7 research outputs found
FlodpÀrlmussla i BratteforsÄn och GÀrebÀcken : - status och trender
BratteforsĂ„n FlodpĂ€rlmusselbestĂ„ndet i BratteforsĂ„n Ă€r liten sett ur ett nationellt perspektiv. MedeltĂ€theten Ă€r lĂ„g men utbredningen Ă€r relativt stor Ă€ven i ett nationellt perspektiv. I VĂ€stra Götaland Ă€r det endast tvĂ„ andra Ă„ar som har en lika stor utbredning av musslor. Minsta funna mussla i Ă„rets inventering var 12 mm. I övrigt pĂ„trĂ€ffades inga musslor mindre Ă€n 2 respektive 5 cm. BratteforsĂ„n bedöms utifrĂ„n Ă„rets inventering ligga i skyddsvĂ€rdeklass II, dvs BratteforsĂ„n har Högt skyddsvĂ€rde. Ă
rets undersökning visar en ökning av bestĂ„ndet jĂ€mfört med 2000, frĂ„n 13 000 till 18 000 musslor. TĂ€theten Ă€r pĂ„ uppgĂ„ng men anses fortfarande vara lĂ„g. Musslornas medellĂ€ngd har under Ă„ren 1989 till 2000 stadigt ökat för att i Ă„r minska. MedeltĂ€theten har mellan 2000 och 2006 ökat pĂ„ alla lokaler utom tvĂ„. Fynd av en 12 mm lĂ„ng mussla indikerar att det förekommer viss rekrytering. Trots positiv trend i Ă„rets undersökning Ă€r det viktigt att arbetet med de biotopförbĂ€ttrande Ă„tgĂ€rderna fortsĂ€tter i BratteforsĂ„n. Vidare bör resurser lĂ€ggas pĂ„ rĂ„dgivning till kringliggande markĂ€gare för att minska nĂ€ringslĂ€ckage och erosion till Ă„n. Enskilda avlopp i avrinningsomrĂ„det bör ocksĂ„ ses över. GĂ€rebĂ€cken BestĂ„ndsstorleken i GĂ€rebĂ€cken Ă€r liten sett ur ett nationellt perspektiv. MedeltĂ€theten Ă€r lĂ„g och utbredningen Ă€r liten. Den minsta funna musslan var 49 mm. I övrigt fanns inga musslor mindre Ă€n 2 respektive 5 cm. GĂ€rebĂ€cken bedöms utifrĂ„n Ă„rets inventering ligga i skyddsvĂ€rdeklass I, dvs GĂ€rebĂ€cken Ă€r SkyddsvĂ€rd. MusselbestĂ„ndet hade i Ă„r minskat jĂ€mfört med bestĂ„ndet Ă„r 1999, frĂ„n cirka 3 200 till cirka 3 000 musslor. TĂ€theten visar pĂ„ nedgĂ„ng och musslornas medellĂ€ngd har ökat. MedeltĂ€theten har mellan 1999 och 2006 minskat pĂ„ sju lokaler. En ökning med avseende pĂ„ medeltĂ€theten har skett pĂ„ sex lokaler. PĂ„ de tvĂ„ lokaler dĂ€r det inte var nĂ„gon skillnad fanns inga musslor alls. Minsta pĂ„trĂ€ffade musslan var 49 mm. Ă
rets undersökning antyder en negativ trend vad gÀller musselpopulationen i GÀrebÀcken. Det Àr viktigt att arbeta med biotopförbÀttrande ÄtgÀrder i GÀrebÀcken. Vidare bör resurser lÀggas pÄ rÄdgivning till kringliggande markÀgare för att minska nÀringslÀckage och erosion till Än. Dessutom bör enskilda avlopp i avrinningsomrÄdet ses över
FlodpÀrlmussla i BratteforsÄn och GÀrebÀcken : - status och trender
BratteforsĂ„n FlodpĂ€rlmusselbestĂ„ndet i BratteforsĂ„n Ă€r liten sett ur ett nationellt perspektiv. MedeltĂ€theten Ă€r lĂ„g men utbredningen Ă€r relativt stor Ă€ven i ett nationellt perspektiv. I VĂ€stra Götaland Ă€r det endast tvĂ„ andra Ă„ar som har en lika stor utbredning av musslor. Minsta funna mussla i Ă„rets inventering var 12 mm. I övrigt pĂ„trĂ€ffades inga musslor mindre Ă€n 2 respektive 5 cm. BratteforsĂ„n bedöms utifrĂ„n Ă„rets inventering ligga i skyddsvĂ€rdeklass II, dvs BratteforsĂ„n har Högt skyddsvĂ€rde. Ă
