Muschelschutztagung vom in Freising zum Thema Muschelzucht

Transkript

1 Liebe Aktive im Muschelschutz, Im aktuellen Newsletter 4/2018 der bayerischen Muschelkoordinationsstelle möchten wir Sie über verschiedene Themen und Veranstaltungen im Muschelschutz informieren. Muschelschutztagung vom in Freising zum Thema Muschelzucht Die Tagung findet am in Freising statt. Dieses Jahr steht das Thema Muschelzucht in Fokus der Tagung. Von nationalen und internationalen Fachleuten und Wissenschaftlern werden spannende Vorträge zum Thema Muschelzucht gehalten und die aktuellsten und neuesten Aspekte beleuchtet. Vor allem Flussperlmuschel und Bachmuschel sind die Muschelarten für die in den letzten Jahren verstärkt Zuchtbemühungen unternommen wurden. Das Programm wird derzeit erstellt. Die Details zur Anmeldung über die Webseite der bayerischen Akademie für Naturschutz und Landschaftspflege ANL ( werden in Kürze bekanntgegeben. Internationale Tagung der Freshwater Mollusk Conservation Society (FMCS) Die erste Tagung der FMCS in Europa fand vom bis in Verbania, Italien statt. Forscher des Lehrstuhls für Aquatische Systembiologie waren mit folgenden Beiträgen beteiligt: Keynote Speaker Common Pitfalls in Freshwater Mussel Cnservation and How to avoid them Juergen Geist 1 1 Aquatic Systems Biology Unit, School of Life and Food Sciences, Technical University of Munich, Muehlenweg 22, D Freising, Germany, geist@wzw.tum.de Due to their important roles as indicator, umbrella, keystone and flagship species, several freshwater mussels have become prime target species in aquatic conservation. In Europe, this is particularly true for the freshwater pearl mussel (Margaritifera margaritifera) and the thick-shelled river mussel (Unio crassus). There is a wealth of captive breeding and propagation programmes as well as habitat restoration work being carried out in many countries to improve declining population trends. Thus, a critical evaluation of the success of these programmes becomes mandatory. Even though there is increasing knowledge on the ecology of many mussel species and their fish hosts, there are several major pitfalls and shortcomings that mussel conservation programmes often face. This presentation highlights some of the most common risks and problems in mussel conservation which is sometimes still driven by gut feeling rather than scientific evidence. Examples of limited success presented herein include erroneously assuming analogies between related mussel species that instead have different habitat requirements, lack of strategic planning, prioritization and proper monitoring, as well as ignoring genetic adaptation, target species conflicts, a lack of exchange among existing programmes and little communication of negative results. In

2 addition, it highlights that restoration work is not always beneficial as evident from an example of stream bed restoration with an overall negative effect on the stream habitat. This presentation is intended to provide some suggestions on how mussel conservation can become more successful in the future. The highly different approaches to mussel conservation in North America and Europe can provide a great opportunity for discussing promising future directions. Poster Präsentationen 1.) Factors determining local mussel distribution patterns Laura Rehlen 1,3, Matthias Hasenbein 1, Marco Denic 2, Mathias Schlagenhauser 3, Kordula Schwarzwälder 3, Juergen Geist 1 1 Chair of Aquatic Systems Biology, Technical University of Munich Germany; 2 Landscape conservation organization Passau Germany; 3 Chair of Hydraulic and Water Resources Engineering, Technical University of Munich Germany; laura.rehlen@tum.de Fresh water mussels are among the most endangered animal groups on earth, yet little is known about the influence of the near bed hydrodynamic conditions on their distribution patterns. This study compared different streambed assessment techniques and 3D numerical simulation to understand the distribution patterns of the freshwater pearl mussel (Margaritifera margaritifera) within a river segment. To build the 3D model, the topography of a river section, was recoded with a tachymeter. Calibration and validation is done with ADCP, ADV and FST hemisphere data. The 3D model topography was processed with the SMS software and transferred onto the simulation software Flow3D. Here a gravity as well as a turbulence and viscosity model were built. The outputs of the model are turbulent energy, excess shear stress and other hydraulic parameters. To estimate the spatial distribution of the fresh water pearl mussel the population was mapped twice, once in early spring and once in early summer. The spatial data and density of the patches was then correlated to the shear stress and turbulent energy results of the simulation. Besides, the degree of aggregation and behavior during spring and summer was tested with different statistical tests. The species and the populations are significantly aggregated and distributed over-dispersed (negative binomial). Whereas the degree of patchiness was higher during early spring, the area of inhabited river bottom does not change significantly between the two mappings. The correlation highlights, that the shear stress, especially under extreme conditions at high flood events, governs the spatial distribution of the population in the river. Moreover, small scale turbulences can also affect the distribution patterns. It can be concluded, that the different methods used to conduct this study on Margaritifera margaritifera and its habitat are highly effective to enforce the knowledge about distribution patterns and can assist future studies in acquisition of valid data. Furthermore, the simulation is complementing conventional measurements of variables during high and low flow. As the significance of flow conditional variables measured at a few discharges is restricted and the influence of parameters on habitat suitability and mussel abundance is limited, hydraulic modelling is essential. 2.) Prioritizing conservation areas for endangered freshwater molluscs in Bavarian riverine systems, Germany

