4 ecwfdlakepeipsi noges

Ecological quality of Lake Peipsi in the light of WFD : 

Ecological quality of Lake Peipsi in the light of WFD Nõges, P.1,2, Nõges, T.1,2, Haberman, J.1, Kangur, K.1, Kangur, A.1, Kangur, P.1, Laugaste, R.1, Mäemets, H.1, Ott, I.1, Timm, H.1, Yastremskij, V.V.3 & Virro, T.2 1 Institute of Zoology and Botany, Estonian Agricultural University 2 Institute of Zoology and Hydrobiology, University of Tartu 3 Pskov Department of the Institute of Lake and River Fishery

Slide2: 

L. Peipsi largest transboundary lake in EUROPE

Slide3: 

present Estonian monitoring ESTONIA RUSSIA Mean fish catch 16 kg ha-1y-1

Slide4: 

‘natural scientist’ knows what lake is ‘social scientist’ knows what lake means

Lake Peipsi is the largest transboundary lake in Europe L. Peipsi is importantimplementation of WFD on L. Peipsi is important: 

Lake Peipsi is the largest transboundary lake in Europe  L. Peipsi is important  implementation of WFD on L. Peipsi is important

MANTRA-East 2001-2004 “Integrated Strategies for the Management of Transboundary Waters on the Eastern European fringe – The pilot study of Lake Peipsi and its drainage basin”  : 

MANTRA-East 2001-2004 “Integrated Strategies for the Management of Transboundary Waters on the Eastern European fringe – The pilot study of Lake Peipsi and its drainage basin”  indicators and criteria for L. Peipsi

WFD requests: 

WFD requests determination of water quality as the range of deviation from the ‘pristine status’ associated to type-specific ‘reference conditions’

ECOLOGICAL STATUS OF L. PEIPSI considering range of deviation: 

ECOLOGICAL STATUS OF L. PEIPSI considering range of deviation

Classification of the water quality of light-coloured Estonian lakes: 

Classification of the water quality of light-coloured Estonian lakes   

Some ‘chemistry’ on L. Peipsi‘Moderate’ status between the borders: 

Some ‘chemistry’ on L. Peipsi ‘Moderate’ status between the borders TN TP CODcr Secchi      

Phytoplankton small ‘plants’ who start food chainif too many – make lake turbid : 

Phytoplankton small ‘plants’ who start food chain if too many – make lake turbid  

Phytoplankton dominants: 

Phytoplankton dominants L. Peipsi s.s. Aulacoseira islandica, Stephanodiscus astraea, Gloeotrichia echinulata, chrysophytes characteristic of moderately eutrophic waters L. Pihkva, Lämmijärv Aulacoseira granulata, Stephanodiscus binderanus, Anabaena spp., Aphanizomenon flos-aquae, green algae typical of highly eutrophic or hypertrophic waters generally remained same since 1900s 

Phytoplankton composition: 

Phytoplankton composition Since 1960s difference between north and south decreased hypertrophic species Planktothrix agardhii & Limnothrix redekei developed in 1988 and 1989 Aphanizomenon flos-aquae, Anabaena, & Stephanodiscus binderanus increased Aulacoseira italica diminished remarkably slight changes  ‘good’ status 

Phytoplankton abundance: 

Phytoplankton abundance May, July, October Estonian & Russian data Peipsi s.s. Pihkva generally same level 

Water blooms : 

Water blooms Gloeotrichia echinulata already in 1895 Anabaena flos-aquae & Microcystis aeruginosa in 1912 A. flos-aquae, A. spiroides and G. echinulata in L. Pihkva in 1929 A. flos-aquae in 1934 in all lake parts yearly blooms common in the 1930s bloom-caused fish-kills in L. Pihkva in 1959 in L. Peipsi in 1972 no significant differences in frequencies and species ‘good’ status 

reduced nitrogen loading in 1990s caused N-limitation and favoured blooms of N2 fixing cyanobacteria: 

reduced nitrogen loading in 1990s caused N-limitation and favoured blooms of N2 fixing cyanobacteria

Reduced nitrogen loading enhance cyanobacterial blooms in Lake Peipsi: 