rets undersökning visar en ökning av bestĂ„ndet jĂ€mfört med 2000, frĂ„n 13 000 till 18 000 musslor. TĂ€theten Ă€r pĂ„ uppgĂ„ng men anses fortfarande vara lĂ„g. Musslornas medellĂ€ngd har under Ă„ren 1989 till 2000 stadigt ökat för att i Ă„r minska. MedeltĂ€theten har mellan 2000 och 2006 ökat pĂ„ alla lokaler utom tvĂ„. Fynd av en 12 mm lĂ„ng mussla indikerar att det förekommer viss rekrytering. Trots positiv trend i Ă„rets undersökning Ă€r det viktigt att arbetet med de biotopförbĂ€ttrande Ă„tgĂ€rderna fortsĂ€tter i BratteforsĂ„n. Vidare bör resurser lĂ€ggas pĂ„ rĂ„dgivning till kringliggande markĂ€gare för att minska nĂ€ringslĂ€ckage och erosion till Ă„n. Enskilda avlopp i avrinningsomrĂ„det bör ocksĂ„ ses över. GĂ€rebĂ€cken BestĂ„ndsstorleken i GĂ€rebĂ€cken Ă€r liten sett ur ett nationellt perspektiv. MedeltĂ€theten Ă€r lĂ„g och utbredningen Ă€r liten. Den minsta funna musslan var 49 mm. I övrigt fanns inga musslor mindre Ă€n 2 respektive 5 cm. GĂ€rebĂ€cken bedöms utifrĂ„n Ă„rets inventering ligga i skyddsvĂ€rdeklass I, dvs GĂ€rebĂ€cken Ă€r SkyddsvĂ€rd. MusselbestĂ„ndet hade i Ă„r minskat jĂ€mfört med bestĂ„ndet Ă„r 1999, frĂ„n cirka 3 200 till cirka 3 000 musslor. TĂ€theten visar pĂ„ nedgĂ„ng och musslornas medellĂ€ngd har ökat. MedeltĂ€theten har mellan 1999 och 2006 minskat pĂ„ sju lokaler. En ökning med avseende pĂ„ medeltĂ€theten har skett pĂ„ sex lokaler. PĂ„ de tvĂ„ lokaler dĂ€r det inte var nĂ„gon skillnad fanns inga musslor alls. Minsta pĂ„trĂ€ffade musslan var 49 mm. Ă
rets undersökning antyder en negativ trend vad gÀller musselpopulationen i GÀrebÀcken. Det Àr viktigt att arbeta med biotopförbÀttrande ÄtgÀrder i GÀrebÀcken. Vidare bör resurser lÀggas pÄ rÄdgivning till kringliggande markÀgare för att minska nÀringslÀckage och erosion till Än. Dessutom bör enskilda avlopp i avrinningsomrÄdet ses över
Lake hydromorphology assessment in Europe: Where are we 20 years after the adoption of the Water Framework Directive?
International audienceThe characterization of lake hydromorphology is crucial to understand the dynamics of biodiversity. In Europe, it isalso a regulatory requirement of the Water Framework Directive. However, according to the literature, few methodsinclude this characterization. The aim of this study is to review the state of the art of the methods currently used orunder development in European countries to assess lake hydromorphological status for the implementation of theWFD. Our analysis is based on responses to a questionnaire distributed to national experts on hydromorphologyof the 28 countries implementing the WFD. Our results highlighted significant progress in the assessment ofhydromorphological features and processes. Water level regime, through the range of water flow or existing watermanagement, and structure of the shore zone through macrophytes and substrate characteristics or measurement oflateral connectivity, are the most frequently assessed features. Stratification, surface/groundwater connection andplanform pattern are the lake features most frequently omitted from the methods. However, in most of the countries,the development of methods was still in progress to meet the WFD requirement. Definition of reference condition is acentral component of all WFD compliant assessment tools but this is a challenge particularly in the assessment ofhydromorphological alteration of reservoirs. Similarly, demonstrating strong links between hydromorphological indicatorsand biological quality elements remains a challenge with many knowledge gaps still evident. These results highlight the need for rapid collection of new environmental data and the need for conceptual and applied research to make methodological progress in assessing lake hydromorphology and ensuring habitat quality
Lake hydromorphology assessment in Europe: Where are we 20 years after the adoption of the Water Framework Directive?
