Dynamic Danube Natural Valuesc/o Duna-IpolyNational Park Directorate1121 Budapest, Költô utca 21., HungaryFunded by the European Union
Monitoring 2011During the 2011 breeding season the whole Danube from theBlack Forest to the Black Sea was surveyed for breedingpairs of Little Ringed Plover and Sand Martin. Nine ProtectedArea administrations from seven Danube countries took partin the monitoring and covered more than 3,100 kilometres,including the branches of the islands of BaltaIalomit˛ei andGreat Brăila Island. Two surveys of the study area (each onein May and June) were completed; in the upper-most part ofGermany and in a section in Serbia only one survey tookplace. The monitoring was mainly done by small boats andthe survey was limited to the main stream of the Danube. Allsuitable habitats for both species were investigated; artificialareas like sand quarries were not considered in the analysis.For each site the number of birds and breeding pairs werecounted or estimated by the observers. Details of the habitatwere noted. For the Little Ringed Plover, habitat was classifiedaccording to one of six possible types (see graph).Considering the compacted methodology with only two surveys,the maximum numbers of territories per location wereused for the analyses. For visualization, the results weresummed up for twenty-kilometre sections. The first survey inMay was distinguished by a very low water level on the wholeDanube, which results in very good breeding conditions especiallyfor Little Ringed Plover. On the second run the waterlevel was more heterogeneous and so there were variousconditions in the different sections. Due to the direct influenceof the water level on the population size of Little RingedPlover, follow-up surveys are planned for the evaluation of theresults, although first local verification of the data fits in wellwith the results of local monitoring programmes.gravel bankriver bank (sand)river bank (gravel)sand island gravel island sand bankgravelsandvegetationlandLITTLE RINGED PLOVER (CHARADRIUS DUBIUS)The Little Ringed Plover is a widespread, long distance migratory bird of the wadergroup. It breeds in Europe from the end of March to the end of July. Primary breedinghabitats are bare or sparsely vegetated sand or gravel structures of freshwater areas.Due to river regulation and damming (in particular for hydro power), this habitat typeand its characteristic conenose is one of the most threatened in Europe. Althoughthe Little Ringed Plover was faced with a decline in central Europe, the species managedto use artificial nesting sites such as quarries or fishponds. Today, more than90% of its European population breeds in secondary habitats.SAND MARTIN (RIPARIA RIPARIA)The Sand Martin is a common species in Europe and occurs in most European countriesas a breeding bird. The European population winters in tropical Africa and the firstbirds return to Europe in March, breeding from May to July in colonies of only a fewup to several thousand pairs. Colony sites are mostly located near river or other freshwatersites and nests are bored into vertical sand or loam walls, basically resultingfrom lateral erosion of dynamic rivers. This habitat structure is shared by Sand Martinwith a wide range of rare species; its loss due to river regulation was compensatedby occupying artificial breeding habitats such as sand quarries.
