Changes in ecosystem services from wetland loss and restoration: An ecosystem assessment of the Danube Delta (1960–2010)

Deltaic flood plains provide critically important ecosystem services, including food production, fresh water, flood control, nutrient cycling, spiritual values and opportunities for recreation. Despite growing recognition of their societal and ecological importance, deltaic flood plains are declining worldwide at alarming rates. Loss of wetland ecosystem services bears socio-environmental costs overlooked in land-use planning. Conversely, wetland restoration can deliver important long-term benefits. This paper examines effects of different land use policies on ecosystem services provided by the Danube Delta, one of Europe’s largest and most outstanding wetlands. First, we identify, characterize and measure the most important ecosystem services provided by the Danube Delta. Second, we assess trends between 1960 and 2010, contrasting periods of economic development (1960–1989) and ecological restoration (1990–2010). Our results indicate that i) the Danube Delta provides important services with benefits accrue from local communities to humanity at large, ii) that two thirds of the Delta’s ecosystem services have declined over the studied period and iii) that ongoing restoration efforts have so far been unable to reverse trends in ecosystem service decline. Benefits from ecological restoration policies are already becoming apparent, but at a scale not yet comparable to the costs from ecosystem decline incurred over previous decades. Ecosystem assessment Socio-environmental costs Wetlands Restoration Danube Delta RomaniaacceptedVersio

Data on the postbreeding migration of marked Romanian Great White Pelicans (Pelecanus onocrotalus Linnaeus, 1758)

Between 1931 and 2018 in the Danube Delta, 1,171 Great White Pelican (Pelecanus onocrotalus Linnaeus 1758) were ringed (731 with metal rings, 440 with coloured plastic rings) at breeding sites. The majority of the captured birds were flightless young individuals. From the ringed birds, 25 (2.13%) were reported as recaptured. Most were reported from Israel (28%), and the rest from 8 other countries. Recovery distance varied between 50 and 3,000 km. 19 birds (76%) were reported within half year after ringing, 2 birds (8%) within a year, and further 4 individuals (16%) were reported after a year. With the exception of a single photographed individual, all the others perished: they were shot or fell victims to accidents. These cases suggest high mortality in the young age cohort. Very little knowledge is available about the African wintering grounds; there are only two reports from Egypt and one from Southern Sudan. Traditional ringing yields little information for this species. Considerably more exact data could be expected from satellite tracking, use of other modern locating techniques and use of genetic methods. The ringing of nestlings is only possible if we can apply less aggressive methods then used to date. Besides its scientific value, the intense research on the still numerous Great White Pelican population would be justified by the outstanding faunistic, economic and cultural importance of this species

Considerations regarding the occurence of the Eurasian Beaver (Castor fiber Linnaeus 1758) in the Danube Delta (Romania)

On its original Romanian name - breb, the Eurasian Beaver (Castor fiber) extinct at us for almost two centuries and reintroduced in some areas of the country, at present is better known under the name of his North American relative, beaver. In the last decades, this specie has been reintroduced within in its old habitats from where itwas extinct, especially under the effect of human pressure. Since 1998, reinsertion actions took place in Romania, in many areas, the closest one to Danube Delta area being the lower part of Ialomita river. By 2011 epigraphic or paleozoology evidences about the presence of this mammalian into the actual Delta have not been found, except the Lower Danube, up to Isaccea, but also near Dobrogea Plateau in Murighiol area. Its last Paleontology evidences come from early medieval period. Until now, the actual delta was considered a territory inappropriate for the Eurasian Beaver, due to high fluctuations of the water levels. But, in April 2011, the spontaneous appearance of the European beaver near Maliuc area was proved, a copy killed by poachers. In July 2011, a Beaver injured after the collision with a boat was found and scientifically investigated. The future observations will have to document if this mammal extends its habitat up here or remains an erratic appearance. In case of success of spontaneous colonization, its consequences and effects on the environment in general and on biodiversity inparticular are required to be monitored

An experimental design for assessing the genetic diversity of colonial waterbirds from the Danube Delta Biosphere Reserve (Romania)

The extensive wetland complex of the Danube Delta provides internationally important stopover sites and breeding sites for millions of migratory birds. Worldwide, natural wetlands are facing an accelerated decline due to the increased urbanization and conversion of open spaces to agriculture. The Danube Delta is no exception, being subject to anthropogenic factors that affect this wildlife hotspot, in spite of considerable conservation efforts. Despite numerous studies focused on Danube Delta waterbird particularities, knowledge of them is limited and highly fragmented. To provide a framework for assessing colonial waterbird populations from the Danube Delta, we developed a comprehensive experimental design to answer existing questions regarding genetic diversity, genetic discontinuities and the degree of genetic differentiation. This paper describes a study which overlaps landscape genetics principles and a small genetic survey in order to provide a feasible framework for studying colonial waterbirds from the Danube Delta Biosphere Reserv

Monitoring of European Mink (Mustela lutreola) in the Danube Delta Biosphere Reserve – Romania, 2003-2011. Current status and setting of goals for the European Mink conservation

The European mink (Mustela lutreola L.) is critically endangered. The Danube Delta Biosphere Reserve (DDBR) is one of the last refuges of this species. Within the DDBR the European mink is still widespread as indicated by 74 life captures in a number of expeditions between 2003 and 2011. No American mink (Neovison vison), a serious threat to the European mink, were trapped or observed during 2000 and 2011 in the DDBR. Trapping success varied both between years and between trapping areas, but up to know the underlying factors for these patterns are not understood. It may be a combination of generally changing mink densities in the Delta due to food availability or reproduction success and habitat quality as a local factor. In this context we discuss potential limiting factors and outline some aspects for a future management plan of the species

Evidence of West Nile Virus (WNV) Circulation in Wild Birds and WNV RNA Negativity in Mosquitoes of the Danube Delta Biosphere Reserve, Romania, 2016

West Nile virus (WNV) is a zoonotic flavivirus whose transmission cycle in nature includes wild birds as amplifying hosts and ornithophilic mosquito vectors. Bridge vectors can transmit WNV to mammal species potentially causing West Nile Fever. Wild bird migration is a mode of WNV introduction into new areas. The Danube Delta Biosphere Reserve (DDBR) is a major stopover of wild birds migrating between Europe and Africa. The aim of this study was to investigate the presence of WNV in the DDBR during the 2016 transmission season in wild birds and mosquitoes. Blood from 68 wild birds (nine different species) trapped at four different locations was analyzed by competitive ELISA and Virus Neutralization Test (VNT), revealing positive results in 8/68 (11.8%) of the wild birds by ELISA of which six samples (three from juvenile birds) were confirmed seropositive by VNT. Mosquitoes (n = 6523, 5 genera) were trapped with CDC Mini Light traps at two locations and in one location resting mosquitoes were caught. The presence of WNV RNA was tested in 134 pools by reverse transcription quantitative PCR (RT-qPCR). None of the pools was positive for WNV-specific RNA. Based on the obtained results, WNV was circulating in the DDBR during 2016