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Percorrer por autor "Brucet, Sandra"

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  • Environmental Drivers of Nightversus Day Zooplankton Populationestimates In Lakes Around the World
    Publication . Goldfarb, Sadye K.; Doubek, Jonathan; Geraldes, Ana Maria; Armengol, Xavier; Avilés-Vargas, Lidia; Bartrons, Mireia; Bartrons, Mireia; Kankılıç, Gökben Başaran; Berger, Stella; Bess, Zach; Brentrup, Jannifer; Brucet, Sandra; Bruesewitz, Denise; Calderó-Pascual, Maria; Carey, Cayelan C.; Chandra, Sudeep; Chapina, Rosaura; Eyto, Elvira de; Erdoğan, Şeyda; Erina, Oxana; Figary, Stephanie; Gerrish, Gretchen; Glass, Lucas; Brett, Johnson; Kainz, Martin; Kalingali, Anthony; Khan, Samiullah; Kimirei, Ismael; Leoni, Barbara; Lepori, Fabio; McCarthy, Valerie; Nava, Veronica; Nejstgaard, Jens; Ogorelec, Ziga; O'Reilly, Catherine; Pate, William; Paterson, Michael; Pinheiro-Silva, Lorena; Qiu, Qianlinglin; Richardson, David; Rusak, James A.; Silver, Douglas; Straile, Dietmar; Suenaga, Erin; Tartarotti, Barbara; Tavşanoğlu, Ülkü Nihan; Tereshina, Maria; Umaña-Villalobos, Gerardo; Walles, Tim; Wander, Heather; Wurtsbaugh, Wayne; Xu, Yaoyang; Zhikharev, Vyacheslav; Stockwell, Jason
    Zooplankton play vital roles in aquatic food webs by grazingon phytoplankton, which affects water quality, andtransferring energy to higher trophic levels. In freshwaterlakes, zooplankton commonly exhibit diel vertical andhorizontal migration. During the day, zooplankton descendto deeper waters, or seek refuge in littoral areas or thesediment-water interface, to avoid visual predators, andthen migrate to open water at night to feed. Consequently,zooplankton may exhibit higher density and biomass atnight versus the day, and estimates and perceptions ofzooplankton dynamics can change with the time of daysampling occurs. To better understand these dielzooplankton differences and their environmental drivers, weconducted a standardized global campaign to samplecrustacean zooplankton in the full water column at day andnight in the pelagic zone of 40 lakes. The lakes spanned agradient in trophic state, size, and other variables such asdissolved oxygen (DO). Mesotrophic and eutrophic lakesexhibited greater zooplankton biomass at night versus daywhile oligotrophic lakes did not. Crustacean zooplanktonhad higher biomass at night versus day in lakes at lowerelevation, with higher chlorophyll a concentration, and lowerhypolimnetic DO levels. Lake area and depth were notrelated to diel zooplankton density or biomass. We provideone of the first global, standardized studies onenvironmental drivers of day versus night zooplanktonpopulation estimates. This study has importantramifications for our understanding of zooplankton ecologyand for sampling regimens.
    2024Documento de conferência Acesso aberto Ver mais
  • The effects of hypoxia on zooplankton population estimates and migration in lakes
    Publication . Goldfarb, Sadye K.; Doubek, Jonathan; Geraldes, Ana Maria; Bartrons, Mireia; Berger, Stella; Brentrup, Jannifer; Brucet, Sandra; Burnet, Sarah; Caputo Galarce, Luciano; Carey, Cayelan C.; Christoffersen, Kirsten Seestern; Eyto, Elvira de; Dur, Gaël; Erdoğan, Şeyda; Erina, Oxana; Grossart, Hans-Peter; Kainz, Martin; Kankılıç, Gökben Başaran; Khan, Sami; Leoni, Barbara; Lepori, Fabio; McCarthy, Valerie; Nava, Veronica; Nejstgaard, Jens; Obertegger, Ulrike; Ogorelec, Ziga; Ozen, Arda; Pascual, Maria; Paterson, Michael; Patelli, Martina; Qiu, Qianlinglin; Richardson, David; Sepulveda-Jauregui, Armando; Silva, Lorena; Straile, Dietmar; Tartarotti, Barbara; Tavşanoğlu, Ülkü Nihan; Tereshina, Maria; Umaña-Villalobos, Gerardo; Walles, Tim; Wander, Heather; Wurtsbaugh, Wayne; Stockwell, Jason
    Many zooplankton species typically exhibit diel vertical migration (DVM), where zooplankton migrate from the hypolimnion to the epilimnion of lakes at night. Zooplankton exhibit this behavior to avoid visual predators and UV radiation by remaining in the bottom waters during the day and ascending to the surface waters to feed on phytoplankton at night. However, hypoxic conditions in the hypolimnion of lakes mayinterfere with DVM and force zooplankton to increase diel horizontal migration (DHM) to find predation refuge in littoral zones. Climate change and eutrophication are expected to increase the prevalence and severity of hypoxic conditions worldwide and thereby possibly alter zooplankton migration patterns. We hypothesize that hypoxia will force zooplankton to shift their migration patterns from predominantly DVM to DHM to avoid oxygen-depleted bottom waters. To test our hypothesis, we are conducting a standardized global sampling program to test whether pelagic, full water column estimates of zooplankton are greater at night versus the day under hypolimnetic hypoxic versus oxic conditions. Participants are aiming to sample at least one lake with an oxic hypolimnion and one lake with a hypoxic hypolimnion during the thermally-stratified period at midday and midnight. With our global dataset (currently expecting about 60 lakes in 22 countries), our goal is to improve our understanding of how global change may alter zooplankton migration behavior and patterns in lakes.
    2019Póster em conferência Acesso aberto Ver mais