Presentation on theme: "SUSTAINABLE MANAGEMENT OF WETLANDS Invasive species in the Danube Delta and their impact on species diversity Teodora Maria ONCIU ROMANIA - “Ovidius” University."— Presentation transcript:
SUSTAINABLE MANAGEMENT OF WETLANDS Invasive species in the Danube Delta and their impact on species diversity Teodora Maria ONCIU ROMANIA - “Ovidius” University – Constanta 2010
The location of the Danube Delta within Romania and Europe (www.deltafishing.ro/en/intara.html [11February 2009 ])www.deltafishing.ro/en/intara.html
The Danube is Europe’s second largest river, 2 860 km long, with a drainage basin of 810 000 km 2, covering almost one third of Europe (major parts of 13 countries with more then 86 million inhabitants) (www.ddbra.ro/en/danube.php [10 February 2009])
During about the last ten thousand years the Danube river built, on its junction with the Black Sea, an unique wetland in Europe: the Danube Delta. The Delta covers a total area of 4 178 km 2, shared by Romania (4/5) and Ukraine (1/5). There are many large lakes, as well as the shallow marine waters that limit the delta, forming a huge wetland complex covering more than 6 700 km 2. ( Diaconu and Nichiforov, 1963 )
The Danube has been connected via several canals with the main Western Europe Rivers (Rhine, Main, and Odder), facilitating communications with the North Sea and the Baltic Sea. After 1984, the opening of the Danube-Black Sea Canal shortened the navigation route towards the Black Sea by 250 km. (www.britannica.com/EBchecked/topic-art/84090/... [11 February 2009]www.britannica.com/EBchecked/topic-art/84090/... [11
great amplitudes of temperatures; annual average air temperature of 11 °C; annual precipitations are generally scarce (average of 450 mm); air humidity, increasing towards the east, due to intense evaporation in the zone. The Danube delta has a continental-temperate climate (Paltineanu et al., 2000)
Arguments for alien specie’s accommodation in the Danube Delta: suitable temperatures for eurythermic organisms; great diversity of habitats; different ecosystems in a strong interdependence with free food-niches; high natural productivity assuring abundant food for each trophic level;
Opportunities for incomers: the Danube Delta is situated in the middle of the northern hemisphere (crossed by the 45° N parallel of latitude) on the main migration routes; communication with the brackish waters of the Atlantic Ocean eastern regions through a large canal network and the Black Sea; inhabitants are enterprising and begin different new farming activities.
Invasive species in the Danube Delta: accidentally introduced species; species that naturally extend their range; deliberately introduced species - object of farming
Accidentally introduced species Anodonta woodiana http://www.naturamediterraneo.it/Public/ data4/Stefano78/A%20cygnea%202.jpg_2006121104729_A%20cygnea%202.jpg [February 2009]
Accidentally introduced species Elodea canadensis agspsrv95.agric.wa.gov.au/dps/version02/01_pl... [11 February] Pseudorasbora parva commons.wikimedia.org/wiki/File:Pseudorasbora... [11 February]
Accidentally introduced species Eriocheiron sinensis www.padil.gov.au/viewPestLargeImage.aspx?id=1... [11 February]
Carassius auratus gibelio penetrated at the beginning of the 70s; became the most abundant species in the Danube Delta replacing the crucian carp, the common carp, etc.; it presents a gynogenetical reproduction; tolerates very well oxygen and temperature variations, being able to survive out of water for 3 hours. (www.caders-weiher.de/fischkunde/galerie/fuenf... )www.caders-weiher.de/fischkunde/galerie/fuenf... [11 February] Leptinotarsa decemlineata www.funet.fi/.../life/warp/album-Savela-20.html Accidentally introduced species
brackish water species, common in the eastern regions of the Atlantic; it was found in the Razelm Lagoon in 1951 by Bacescu; enriched species diversity in the Danube Delta without harmful action on other species. (Skolka and Gomoiu, 2004 ) Rhithropanopaeus harrisi tridentatus nas.er.usgs.gov/.../FactSheet.asp?speciesID=197 [11 February]
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