the West African Sahel requires water management tools to assess the ecological status of surface water bodies threatened by mounting pressures from agricultural intensification and urbanization. Macroinvertebrate communities of Sahelian rivers were examined to test if a multi-metric index approach could be developed to assess the ecological quality of rivers. A total of 40 sample sites falling within a continuum ranging from "unimpaired reference sites" to "impaired sites" were assessed during this study. Macroinvertebrates were sampled with a hand net following a multi-habitat sampling approach. Key environmental parameters, both physico-chemical and hydro-morphologic, were recorded. More than 20 candidate metrics were evaluated in four categories: composition, functional feeding, diversity, and tolerance. We used detailed analysis procedures to exclude unsuitable metrics from the data set. After excluding redundant metrics, six-core metrics were selected to compose the Sahel River Multimetric Index (SRMI): Total-taxa, Shannon & Weiner index, EPT-taxa, ASPT-NEPBIOS and ASPT-SASS and Collector-filterers. The final index derived from these metrics was divided into five ecological quality classes (high, good, moderate, poor, and bad). The results showed that the SRMI responded to a set of environmental parameters associated with a gradient of human pressures affecting the ecological integrity of water bodies (R2≥|0.50|; p < 0.05; p < 0.001). This work produced a data base and analysis that confirms the usefulness of an unprecedented and promising tool for biological monitoring and decision-making in Sahelian regions' water management.
Environmental Monitoring and Assessment, 2017
Awareness of sustainable management of water and its biological resources is rising in West Afric... more Awareness of sustainable management of water and its biological resources is rising in West Africa, but application of effective tools for biomonitoring and detecting habitats at risk in aquatic ecosystems is limited. In this study, we provide key environmental descriptors to characterize reference sites by applying the following Ba priori criteria^(physical and chemical, hydromorphological, and land use parameters) by exploring their potential to determine suitable reference sites. Using data collected from 44 sites, we identified 37 criteria that reliably identify reference conditions in semi-arid rivers by reflecting the impacts of multiple pressures ranging from low to very high intensity of human uses and impairments. We integrated all these impacts in an overall pressures index, which showed that protected areas can reasonably be considered as credible reference sites as far as they show low overall impact levels from cumulative pressures. We recommend that development of bio-indicator standards should be based on the collection and integration of all the available information, especially quantitative, spatially-explicit data, from benthic macroinvertebrates and fish. Rigorous standardization of bio-indicator protocols will make them more easily applicable for management and conservation of aquatic ecosystem resources in semi-arid zones of Africa.
International Journal of Biological and Chemical Sciences, 2017
The benthic macroinvertebrates communities dynamic were investigated in rivers from Burkina Faso ... more The benthic macroinvertebrates communities dynamic were investigated in rivers from Burkina Faso in the purpose to analyze the taxonomic composition, the structure of benthic macroinvertebrates community and the composite environmental variables that correspond to the major distribution patterns of this community. The results showed that a total of 132 taxa was recorded and the large majority of these (103 taxa) belonged to 57 families from 8 orders of insects that represent 95% of relative abundance. We also observed some distinct differences relative to the spatial and temporal variation in the taxonomic composition. The canonical correspondance analysis (CCA) revealed a strong correlationship between Chironomidae, Syrphidae, Culicidae, Psychodidae, as well as the Pulmonates molluscs and organic nutriments feeding dynamics. These findings showed the sensitivity of benthic macroinvertebrates at different level: sensitivity which could be attributable to man-induced activities.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2000
1. One hundred and sixty rivers in Scotland with historical records of freshwater pearl mussel Ma... more 1. One hundred and sixty rivers in Scotland with historical records of freshwater pearl mussel Margaritifera margaritifera were surveyed between 1996 and 1999 for the presence of the species. 2. M. margaritifera populations were classed as either 'extinct' (no mussels remaining), 'not currently viable' (ranging from only dead shells present to no juveniles present, regardless of the number of adults found), or 'functional' (at least one juvenile was found, regardless of the overall numbers of adults present). 3. M. margaritifera populations could be classed as 'functional' in only 52 rivers (34% of total surveyed) and in only 17 of these were juveniles below 20 mm (5 yrs old) present. Furthermore, in only 10 of these functional rivers were mussels also still considered either to be common or abundant and these included both large easterly-flowing rivers and small western rivers and streams. 4. In approximately two-thirds (101) of the 155 rivers occupied 100 years ago, M. margaritifera is now extinct or is about to become extinct. Furthermore, analysis indicates that the rate of mussel population extinction has accelerated since 1970, with a recent average of two mussel river extinctions per year. 5. The predominant threat to the mussel populations has undoubtedly been pearl fishing. This has been occurring at every river, even in the most remote northwest areas, where most of the 'functional' populations remain. Recent legislation has provided full protection to M. margaritifera, so that all pearl harvesting is now illegal. 6. Locally, river engineering and host salmonid stock decline poses a serious threat and eutrophication has already eliminated populations in southern and eastern Scotland. 7. In every part of its global range, M. margaritifera has declined substantially and is now either threatened with extinction or is highly vulnerable. Based on recent estimates from across the species range, it appears that Scotland now probably holds at least half of the world's remaining functional M. margaritifera populations.
