Detecting Climate Driven Changes in Chlorophyll-a Using High Frequency Monitoring: The Impact of the 2019 European Heatwave in Three Contrasting Aquatic Systems
Gary Free,
Mariano Bresciani,
Monica Pinardi,
Claudia Giardino,
Krista Alikas,
Kersti Kangro,
Eva-Ingrid Rõõm,
Diana Vaičiūtė,
Martynas Bučas,
Edvinas Tiškus,
Annelies Hommersom,
Marnix Laanen,
Steef Peters
Affiliations
Gary Free
Institute of Electromagnetic Sensing of the Environment, National Research Council of Italy (CNR-IREA), via Bassini 15, 20133 Milan, Italy
Mariano Bresciani
Institute of Electromagnetic Sensing of the Environment, National Research Council of Italy (CNR-IREA), via Bassini 15, 20133 Milan, Italy
Monica Pinardi
Institute of Electromagnetic Sensing of the Environment, National Research Council of Italy (CNR-IREA), via Bassini 15, 20133 Milan, Italy
Claudia Giardino
Institute of Electromagnetic Sensing of the Environment, National Research Council of Italy (CNR-IREA), via Bassini 15, 20133 Milan, Italy
Krista Alikas
Tartu Observatory, University of Tartu, Observatooriumi 1, Tõravere, 61602 Tartu, Estonia
Kersti Kangro
Tartu Observatory, University of Tartu, Observatooriumi 1, Tõravere, 61602 Tartu, Estonia
Eva-Ingrid Rõõm
Chair of Hydrobiology and Fishery, Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, Kreutzwaldi 5, 51006 Tartu, Estonia
Diana Vaičiūtė
Marine Research Institute, Klaipėda University, Universiteto Ave. 17, 92294 Klaipėda, Lithuania
Martynas Bučas
Marine Research Institute, Klaipėda University, Universiteto Ave. 17, 92294 Klaipėda, Lithuania
Edvinas Tiškus
Marine Research Institute, Klaipėda University, Universiteto Ave. 17, 92294 Klaipėda, Lithuania
Annelies Hommersom
Water Insight, Fahrenheitstraat 42, 6716 BR Ede, The Netherlands
Marnix Laanen
Water Insight, Fahrenheitstraat 42, 6716 BR Ede, The Netherlands
Steef Peters
Water Insight, Fahrenheitstraat 42, 6716 BR Ede, The Netherlands
The frequency of heatwave events in Europe is increasing as a result of climate change. This can have implications for the water quality and ecological functioning of aquatic systems. We deployed three spectroradiometer WISPstations at three sites in Europe (Italy, Estonia, and Lithuania/Russia) to measure chlorophyll-a at high frequency. A heatwave in July 2019 occurred with record daily maximum temperatures over 40 °C in parts of Europe. The effects of the resulting storm that ended the heatwave were more discernable than the heatwave itself. Following the storm, chlorophyll-a concentrations increased markedly in two of the lakes and remained high for the duration of the summer while at one site concentrations increased linearly. Heatwaves and subsequent storms appeared to play an important role in structuring the phenology of the primary producers, with wider implications for lake functioning. Chlorophyll-a peaked in early September, after which a wind event dissipated concentrations until calmer conditions returned. Synoptic coordinated high frequency monitoring needs to be advanced in Europe as part of water management policy and to improve knowledge on the implications of climate change. Lakes, as dynamic ecosystems with fast moving species-succession, provide a prism to observe the scale of future change.
