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A total of 100 larval and 101 pupal taxa were found belonging to 60 and 36 genera, respectively, in 25 river sites in Catalonia (NE Spain). If we correct for the total number of individuals examined (7629 larvae, 1589 pupal exuviae) the number of genera per 100 individuals is 0.84 for larvae and 2.26 for pupal exuviae and the number of taxa per 100 individuals 1.40 and 6.10, respectively. The following points explain why a similar number of taxa have been found for larvae and pupae (despite the large difference in the number of genera): i) difficulties in differentiating the larvae species, especially in some complex rich and frequent genera, such as Cricotopus-Orthocladius (only six taxa as larvae but 31 as pupae); ii) many (24) larval genera were not found as pupae (even two subfamilies) while only three genera where found only as pupal exuviae. This is because of the larger number of larvae examined, but also because not all the larvae present at one site had emerged at the time of sampling. Given the difficulties in classifying the larvae to species level, the collection of pupae remains a useful method to complement quantification of chironomid biodiversity in a region; until massive DNA-sequencing of field samples of such invertebrates will be possible and easily available to many researchers (especially those in low income countries). [ABSTRACT FROM AUTHOR]

ABSTRACT The assessment of the ecological status of water bodies, as requires by the European Water Framework Directive, can raise a number of problems when applied to temporary streams. These problems are because of the particular physical, chemical and biological conditions resulting from the recurrent cessation of flow or even the complete drying of the stream beds. In such non-permanent water bodies, the reference quality standards developed for permanent streams may only be applicable under certain circumstances or may not be applicable at all. Work conducted within the collaborative EU-funded project Mediterranean Intermittent River ManAGEment (MIRAGE) has addressed most of these difficulties and has used diverse approaches to solve them. These approaches have been brought together in the so-called MIRAGE Toolbox. This toolbox consists of a series of methodologies that are designed to be used in a sequential manner to allow the establishment of the ecological and chemical status of temporary streams and to relate these findings to the hydrological status of the streams. The toolbox is intended to serve the following purposes: (i) the determination of the hydrological regime of the stream; (ii) the design of adequate schedules for biological and chemical sampling according to the aquatic state of the stream; (iii) the fulfillment of criteria for designing reference condition stations; (iv) the analysis of hydrological modifications of the stream regime (with the definition of the hydrological status); and (v) the development of new methods to measure the ecological status (including structural and functional methods) and chemical status when the stream's hydrological conditions are far from those in permanent streams. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Bushfires occur in most environments in Australia and yet there are few studies about fire effects on aquatic ecosystems. To study the effects of fire on aquatic macroinvertebrates we sampled three streams in burnt catchments (i.e. burnt) and three streams in unburnt catchments (i.e. control), nine months after severe bushfires in northern Victoria. The sampling period coincided with a severe and prolonged period of drought - during the 8th year of a series of thirteen consecutive years of below average rainfall. There was a significant effect of bushfire on macroinvertebrate richness, composition and function. At the burnt sites, there was lower taxon richness but a 4-fold increase in abundance, which was mainly to the result of increases in taxa such as Chironomidae, Simuliidae, Dinotoperla sp. and Taschorema sp. A higher percentage of gathering collectors was found at the burnt sites, whereas scrapers and shredders were co-dominant in the control streams. The responses of the macroinvertebrates may have been impaired by post-fire persistence of low flows associated with the continuing drought, in comparison with the rapid recovery of the catchment overstorey vegetation (Eucalyptus spp.). The consequences of the megadrought combined with catchment bushfires, have no doubt reduced the resilience of the macroinvertebrate communities. Bushfire effects on aquatic macroinvertebrates in northern Victorian streams (Australia) have been studied. Nine months after the bushfires, coinciding with a severe a prolonged period of drought, there was a significant effect of bushfire on macroinvertebrate richness, composition and function. The consequences of the megadrought, combined with catchment bushfires, have no doubt reduced the resilience of the macroinvertebrate communities. [ABSTRACT FROM AUTHOR]

Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The structure and composition of biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. Therefore, the structural and functional characteristics of aquatic fauna to assess the ecological quality of a temporary stream reach cannot be used without taking into account the controls imposed by the hydrological regime. This paper develops methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the transient sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: Hyperrheic, Eurheic, Oligorheic, Arheic, Hyporheic and Edaphic. When the hydrological conditions lead to a change in the aquatic state, the structure and composition of the aquatic community changes according to the new set of available habitats. We used the water discharge records from gauging stations or simulations with rainfall-runoff models to infer the temporal patterns of occurrence of these states in the Aquatic States Frequency Graph we developed. The visual analysis of this graph is complemented by the development of two metrics which describe the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of temporary streams in four aquatic regimes in terms of their influence over the development of aquatic life is updated from the existing classifications, with stream aquatic regimes defined as Permanent, Temporary-pools, Temporary-dry and Episodic. While aquatic regimes describe the long-term overall variability of the hydrological conditions of the river section and have been used for many years by hydrologists and ecologists, aquatic states describe the availability of mesohabitats in given periods that determine the presence of different biotic assemblages. This novel concept links hydrological and ecological conditions in a unique way. All these methods were implemented with data from eight temporary streams around the Mediterranean within the MIRAGE project. Their application was a precondition to assessing the ecological quality of these streams. [ABSTRACT FROM AUTHOR]

Temporary streams are those water courses that undergo the recurrent cessation of flow or the complete drying of their channel. The biological communities in temporary stream reaches are strongly dependent on the temporal changes of the aquatic habitats determined by the hydrological conditions. The use of the aquatic fauna structural and functional characteristics to assess the ecological quality of a temporary stream reach can not therefore be made without taking into account the controls imposed by the hydrological regime. This paper develops some methods for analysing temporary streams' aquatic regimes, based on the definition of six aquatic states that summarize the sets of mesohabitats occurring on a given reach at a particular moment, depending on the hydrological conditions: flood, riffles, connected, pools, dry and arid. We used the water discharge records from gauging stations or simulations using rainfall-runoff models to infer the temporal patterns of occurrence of these states using the developed aquatic states frequency graph. The visual analysis of this graph is complemented by the development of two metrics based on the permanence of flow and the seasonal predictability of zero flow periods. Finally, a classification of the aquatic regimes of temporary streams in terms of their influence over the development of aquatic life is put forward, defining Permanent, Temporary-pools, Temporary-dry and Episodic regime types. All these methods were tested with data from eight temporary streams around the Mediterranean from MIRAGE project and its application was a precondition to assess the ecological quality of these streams using the current methods prescribed in the European Water Framework Directive for macroinvertebrate communities. [ABSTRACT FROM AUTHOR]

1. Macroinvertebrate assemblages of five non-glacial intermittent high altitude headwater streams (above 1400 m – Serra da Estrela, Portugal), with dry periods of different lengths (0–3 months), were investigated in nearly undisturbed conditions to (i) examine spatial differences and identify environmental variables responsible for the observed invertebrate patterns, (ii) assess the association of dry period length with invertebrate community structure and (iii) determine the influence of using different taxonomic identification levels (order, family and genus) to assess invertebrate community patterns. 2. More than 100 macroinvertebrate genera were identified. Insects clearly dominated these communities with more than 95% of total captures and around 95% of the total richness. Diptera were the most rich and abundant group with chironomid occurrences comprising over 70% of macroinvertebrate captures. 3. The highest taxon richness, diversity, EPT (Ephemeroptera + Plecoptera + Trichoptera) and OCH (Odonata + Coleoptera + Heteroptera) genus richness, the greatest number of exclusive and characteristic taxa identified by the Indicator Value (IndVal), and a distinct community structure shown by Canonical Correspondence Analyses (CCA), were found in the only stream that was never totally dry, with pools lasting over summer. Environmental gradients that spatially structured the macroinvertebrate communities were always related to flow variations. 4. Over time, the highest abundances found in these systems were also related to flow variations and maximum genus richness occurred in the connected pools or in isolated pools. Streams with longer dry periods presented a distinct recolonization phase, with higher abundance of the stonefly larvae Nemoura sp. and the presence of the chironomid larvae Krenosmittia sp., possibly arriving from the hyporheos. 5. Taxonomic level of invertebrate identification was vital for recognizing the characteristic taxa (IndVal) of streams yet was not critical for identifying streams with the highest macroinvertebrate richness/diversity or structuring environmental gradients. 6. Overall, this study emphasizes the variability of high altitude intermittent streams macroinvertebrate communities, despite spatial proximity. This variability was probably related to flow intermittency and hydrologic permanence, different vegetation covers and riverbed substrata. Consequently, the establishment of reference conditions should involve long-term data collections and more detailed physical characterization. Also, these findings have significant implications for accurately predicting the ecological consequences of future climate change in high altitude scenarios. [ABSTRACT FROM AUTHOR]

