@article{RusakTanentzapKlugetal.2018, author = {Rusak, James A. and Tanentzap, Andrew J. and Klug, Jennifer L. and Rose, Kevin C. and Hendricks, Susan P. and Jennings, Eleanor and Laas, Alo and Pierson, Donald C. and Ryder, Elizabeth and Smyth, Robyn L. and White, D. S. and Winslow, Luke A. and Adrian, Rita and Arvola, Lauri and de Eyto, Elvira and Feuchtmayr, Heidrun and Honti, Mark and Istvanovics, Vera and Jones, Ian D. and McBride, Chris G. and Schmidt, Silke Regina and Seekell, David and Staehr, Peter A. and Guangwei, Zhu}, title = {Wind and trophic status explain within and among-lake variability of algal biomass}, series = {Limnology and oceanography letters / ASLO, Association for the Sciences of Limnology and Oceanography}, volume = {3}, journal = {Limnology and oceanography letters / ASLO, Association for the Sciences of Limnology and Oceanography}, number = {6}, publisher = {Wiley}, address = {Hoboken}, issn = {2378-2242}, doi = {10.1002/lol2.10093}, pages = {409 -- 418}, year = {2018}, abstract = {Phytoplankton biomass and production regulates key aspects of freshwater ecosystems yet its variability and subsequent predictability is poorly understood. We estimated within-lake variation in biomass using high-frequency chlorophyll fluorescence data from 18 globally distributed lakes. We tested how variation in fluorescence at monthly, daily, and hourly scales was related to high-frequency variability of wind, water temperature, and radiation within lakes as well as productivity and physical attributes among lakes. Within lakes, monthly variation dominated, but combined daily and hourly variation were equivalent to that expressed monthly. Among lakes, biomass variability increased with trophic status while, within-lake biomass variation increased with increasing variability in wind speed. Our results highlight the benefits of high-frequency chlorophyll monitoring and suggest that predicted changes associated with climate, as well as ongoing cultural eutrophication, are likely to substantially increase the temporal variability of algal biomass and thus the predictability of the services it provides.}, language = {en} } @article{GilingStaehrGrossartetal.2017, author = {Giling, Darren P. and Staehr, Peter A. and Grossart, Hans-Peter and Andersen, Mikkel Rene and Boehrer, Bertram and Escot, Carmelo and Evrendilek, Fatih and Gomez-Gener, Lluis and Honti, Mark and Jones, Ian D. and Karakaya, Nusret and Laas, Alo and Moreno-Ostos, Enrique and Rinke, Karsten and Scharfenberger, Ulrike and Schmidt, Silke R. and Weber, Michael and Woolway, R. Iestyn and Zwart, Jacob A. and Obrador, Biel}, title = {Delving deeper: Metabolic processes in the metalimnion of stratified lakes}, series = {Limnology and oceanography}, volume = {62}, journal = {Limnology and oceanography}, publisher = {Wiley}, address = {Hoboken}, issn = {0024-3590}, doi = {10.1002/lno.10504}, pages = {1288 -- 1306}, year = {2017}, abstract = {Many lakes exhibit seasonal stratification, during which they develop strong thermal and chemical gradients. An expansion of depth-integrated monitoring programs has provided insight into the importance of organic carbon processing that occurs below the upper mixed layer. However, the chemical and physical drivers of metabolism and metabolic coupling remain unresolved, especially in the metalimnion. In this depth zone, sharp gradients in key resources such as light and temperature co-occur with dynamic physical conditions that influence metabolic processes directly and simultaneously hamper the accurate tracing of biological activity. We evaluated the drivers of metalimnetic metabolism and its associated uncertainty across 10 stratified lakes in Europe and North America. We hypothesized that the metalimnion would contribute highly to whole-lake functioning in clear oligotrophic lakes, and that metabolic rates would be highly variable in unstable polymictic lakes. Depth-integrated rates of gross primary production (GPP) and ecosystem respiration (ER) were modelled from diel dissolved oxygen curves using a Bayesian approach. Metabolic estimates were more uncertain below the epilimnion, but uncertainty was not consistently related to lake morphology or mixing regime. Metalimnetic rates exhibited high day-to-day variability in all trophic states, with the metalimnetic contribution to daily whole-lake GPP and ER ranging from 0\% to 87\% and < 1\% to 92\%, respectively. Nonetheless, the metalimnion of low-nutrient lakes contributed strongly to whole-lake metabolism on average, driven by a collinear combination of highlight, low surface-water phosphorous concentration and high metalimnetic volume. Consequently, a single-sensor approach does not necessarily reflect whole-ecosystem carbon dynamics in stratified lakes.