Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - MANTEL (Management of Climatic Extreme Events in Lakes Reservoirs for the Protection of Ecosystem Services)

Teaser

Environmental perturbations to freshwater bodies occur largely in the form of episodic climatic events. These range from relatively short mixing events to storms and heat waves. A common characteristic is that their effect is generally longer lasting than the duration of...

Summary

Environmental perturbations to freshwater bodies occur largely in the form of episodic climatic events. These range from relatively short mixing events to storms and heat waves. A common characteristic is that their effect is generally longer lasting than the duration of the event itself. Understanding the impact of these events in lakes and reservoirs requires monitoring that captures the event (hours–days) as well as the ensuing impact that can last for months or even years. Only recently have such automated high frequency monitoring systems been widely adopted on lakes and reservoirs throughout Europe. Extreme weather events are also becoming more frequent, a trend that has been linked to directional climate change and is projected to continue in the coming decades. As near real time monitoring of the freshwater environment has become more common, the true importance of such episodic events is becoming clear. New insights require new theoretical frameworks and approaches to managing lakes and reservoirs. MANTEL (Management of Climatic Extreme Events in Lakes & Reservoirs for the Protection of Ecosystem Services) EJD ITN brings together eight Beneficiaries, ten Partner Organisations and five awarding universities to train a cohort of Early Stage Researchers to investigate the effects on water quality of the climatic extreme events, while at the same time giving training in state-of-the art technology, data analysis and modelling, and linking to the water management sector. The aim of MANTEL is to ensure that future scientists gain expertise in the effects of episodic and extreme events in lakes and reservoirs, so that future management strategies in Europe can explicitly account for their occurrence.

The objectives are:
1. To interrogate high frequency monitoring data archives from lakes and reservoirs for the occurrence and intensity of climate-driven episodic events and to understand which conditions produce physical, chemical and biological responses in lakes.
2. To inform adaptation to climate change by simulating the effects of episodic events in lakes, either using models or using an experimental approach.
3. To assess to what extent climate-driven events affect the biological functioning of lake ecosystems, and to quantify if ecosystems approach critical transitions (tipping points).
4. To quantify the management implications of episodic events for two key challenges for the water sector: increases in dissolved organic matter loading, and toxic algal blooms.

Work performed

The objectives are being investigated in four science Work Packages (WPs).

WP 2: Work undertaken to define episodic events has included a comprehensive literature review and method assessment to provide a new and robust metric for defining mixing events in lakes. This will now be applied across multiple sites to assess the effect of location and lake morphology on mixing events. Phytoplankton biomass and community structure are very sensitive to changes in local weather. A comprehensive assessment of the drivers of long-term trends in phytoplankton biomass and community structure using a unique >50 year dataset from Estonian lakes has been undertaken and submitted to an academic journal. Work has also included an analysis of carbon cycling in eight Estonian lakes and assessing the impacts of storms on the bacterioplankton population in a humic lake in Ireland. An assessment of the drivers of change in mixotrophic plankton has been published.

WP 3: An assessment of the impacts of different levels of global warming on the thermal structure of Lake Erken (Sweden) includes a contribution to the Inter-Sectorial Impact Model Intercomparison (ISIMIP) Project. In addition, work is on-going on comparing three 1D hydrodynamic models of lake physical structure. Work using LakeLab mesocosms has contributed to assessing future changes in phytoplankton and microbial dynamics to assess effects of storm-induced ‘browning events’ (sudden influx of coloured dissolved organic matter) on lake biota. Work on developing universal metrics to quantify critical thresholds for the effect of episodic events on lake ecosystem functioning has included a review of internal feedbacks that are coupled to mixing regime shifts in deep lakes. Field investigations into the effects of storms on the formation of disinfection by-products are also being conducted to better supply models with observations for calibration.

WP 4: Work undertaken on assessing episodic events in terms of ecosystem resilience has included an assessment of how lakes respond to extreme wind events in terms of ecological stability using data from Müggelsee (DE). The working hypothesis is that there will be varying degrees of resistance and resilience patterns in response variables depending on the nature and timing of a storm. Detecting effects of episodic events on resilience includes research on resilience and ecosystem stability using a wide range of stressors and response variables across several MANTEL sites using data provided by the consortium. A draft review paper focusing on observation of early warning signals of regime shift in experimental data has also been completed.

WP 5: An assessment of the link between extreme events and inputs of organic matter from the watershed is using archived data to test the hypothesis that improvement of wastewater treatment plants upstream of a drinking water reservoir improves the resilience of the reservoir to extreme events. Laboratory experiments to understand the spatial variation in precursor compounds and disinfection by-product potential are also being conducted. A collaborative microcosm experiment on the effect of extreme precipitation events on the competition of different phytoplankton groups; and the assessment of disinfection by-product formation, has also been undertaken. Identifying measures for a benefit-oriented rehabilitation plan to increase resilience of degraded lakes has included an assessment of how water authorities are developing Programme of Measures for their river basin district under the Water Framework Directive. Work on increasing awareness on how benefits of lake rehabilitation using the Benefit Game, a tailor-made board game, has commenced and will continue of the next two years.

Final results

MANTEL is training a cohort of highly qualified, motivated professionals with a unique expertise in cutting edge science and technology that is essential if we are to understand and manage lakes under changing climatic conditions. Involvement in the MANTEL ITN will ensure the cohort will have strong specialist research competencies: they will also have multi-sectoral insight, an interdisciplinary perspective on water science and resource management, and an entrepreneurial attitude that draws on a range of transferable skills. MANTEL will provide innovative training to generate professionals who have an understanding of and international training in the interdisciplinary science, technological solutions and social science aspects associated with impacts of extreme climatic events on lake ecosystem function and services at an global scale, have inter-sectoral experience of working on and delivering a research project that includes meeting the real needs of the non-academic sector and have formal training in business skills (including project management and teamwork), delivered by practitioners who are working in the industry and the policy sector.

Website & more info

More info: http://www.mantel-itn.org.