Search results for "UAT"
showing 10 items of 12350 documents
Environmental sensitivity of Neogoniolithon Brassica-Florida associated with vermetid reefs in the Mediterranean Sea
2016
Vermetid reefs in the Mediterranean Sea are increasingly affected by both anthropogenic actions and global climate change, which are putting this coastal ecosystem at risk. The main species involved in building these reefs are two species of intertidal vermetid gastropods and the crustose calcareous alga, Neogoniolithon brassica-florida, which cements the gastropod shells and thus solidifying the reef edges. In the present study, we examined the pattern of distribution in the field and the environmental sensitivity (thermal tolerance, resilience to low pH, high light intensity and desiccation) of N. brassica-florida along the coasts of Sicily and Israel by means of chlorophyll fluorescence …
Phytoplankton Reservoir Trophic Index (PRTI): a new tool for ecological quality studies
2019
The Phytoplankton Reservoir Trophic Index (PRTI), based on the relative abundance of phytoplankton in reservoirs, was applied to 62 reservoirs, all in the territorial division of the Ebro River Basin, Spain. We compared the results of the PRTI to the Carlson Trophic State Index (TSI), based on the concentration of chlorophyll a in an integrated water sample through the photic depth. The PRTI allows assessment of the trophic status of different reservoirs based on phytoplankton densities from an aliquot of a vertically integrated sample. The occurrence of each phytoplankton species in relation to eutrophication was derived from a canonical correspondence analysis between the phytoplankton sp…
2021
Plankton assembly in an ultra-oligotrophic Antarctic lake over the summer transition from the ice-cover to ice-free period: A size spectra approach
2017
Abstract Lakes from the Antarctic maritime region experience climate change as a main stressor capable of modifying their plankton community structure and function, essentially because summer temperatures are commonly over the freezing point and the lake's ice cap thaws. This study was conducted in such seasonally ice-covered lake (Lake Limnopolar, Byers Peninsula, Livingston Is., Antarctica), which exhibits a microbial dominated pelagic food web. An important feature is also the occurrence of benthic mosses ( Drepanocladus longifolius ) covering the lake bottom. Plankton dynamics were investigated during the ice-thawing transition to the summer maximum. Both bacterioplankton and viral-like…
Invertebrate communities of the High Arctic ponds in Hornsund
2016
How environmental conditions influence current distributions of organisms at the local scale in sensitive high Arctic freshwaters is essential to understand in order to better comprehend the cascading consequences of the ongoing climate change. This knowledge is also important background data for paleolimnological assessments of long-term limnoecological changes and in describing the range of environmental variability. We sampled five limnologically different freshwater sites from the Fuglebergsletta marine terrace in Hornsund, southern Svalbard, for aquatic invertebrates. The invertebrate communities were tested against non-climatic environmental drivers (limnological and catchment variabl…
Decreasing in patch-size of Cystoseira forests reduces the diversity of their associated molluscan assemblage in Mediterranean rocky reefs
2021
Abstract Canopy-forming seaweeds of the genus Cystoseira (Fucales, Phaeophyceae) form diverse and productive habitats along temperate rocky coasts of the Mediterranean Sea. During the last decade, Cystoseira forests have retracted their range considerably due to many interacting environmental, biological and anthropogenic pressures. We investigated how reducing in patch-size of C. montagnei affects their associated molluscan communities at the shallow northwest rocky shores of Palermo (Sicily, Italy). Molluscs were sampled from the fronds of individual thalli, clumps of 3 and 5 thalli of C. montagnei over an annual vegetative cycle (May–September) in two sites within the Marine Protected Ar…
Changes of energy fluxes in marine animal forests of the anthropocene: Factors shaping the future seascape
2019
12 pages, 3 figures
Current and Future Influence of Environmental Factors on Small Pelagic Fish Distributions in the Northwestern Mediterranean Sea
2020
Managing for the Future: Understanding the Relative Roles of Climate and Fishing on Structure and Dynamics of Marine Ecosystems.-- 20 pages, 15 figures, supplementary material https://www.frontiersin.org/articles/10.3389/fmars.2020.00622/full#supplementary-material
The macro- and megabenthic fauna on the continental shelf of the eastern Amundsen Sea, Antarctica.
2013
11 pages; International audience; In 2008 the BIOPEARL II expedition on board of RRS James Clark Ross sailed to the eastern Amundsen Sea Embayment and Pine Island Bay, one of the least studied Antarctic continental shelf regions due to its remoteness and ice cover. A total of 37 Agassiz trawls were deployed at depth transects along the continental and trough slopes. A total of 5469 specimens, belonging to 32 higher taxonomic groups and more than 270 species, were collected. Species richness per station varied from 1 to 55. The benthic assemblages were dominated by echinoderms and clearly different to those in the Ross, Scotia and Weddell seas. Here we present the macro- and megafaunal assem…
An invasive species, Carassius gibelio, alters the native fish community through trophic niche competition
2019
Carbon and nitrogen stable isotope analyses were used to determine isotopic niche width of the invasive fish species Carassius gibelio to help assess the niche overlap and potential impact of this species on the native fish fauna in the Karamenderes River, northwest Turkey. C. gibelio had the highest niche area of the coexisting species. The greatest overlap of isotopic niche was between C. gibelio and Mugil cephalus in the river mouth. The freshwater species displayed similar patterns when taking into consideration their relative abundance and isotopic overlap. While C. gibelio is likely to outcompete some species at some localities, the species was found co-occurring with others by maximu…