RS03 – Presentation

Invasion effects on native species: positive or negative?

Sajad Ashghali Farahani (s_farahani@yahoo.com), Groningen institute for evolutionary life sciences
Dr.Jan Komdeur
Ecologists neglect about parasite spillback or resource competition as a potential threat to native species in relation with energy flow during invasion. Invasions could have effect on ecological tolerance and geographic distribution of native species, predators and their parasites. But on the other hand, economists discuss about positive effects like Biological control or increasing catch per unit area during some invasions.
Taxonomical relation between native species and invaders are very important in invasive host –parasite coevolution. For example, population of native amphipods in central European rivers are progressively displaced by highly adaptive invasive species of amphipods with different salinity, temperature or drought tolerance. We hypothesized that deviations from normal behavior due to infection are more distinct in native species compared to the invasive one. According to our results invader amphipods (Echinogammarus berilloni ) are less active and save energy to be used for survival in areas with high pollution and salinity. They also avoid predator odor more than native species. We discuss to what extent these results may explain the distribution patterns and invasion processes in relation to parasitism found in nature.
SS10 – Poster

In order of disappearance: macroinvertebrate community changes along an experimental stream drought gradient

Thomas Aspin (twa436@bham.ac.uk), University of Birmingham
Mark Ledger, Zining Wang, Kieran Khamis, Matt O'Callaghan and Alexander Milner
Climate models forecast an increase in the frequency of severe, supraseasonal droughts, yet ecosystem impacts remain poorly understood. In particular, disturbance gradients that are needed to characterise ecological responses across critical physical habitat transitions (loss of longitudinal connectivity, streambed drying) have rarely been studied. We analysed macroinvertebrate community changes along a gradient of drought intensity, simulated across twenty-one experimental channels (mesocosms) which mimicked chalk stream headwaters. Responses to one year of drought disturbance varied among taxa, and four broad groups were distinguishable: (1) rheophilic caddisflies, herbivorous chironomids and worms were highly sensitive to moderate drought stress (loss of longitudinal connectivity); (2) standing water specialists (mosquitoes, riffle bugs) and predatory chironomids exploited longitudinal fragmentation but were sensitive to complete surface water loss, which favoured (3) a small number of semi-aquatic Diptera; and (4) a minority of taxa (primarily leeches and flatworms) maintained stable populations along the entire gradient. Despite highly nonlinear responses among many taxa, community level response to drought (total abundance, community structure) was broadly linear. However, the persistence of small populations of some taxa in dry streambed refugia negated any trend in richness. Some of these observations, such as the reversal of natural predator: prey ratios among chironomids as channels fragmented, suggest that small changes in streamflow could trigger abrupt shifts in food web dynamics.
SS03 – Presentation

Robust solid contact ion selective electrodes for high resolution in-situ profiling of ammonium, pH and carbon dioxide in eutrophic lakes

Rohini Athavale (rohini.athavale@eawag.ch), Eawag, Swiss Federal Institute of Aquatic Science and Technology
Bernhard Wehrli1,2, Gaston A. Crespo3, Eric Bakker3, Andreas Brand1,2

1) Eawag, Swiss Federal Institute of Aquatic Science and Technology, Surface Waters – Research and Management, Kastanienbaum, Switzerland
2) Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Switzerland
3) Department of Inorganic and Analytical Chemistry, University of Geneva, Switzerland
Biogeochemical processes are often confined to very narrow zones in aquatic systems. In order to identify and study such processes, highly resolved measurements are required. Potentiometric solid contact ion selective electrodes (SC-ISEs) are promising tools for high resolution profiling of a variety of ions. While conventional SC-ISEs work well under controlled laboratory conditions they can fail to meet the challenges of natural water matrices. In-situ application requires SC-ISEs which are insensitive to changes in redox conditions, pH, and light and to reactive solutes like sulfide. We developed a design using different combinations of transducing materials and membrane matrices for fabrication of SC-ISEs selective to NH4+, pH, and CO2. With the use of modified multiwallcarbon nanotubes as a tranducing solid contact and an acryl based polymer as membrane matrix we built sensors that are insensitive to light and high sulfide concentrations.We integrated these sensors in a custom built in-situ profiling set up and successfully recorded high resolution profiles in the eutrophic lake Rotsee during summer stratification.
RS02 – Presentation

A study of the potential impacts of Climate Change on oyster production in Whin Estuary in Ghana