3 Dobler AH1, Stoeckl K1, Geist J1, Inoue K2 1 Chair of Aquatic Systems Biology, Technical University of Munich, Munich, Germany 2 Institute of Renewable Natural Resources, Texas A&M University, TX 77843, USA The establishment of protected areas is considered a key measure to counteract the decline of species and habitat diversity. In particular, this applies to freshwater mollusks, which strongly depend on processes in the catchments. The objectives of this study were to assess the current overlap between different categories of protected areas with current and potential mussel distribution of two endangered species, Margaritifera margaritifera and Unio crassus. This approach included ecological niche modeling of both species as well as an assessment of the appropriateness of current protected area status. Ecological niche models (ENMs) were based on presence-only data using MAXENT. In a GIS-based GAP-analysis, predicted suitable habitats were compared with their currently assigned legal protection status. We distinguished between different categories of protected areas, including nature conservation areas, special areas of conservation and protected landscapes, which highly differ in their level of protection. ENMs for M. margaritifera revealed a spatially restricted distribution with significant model performance, the predicted spatial distribution of U. crassus was wider and model performance was significantly weaker. A high percentage of suitable habitat of M. margaritifera is already under protection, albeit mostly at low protection level. In contrast, only half of the suitable habitats of U. crassus are under any sort of protection. The results of this study suggest that different priorities in the protected area management of M. margaritifera and U. crassus should be set: Whilst for M. margaritifera, an increase in protection status of already protected areas would be most useful, U. crassus may most strongly benefit from expansion of protected areas along its distribution. Mündliche Präsentationen 1.) GENETIC DIVERSITY AND DIFFERENTIATION OF THE ENDANGERED THICK SHELLED RIVER MUSSEL (UNIO CRASSUS PHILIPSSON, 1788) CONSERVATION UNITS AND LINEAGES FROM BELGIUM TO ROMANIA Sarah Feind1,2, Juergen Geist1, Ralph Kuehn2 1 Aquatic Systems Biology Unit, Department of Ecology and Ecosystem Management, Technical University of Munich, Muehlenweg 22, Freising, Germany 2 Unit of Molecular Zoology, Chair of Zoology, Department of Ecology and Ecosystem Management, Technical University of Munich, Hans-Carl-von-Carlowitz-Platz 2, Freising, Germany The thick shelled river mussel (Unio crassus Philipsson, 1788) is one of the phenotypically most variable freshwater Unionoids in Europe. The species taxonomy still remains unclear, since a plethora of geographic variants are described from different authors, with more than 300 known, but unverified synonyms for U. crassus. To date, a comprehensive risk assessment and conservation management of U. crassus are lacking since many questions about the within-species differentiation remain unresolved. Neither the comparatory nor the biological species morphology concept could help solving taxonomic contradictions about the U. crassus complex. The last decade of genetic research on unionoid species showed that genetic data is extremely helpful for freshwater mollusc conservation. We therefore

