An online database to collate, analyze, and synthesize data on the biodiversity and ecology of intermittent rivers worldwide

Key questions dominating contemporary ecological research and management concern interactions between biodiversity, ecosystem processes, and ecosystem services provision in the face of global change. This is particularly salient for freshwater biodiversity and in the context of river drying and flow-regime change. Rivers that stop flowing and dry, herein intermittent rivers, are globally prevalent and dynamic ecosystems on which the body of research is expanding rapidly, consistent with the era of big data. However, the data encapsulated by this work remain largely fragmented, limiting our ability to answer the key questions beyond a case-by-case basis. To this end, the Intermittent River Biodiversity Analysis and Synthesis (IRBAS; http://irbas.cesab.org) project has collated, analyzed, and synthesized data from across the world on the biodiversity and environmental characteristics of intermittent rivers. The IRBAS database integrates and provides free access to these data, contributing to the growing, and global, knowledge base on these ubiquitous and important river systems, for both theoretical and applied advancement. The IRBAS database currently houses over 2000 data samples collected from six countries across three continents, primarily describing aquatic invertebrate taxa inhabiting intermittent rivers during flowing hydrological phases. As such, there is room to expand the biogeographic and taxonomic coverage, for example, through addition of data collected during nonflowing and dry hydrological phases. We encourage contributions and provide guidance on how to contribute and access data. Ultimately, the IRBAS database serves as a portal, storage, standardization, and discovery tool, enabling collation, synthesis, and analysis of data to elucidate patterns in river biodiversity and guide management. Contribution creates high visibility for datasets, facilitating collaboration. The IRBAS database will grow in content as the study of intermittent rivers continues and data retrieval will allow for networking, meta-analyses, and testing of generalizations across multiple systems, regions, and taxa

A landscape approach to advance intermittent river ecology

Intermittent rivers are increasingly viewed as shifting mosaics of lotic (flowing water), lentic (standing water) and terrestrial (dry riverbed) habitats. The diversity, spatial arrangement, temporal turnover and connectivity of these habitats are controlled by the magnitude, frequency, duration and extent of drying and rewetting events, which maintain habitat heterogeneity and control biodiversity and biogeochemical processes in intermittent rivers. We consider intermittent rivers as spatiotemporal landscape mosaics to identify the implications such a view has for empirical and theoretical developments in landscape and river ecology. Using observational data of flow states collected by citizen scientists along 1400 km of river channels in western France, we used landscape metrics and ecologically scaled indices for four hypothetical, aquatic species (two fish and two insects) to describe the dynamics of intermittent river mosaics for five catchments. Dry patches dominated most observation dates but flowing patches had the longest average length and occupied the greatest proportion of channel length. At the start of each summer, catchments were almost entirely composed of flowing patches but lentic and dry patches could represented up to 80% of the catchments as summer progressed. Patch dynamics were typified by high levels of spatiotemporal variability. In contrast, ecologically scaled indices did not vary greatly among catchments within species. The ecologically scaled indices representing small fish were the most affected by habitat fragmentation. Such a landscape perspective could affect understanding of biodiversity patterns and biogeochemical processes in intermittent rivers. We outline the methodological developments required to integrate landscape approaches into intermittent river research, the associated challenges and current limitations in landscape ecology tools and models and the benefits of citizen science data sets. The continued quantification of shifting habitat mosaics in intermittent rivers will provide multiple opportunities to advance river and landscape ecology

Caracterisation des vallees alluviales : rapport final

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : GR 1837 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Atlas of European Eel Distribution (Anguilla anguilla) in Portugal, Spain and France

The SUDOANG project aims at providing common tools to managers to support eel conservation in the SUDOE area (Spain, France and Portugal). VISUANG is the SUDOANG Interactive Web Application that host all these tools . The application consists of an eel distribution atlas (GT1), assessments of mortalities caused by turbines and an atlas showing obstacles to migration (GT2), estimates of recruitment and exploitation rate (GT3) and escapement (chosen as a target by the EC for the Eel Management Plans) (GT4). In addition, it includes an interactive map showing sampling results from the pilot basin network produced by GT6. The eel abundance for the eel atlas and escapement has been obtained using the Eel Density Analysis model (EDA, GT4's product). EDA extrapolates the abundance of eel in sampled river segments to other segments taking into account how the abundance, sex and size of the eels change depending on different parameters. Thus, EDA requires two main data sources: those related to the river characteristics and those related to eel abundance and characteristics. However, in both cases, data availability was uneven in the SUDOE area. In addition, this information was dispersed among several managers and in different formats due to different sampling sources: Water Framework Directive (WFD), Community Framework for the Collection, Management and Use of Data in the Fisheries Sector (EUMAP), Eel Management Plans, research groups, scientific papers and technical reports. Therefore, the first step towards having eel abundance estimations including the whole SUDOE area, was to have a joint river and eel database. In this report we will describe the database corresponding to the river’s characteristics in the SUDOE area and the eel abundances and their characteristics. In the case of rivers, two types of information has been collected: River topology (RN table): a compilation of data on rivers and their topological and hydrographic characteristics in the three countries. River attributes (RNA table): contains physical attributes that have fed the SUDOANG models. The estimation of eel abundance and characteristic (size, biomass, sex-ratio and silver) distribution at different scales (river segment, basin, Eel Management Unit (EMU), and country) in the SUDOE area obtained with the implementation of the EDA2.3 model has been compiled in the RNE table (eel predictions)