SCOPE-ALOHA Project: Constraining the Metabolic State of the North Pacific
The rate of primary production (PP) in the ocean is a significant and highly variable component of the global carbon cycle, which also drives the biogeochemical cycling of major chemical elements such as nitrate, phosphate and silicate. The magnitude of this rate sets the carrying capacity of the ocean, the upper boundary of export production and drives air-sea carbon dioxide exchange. Yet, despite its importance in the Earth’s carbon cycle, the rate of PP in the ocean is not particularly well constrained, specifically not at high-resolution temporal or spatial scales. This is an issue that must be addressed by the oceanographic community, as accurate and unbiased estimations of primary and community production are essential to understanding the ecological consequences of climate change on the base of the oceanic food chain.
SCOPE is poised to address this challenge in creative and collaborative ways in the world’s largest contiguous ecosystem, the North Pacific Subtropical Gyre. Through collaboration with other SCOPE investigators, we will generate high-resolution Lagrangian and Eulerian measurements of the metabolic state of the surface ocean using bio-optical and radiotracer approaches, conduct a thorough and necessary cross-validation of existing methods for estimation of ocean productivity, and connect diel changes in carbon and oxygen to changes in elemental stoichiometry, community structure and particle size. In combination with laboratory studies of model organisms, this project will help to quantify biases between in vitro and in situ PP methods.
The White lab is working collaboratively with the SCOPE-Gradients team to explore linkages between plankton diversity, production and elemental cycling. We contribute a wide range of research skills including imaging- and optically-based assessments of the particle size distribution, machine learning based measurements of plankton diversity specific to these ecotones, measurements of the rate of primary production and nitrogen fixation, and novel high-resolution measurements of elemental stoichiometry in dissolved and particulate matter. Ultimately these coordinated research activities are aimed at testing model-based hypotheses regarding the underlying drivers of ecosystem structure and function across natural ecological gradients.
Angelicque White is Associate Professor in the Oceanography Department of the University of Hawaii at Manoa. She received her B.S. and M.S. from the University of Alabama in Huntsville and her Ph.D. from Oregon State University. White’s research employs various biochemical and optical approaches to characterize elemental stoichiometry and phytoplankton production in oligotrophic oceanic regimes. White was named an Alfred P. Sloan Fellow in 2012.