Nepal Journal of Science and Technology, 2003
Although stream poisoning by local herbs 1ike Lyonia ovalifolia, Juglans regia and Euphorbia royl... more Although stream poisoning by local herbs 1ike Lyonia ovalifolia, Juglans regia and Euphorbia royleana is a common fishing practice in many parts of Nepal, the effects of this practice on the environment are more or less unknown. Quantitative study of the benthic invertebrate fauna in a middle sized mid hill stream of Nepal indicated that herb poisoning caused substantial reduction of taxa richness and diversity as well as a significant decrease of the individual and biomass density and composition of macroinvertebrates, irrespective of the systematic afiliation of the fauna. EPT (Ephemeroptera, Plecoptera and Trichoptera), Coleoptera and Diptera were among the most affected groups of macroinvertebrates that have been extirpated up to 95%. Ten core metrics with a significant discriminatory power to detect the herb effects on the benthic fauna have been found. Although this fishing technique mobilises the fine sediment in a significant way that leads to a severe turbidity of the water there were no effects of increased putrescible effects. The assessments based on NEPBIOS-ASPTindicated no change of the saprobic water quality by the disturbance activities. The major impairment to these fauna was narcotisation initiated by poisoning and mechanical disturbances of the river bottom habitats. Both effects lead to lethal effects as well as to an increased drift activity (400%) irrespectively from fauna's natural drifting character. Although only few percent of the standing crop of benthic invertebrates remained in the treated river sections, this type of impairment can be classified as of spatial and temporal importance if the procedure is undertaken within the re-colonisation capacity of the entire benthic fauna.
Verhandlungen, Jun 1, 1991
River Systems, Apr 13, 2000
Quantitative sampling in large, deep rivers is both difficult and cost-intensive. Areas such as s... more Quantitative sampling in large, deep rivers is both difficult and cost-intensive. Areas such as steep banks, deep runs and in high current velocity are often inaccessable and standard methods are difficult to apply. Dredging nets, grabs, corers and air-lift samplers can be used, but they have been developed for research and are usually too expensive for routine monitoring programs. Colonization samplers containing artificial substrate can provide a valid alternative, but nevertheless are mostly too complicated for routine use. To overcome these problems a new colonization sampler based on the Belgian artificial substrate sampler (DE PAUW 1993) was developed and tested for its efficiency were used for the study. At two sites in the Danube near Vienna samples from the colonizing device were compared with samples taken from natural substrates with a Surber-sampler. The sampling method decribed proved to produce reproducible results and is practicable for routine monitoring. The collecting gear consists of inexpensive and readily available materials, sampling can be carried out quickly with few personnel, and handling is easy. Although the Danube-Net-Basket-Sampler seems to display some degree of selectivity, it provides a representative sample of macroinvertebrate fauna with respect to taxonomic composition, individual numbers, and biomass, sufficient for a correct assessment of a given set of metrics used for routine water quality assessment. The colonization samples also support the analysis of functional ecosystem aspects, such as the distribution of functional-feeding guilds and zonation aspects.
