Preliminary Plan for Conservation of Sturgeon ... - DANUBEPARKS

danubeparks.org

Preliminary Plan for Conservation of Sturgeon ... - DANUBEPARKS

Historical sturgeon fishery7000-9000 years ago, Paleolithic Age11-15. cent. fishery flourishedBuda & Peststurgeon fishing site17 th centuryHusonum piscarioGreat sturgeon (Huso huso)sturgeonfishing siteDanubeBudapest d.s.17th century(Marsigli)2633 ind. within 30 years (1552-1581),77 ind. in one day at one site (1553)


Decline of sturgeon catch in Hungary18th century. Regular sturgeon fishery ended in the Hungarian Danube section20th century. anadromous sturgeon species are at risk of extinson19101958195119481910,1920,192519291907,1908,1909,195519501932,1944,1953,1955,1956,19721900,1911,1912,19271947195319361906,1954,1957,1987192319221900,195746 ind. in 100 years (20th cent.)Difference: 5-6 order of magnitude77 ind. in one day at one site (1553)Paks, May 16, 1987


Occurrence of 3 sturgeon species in the 20th centuryAcipensergueldenstaedti193219871997,200719991949,19501965,19681960 1965198919981970199819921900,199419801917190936 ind.18 sitesDunakiliti,1999Acipensernudiventris19362005199219561940 194019401939197519171952195719491921,1922,1929,1932,195727 ind.18 sites1989Mohács 20102003Acipenserstellatus192619?? (


Occurrence of Acipenser ruthenus in Hungaryfrom database of the Hungarian fish faunaannual catch (1000 kg)országos kecsegefogás (t)40.030.020.010.00.01947 1951 1955 1959 1963 1967 1971 1975 1979 1983 1987 1991 1995 1999 20034000035000300002500020000150001000050000összes kecsege fogás (kg)fogásmax.37.2 tmedianmin.5.5 t


Conservation measures”Species are on verge of extinctionHigh economic valuecaviar price:6.000-12.000 €/kgDevelopment of breedingand farming technologiesStocking actions are appliedPopular eventsEfficiency forrehabilitation?


Main reasons of decline of sturgeon populationsOverfishingHabitat degradation,fragmentationPopulation, declineof genetic integrityRegulationand controlof fisheryDecline Fromstarted secondin half theof 16th Started thecent.20th incent.the 19th cent.Higher Introduction in the Middle of non-native Danube TypicalsturgeonsproblemsHigh bynumber uncontrolled of fishing stocking ●siteschange of bedload transportHybridization ● bed incision● intense sedimentationFragmentation of migratory wayHabitat protection,restoration,continuitySpecies andpopulationconservation


Main reasons of decline of sturgeon populationsOverfishingHabitat degradation,fragmentationPopulation, declineof genetic integrityRegulationand controlof fisheryHabitat protection,restoration,continuitySpecies andpopulationconservation


Sturgeon conservation in consideration of holistic approachFish fauna – indicator ofenvironmental changes200 out of 522 of Europe’sfreshwater fish species areat risk for extinction60% of riverine speciesare endageredFrequency of endangered fish sp.Frequency of extirpateded fish sp.Kottelat & Freyhof 2007Kottelat & Freyhof 2007frequency of endangered fishspecies is positively relatedto indicators of ‘‘humanactivity’’- GDP,- population density,- percentage of urban areaSturgeons are best indicator ofecological integrity of the DanubeConsider as ‘flagship species’ inassessment of ecological statusDevelop a benchmarking systemto complement biotic evaluationsof the WFD


Social and economic benefits of large riversLand use in floodplainNavigation wayDomestic waterHydropowerIndustrial waterIrrigation


Human activity – decline ecological integrity of riversinterruption of lateral fragmentation of longitudinalconnectivity – channelization connectivity – dammingriver bed incisionincreasing floodplainsedimentationpollution (eutrophication,pesticides, heavy metals …)invasion ofnon-native species


