Search results for "Macrophyte"
showing 10 items of 92 documents
Remote sensing of cyanobacterial blooms in a hypertrophic lagoon (Albufera of València, Eastern Iberian Peninsula) using multitemporal Sentinel-2 ima…
2018
Eutrophy in Albufera of Valencia (Eastern Iberian Peninsula) is a quite old problem since after the intense eutrophication processes throughout the 1960s. The system shifted to a turbid stable state consolidated by the virtual disappearance of macrophytes by the early 1970s. The lagoon has been studied extensively since the 1980s, but efforts to revert the system to a clear state have not yielded the expected results because cultural eutrophication due to the growth of population in its area of influence and the effects of climate change, decreasing rainfall and increasing evaporation. This has driven to an increase in water retention times in the lagoon in recent years, resulting in a phyt…
Les macrophytes pour estimer l'état écologique des cours d'eau : l'Indice Biologique Macrophytique en Rivière et la Directive Cadre sur l'Eau
2005
Les macrophytes sont explicitement désignés par la Directive européenne et les textes français de son application comme éléments biologiques à considérer pour évaluer l`état écologique des cours d`eau dans le cadre de la DCE. A l`issu de tests comparatifs d`indices pré-existants et de différents travaux et tests nationaux, le premier protocole formalisé (indices GIS, Haury et al., 1996) a évolué vers l`Indice Biologique Macrophytique en Rivière (IBMR), normalisé par l`AFNOR en 2003. Quelles réponses ce protocole d`évaluation de l`état écologique des cours d`eau peut-il apporter aux besoins liés à l`application de la DCE en France, et comment complète-t-il les outils développés actuellement …
Comparaison des réponses de l'Indice Biologique Macrophytique en Rivière et d'autres indices hydrobiologiques.
2005
National audience
Investigating the impact of anthropogenic land use on a hemiboreal lake ecosystem using carbon/nitrogen ratios and coupled-optical emission spectrosc…
2019
Anthropogenic impacts on lake ecosystems have increased substantially towards the present. However, the strength and timing in most cases are not evaluated in detail, missing valuable information on the response and recovery of an aquatic system. In this study, we use the sediment total organic carbon/total nitrogen ratio (C/N) and inductively coupled-optical emission spectroscopy (ICP-OES) elements and the available information about the biological processes to explore anthropogenic land use impact on the lake ecosystem. As a case study we selected a hemiboreal lake Trikātas (Latvia, NE Europe). The Pearson correlation was used to statistically test the correlations of all variables. Our r…
COMPOSITION AND QUALITY OF FRESHWATER LAKE SEDIMENTS (BALVU AND PĒRKONU LAKES)
2019
Water quality, watershed basin and urbanization are key factors from the perspective of freshwater management; however, actual depth of waterbodies is often an overlooked element. Actual depth represents the overall depth of lake bed and depth of sediments. Some cases have been reported, where with increase of average depth of lake , it is possible to expect improvements of water quality when sediments are removed. If lakes are eutrophic, shallow, overgrown with macrophytes and contain high concentrations of biogenic elements water and lake ecosystem quality can be endangered. Removal of sediments can be an expensive procedure and also depends on the composition, structure, local conditions…
Effects of UVB radiation exposure from the molecular to the organism level in macrophytes from shallow Mediterranean habitats
2015
Abstract The available data on the effects of UVB radiation (UVBR) are scarce for submerged macrophytes, particularly charophytes. We studied the effects of UVBR on Chara baltica, Chara hispida, Chara vulgaris, Nitella hyalina and Myriophyllum spicatum, collected from shallow Mediterranean waterbodies. In a short-term laboratory experiment, we subjected these species to three different UVBR treatments corresponding to daily biologically effective integrated doses of 0, 1 and 6 kJ m−2. The analysed response variables were DNA damage, UV-absorbing compounds (both the methanol-soluble–SUVACs- and, for the first time in charophytes, the methanol-insoluble cell wall-bound fraction–WUVACs-), the …
Photoautotrophic community changes in Lagunillo del Tejo (Spain) in response to lake level fluctuation: Two centuries of sedimentary pigment records
2009
Lagunillo del Tejo is a small doline lake in a karstic region of the Iberian Ranges (central-eastern Spain) that undergoes significant lake level fluctuation in response to changing aquifer influxes. In order to assess changes in the primary producer community in the lake over the last two centuries and to elucidate whether these were conditioned by climatic variability, photosynthetic pigments and their derivatives were extracted from the sediments and the data analysed using multivariate statistical techniques. Quantitative variations in total pigment concentrations through the sedimentary sequence are considered a result of changes in sedimentation rate, largely due to lake level fluctua…
Citizens and scientists work together to monitor marine alien macrophytes
2018
The introduction of non-indigenous species (NIS) is an ongoing phenomenon which has been pointed out as a major threat to biodiversity at different levels. NIS may in time become invasive (Invasive Alien Species “IAS”) and may cause biodiversity loss and ecosystem service changes. The Mediterranean Sea is an important hotspot for marine NIS (ca. 1,000 such species recorded to date. To reduce the risk of future IAS introduction and to better understand their invasive potential and spread dynamics, monitoring and surveillance plans are required. The creation of permanent alarm systems and public awareness campaigns are crucial for reducing the risk of IAS introduction. Since intensive monitor…
Treatment of Combined Dairy and Domestic Wastewater with Constructed Wetland System in Sicily (Italy). Pollutant Removal Efficiency and Effect of Veg…
2021
Dairy wastewater (DWW) contains large amounts of mineral and organic compounds, which can accumulate in soil and water causing serious environmental pollution. A constructed wetland (CW) is a sustainable technology for the treatment of DWW in small-medium sized farms. This paper reports a two-year study on the performance of a pilot-scale horizontal subsurface flow system for DWW treatment in Sicily (Italy). The CW system covered a total surface area of 100 m2 and treated approximately 6 m3 per day of wastewater produced by a small dairy farm, subsequent to biological treatment. Removal efficiency (RE) of the system was calculated. The biomass production of two emergent macrophytes was dete…
Natural recruitment contributes to high densities of grass carp Ctenopharyngodon idella (Valenciennes, 1844) in Western Europe
2015
Introductions of grass carp, well known for their potentially negative ecosystem effects, have been performed in several countries around the world. As the species was considered unable to reproduce naturally under non-native environmental conditions, little attention was initially given to its invasive potential. We studied an area in northern-Italy where, contrary to expectations, introductions that were performed in the early 80s still exert a considerable pressure on aquatic macrophytes. In order to reveal whether the observed population dynamics are the result of natural events or stocking we analysed the density, age- and size-structure of the grass carp population and the migration p…