Hydrobiologia, Sep 14, 2016
In this paper, a monitoring and modelling concept for ecological optimized harbour dredging and f... more In this paper, a monitoring and modelling concept for ecological optimized harbour dredging and fine sediment disposal in large rivers is presented. According to the concept, first a preliminary assessment should be performed previous to the dredging and dumping procedure to derive knowledge about the current status in hydrodynamics, morphology and instream habitat quality. During the performance of the maintenance work, a high-resolution monitoring program has to be organized to measure flow velocities, the suspended sediment concentrations and the extent of the occurring plume. These data can then be compared with natural suspended sediment conditions and serve as input data for numerical sediment transport modelling. Furthermore, bathymetric surveys and biotic sampling enable the detection of possible effects of dredging and disposal in the postdumping stage. Based on sediment transport modelling approaches, short-to mid-term developments of the sediment plume can be predicted with an additional and final habitat evaluation at the end of the project. This concept was applied and optimized during the maintenance work at the case study winter harbour Linz at the Danube River. The findings of the presented study highlight the necessity of integrated monitoring and modelling approaches for harbour dredging especially in large river systems.
Hydrobiologia, Feb 1, 2015
This study presents the development of a multimetric index using benthic macroinvertebrates (BMI)... more This study presents the development of a multimetric index using benthic macroinvertebrates (BMI) to assess the ecological health of highland rivers in Ethiopia. BMI were collected from 22 reference and 82 impaired sites determined based on hydro-morphological, land use, and physical and chemical criteria. Of 75 potential metrics tested to integrate the multimetric index, only nine core metrics were selected based on their abilities to distinguish reference and impaired sites, strength of correlation with pertinent environmental parameters, and their independence from other metrics. The metrics retained in the multimetric index were total number of taxa, EPT-BH [ 1sp (Ephemeroptera, Plecoptera, and Trichoptera taxa where Baetidae and Hydropsychidae taxa are considered if they consist more than one taxon), % Oligochaeta and Red Chironomidae, % COPTE (Coleoptera, Odonata, Plecoptera, Trichoptera, and Ephemeroptera), % EPT-BCH (EPT without Baetidae, Caenidae, and Hydropsychidae), ASPT-SASS (Average South African Scoring System Per Taxa), FBI (Family Biotic Index), % shredders, and % collector gathering. The final index derived from these metrics was divided into five river quality class (high, good, moderate, poor, and bad). A validation procedure showed that the index is stable along different hydrological conditions and sensitive to the current range of anthropogenic disturbances in Ethiopian highland rivers.
Regulated rivers, May 1, 1993
The effects of intermittent power generation on the fish fauna and benthic invertebrates of sever... more The effects of intermittent power generation on the fish fauna and benthic invertebrates of several Austrian rivers have been investigated quantitatively. In contrast to the more or less local adverse effects of impoundments or stream channelization, artificial flow fluctuations generally disturb a long section of a given river. Within all the river sections investigated, a breakdown of the benthic invertebrate biomass of between 75 and 95% was observed within the first few kilometres of river length. A reduction of between 40 and 60% of biomass compared with undisturbed areas could be detected within the following 20–40 km. The reduction of the fish fauna is within the same order of magnitude and correlates well with the amplitude of the flow fluctuations. Several reasons for the breakdown are summarized and proposals for the minimization of these detrimental effects of artificial short‐term fluctuations are given.
Verhandlungen, Sep 1, 2001
CRC Press eBooks, Sep 3, 2008
The Hindu Kush-Himalayan (HKH) region is covering some 3500 km over eight countries from Afghanis... more The Hindu Kush-Himalayan (HKH) region is covering some 3500 km over eight countries from Afghanistan in the west to Myanmar in the east. This region is world's youngest mountain range offering highest altitudinal variation on Earth with extreme climatic contrasts. Despite such unique features, very less is known in terms of taxonomic knowledge of aquatic macroinvertebrates from this region. This paper introduces 8097 macroinvertebrate taxa.
