Award: OCE-1655686

Intellectual Merit Broad continental shelves in temperate latitude regions are among the most productive marine ecosystems. One such ecosystem--the Northeast U.S. Shelf (NES)--supports valuable commercial fisheries and provides habitat for numerous threatened and protected species, all of which depend on complex and productive planktonic food webs. The ongoing NES Long-Term Ecological Research (NES-LTER) project focuses on understanding and predicting how the composition and structure of these planktonic food webs change through space and time in response to the physical environment and how those changes impact ecosystem productivity, particularly of higher trophic levels. In establishing a long-term study of shelf-wide pelagic dynamics on the NES, Phase I of the NES-LTER project has (1) characterized community structure and food web changes in the plankton, (2) identified mechanisms that underlie shifts in planktonic communities, and (3) contributed to understanding the transfer of energy from the bottom of the food web to higher trophic levels. Study approaches include field observations, process studies, and various population, biogeochemical, and ocean models. The Intellectual Merit of Phase I of the NES-LTER project is reflected in substantive new findings now reported in the scientific literature. Highlights include: (1) characterization of systematic seasonal differences in plankton community structure, and associated changes in productivity, grazing rates, food webs and trophic transfer pathways; (2) insights into the ways temperature, nutrients, and light availability interact to influence seasonality in phytoplankton across decadal and regional scales; (3) novel understanding of the processes influencing shelfbreak frontal dynamics, including exchanges between shelf and slope waters and impacts on plankton communities; (4) knowledge about the occurrence of unusual phytoplankton blooms and their impacts on productivity and grazing rates; (5) evidence that small eukaryotic phytoplankton appear to be eaten faster than other types and contribute more to the regions productivity than would be inferred from their abundance alone; (6) revealing links between zooplankton and forage fish populations, including observed and forecasted responses to climate variability; and (7) insights into the ways that population dynamics and ocean physical processes interact to control patterns of spatiotemporal synchrony in important phytoplankton and zooplankton taxa. Broader Impacts Broader Impacts during NES-LTER Phase I spanned public outreach and communication with stakeholders, engagement with K12 students and educators, and higher education and training in STEM. Public outreach activities focused on informal learning at museum events, community science events, "Ask-a-Scientist" style webinars, and through social media posts. NES scientists shared findings and responded to interests and needs of communities of users and managers of living marine resources in the study region. The NES-LTER Schoolyard program was launched to link concepts in marine ecosystem ecology to the core curricula in middle and high school classrooms. Hands-on research experiences were provided for teachers and annual Data Jam projects at the classroom, small-group, or individual-student level provided a structure to promote data literacy skills and creativity in presenting data about the ocean and climate. The NES-LTER leadership team actively engages in promoting an inclusive and welcoming environment for education and training of early career scientists. During the grant period, NES-LTER research activities and data sets enabled completion of 6 undergraduate honors theses, 1 Master of Science thesis, and 6 PhD theses. Over 56 undergraduates, 28 graduate students, and 14 postdoctoral researchers were involved in field work and other research activities during NES-LTER Phase I. Many of the early career participants involved in the research identify with underrepresented groups in marine science. Data generated by the NES-LTER project are openly accessible through the Environmental Data Initiative, Rolling-Deck-to-Repository, the National Center for Biotechnology Information, and other public repositories. Last Modified: 06/12/2024 Submitted by: HeidiMSosik