4 determined genetic diversity and differentiation of U. crassus from central and eastern Europe including the major catchments of the Rhine and the Danube. Microsatellite analysis revealed at least two lineages within Central Europe with contact zones and possible hybridization. U. crassus populations from the Southern Upper Danube system showed higher genetic differentiation with low genetic diversity, whereas populations from the Northern Upper Danube system and Rhine system showed a lower genetic differentiation having an admixed population structure. Morphologically described subspecies from these regions were also compared to the conservation units/lineages revealed from the microsatellite analysis. Like for other unionoid species, genetic data is an important tool in conservation management for U. crassus, e.g. to aid in assessment of the IUCN red list of species, or unravel taxonomic contradictions. 2.) ASSESSING HABITAT CHARACTERISTICS OF THE PAINTER S MUSSEL (UNIO PICTORUM, LINNAEUS 1758) IN THE BAVARIAN CATCHMENT AREA OF THE DANUBE Helmut Bayerl1, Juergen Geist1 1 Aquatic Systems Biology Unit, School of Life and Food Sciences, Technical University of Munich, Muehlenweg 22, D Freising, Germany, helmut.bayerl@tum.de; geist@wzw.tum.de Freshwater bivalve molluscs play a key role in the ecosystems where they occur, however they count among the most endangered taxa worldwide and many species have suffered a dramatic decline. It has been realized that for the conservation of freshwater bivalves a profound understanding of habitat requirements of individual species is needed in order to infer conservation measures for a particular species. In Europe, conservation studies so far have been mainly focused on the highly endangered freshwater pearl mussel (Margaritifera margaritifera) and thick shelled river mussel (Unio crassus). However much less is known about habitat preferences of the painter s mussel which is classified as species of national responsibility in Germany. Unio pictorum is found in stagnant as well as in flowing waters suggesting a wider tolerance towards environmental conditions than in highly specialized species as the freshwater pearl mussel. We assessed density and age structure of U. pictorum in relation to substrate and water quality in 10 water bodies (rivers, backwaters, and lakes) in the catchment area of the Danube in Bavaria. Sediment quality was characterized by penetration resistance, grain size analysis and redox potential in 5 and 10 cm depth compared to the free flowing water. Water quality was assessed by measuring nitrate, nitrite, ammonium, total phosphorus, and oxygen concentrations, ph, specific conductivity, current velocity and depth. Chemical analyses were conducted for free flowing water and interstitial water from 5 and 10 cm depth. First findings indicate that U. pictorum is tolerant towards high proportions of fine sediment and associated with low current velocity. Findings of this study will help to characterize the range of habitat parameters which is needed for the development of conservation measures, management plans, or river restoration related to U. pictorum. 3.) ENVIRONMENTAL DNA AS A SURVEY TOOL FOR CONSERVATION AND MANAGEMENT OF FRESHWATER MUSSELS Bernhard Stoeckle1, Ralph Kuehn2 and Juergen Geist1. 1 Aquatic Systems Biology Unit, School of Life and Food Science, Technical University of Munich, D Freising, Germany, bernhard.stoeckle@tum.de; geist@wzw.tum.de;