Sandra, Akugpoka Atindana (sandybrownatindana@gmail.com), University for Development Studies, Ghana
Sandra Brucet, Olajire, Fagbola
Ghana depends heavily on her coastal resources for food, income and employment with the Whin Estuary being no exception. It is feared that this ecosystem could be lost in the event of Climate Change (CC) because of its close tie to the sea. This could be magnified by land use activities due to potential impact on food security, livelihood and water. Using case scenarios, historic mollusc catch and current catch data of West African Oyster (Crassostrea tulipa) and environmental factors were used as surrogates of the ecological status and sustainability of oyster fishery. Triangulation approach involving the use of focus group discussions, key informant interview, field measurements and observations were employed to solicit data on catch, land use activities and perception of oyster harvesters on the fishery. A general linear model was performed to determine the influence of environmental variables on oyster abundance and spatial distribution. Ranking of identified land use stressors were done using the ( Battisti et al., 2009) Salafsky et al. (2003) ranking method. The results of the study showed that mollusc catch decline with increase temperatures and increase in volume of rainfall. Among the non climatic stressors in the area, the presence of sewage outlets were the major threat (8), followed by uncontrolled mangrove cutting (7), sand winning (6) and the least of the threats were refuse damps(4) and farming activities (3). There was no significant differences in the magnitude of threats of refuse dumps and farming activities.

Keywords: Abundance, Catch, Ecological, Oyster, Threats,

RS06 – Poster


Sandra, Akugpoka Atindana (sandybrownatindana@gmail.com), UNIVERSITY FOR DEVELOPMENT STUDIES
The utilization of ''invisible'' marine resources like the West African oyster Crassostrea tulipa are capable of reducing food insecurity and malnutrition and providing income to fishers in Ghana. Loss of coastal wetlands to climate change will directly have impacts on food, water and livelihood security. Many artisanal fisheries stocks and the livelihoods of those who make their living from fishing are in decline, and these declines are exacerbated by uncertainties associated with increased climate variability and change. This paper examines how oyster fishers in the Whin Estuary in western Ghana (longitude 10 48W and latitude 40 56N) utilize fish products of C. tulipa and how they perceive and adapt to indicators of climate change. Mixed method involving participatory approaches such as focus group discussions, individual and key informant interviews using a checklist, semi structured questionnaire and interview guide respectively. Thirty oyster fishers were purposively sampled and interviewed through snowball technique to identify respondents. Moisture, crude protein, crude fat, minerals and ash were determined at the Technology Village of the University of Cape Coast following the procedures of the Official Analytical Association of Chemist. The research showed that the mean percentage nutritional values determined for its meat were 43.28 ± 0.35 protein, 8.67 ± 0.24 % carbohydrate, 0.03 ± 0.001mg of Iron, 22.98 ± 0.78 calcium, 10.89 ± 2.18 % ash and 79.03 ± 0.97 % moisture. The shells are used in manufacturing of poultry feed, powder for demarcation of fields and paint for building. Women adapt differently to climate indices and also have rich indigenous knowledge in the prediction of these indicators.
Keywords: Oyster, Climate change, vulnerability, adaptation

SS02 – Poster

Spatio - temporal analyses of macroinvertebrates, plankton and fish abundance in whin estuary in Ghana

Sandra, Akugpoka Atindana (sandybrownatindana@gmail.com), University for Development Studies, Ghana
Sandra Brucet
A six month study of Whin estuary (longitude 10 48W and latitude 40 56N) reflects deteriorating quality of the water. This is capable of posing hazardous effects on life in the water and humans who depend on its resources. This system though has maintained pristine conditions over a long period of time in an area of intense human activities, requires serious attention since its status could further be magnified by threats emanating from the adverse effects of climate change. While the use of biotic indices is common in temperate waters, there is a lack of their use in Ghana probably because there is none developed for Ghanaian waters. The ecological status of the estuary will be assessed through the functional feeding groups and habit trait groups of macroinvertebrates, fish and plankton. Hydrographic factors, nutrients, Chlorophyl a, heavy metals and microbial assessment of water samples will be done following procedures of APHA (2009). The study seeks to identify the types and abundance of macroinvertebrates, plankton and fish present in the water; develop an appropriate pollution index for use for biomonitoring of wetland systems in Ghana and to develop a manual to train community leaders for use to monitor their water to enhance their livelihoods.