Conservation of indicatorspecies and their habitatsThis monitoring was conducted to learn more from the distributionpattern of the indicator species about the Danubewidestatus of dynamic river habitats, which are threatenedon a Europe-wide scale. Consequently, the presence and absenceof these indicator species illustrates the status of thesehabitats, stressing the need for conservation or restoration.Apart from lower densities of Little Ringed Plover and SandMartin in specific Danube sections for natural reasons (e.g. ingorges, on the Delta), human made hydro-morphological alterationssuch as dams, embankments or channelling of theriver are generally identified as the main factors impacting thedistribution of these species. Conversely, important breedingsites demonstrate valuable river sections in terms of dynamicriver habitats. As a result of this monitoring, the Danube ProtectedAreas have formulated the following demands for thelong-term conservation of Little Ringed Plover and Sand Martin,representative of habitats and hydro-morphologicalprocesses:1. River dynamics and active morphological processes arevital for the Danube River ecosystem. Consequently, theconstruction of new dams and hydropower plants alongthe Danube is not compatible with the preservation ofriver dynamic habitats and their characteristic coenoses!2. Permanent relocation of river sediments, arising from riverdynamics combined with intact sediment balances, isneeded to initiate the highly valuable habitats in youngstages of succession. Development and implementationof (hydro-morphological) concepts are needed to ensureand restore the longitudinal continuity of sediment transportationalong the Danube and its tributaries, and to assurethe balance in material load per section as well as torestore consequent lateral mobilization of sediments.3. Breeding sites of Sand Martin are priority subjects of protection!River regulation and embanking needs to beavoided at breeding colonies*, and the inclusion of thesites in Danube Protected Areas has to be intensified toensure long-term conservation, in particular at thehotspots in the Lower Danube.*As most colonies are located at erosion sites of plateaus,conflicts with flood prevention are not expected.4. Gravel and sand islands are key habitats in the Danubeecosystem! These sites must not be negatively impactedby further river regulation and should consequently be includedin Danube Protected Areas. Their hydro-morphologicalinitiating and obtaining processes Danube-wide,as well as on a local scale, have to be preserved; investigationsshould be done for creation of additional sites.In particular in the Middle and Lower Danube, building upa network of protected islands is seen as a relevant contribution.5. In the Middle Danube, as well as existing colonies, potentialnesting sites of Sand Martin (all steep natural riverbanks) are also to be strongly taken into consideration forconservation; embanking is to be avoided.Despite numerous Sand Martin colonies in the hinterland,the number of breeding sites on the Danube between Budapestand Belgrade is relatively low and should be positivelydeveloped. (Potential) Sand Martin breeding sitesindicate the capacity for natural positive recovery in thissection.6. The high restoration potential along the last remainingfree-flowing sections of the Upper Danube needs to beused to restore dynamic river habitats!The highest abundance of Little Ringed Plover in some“gravel sections” underlines the potential capacity for thisspecies and its characteristic habitat structures in theUpper Danube, additionally highlighted by the positive impactof restoration projects. Removal of embankments isexpected to create potential breeding slopes for SandMartin.7. In Danube sections altered by dams and hydropowerplants, the (limited) restoration capacity should be usedby specific revitalization actions.Small breeding “populations” of Little Ringed Plovers inthese sections show the potential for revitalization in particularat the beginning of backwaters.8. The consequent implementation of NATURA 2000 andthe Water Framework Directive, taking stronger river dynamicsand morphological process into consideration, isto be used as a tool for the long-term conservation ofthese species, habitats and initiating processes.The consequent implementation of these demands is along-term investment in the future. In the short term, bothspecies react very quickly to changes in their habitats.Successful examples of river restorations have a positiveinfluence not only on Little Ringed Plover and Sand Martin– transparent representatives for the endangered coenosisof these valuable habitats – but on many other plantand animal species and, ultimately, on humans by providinghabitats also suitable for recreation. Finally, conservationand restoration actions for the habitats of LittleRinged Plover and Sand Martin on a Danube-wide scaleoften contribute to ecological flood prevention by givingmore space to the river. Long-term and integrativepreservation of the ecological value of the Danube has toconsider intact river morphology as a basic process ofthe river ecosystem.INVOLVEMENT OF THE PUBLICDANUBEPARKS intends to bring more attention toriver morphological processes as a key for natureconservation along the Danube. The adaptation ofLittle Ringed Plover and Sand Martin to their habitatsmakes river dynamics visible and appreciable.Special excursions in Protected Areas, schoolevents on Danube Day, an online video game onthe DANUBEPARKS website, press events andvideo clips produced for the EU Strategy for theDanube Region have accompanied the monitoring.The great interest and positive feedback of stakeholdersand the public qualifies the Little RingedPlover and the Sand Martin as drivers for more riverdynamics along the Danube.Some of the most significan t th rea ts for the habitats of Little Ringed Plover and Sand Martin: riprap embankments, gravel excavation, hydropower dams,inland waterway traffic and human disturbance.
c/o Duna-IpolyNational Park Directorate1121 Budapest, Költô utca 21., Hungary