Caddisflies are a well represented group with high species diversity in Mediterranean climate rivers. Although they are widely used in water quality assessment, little is known of the ecological profiles of families or species. We present a simple score for ecological profiles which measures intolerance to water quality. The ecological profiles of caddisflies are diverse and the degree of tolerance at the family level is related to species diversity and the tolerance of individual species to water quality. Comparisons with the scores used in the biotic index IBMWP show general agreement between the degree of intolerance of a family and its score in the IBMWP, with few exceptions. Studies on tolerance are required to elucidate the autecology of taxa, and to develop biological indices, especially in areas with high species diversity. [Copyright &y& Elsevier]

Presents an index of riparian quality useful for the management of streams and rivers. Purpose of the index with respect to habitat quality; How the index is calculated and can be used together with any other index of water quality to assess the ecological status of streams and rivers; Components the index, named QBR, is based on including total riparian vegetation cover, cover structure, cover quality and channel alterations; Results indicating that the QBR index may be used despite regional differences in plant communities; Number of watersheds along the Mediterranean Spanish coast where the index is being used by different research teams and tested.

SUMMARY1. The taxonomy, distribution and habitat preferences of Chironomus larvae from profundal benthos of reservoirs and natural lakes in Spain are presented. The 114 water bodies studied were medium to large reservoirs and lakes throughout Spain, and were visited on at least two occasions (summer and winter). Out of the natural lakes investigated, Chironomus larvae were found only in one karstic lake (Banyoles), and to date, these have not been found in the high mountain lakes of the Spanish Pyrenees or Sierra Nevada, or in Spain's largest oligotrophic lake (Sanabria). 2. Multiple regression with environmental data from reservoirs showed that the density of Chironomus larvae was inversely correlated with water depth, temperature and sulphide content of the bottom water, but positively correlated with alkalinity and particulate organic nitrogen (PON) content of bottom water. Thus, the density of Chironomus larvae was higher in shallow reservoirs from the eastern part of Spain (calcareous water and higher PON), but markedly lower in southern reservoirs (higher temperature and higher sulphide). 3. According to morphological and cytological characteristics, three species of this genus have been identified in the samples examined: C. bernensis, C. plumosus and C. nuditarsis. Reasons for the absence of other widespread European species are discussed. 4. Using canonical correspondence analysis to relate species and environmental variables, C. bernensis showed a significant preference for reservoirs with higher oxygen concentrations in bottom water and lower total reactive phosphorus (TRP) content at the surface than those reservoirs where C. plumosus-type were found. This suggests that the smaller C. bernensis prefers mesotrophic reservoirs and the larger C. plumosus-type (C. plumosus + C. nuditarsis) prefers eutrophic reservoirs. Taking into account the TRP/depth index for those samples collected at depths below the thermocline, and thus, where oxygen can be a limiting factor, C. bernensis and C. nuditarsis were present in reservoirs in which the index was low (< 1:170 for C. bernensis and >1:800 for C. nuditarsis), while C. plumosus thrived in reservoirs with higher index values (<1:20). These differences may reflect the preference of C. bernensis and C. nuditarsis for detrital material, while C. plumosus prefers phytoplankton. These observations are in agreement with the depth distribution of each species: C. plumosus was restricted to reservoirs less than 46 m deep, whereas the other two species (i.e. C. bernensis and C. nuditarsis) were found up to depths of 65 and 80 m, respectively. 5. Data from a transect (5–20 m deep) in Lake Banyoles are consistent with the general pattern described in reservoirs. In this lake, a high density of C. bernensis was recorded from littoral and sublittoral areas with abundant oxygen (above or close to the thermocline), whereas C. plumosus was scarce in several parts of the lake, especially in oxygen-deficient areas during the summer. This karstic, oligotrophic lake has a low TRP/depth index, and therefore, we expected C. bernensis to be dominant in the littoral, as is the case. Nevertheless, the severe depletion of oxygen caused by meromixis, and the high hydrogen sulphide concentration benefit C. plumosus in deeper zones. Chironomus nuditarsis was scarce in Lake Banyoles and only found at considerable depths. [ABSTRACT FROM AUTHOR]