}, language = {en} } @article{BrentrupWilliamsonColomMonteroetal.2016, author = {Brentrup, Jennifer A. and Williamson, Craig E. and Colom-Montero, William and Eckert, Werner and de Eyto, Elvira and Großart, Hans-Peter and Huot, Yannick and Isles, Peter D. F. and Knoll, Lesley B. and Leach, Taylor H. and McBride, Chris G. and Pierson, Don and Pomati, Francesco and Read, Jordan S. and Rose, Kevin C. and Samal, Nihar R. and Staehr, Peter A. and Winslow, Luke A.}, title = {The potential of high-frequency profiling to assess vertical and seasonal patterns of phytoplankton dynamics in lakes: an extension of the Plankton Ecology Group (PEG) model}, series = {Inland waters : journal of the International Society of Limnology}, volume = {6}, journal = {Inland waters : journal of the International Society of Limnology}, publisher = {Freshwater Biological Association}, address = {Ambleside}, issn = {2044-2041}, doi = {10.5268/IW-6.4.890}, pages = {565 -- 580}, year = {2016}, abstract = {The use of high-frequency sensors on profiling buoys to investigate physical, chemical, and biological processes in lakes is increasing rapidly. Profiling buoys with automated winches and sensors that collect high-frequency chlorophyll fluorescence (ChlF) profiles in 11 lakes in the Global Lake Ecological Observatory Network (GLEON) allowed the study of the vertical and temporal distribution of ChlF, including the formation of subsurface chlorophyll maxima (SSCM). The effectiveness of 3 methods for sampling phytoplankton distributions in lakes, including (1) manual profiles, (2) single-depth buoys, and (3) profiling buoys were assessed. High-frequency ChlF surface data and profiles were compared to predictions from the Plankton Ecology Group (PEG) model. The depth-integrated ChlF dynamics measured by the profiling buoy data revealed a greater complexity that neither conventional sampling nor the generalized PEG model captured. Conventional sampling techniques would have missed SSCM in 7 of 11 study lakes. Although surface-only ChlF data underestimated average water column ChlF, at times by nearly 2-fold in 4 of the lakes, overall there was a remarkable similarity between surface and mean water column data. Contrary to the PEG model's proposed negligible role for physical control of phytoplankton during the growing season, thermal structure and light availability were closely associated with ChlF seasonal depth distribution. Thus, an extension of the PEG model is proposed, with a new conceptual framework that explicitly includes physical metrics to better predict SSCM formation in lakes and highlight when profiling buoys are especially informative.}, language = {en} } @misc{MarceGeorgeBuscarinuetal.2016, author = {Marce, Rafael and George, Glen and Buscarinu, Paola and Deidda, Melania and Dunalska, Julita and de Eyto, Elvira and Flaim, Giovanna and Grossart, Hans-Peter and Istvanovics, Vera and Lenhardt, Mirjana and Moreno-Ostos, Enrique and Obrador, Biel and Ostrovsky, Ilia and Pierson, Donald C. and Potuzak, Jan and Poikane, Sandra and Rinke, Karsten and Rodriguez-Mozaz, Sara and Staehr, Peter A. and Sumberova, Katerina and Waajen, Guido and Weyhenmeyer, Gesa A. and Weathers, Kathleen C. and Zion, Mark and Ibelings, Bas W. and Jennings, Eleanor}, title = {Automatic High Frequency Monitoring for Improved Lake and Reservoir Management}, series = {Frontiers in plant science}, volume = {50}, journal = {Frontiers in plant science}, publisher = {American Chemical Society}, address = {Washington}, issn = {0013-936X}, doi = {10.1021/acs.est.6b01604}, pages = {10780 -- 10794}, year = {2016}, abstract = {Recent technological developments have increased the number of variables being monitored in lakes and reservoirs using automatic high frequency monitoring (AHFM). However, design of AHFM systems and posterior data handling and interpretation are currently being developed on a site-by-site and issue-by-issue basis with minimal standardization of protocols or knowledge sharing. As a result, many deployments become short-lived or underutilized, and many new scientific developments that are potentially useful for water management and environmental legislation remain underexplored. This Critical Review bridges scientific uses of AHFM with their applications by providing an overview of the current AHFM capabilities, together with examples of successful applications. We review the use of AHFM for maximizing the provision of ecosystem services supplied, by lakes and reservoirs (consumptive and non consumptive uses, food production, and recreation), and for reporting lake status in the EU Water Framework Directive. We also highlight critical issues to enhance the application of AHFM, and suggest the establishment of appropriate networks to facilitate knowledge sharing and technological transfer between potential users. Finally, we give advice on how modern sensor technology can successfully be applied on a larger scale to the management of lakes and reservoirs and maximize the ecosystem services they provide.}, language = {en} }