5 2 Unit of Molecular Zoology, Chair of Zoology, School of Life and Food Science, Technical University of Munich, D Freising, Germany; Knowledge of species distribution patterns are a prerequisite for conservation of freshwater mussels. However, obtaining occurrence data for rare mollusk species can often be challenging with classical surveys due to the effort involved and since individuals can be overseen. Environmental DNA (edna) analyses have recently emerged as an effective tool to detect and monitor mussel populations. Yet, edna studies with mollusks are still severely underrepresented in comparison to other taxonomic groups, such as fishes. The objectives of this study were to establish edna detection systems for Margaritifera margaritifera and Unio crassus and to evaluate the PCR systems on water samples from streams with detailed knowledge on spatial distribution patterns of both species and population sizes varying from 0 to 50,000. Additionally, we investigated the influence of different environmental parameters on the detection success of edna by using a standardized experimental setup. Mussel detection by edna was possible up to 3.2 km downstream living mussels, with differences in detection sensitivity largely been driven by fine sediment, inhibitors, and sampling processing protocols. The results of the laboratory setup showed that the presence of sediment was mainly responsible for lower edna detection and a delayed release of edna. Humic substances had the highest inhibitory effect on edna detection followed by algae and siliceous sediment particles. The results of this study suggest a great potential of using edna in mussel monitoring, yet they also warrant better validation of false positives, optimization of sampling protocols and combination with classical survey data. Saatkrähen erbeuten Bachmuscheln Wie bereits berichtet haben, haben vielerorts Krähen Muscheln als Futterquelle ausgemacht. Sie erbeuten Muscheln aus Flüssen und knacken diese anschließend durch Fallenlassen auf Straßen oder Dächer. Dieses Verhalten wurde bereits an mehreren Orten in Bayern, beispielsweise an der Schmutter im Landkreis Donau-Ries, am Schwarzenbach im Landkreis Lindau und an der Ach in Uffing beobachtet. Auch am Falchengraben in Erkheim wurde ein Brutpaar dabei beobachtet wie es Bachmuscheln erbeutete und diese auf einer Straße knackte. Das bereits erwähnte Phänomen findet sich weit verbreitet wieder. Unter anderem berichtete die Augsburger Allgemeine am darüber. seltene-bachmuscheln-aus-dem-weiherbach-id html Insbesondere bei Niedrigwasser scheint es für Saatkrähen möglich und attraktiv zu sein, Bachmuscheln aus den Gewässern zu fischen. Wir bitten deshalb um Ihre Mithilfe: Sollten Sie bei Gewässerbegehungen ein solches Geschehen beobachten, nehmen Sie dies mit auf und geben den Hinweis an die Muschelkoordinationsstelle weiter. Vielen Dank!

6 Beiträge zur Flussperlmuschelzucht im Bayerischen Rundfunk Die Sendung regionalzeit Franken des Bayerischen Rundfunks sendete am einen Beitrag zur Flussperlmuschelzucht des Bund Naturschutz in Regnitzlosau. Der Beitrag kann in der BR-Mediathek unter folgendem Link abgerufen werden: Der bayerische Rundfunk brachte am einen Bericht über die Flussperlmuschelzucht im Landkreis Hof. Der Beitrag kann unter folgendem Link abgerufen werden: Termin Muschelberaterkurs für 2019 Die Ausbildung zum Muschelberater findet im kommenden Jahr an folgendem Termin statt: in Erkheim, Landratsamt Memmingen. Weitere Details zur Anmeldung folgen noch. Weitere Aktuelle Veranstaltungen Workshop: Süßwassermuscheln: Suche nach Auswilderungshabitaten und Evaluation der Schutzmaßnahmen ; Wasser, Ökosysteme, Artenschutz; Penck Hotel Dresden Search-for-resettlement-habita/ /eid/MTYyNA

7 Zum Abschluß des erfolgreichen Jahres 2018 Da sich das Jahr nun bald dem Ende neigt, möchten wir vor dem ganz großen Weihnachtstrubel schon mal die Gelegenheit nutzen, um unsere Festtagswünsche zu äußern. Seitens der Koordinationsstelle für Muschelschutz wünschen wir Ihnen/Euch ein Frohes Weihnachtsfest, ein paar besinnliche Tage zwischen den Jahren und einen guten Rutsch ins gesunde und erfolgreiche neue Jahr Mit freundlichen Grüßen Dr. Matthias Hasenbein Hinweise - Sie haben Fragen oder Anregungen zu bestimmten Themen im Muschelschutz? Wir möchten das Angebot der Koordinationsstelle kontinuierlich optimieren. Wir freuen uns daher über Ideen, schreiben Sie uns einfach eine Mail oder kontaktieren Sie uns persönlich! muschel@tum.de ; Tel.: 08161/