Restoration strategy of large rivers – (according to Jungwirth et al. 2002)Status quo assessmentWater managementFlood protectionNavigability improvementRiver engineering, …EcologyHydro-morphologyLandscape, habitatsFlora, fauna, …EU WFDStatus quo evaluationAssessment of ecosystem deficitsHistorical reference conditionsPre-regulation system, ecologyTarget visionDelineation environmental objectivesConsideration existing constraintsRestoration programMonitoring programEvaluation of restoration or rehabilitation measuresFramework conditionsLand useWater utilizationUrban areasLegal aspectsWater Framework Directive,FFH Directive, …


Iron Gate Dam – fragmentation of river systemInsurmountable barrierto upstreamturbinesGenerate high mortality of migratoryfish to downstream direction- particularly for large adult fish


Iron Gate Dam – Rehabilitation of longitudinal connectivityemphasized goal,high priority measurein significant action plansSAP - 2005DRBMP - ICPDR 2006800 m30 mShip lock as fish lock


Iron Gate Dam – Prediction of impact of fish passHistorical catch ofgreat sturgeonAre there any migratingspecimens at the Iron Gate?High priority measure?Lower Danube has priorityin conservation ofanadromous species16th century2633 ind./30 year18th centuryEnd of regularsturgeon fishery2 order18th century25000 ind./year40 years beforeIron Gate dam1930s2 ind./10 year1930s3 order>500 t/year 3 order


Estimation of impact of sterlet stocking in HungaryArtificial propagation was developed in the 1970s and 1980sStocking of juveniles in the 1980s (regular):Stocking in the 1990s (became occasional):Stocking from 2000 (regular):Stocking does not havesignificant impact on recruitment10.000-100.000 ind./year10.000-20.000 ind./year50.000-150.000 ind./yearL (mm)7006005004003002001000growth tonna(Kovrižnych Sterlet35.0 1988) catch1947-198830.025.020.015.08007006005004001 2 3 4 5 3006 7 8 9 1010.0age group2005.00.0influence of stocking can be estimatedby population dynamical parameters1000age distribution(Jankovic 1958)survival rate: S=0.54N = 1246 ind.3 4 5 6 7 8 9 10 11 12 13Data from Jankovic 1958age group1947194919511953195519571959196119631965196719691971450400350300250200150100500Etimated biomass of recruitmentStocking of 10.000 ind. juv. (L=100mm)protected species1973Cost of surplus:120 €/kg1975fishery size limitbiomass: 175 kgyield: 35 kg (25-55)(M F=0.20)0 1 2 3 4 5 6 7 8 9 10kor (év)1977stocking19791981198319851987Succes story?


Long-term seasonal water level fluctuationof the Danube at Budapest80070060050040030020010001935194019451950monthly average1935-20051955196019651970197519801985199019952000NovSzeJúlMájMárJanseasonal water level fluctuation is a key factor of the fish production in the large lowland rivers


Long-term seasonal water level fluctuation and annual sterletcatch in the Hungarian section of the Danube (1950-1977)Duna vízállás Bp.(cm)Water level700-800600-700500-600400-500300-400200-300100-2000-100195019501951195219521953195419541955195619561957195819581959196019601961196219621963196419641965196619661967196819681969197019701971197219721973197419741975197619761977JanFebMárÁprMájJúnJúlAugSzeOktNovDec0100020003000400050006000700080009000Sterlet kecsege catch fogás (kg) (kg) - fishermen - halászat10000