RS08 – Poster

The value of a desk study in building a river obstacle inventory

Siobhan Atkinson (siobhan.atkinson@ucdconnect.ie), School of Biology and Environmental Science, University College Dublin
Jens Carlsson(1), Bernie Ball(1), Michael Bruen(2), Jonathan Turner(3), Craig Bullock(4), John O’ Sullivan(2), Colm Casserly(3), Mary Kelly-Quinn(1).
1. School of Biology and Environmental Science, University College Dublin
2. UCD Dooge Centre for Water Resources Research, School of Civil Engineering, University College Dublin
3. School of Geography, University College Dublin
4. School of Geography, Planning and Environmental Policy, University College Dublin
This paper evaluates a desk-based approach for creating an inventory of man-made obstacles or barriers in rivers, such as dams, bridge aprons, weirs, and culverts. It is part of an Environmental Protection Agency funded project (Reconnect) to study the impact of obstacles on hydromorphology, aquatic ecology and connectivity in Irish rivers.

The creation of a river obstacle inventory is a logical first step in developing a prioritisation process for obstacle removal and/or modification. An efficient desk-based method of locating obstacles using various maps is presented. As an example, a desktop GIS analysis was undertaken of two rivers and their tributary network, using historic maps, satellite imagery and OSI discovery series maps, to create a geo-referenced layer of all the potential obstacles. In order to determine the effectiveness of the desk study, the located obstacles were cross-referenced with obstacles recorded in the field.

The desk study identified several thousand potential obstacles, of which over 80% were road crossings. Over 90% of the obstacles located in the field were successfully identified via the desk study.

The results of this research indicate that a desk study can be an efficient and effective method of locating river obstacles and can guide subsequent field surveying of the obstacles, in particular eliminating large stretches of the river that would otherwise need to be walked, thus reducing the time and cost involved.
SS06 – Presentation

Time of day matters – Diurnal changes of CO2 fluxes across European streams

Katrin Attermeyer (katrin.attermeyer@ebc.uu.se), Uppsala University, Department of Ecology & Genetics, Limnology
Katrin Attermeyer1, Joachim Audet2, Laura Barral-Fraga3, Tea Basic4, Adam Bednařík5, Georgina Busst4, Joan Pere Casas-Ruiz6, Núria Catalán6, Sophie Cauvy-Fraunie7, Miriam Colls6, Elvira de Eyto8, Anne Deininger9, Alberto Doretto10, Brian C. Doyle11, Vesela V. Evtimova12, Stefano Fenoglio13, David Fletcher4, Jérémy A. Fonvielle14, Anna Freixa6, Thomas Fuß15, Peter Gilbert16, Catie Guttman-Roberts4, Sonia Herrero14, Lyubomir A. Kenderov17, Marcus Klaus9, José L. J. Ledesma2, Liu Liu18, Clara Mendoza-Lera7, Juliana Monteiro19, Jordi-René Mor6,20, Magdalena Nagler21, Georg H. Niedrist22, Christian Noss18, Anna C. Nydahl1, Nina Pansch14, Ada Pastor6, Josephine Pegg4,23, Francesca Pilotto9, Ana Paula Portela19, Clara Romero15, Ferran Romero6, Martin Rulík5, Wiebke Schulz9, Danny Sheath4, Nikolay Simov24, Xisca Timoner6, Pascal Bodmer18,25