Benthic invertebrates were used as bioindicators to document the effect of restoration measures i... more Benthic invertebrates were used as bioindicators to document the effect of restoration measures in the backwater Alte Donau in Vienna, a former side-arm of the Danube. The study covers four periods of lake management: (1): the mesotrophic year before eutrophication (1987), (2): the 2 years of chemical iron chloride treatment aimed at the phosphate precipitation in the water column and the oxidization of nitrate-treated sediment surface layers (1995–1996), (3): further 3 years of other lake management measures during the restoration period (1995–1999), and (4): an early stage of the re-establishment of underwater vegetation (2000, 2003). Over eight survey years from 1987 to 2003, about 330 benthic invertebrate taxa with three most abundant systematic groups were identified: 37 species of oligochaetes, 23 species of molluscs (18 gastropods and 5 bivalves), and 190 species of the chironomids and other dipterans. The trophic classification index that refers to a habitat quality score by chironomids indicates the year 1987 as mesotrophic (3.46, the index range for mesotrophic conditions is 2.50–3.49). In this year the chironomids and oligochaet species inhabited a variety of diverse habitats ranging from soft sediments (clay and mud), sand, gravel, pebbles and stones to dense stands of macrophytes. The biomonitoring record of 15 mollusc species was significantly higher in this mesotrophic reference year than in any other following survey year. The trophic classification index denotes 1995 as the most eutrophied year. With the restoration and the re-establishment of macrophytes the values of this index decreased but remained higher than during the mesotrophic condition. In the years 1995 and 1996, when the chemical treatment with iron chloride, slaked lime and calcium nitrate was applied and the macrophytes were rare, the biomass of chironomids and oligochaets was particularly low. Among the three important taxonomic groups, i.e. the chironomids, bivalves, and oligochaets, only the first two groups achieved relative biomass dominance. The relative importance of chironomids over oligochaets during these both years of the Riplox-treatment might rather mirror the losses of oligochaets being affected by nitrate exposure than the re-colonization by ‘new’ chironomid species in the sediment. In addition, in particular active filter feeders such as bivalves seemed to adjust well to the muddy sediment environment after chemical treatment. In the following years of the restoration and the early stage of macrophyte re-establishment, oligochaets and bivalves became the dominant groups mainly contributing to the macrozoobenthic biomass, while the biomass of chironomids remained relatively low. Different from the indication by enhanced water transparency and low phytoplankton biomass achieved by restoration measures in 2004, the shift towards a mesotrophic environment seemed to be retarded when assessing Alte Donau by the chironomid habitat quality score index. The main reason why the chironomid assemblage did not follow the other indicators of mesotrophic conditions in 2004 can be seen in the disruption of the sediment (e.g. by sedimentation of precipitation chemicals) and associated loss of underwater habitat structure due to still relatively low macrophyte biomass during the last invertebrate survey. The phytophilic chironomid species still had a low abundance when only about 50% of the macrophyte biomass was recorded if compared with the mesotrophic situation in 1987. Despite the wax and wane of benthic invertebrates described during the eight-year survey, invertebrate biomass is relatively high in the long-term average and thus characterises Alte Donau as a lowland environment along habitats from low- to high altitudes.
Verhandlungen, Dec 1, 2000
International Journal of Speleology
Between 2015 and 2019, the list of Lepidoptera from “cave” habitats (i.e., proper caves, rock she... more Between 2015 and 2019, the list of Lepidoptera from “cave” habitats (i.e., proper caves, rock shelters and artificial subterranean structures) in Austria grew from 17 to 62 species, although the effort of data collection remained nearly constant from the late 1970s onwards. The newly recorded moths and butterflies were resting in caves during daytime in the the warm season, three species were also overwintering there. We observed Catocala elocata at 28 cave inspections, followed by Mormo maura (18), Catocala nupta (7), Peribatodes rhomboidaria, and Euplagia quadripunctaria (6). More than half of the species have been repeatedly observed in caves in Austria or abroad, so their relationship with such sites is apparently not completely random. Since the increase of records in Austria coincided with a considerable rise in the annual number of hot days (maximum temperatures ≥30°C) from 2015 onwards, we interpret the growing inclination of certain Lepidoptera towards daytime sheltering in...
Journal of Environmental Management, 2022
Conserving aquatic resources in the West African Sahel requires water management tools to assess ... more Conserving aquatic resources in the West African Sahel requires water management tools to assess the ecological status of surface water bodies threatened by mounting pressures from agricultural intensification and urbanization. Macroinvertebrate communities of Sahelian rivers were examined to test if a multi-metric index approach could be developed to assess the ecological quality of rivers. A total of 40 sample sites falling within a continuum ranging from "unimpaired reference sites" to "impaired sites" were assessed during this study. Macroinvertebrates were sampled with a hand net following a multi-habitat sampling approach. Key environmental parameters, both physico-chemical and hydro-morphologic, were recorded. More than 20 candidate metrics were evaluated in four categories: composition, functional feeding, diversity, and tolerance. We used detailed analysis procedures to exclude unsuitable metrics from the data set. After excluding redundant metrics, six-core metrics were selected to compose the Sahel River Multimetric Index (SRMI): Total-taxa, Shannon & Weiner index, EPT-taxa, ASPT-NEPBIOS and ASPT-SASS and Collector-filterers. The final index derived from these metrics was divided into five ecological quality classes (high, good, moderate, poor, and bad). The results showed that the SRMI responded to a set of environmental parameters associated with a gradient of human pressures affecting the ecological integrity of water bodies (R2≥|0.50|; p < 0.05; p < 0.001). This work produced a data base and analysis that confirms the usefulness of an unprecedented and promising tool for biological monitoring and decision-making in Sahelian regions' water management.
