In 2021, a field campaign was conducted in Lake Saroma, Hokkaido, Japan. The leader of the campaign was Dr. Nomura at the Field Science Center for Northern Biosphere, Hokkaido University. During winter and early spring, Lake Saroma is covered with ice. Dr. Nosaka at the Department of Marine Biology and Sciences, School of Biological Sciences, Tokai University conducted zoo plankton observation. A special net was used to collect zooplankton in the seawater under the ice. Dr. Nosaka explained about the observation in the video. I, UMEZAWA Sachi, a first-year master's student at the Graduate School of Fisheries Sciences, Hokkaido University, filmed, edited, and produced the video. I also participated in the observation as a member of Dr. Nomura's team. Dr. Nosaka has been teaching me about phytoplankton cultivation for my research theme: biogeochemical cycle of the coastal ocean related to primary production.