International audienceThe characterization of lake hydromorphology is crucial to understand the dynamics of biodiversity. In Europe, it isalso a regulatory requirement of the Water Framework Directive. However, according to the literature, few methodsinclude this characterization. The aim of this study is to review the state of the art of the methods currently used orunder development in European countries to assess lake hydromorphological status for the implementation of theWFD. Our analysis is based on responses to a questionnaire distributed to national experts on hydromorphologyof the 28 countries implementing the WFD. Our results highlighted significant progress in the assessment ofhydromorphological features and processes. Water level regime, through the range of water flow or existing watermanagement, and structure of the shore zone through macrophytes and substrate characteristics or measurement oflateral connectivity, are the most frequently assessed features. Stratification, surface/groundwater connection andplanform pattern are the lake features most frequently omitted from the methods. However, in most of the countries,the development of methods was still in progress to meet the WFD requirement. Definition of reference condition is acentral component of all WFD compliant assessment tools but this is a challenge particularly in the assessment ofhydromorphological alteration of reservoirs. Similarly, demonstrating strong links between hydromorphological indicatorsand biological quality elements remains a challenge with many knowledge gaps still evident. These results highlight the need for rapid collection of new environmental data and the need for conceptual and applied research to make methodological progress in assessing lake hydromorphology and ensuring habitat quality
WG ECOSTAT report on common understanding of using mitigation measures for reaching Good Ecological Potential for Heavily Modified Water Bodies - Part 3: Impacted by drainage schemes
Hydromorphological alterations for drainage are widespread pressures on water bodies in Europe. Because of the importance of the water uses relying on drainage schemes, such as agriculture and urban areas, not all necessary restoration measures can be taken without significant adverse effect on the water use. Therefore many of the affected water bodies have been designated as heavily modified (HMWB). Still, in a substantial number of these water bodies, some mitigation measures should be taken to reach Good Ecological Potential (GEP).
This report presents responses of European countries on a detailed questionnaire distributed in 2015 on the impacts of land drainage on the water environment and the measures that can mitigate those impacts. The questionnaire also included questions on impacts of flood prevention, presented in the accompanying report âPart 2: Impacted by flood protection structuresâ.
A key objective of the questionnaire was to compare the understanding of impacts caused by drainage to continuity, hydrological regime, morphological alterations and aquatic biology. Information was requested on 1) national definitions of drainage and existing guidelines, 2) water uses and regulatory regimes linked to drainage, 3) hydromorphological alterations due to drainage and their assessment, and 4) mitigation measures. A list of mitigation measures and their definition is presented. In total, 20 countries responded to the questions on land drainage.
Key findings of the exercise are as follows:
âą Comparing the mitigation expected for good ecological potential by different countries provided a good basis for identifying similarities and differences between those countriesâ standards for good ecological potential. It also provided a valuable opportunity for the exchange of information.
âą It is possible to reach a harmonized understanding between countries of the environmental objective for HMWBs impacted by drainage.
âą There is no common EU wide definition of the term drainage, although a common understanding exists of what it entails.
âą There are several methods to detect impacts from hydromorphological pressures and many countries do not have methods to detect all the parameters affected by drainage.
âą There is no common understanding on minimum ecological requirements for GEP related to impacts from drainage.
âą The standard for ecological potential seems to vary between water bodies and countries and few countries have a national definition on significant impact on water use.
âą There are some indications that the majority of countries probably rule-out mitigation measures when considering (often site-specific) evaluating criteria.
âą It would be interesting to compare different countriesâ national methods to a common and comparable set of water bodies/catchments impacted by drainage. Such an exercise would be valuable in further identifying and elaborating on emerging good practice, implementation of measures in practice and possibly also for handling multiple pressures and intercalibrated Ecological Quality Ratios/Methods related to e.g. pollution in a comparable way.
Key recommendations for next steps presented in the conclusions of this report include:
âą A generalised framework for deciding on the mitigation required for good ecological potential should be developed to achieve further harmonisation of GEP. Such a generalised framework can be used to supplement CIS Guidance no. 4 on HMWB.
âą The existing approach should be further developed to allow for harmonizing the levels/requirements of ecological potential based on mitigation measures.
âą Future exercises under the Common Implementation Strategy should use the common technical terminology and mitigation measures provided in this report.
âą Harmonized hydromorphological classification methods should be developed in order to have a comparable assessment of the hydromorphological alterations due to drainage, among the different countries.
âą More common understanding on ecological minimum criteria for GEP should be developed.
âą Countries should exchange and establish transparent criteria for deciding if mitigation would have a significant effect on drainage and benefits for society.
âą Reasons for ruling out measures should be made clear and more transparent .
It is recommended to compare the outcomes produced by countriesâ national methods by applying them to a comparable set of heavily modified water bodies included in generic cases. Consideration should then be given to incorporating the results of both exercises into a good practice guideJRC.D.2-Water and Marine Resource
MarkÀgare som vattenförvaltare i ett förÀndrat klimat
Projektet har delfinansierats av The Interreg IVB North Sea ProgrammeAquariusprojekte