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Colin, N., Villeger, S., Wilkes, M., de Sostoa, A., & Maceda-Veiga, A. (2018). Functional diversity measures revealed impacts of non-native species and habitat degradation on species-poor freshwater fish assemblages. Sci. Total Environ., 625, 861–871.
Résumé: Trail-based ecology has been developed for decades lo infer ecosystem responses to stressors based on the functional structure of communities, yet its value in species-poor systems is largely unknown. Here, we used an extensive clataset in a Spanish region highly prone to non-native fish invasions (15 catchments, N 389 sites) to assess for the first time how species-poor communities respond to large-scale environmental gradients using a taxonomic and functional trait-based approach in riverine fish. We examined total species richness and three functional trait-based indices available when many sites have <= 3 species (specialization, FSpe; onginaliy, FOri and entropy, FEnt). We assessed the responses of these taxonomic and functional indices along gradients of altitude, water pollution, physical habitat degradation and non-native fish biomass. Whilst species richness was relatively sensitive to spatial effects, functional diversity indices were responsive across natural and anthropogenic gradients. All four diversity measures declined with altitude but this decline was modulated by physical habitat degradation (richness, FSpe and FEnt) and the non-native total fish biomass ratio (FSpe and FOri) in ways that varied between indices. Furthermore, FSpe and FOri were significantly correlated with Total Nitrogen. Non-native fish were a major component of the taxonomic and functional structure of fish communities, raising concerns about potential misdiagnosis between invaded and environmentally-degraded river reaches. Such misdiagnosis was evident in a regional fish index widely used in official monitoring programs. We recommend the application of FSpe and FOri to extensive clatasets from monitoring programs in order to generate valuable cross-system information about the impacts of non-native species and habitat degradation, even in species-poor systems. Scoring non-native species apart from habitat degradation in the indices used to determine ecosystem health is essential to develop better management strategies. (C) 2013 Elsevier B.V. All rights reserved.
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Delord, K., Roudaut, G., Guinet, C., Barbraud, C., Bertrand, S., & Weimerskirch, H. (2015). Kite aerial photography: a low-cost method for monitoring seabird colonies. J. Field Ornithol., 86(2), 173–179.
Résumé: Obtaining aerial high-resolution images of bird nesting colonies using remote-sensing technology such as satellite-based remote sensing, manned aircraft, or Unmanned Aerial Vehicles might not be possible for many researchers due to financial constraints. Kite Aerial Photography (KAP) provides a possible low-cost alternative. We collected digital images of ground-nesting seabirds (i.e., cormorants and penguins) in two different ecosystems using a kite-based platform equipped with consumer-grade digital cameras with time-lapse capability to obtain estimates of breeding population size. KAP proved to be an efficient method for acquiring high-resolution aerial images. We obtained images of colonies of seabirds ranging in size from hundreds to several hundreds of thousands breeding pairs during flights lasting from a few minutes up to three hours, from flat to very steep areas, and in contrasted wind conditions (from 0.5 to 6 Beaufort force). KAP is an efficient low-cost method for acquiring high-resolution aerial images and an alternative to ground-based censuses, especially useful in rugged areas.
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Draredja, M. A., Frihi, H., Boualleg, C., Gofart, A., Abadie, E., & Laabir, M. (2019). Seasonal variations of phytoplankton community in relation to environmental factors in a protected meso-oligotrophic southern Mediterranean marine ecosystem (Mellah lagoon, Algeria) with an emphasis of HAB species. Environ. Monit. Assess., 191(10), 603.
Résumé: The spatial and temporal variation of phytoplankton communities including HAB species in relation to the environmental characteristics was investigated in the protected meso-oligotrophic Mellah lagoon located in the South Western Mediterranean. During 2016, a biweekly monitoring of phytoplankton assemblages and the main abiotic factors were realized at three representative stations. Taxonomic composition, abundance, and diversity index were determined. In total, 227 phytoplankton species (160 diatoms and 53 dinoflagellates) were inventoried. There was a clear dominance of diatoms (62.9%) compared with dinoflagellates (36.8%). Diatoms dominated in spring and dinoflagellates developed in summer and early autumn in Mellah showing a marked seasonal trend. Data showed that the dynamic of the phytoplankton taxa evolving in the lagoon was mainly driven by temperature and salinity. For the first time, a number of potentially toxic species have been identified, including 2 diatoms (Pseudo-nitzschia group delicatissima, Pseudo-nitzschia group seriata) and 5 dinoflagellates (Alexandrium minutum, Alexandrium tamarense/catenella, Dinophysis acuminata, Dinophysis sacculus, Prorocentrum lima). These harmful species could threat the functioning of the Mellah lagoon and human health and require the establishment of a monitoring network. Finally, our study suggests that the observed decrease of the phytoplankton diversity between 2001 and 2016 could result from the reduction in water exchanges between the lagoon and the adjacent coast following the gradual clogging of the channel.
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Fowe, T., Karambiri, H., Paturel, J. - E., Poussin, J. - C., & Cecchi, P. (2015). Water balance of small reservoirs in the Volta basin: A case study of Boura reservoir in Burkina Faso. Agricultural Water Management, 152, 99–109.
Résumé: Effective water resources development and management is crucial for sustainable economic growth and poverty reduction in many developing countries. In West Africa, large numbers of small reservoirs with volumes from 104 to 107 m3 play a considerable role in maintaining and developing activities in remote areas and in providing irrigation water for agriculture and supply water for both livestock and people. The lack of baseline data on reservoir operation hinders their optimal management. The objective of this study was to enhance the knowledge of water resources of the small reservoirs in order to improve their management in the context of multiple uses. This study was carried out on a small reservoir located in Southern Burkina Faso which was monitored for 2 years (from April 2012 to April 2014). A simple approach based on the mass conservation equation was developed for estimating reservoir fluxes. For a short hydrological monitoring period, the rainfall, evaporation and reservoir filling patterns revealed a different hydrological balance of the reservoir between these 2 years. A decrease of 32% in the annual rainfall leads to a 50% reduction in the annual runoff coefficient. The results showed that about 60% of water was lost by evaporation, whereas less than 20% of water caught in the reservoir was withdrawn for various uses. The available water resources in the studied system are largely sufficient to satisfy the current demands. There are still possibilities for developing uses of water storage and for enhancing the irrigation potential of the small reservoir. This analysis indicates that small reservoirs are under-performing. The results highlighted that estimating water fluxes in a reservoir is a central task to support water management authorities and stakeholders in operational strategies for water supply and irrigated agriculture.
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Gaertner-Mazouni, N., & De Wit, R. (2012). Exploring new issues for coastal lagoons monitoring and management. Estuarine Coastal and Shelf Science, 114, 1–6.
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