1 Limnology/Department of Ecology and Genetics, Uppsala University, Uppsala, Sweden
2 Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden
3 Institute of Aquatic Ecology, University of Girona (UDG), Girona, Spain
4 Department of Life and Environmental Sciences, Bournemouth University, BH12 5BB, UK
5 Department of Ecology and Environmental Sciences, Palacky University in Olomouc, Olomouc, Czech Republic
6 Resources and Ecosystems/Catalan Institute for Water Research (ICRA), Girona, Spain
7 Irstea, UR MALY, Centre de Lyon-Villeurbanne, Villeurbanne, France
8 Marine Institute, Furnace, Newport, Co Mayo, Ireland
9 Department of Ecology and Environmental Science, Umeå University, Umeå, Sweden
10 Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy
11 Centre for Freshwater and Environmental Studies, Dundalk Institute of Technology, Dundalk, Co Louth, Ireland
12 Department of Aquatic Ecosystems, Institute of Biodiversity and Ecosystem Research, Bulgarian Academy of Sciences, Sofia, Bulgaria
13 Department of Science, Innovation and Technology, University of Piemonte Orientale, Alessandria, Italy
14 Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Stechlin, Germany
15 Ecohydrology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Berlin, Germany
16 Environmental Research Institute, Thurso, Scotland, UK
17 Department of General and Applied Hydrobiology, Sofia University “St. Kliment Ohridski”, Sofia, Bulgaria
18 Institute for Environmental Sciences, University of Koblenz-Landau, Landau, Germany
19 Museu de História Natural e da Ciência da Universidade do Porto (MHNC-UP), Porto, Portugal
20 Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, University of Barcelona (UB), Barcelona, Spain
21 Microbial Resource Management, Institute of Microbiology, University of Innsbruck, Innsbruck, Austria
22 River Ecology and Conservation Research, Institute of Ecology, University of Innsbruck, Innsbruck, Austria
23 Sparsholt College, Winchester, SO21 2NF, UK
24 National Museum of Natural History, Sofia, Bulgaria
25 Chemical Analytics and Biogeochemistry, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
Running waters are major CO2 emitters, accounting globally for approximately 70% of the total flux from inland waters. Nonetheless, the magnitude and mechanisms of these fluxes are still not adequately quantified or understood, contributing to a high uncertainty in small- to large-scale carbon budgets. In the EuroRun project (“Assessing CO2 fluxes from European running waters”), representing the 1st Collaborative European Freshwater Science Project for Young Researchers initiated by the European Federation of Freshwater Sciences board, the European Fresh and Young Researchers, and representatives of the Fresh Blood for Fresh Water meetings, we aimed to assess spatial and temporal variability of CO2 fluxes from European running waters. A team of early career scientists from all over Europe measured CO2 fluxes with drifting flux chambers equipped with CO2 mini-loggers. We performed the measurements in 11 countries in 34 streams at day and night within coordinated periods covering several seasons. Altogether, the investigated European streams showed both CO2 uptake and emissions with a higher frequency of emissions. Furthermore, for the majority of the studied streams we recorded higher CO2 fluxes at night, while some streams even turned from a sink of CO2 during the day into a source of CO2 during the night. Our results highlight that the time of measurement is important to accurately determine CO2 fluxes from streams and future efforts to upscale those fluxes should include day and night-time measurements from running waters.
RS09 – Presentation

A new paradigm for biomonitoring: An example building on the Danish Stream Plant Index

Annette Baattrup-Pedersen (abp@bios.au.dk), Aarhus University, Dept. of Bioscience
Emma Göthe, Tenna Riis, Dagmar K. Andersen and Søren E. Larsen
Despite intensive efforts for more than a decade to develop Water Framework-compliant assessment systems, shortcomings continue to appear. In particular, the lack of reference conditions has hindered the development of assessment systems capturing the heart of the WFD – that ecological status should be set as the deviation from the natural, undisturbed condition. Recently, the Danish Stream Plant Index (DSPI) was developed. This system contrasts existing systems in that it builds on an expert interpretation of the normative definitions of ecological status classes in the WFD without taking pressure-impact relationships into account. Here we present a paradigm for biomonitoring exemplified by DVPI that build on a framework consisting of three separate steps. First an ecological assessment should be conducted applying DVPI, then causes of failure to meet ecological goals should be explored by investigating trait composition of the aquatic plant community and finally mitigation measures should be selected that specifically target the identified causes of not meeting the ecological goals. Applying this framework enables managers to target the overlying stressor first. In Danish streams eutrophication and modifications of the stream planform together with frequent management in terms of weed cutting constitute major stressors. Targeted mitigation actions in Danish streams are therefore to 1) stop or reduce weed cutting, 2) restore in-stream or border habitats and 3) reduce nutrient emissions. These mitigation actions can be applied alone or in different combinations depending on the overlying stressor identified from plant trait composition.
RS10 – Presentation

eDNA describes long-term community change under human pressure

Miki Bálint (mbalint@senckenberg.de), Senckenberg Biodiversity and Climate Research Centre
Orsolya Márton, Marlene Schatz, Rolf-Alexander Düring, Hans-Peter Grossart
Long community time series are exceedingly rare, but they are necessary to evaluate the results of natural experiments on ecosystems. These experiments were frequent during the last century as humans modified the composition and functioning of most communities on Earth. We used sediment-preserved DNA to evaluate how lake eukaryotes react to decade-long chemical and thermal pollution, and whether their communities recover when impacts cease. Communities clearly followed changes in stressors. Decrease in chemical pollution is accompanied with successional patterns, while periods of thermal stress cause abrupt shifts in community composition. The results emphasize the potentials of eDNA to link community ecology and paleoecology through taxonomically comprehensive time series of community composition.