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].