Dumitrascu M.,Institute of Geography |
Grigorescu I.,Institute of Geography |
Doroftei M.,Danube Delta National Institute |
Kucsicsa G.,Institute of Geography |
And 3 more authors.
International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM | Year: 2013
Floodplain areas host unique ecosystems displaying particular habitats with high biodiversity hosting different species of fauna and flora. Under the recent human-induced influences, these vulnerable ecosystems become highly exposed to a wide range of environmental threats. Therefore, one of the leading pressures on habitats and biodiversity is related to biological invasions, wetland ecosystems proving to be among the most vulnerable environments to Invasive Terrestrial Plant Species (ITPS). One of the most aggressive ITPS in wetland areas is Amorpha fruticosa ranging first in terms of impact on local habitats and flora. In Romania, this ITPS is adapted to all types of environments, but it regularly prefers riparian habitats. The authors put forward a comparative approach of this ITPS in three major protected areas in Romania (both Natura 2000 and Ramsar sites): Danube Delta Biosphere Reserve, Comana Natural Park and Mureş Floodplain Natural Park. The paper will focus on assessing species' habitat requirements, key environmental driving forces (both natural and human-induced) and relevant biological indicators. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM.
Jaric I.,Serbian Institute for Multidisciplinary Research |
Lenhardt M.,Sinisa Stankovic Institute for Biological Research |
Pallon J.,Lund University |
Elfman M.,Lund University |
And 4 more authors.
Environmental Biology of Fishes | Year: 2011
Sturgeon populations in the Danube River have experienced severe decline during the last several decades, mostly due to the poorly regulated fishery, river fragmentation and water pollution. This study focuses on gaining better understanding of sturgeon life history primarily by addressing the assessment of microelement accumulation in sturgeon pectoral fin rays, especially of strontium and calcium, as a method that can reveal migration patterns of anadromous sturgeons. Analysis was performed on pectoral fin samples of three anadromous Danube sturgeon species (beluga, Russian sturgeon and stellate sturgeon) by the use of a Nuclear Microprobe technique. The most frequent pattern in analyzed samples was represented by a low Sr:Ca ratio in the innermost annuli, followed by an increased ratio in the middle annuli segment, and often with a decreased ratio in the outermost annuli. Probability density estimate has revealed three distinguished maxima of the Sr:Ca ratio, 7.08 × 10-3, 8.98 × 10-3 and 9.90 × 10-3, which might correspond, respectively, to fresh, brackish and saltwater. Although the analysis of the Sr:Ca ratio in sturgeon pectoral fin rays has revealed changes that might indicate probable migration between habitats with different water salinity, further studies are needed for improvement of this method. This study represents the first analysis of this kind that was conducted on sturgeon species from the Black Sea basin. © 2010 Springer Science+Business Media B.V.
Dudu A.,University of Bucharest |
Suciu R.,Danube Delta National Institute |
Paraschiv M.,Danube Delta National Institute |
Georgescu S.E.,University of Bucharest |
And 2 more authors.
International Journal of Molecular Sciences | Year: 2011
Acipenseriformes are composed of 25 sturgeon species and two paddlefish species distributed exclusively in the northern hemisphere. The Danube River and the Black Sea were originally inhabited by six sturgeon species but two are extinct and only four are still reproducing currently in the Lower Danube: Huso huso, Acipenser stellatus, A. gueldenstaedtii and A. ruthenus. Sturgeon species hybridize more easily than other fish and the determination of pure species or hybrid status is important for conservation and for breeding in fish farms. This survey demonstrated that morphological determination of this status is not reliable and a molecular tool, based on eight microsatellites genotypes is proposed. This method, based on three successive statistical analyses including Factorial Correspondence Analysis (FCA), STRUCTURE assignation and NEWHYBRIDS status determination, showed a high efficiency in discriminating pure species specimens from F1, F2 and two kinds of backcross individuals involving three of the four reproducing Lower Danube sturgeon species. © 2011 by the authors; licensee MDPI, Basel, Switzerland.
Tudor I.-M.,Danube Delta National Institute |
Ibram O.,Danube Delta National Institute |
Teodorof L.,Danube Delta National Institute |
Burada A.,Danube Delta National Institute |
Tudor M.,Danube Delta National Institute
Journal of Environmental Protection and Ecology | Year: 2016
This paper presents a study on the zooplankton and benthic invertebrate community in shallow lakes from Danube Delta Biosphere Reserve. Samples have been collected three times in each season except winter in 2014. At each lake zooplankton was collected with plankton net from 5 stations and benthic invertebrates with an Ekmann dredge from three stations. Additionally, environmental factors (temperature, transparency, conductivity, dissolved oxygen, total nitrogen and total phosphorus) were measured. A variety of metrics (e.g. diversity, evenness) were calculated and used to provide an image of the status of analysed community structure in investigated aquatic ecosystems. The significance of differences in composition and abundance between lakes and sampling seasons were tested using ANOVA. The main goal of the paper was to explore environmental factors underlying variation in biological community structure.
Lupu G.,Danube Delta National Institute |
Doroftei M.,Danube Delta National Institute
Brukenthal. Acta Musei | Year: 2012
Observed for the first time in south-eastern Romania by Ramme in 1951 and described as a new subspecies from Cogealac (Constanţa County), Asiotmethis limbatus motasi (Ramme, 1951) is endemic for the Romanian territory, being known only from central and southern Dobrogea. The species was discovered in-situ by its calling song and body colour, two major elements in identifying this very mobile insect. There are three major NATURA 2000 habitat types where this taxa have been identified: Subpannonic steppe grasslands described as xerophilous feathergrass steppe grasslands, dry grasslands described as hill and plateau xero-mesophilous grassland, and limestone few fallow steppe grasslands from Dobrogea described as steppe grassland on hill limestone, with an average altitude oscillating between 100 and 150 meters a.s.l.
Popescu I.,UNESCO-IHE Institute for Water Education |
Cioaca E.,Danube Delta National Institute |
Pan Q.,UNESCO-IHE Institute for Water Education |
Jonoski A.,UNESCO-IHE Institute for Water Education |
Hanganu J.,Danube Delta National Institute
Environmental Science and Policy | Year: 2015
Due to its high biodiversity the Danube Delta, in Romania, is recognized as a UNESCO World Heritage Natural Site and it is listed as a RAMSAR wetland. The Danube River variable discharges have a great impact on the habitats and the overall ecological status of the delta. One of its most vulnerable parts, from both hydrodynamic and morphological point of view is the Sontea-Fortuna wetland located in the upstream of the Danube Delta. Sontea-Fortuna wetland is susceptible to both floods and droughts. On a long term, decision makers in the area need to know which measures to implement and how these will impact/improve the environment. This article presents how a 3D hydrodynamic model can be used as support for making sound decisions regarding the management of deltaic ecosystems. In particular, the methodology is applied on the Sontea-Fortuna wetland. The case study is part of a wider research in the area, which was developed within the EnviroGRIDS EU FP7 research project. EnviroGRIDS aimed at building capacity for scientists, decision-makers and the general public in the Black Sea Catchment, through collection and sharing of environmental data and models at the basin scale. © 2014 Elsevier Ltd.