Environmental Monitoring and Assessment, 2017
Awareness of sustainable management of water and its biological resources is rising in West Afric... more Awareness of sustainable management of water and its biological resources is rising in West Africa, but application of effective tools for biomonitoring and detecting habitats at risk in aquatic ecosystems is limited. In this study, we provide key environmental descriptors to characterize reference sites by applying the following Ba priori criteria^(physical and chemical, hydromorphological, and land use parameters) by exploring their potential to determine suitable reference sites. Using data collected from 44 sites, we identified 37 criteria that reliably identify reference conditions in semi-arid rivers by reflecting the impacts of multiple pressures ranging from low to very high intensity of human uses and impairments. We integrated all these impacts in an overall pressures index, which showed that protected areas can reasonably be considered as credible reference sites as far as they show low overall impact levels from cumulative pressures. We recommend that development of bio-indicator standards should be based on the collection and integration of all the available information, especially quantitative, spatially-explicit data, from benthic macroinvertebrates and fish. Rigorous standardization of bio-indicator protocols will make them more easily applicable for management and conservation of aquatic ecosystem resources in semi-arid zones of Africa.
International Journal of Biological and Chemical Sciences, 2017
The benthic macroinvertebrates communities dynamic were investigated in rivers from Burkina Faso ... more The benthic macroinvertebrates communities dynamic were investigated in rivers from Burkina Faso in the purpose to analyze the taxonomic composition, the structure of benthic macroinvertebrates community and the composite environmental variables that correspond to the major distribution patterns of this community. The results showed that a total of 132 taxa was recorded and the large majority of these (103 taxa) belonged to 57 families from 8 orders of insects that represent 95% of relative abundance. We also observed some distinct differences relative to the spatial and temporal variation in the taxonomic composition. The canonical correspondance analysis (CCA) revealed a strong correlationship between Chironomidae, Syrphidae, Culicidae, Psychodidae, as well as the Pulmonates molluscs and organic nutriments feeding dynamics. These findings showed the sensitivity of benthic macroinvertebrates at different level: sensitivity which could be attributable to man-induced activities.
Aquatic Conservation: Marine and Freshwater Ecosystems, 2000
1. One hundred and sixty rivers in Scotland with historical records of freshwater pearl mussel Ma... more 1. One hundred and sixty rivers in Scotland with historical records of freshwater pearl mussel Margaritifera margaritifera were surveyed between 1996 and 1999 for the presence of the species. 2. M. margaritifera populations were classed as either 'extinct' (no mussels remaining), 'not currently viable' (ranging from only dead shells present to no juveniles present, regardless of the number of adults found), or 'functional' (at least one juvenile was found, regardless of the overall numbers of adults present). 3. M. margaritifera populations could be classed as 'functional' in only 52 rivers (34% of total surveyed) and in only 17 of these were juveniles below 20 mm (5 yrs old) present. Furthermore, in only 10 of these functional rivers were mussels also still considered either to be common or abundant and these included both large easterly-flowing rivers and small western rivers and streams. 4. In approximately two-thirds (101) of the 155 rivers occupied 100 years ago, M. margaritifera is now extinct or is about to become extinct. Furthermore, analysis indicates that the rate of mussel population extinction has accelerated since 1970, with a recent average of two mussel river extinctions per year. 5. The predominant threat to the mussel populations has undoubtedly been pearl fishing. This has been occurring at every river, even in the most remote northwest areas, where most of the 'functional' populations remain. Recent legislation has provided full protection to M. margaritifera, so that all pearl harvesting is now illegal. 6. Locally, river engineering and host salmonid stock decline poses a serious threat and eutrophication has already eliminated populations in southern and eastern Scotland. 7. In every part of its global range, M. margaritifera has declined substantially and is now either threatened with extinction or is highly vulnerable. Based on recent estimates from across the species range, it appears that Scotland now probably holds at least half of the world's remaining functional M. margaritifera populations.