Periodic Reporting for period 2 - MANTEL (Management of Climatic Extreme Events in Lakes Reservoirs for the Protection of Ecosystem Services)
Periodo di rendicontazione: 2019-01-01 al 2021-06-30
Environmental perturbations to lakes and reservoirs occur largely in the form of climate-related episodic events. These range from relatively short mixing events to climate extremes such as storms and heat waves. A common characteristic is that the impacts are generally longer lasting than the duration of the event itself. Understanding these effects requires monitoring that captures the event itself (hours to days) as well as the ensuing impact, which can last for months or even years. Only recently have automated high frequency monitoring (HFM) systems, with suites of sensors that measure in hours and minutes, been widely adopted on lakes and reservoirs throughout Europe. Climate extremes in particular are now becoming more frequent, a trend that has been linked to global warming and is projected to continue in the coming decades. As near-real-time monitoring of lakes using HFM systems has become more common, the true importance of these events, and of even less extreme changes, is becoming clear. The new insights into lake ecosystem dynamics require new theoretical frameworks and approaches to increase our understanding of why some lakes appear to be more resilient in the face of such pressures, while others can be tipped into an alternative state from which they may not recover. MANTEL (Management of Climatic Extreme Events in Lakes & Reservoirs for the Protection of Ecosystem Services) European Joint Doctorate Innovative Training Network (ITN) investigated the effects of episodic climatic events on lake water quality, while at the same time providing training in state-of-the-art technology, data analysis and modelling, all with strong links to the management sector. The aim was to ensure that a new cohort of scientists gained expertise in the implications of episodic and extreme events for lakes and reservoirs, so that future management strategies in Europe could explicitly account for their effects.
The following objectives were investigated in four science Work Packages (WPs):
1. To interrogate HFM 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 [WP2].
2. To inform adaptation to climate change by simulating the effects of episodic events in lakes, either using models or using an experimental approach [WP3].
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) [WP4].
4. To quantify the management implications of episodic events for two key challenges for the water sector: increases in dissolved organic matter (DOM) loading, and toxic algal blooms [WP5].
The following objectives were investigated in four science Work Packages (WPs):
1. To interrogate HFM 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 [WP2].
2. To inform adaptation to climate change by simulating the effects of episodic events in lakes, either using models or using an experimental approach [WP3].
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) [WP4].
4. To quantify the management implications of episodic events for two key challenges for the water sector: increases in dissolved organic matter (DOM) loading, and toxic algal blooms [WP5].
The four MANTEL objectives were addressed in 12 projects, each carried out by an early stage researcher (ESR), supervised by two Beneficiaries and who was jointly registered in two awarding universities. The work in these ESR projects investigated the effects of episodic and extreme events on lakes at both shorter- and longer-term timescales using HFM data from stations on lakes across Europe, together with longer term data from historical archives, and new field based studies [WP2]. The HFM data also facilitated the calibration of dynamic models of lake processes which were then used to provide new projections of the impacts on extreme events on lake physics, chemistry and biology due to global warming [WP3]. Work in WP4 assessed the application of theory and methodology on ecosystem resilience and resistance to lake ecosystems and used both modelling and experimental work. In WP5, the focus was on real-world issues related to the management of water resources. Work investigated the interactions between management actions commonly used in aquatic systems and climate extremes. Understanding these complexities will allow managers to take more effective decisions while maintaining safe and sustainable water supplies for citizens. This WP also carried out new research which was then integrated into two new unique tools, as ‘serious games’, for communicating this complexity to water professional (Water Management Benefit Game) and other stakeholders (Flipping Lakes). Dedicated WPs for dissemination and outreach ensured that that not only did results reach a wide audience, but that the ESRs developed transferable communication skills that could be applied in a range of employment sectors. This included ESRs undertaking local outreach events and the production of a set of education videos on the effects of climate on lakes that were made by the ESRs during the initial COVID-19 pandemic restrictions in 2020.
MANTEL outputs have provided new insights into the effects of changes in weather and climate on lakes that contributes to scientific knowledge and ensures more sustainable water resources in the future. Prior to MANTEL, there was fragmentary and circumstantial evidence of the impacts of climate extremes on lake physics, chemistry and biology. Discussion in a climate change context were mostly restricted to scientific literature and absent from policy relevant documents. While there were abundant theoretical studies on tipping points in ecosystems generally, few applications focused on impacts of in lakes. In the water management sector, while there was a universal acceptance of the existence of problems related to climate extremes for reservoirs, there was inconclusive evidence on how climate change would interact with management and subsequent impacts on water quality. Work undertaken in MANTEL has resulted in a solid theoretical background on the impacts of extreme events on lake physics, chemistry, and biology across timescales (WT 2.1 WT 2.2) and the first generalisations of the impacts on phytoplankton and bacterial communities that can be used to anticipate how extreme events will affect water quality in climate change scenarios (WT 2.3 WT 2.4). MANTEL has also advanced the statistical approaches needed to identify critical transitions (WT 3.3) and early warning signals of change in lakes and developed and fine-tuned these for water quality variables (WT4.1 WT4.2). It has also provided a solid theoretical and empirical basis on the applicability of these concepts for the occurrence of phytoplankton blooms due to episodic and extreme events (WT 4.3 WT4.4) and for the definition of remediation and adaption measures (WT5.5). Research was also co-developed with the non-academic sector, links that enhance its applicability (WT 3.4) and public awareness (WT5.6). These outputs with the water sector will potentially reduce impacts of DOM on disinfection-by-products formation during water treatment, switching from end-of-pipe solutions to water source (lake) control (WT5.1 WT5.2). MANTEL has also resulted in a step forward in our understanding of toxic algal blooms and episodic events but acknowledging that uncertainties are still present when informing water management (WT4.5). Importantly, it has also shown clear interactions between climate extremes and impacts on the ecosystem services that are provided by lakes (WT5.4). In addition to communicating this work through academic dissemination, MANTEL has produced two new 'serious games' for communicating these complexities to water professionals and other stakeholders, and a set of policy briefs based on published papers.