Hydrological data for assessing the regime of temporary rivers are often non-existent or scarce. The scarcity of flow data makes impossible to characterize the hydrological regime of temporary streams and, in consequence, to select the correct periods and methods to determine their ecological status. This is why the TREHS software is being developed, in the framework of the LIFE Trivers project. It will help managers to implement adequately the European Water Framework Directive in this kind of water body. TREHS, using the methodology described in Gallart et al. (2012), defines six transient ‘aquatic states’, based on hydrological conditions representing different mesohabitats, for a given reach at a particular moment. Because of its qualitative nature, this approach allows using alternative methodologies to assess the regime of temporary rivers when there are no observed flow data. These methods, based on interviews and high-resolution aerial photographs, were tested for estimating the aquatic regime of temporary rivers. All the gauging stations (13) belonging to the Catalan Internal Catchments (NE Spain) with recurrent zero-flow periods were selected to validate this methodology. On the one hand, non-structured interviews were conducted with inhabitants of villages near the gauging stations. On the other hand, the historical series of available orthophotographs were examined. Flow records measured at the gauging stations were used to validate the alternative methods. Flow permanence in the reaches was estimated reasonably by the interviews and adequately by aerial photographs, when compared with the values estimated using daily flows. The degree of seasonality was assessed only roughly by the interviews. The recurrence of disconnected pools was not detected by flow records but was estimated with some divergences by the two methods. The combination of the two alternative methods allows substituting or complementing flow records, to be updated in the future through monitoring by professionals and citizens. [ABSTRACT FROM AUTHOR]

Many streams in the Mediterranean Basin have temporary flow regimes. While timing for seasonal drought is predictable, they undergo strong inter-annual variability in flow intensity. This high hydrological variability and associated ecological responses challenge the ecological status assessment of temporary streams, particularly when setting reference conditions. This study examined the effects of flow connectivity in aquatic macroinvertebrates from seven reference temporary streams across the Mediterranean Basin where hydrological variability and flow conditions are well studied. We tested for the effect of flow cessation on two streamflow indices and on community composition, and, by performing random forest and classification tree analyses we identified important biological predictors for classifying the aquatic state either as flowing or disconnected pools. Flow cessation was critical for one of the streamflow indices studied and for community composition. Macroinvertebrate families found to be important for classifying the aquatic state were Hydrophilidae, Simuliidae, Hydropsychidae, Planorbiidae, Heptageniidae and Gerridae. For biological traits, trait categories associated to feeding habits, food, locomotion and substrate relation were the most important and provided more accurate predictions compared to taxonomy. A combination of selected metrics and associated thresholds based on the most important biological predictors (i.e. Bio-AS Tool) were proposed in order to assess the aquatic state in reference temporary streams, especially in the absence of hydrological data. Although further development is needed, the tool can be of particular interest for monitoring, restoration, and conservation purposes, representing an important step towards an adequate management of temporary rivers not only in the Mediterranean Basin but also in other regions vulnerable to the effects of climate change. [ABSTRACT FROM AUTHOR]