-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1Relationship between monthly water levels and annual catchanalysed by cross-correlation (1950-1977)Danube, fishermen: water level Jan./a.catch 1950-1977Danube, fishermen: water level Feb./a.catch 1950-1977Danube, fishermen: water level Mar./a.catch 1950-1977CorrelationCorrelationCorrelationCorrelation10.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3-0.4Danube, fishermen: water level Apr./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3-0.4-0.5-0.5Lag-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1Danube, fishermen: water level Jul./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3-0.4-0.3Lag-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1Danube, fishermen: water level Oct./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2Lag-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1LagCorrelationCorrelationCorrelation10.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3Jan. Feb. Mar.-0.4-0.3-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1LagDanube, fishermen: water level May/a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2Apr. May Jun.-0.5-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1LagDanube, fishermen: water level Aug./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3-0.4Jul. Aug. Sep.Correlation-0.3-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1LagDanube, fishermen: water level Nov./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2Oct. Nov. Dec.-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1LagCorrelationCorrelationCorrelationCorrelation10.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3-0.4-0.5-0.3-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1Danube, fishermen: water level Jun./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2-0.4Lag-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1Danube, fishermen: water level Sep./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2-0.3-0.3Lag-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1LagDanube, fishermen: water level Dec./a.catch 1950-197710.90.80.70.60.50.40.30.20.10-0.1-0.2-13 -12 -11 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1Lagsign. negativecorrelationannual catchmonthly water lev.in previous 1-4 y.negativeretarded effectof floods onsterlet catchreproductivesuccesdependson water level,incresing bedshear stress


Correlation: 5 year average of monthly mean water levels5 year average of commercial catch32,72,4Carp Szigetköz (1967-1991)R = 0,8684catch of com. fishery (ton)1,281,120,960,80,640,480,32Sterlet Szigetköz (1967-1991)R = - 0,7790catch of com. fishery (ton)12,811,29,686,44,83,21,6Barbel Szigetköz (1967-1991)R = - 0,78490108,2 108,4 108,6 108,8 109 109,2 109,4 109,6 109,8water level (m a.s.l.)catch of com. fishery (ton)2,11,81,51,20,90,60,30108,2 108,4 108,6 108,8 109 109,2 109,4 109,6 109,8water level (m a.s.l.)6,4Pike Szigetköz (1967-1991)R = 0,95570,160108,2 108,4 108,6 108,8 109 109,2 109,4 109,6 109,8water level (m a.s.l.)catch of com. fishery (ton)5,64,843,22,41,60,80108,2 108,4 108,6 108,8 109 109,2 109,4 109,6 109,8water level (m a.s.l.)


Habitat degradation – Szigetköz case studyAnabranching systemHistorical spawning habitatSzigetköz floodplain18th century19 th century:River engineeringnavigation way,flood protection works1992Discharge diversion(85%),Hydrower stationmain arm(end 19 th c.)floodplainsidearmsGabčikovo hydroelectricpower station (1992)bypass canal(end 20 th c.)Intense humanmodificationsdike(end 19 th c.)


Sterlet catch - Szigetköz(1950-2005)Acipenser ruthenus20001600catch (kg)water qualityimprovementSterletspawning site1200800400Danubediversion01950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005Bagoméri side arm (1992-2004)former spawning habitataggradationsedimentationbed incisionerosion400.000 m 3 soft sediment accumulated in a 4 km long sectionsterlet – important indicator of the habitat change


Improvement of habitats – key element of rehabilitationReliable information need to target visionlocalisation of key habitats - telemetry2D and 3D hydraulics modelsSonar image processingDescription of local hydromorphologicalprocessessand, siltgravelseepageBedrock or impermeable materialDelineation ofenvironmental objectivesfor habitat restorations


EU Danube Region StrategyImprovement of habitat quality is relevant to EDRSEU – Danube – Black Sea – Central AsiaNew opportunities fordevelopment of sectoral policies● socio-economic development● competitiveness● environmental management● modernisation of transport corridorDecline of biodiversityAlteration of natural ecosystemEnvironmental protectionSustainable utilization approachTo achieve goal of sustainable utilizationNeed to investment in environmental research to identify new tools for● improvement ecosystem integrity● reduce human pressure on river ecosystem


Principle of ecological restoration (according to Williams et al. 1997)increasingecosystemfunctionReplacementreplaced functionbut not structure”ecological husbandry”restorationhistoricconditionrestoredsystemrehabilitationexistingconditiondegradedsystemdegradationReplacementreplaced structurebut not function”ecological gardening”increasingecosystemstructure

More magazines by this user
Similar magazines