NGA LTER 2023 1 of 2

The research focus of the NGA LTER site will be on mechanistic understanding of processes that underlie environmental variability, and the role of the latter in promoting high productivity and resilience. Building on prior knowledge, the investigators will test three hypotheses centered on ecosystem emergent properties: 1. Changes in the hydrologic cycle affect spring bloom production through changes in cloud cover, the stratification/mixing balance, macro- and micronutrient supplies, and transport pathways. 2. Hot-spots of high summer primary and secondary production result from interactions between the fresher Alaska Coastal Current and more saline offshore waters as promoted by shelf morphology and regional winds; hot spot timing and magnitude will be influenced by changes in the hydrologic cycle. 3. Nutritional and life history patterns of NGA consumers minimize trophic mismatch, buffering spatial and temporal variability in lower trophic level production and leading to resilience in the face of long-term climate change. The investigators will address these hypotheses with an integrated research program that includes: a) seasonal time series studies addressing short- and long-term environmental and ecosystem variability through a spring-to-fall field cruise- and mooring-based observational program, building upon and enhancing the Seward Line times series, and leveraging existing collaborations to obtain higher trophic level data; b) process studies that focus on hypothesized mechanisms leading to variability and enhancement of NGA production in time and space; c) modeling studies that incorporate physical and biogeochemical observations, provide a framework for testing hypotheses, and predict ecosystem responses to projected environmental changes; d) a data management component that provides a public platform for data visualization and synthesis by LTER colleagues, educators & students, and resource managers.