Reduced nitrogen loading enhance cyanobacterial blooms in Lake Peipsi Nõges, T. 1,2, Blinova, I. 3, Jastremski, V. 5, Laugaste, R. 1, Loigu, E. 3 Skakalski, B.4, Tõnno, I.1,2 1Institute of Zoology and Botany, Estonian Agricultural University, Võrtsjärv Limnological Station 2Institute of Zoology and Hydrobiology, University of Tartu 3Tallinn Technical University, Department of Environmental Engineering 4 Russian Hydrometeorological University, St.-Petersburg. 5Pskov Department of State Lake and River Fishery Research Institute Poster

Changed loadings: 

Changed loadings Poster Velikaya N P N/P

Slide19: 

present situation reminds 1960s Poster CY% decresed at heavy N loading in 1980s

‘pristine’ conditions???: 

‘pristine’ conditions ???

Slide21: 

Maybe ? reduced nitrogen loading is driving the ecosystem closer to ‘pristine’ conditions  blooms may not always indicate the declining water quality paleolimnology and modelling needed 

Zooplankton – small animals- eat phytoplankton- food for fish: 

Zooplankton – small animals - eat phytoplankton - food for fish 

Zooplankton : 

Zooplankton key link between phytoplankton and fish  determins the efficiency of the aquatic food web lacking from WFD 

Zooplankton of L. Peipsi: 

Zooplankton of L. Peipsi oligotrophic indicators Holopedium gibberum and Asplanchna herricki found in early 1900s disappeared dominating complex has remained same for the last 40 years increasing degree of domination by rotifers rising number of small-sized crustaceans decreasing mean individual weight decreasing zoopl. to phytopl. biomass ratio slight disturbance ‘good’ status 

Macrophytes: 

Macrophytes Dominating species: Potamogeton perfoliatus, submerged Phragmites australis (reed), emergent Since 1970s reed belt of L. Peipsi s.s. expanded reed increased P. perfoliatus decreased species from L. Pihkva expanded to L. Peipsi s.s. most sensitive taxa e.g. Isoёtes setacea, Subularia aquatica disappeared abundance of filamentous green algae increased ecological status ‘good’- ‘moderate’ Reed 

Macrozoobenthos: 

Macrozoobenthos Since 1960s + Chironomus plumosus has not increased + high species diversity has not decreased + oligo-mesotrophic species still there Monodiamesa bathyphila, Potthastia longimana, Paracladopelma rolli + small bivalves (Pisidiidae, Sphaeriidae) abundant - increasing of zebra mussel (Dreissena polymorpha) invader from 1935 (but !clean water species!) - gammaridean amphipod Gmelinoides fasciatus was introduced accidentally from L. Baikal in 1970s replaced completely native Gammarus lacustris benthic fauna strongly modified  ‘moderate’ status high species diversity & survival of sensitive species  high quality  

Fishes of L. Peipsi: 

Fishes of L. Peipsi Historically heavily exploited fish stock Baer, 1852: overfishing has reduced bream cacthes 70-150 yr ago smelt was the main commercial fish large fluctuations caused by climate, oxygen, algal blooms sharp decrease of vendace in 1990s siltation of the spawning grounds winter oxygen depletion increased predation by pikeperch sharp increase of pikeperch from late 1980s-late 1999s overfishing  decrease of pikeperch and perch in last years  increase of ruffe endangering the eggs of vendace decrease of sensitive species (vendace, whitefish), episodic fish kills, decrease of older age classes of top predators, increse of omnivores and habitat generalists (ruffe)  ‘moderate’ status 

Water quality of Lake Peipsi: 

Water quality of Lake Peipsi P, N, Chl, phytoplankton, zooplankton, macroinveretebrates  ‘good’ Secchi depth & fish fauna  ‘moderate’  

So, and …?: 

So, and …?

Slide30: 

‘natural scientist’: not too bad! ‘social scientist’: what to do with all that? ‘people’: turbid water! too few fish!

Suggestions: 

Suggestions Examine what people need Explain to people & politicians keep loadings low ! keep phosphorus loading low ! protect carnivorous fish wait and pray that we were right !

Thank you all !and: 

Thank you all ! and Estonian program of environmental monitoring EC projects ECOFRAME (contract EVK1-CT-1999-39) MANTRA-East (contract EVK1-CT-2000-00076) Estonian Science Foundation for financial support !