Using optics to investigate global marine phytoplankton composition

Alison Chase, University of Maine, alisonpchase@gmail.com (Presenter)
Emmanuel Boss, University of Maine, emmanuel.boss@maine.edu

Marine phytoplankton are the base of the ocean food web and exist in a wide variety of types. Knowledge of where and when these different types dominate is important, given that higher trophic levels (e.g. zooplankton, larval fish) and ocean biogeochemistry (e.g. nutrient cycling) are influenced by phytoplankton. Using discrete water samples is impractical for regional or global scale understanding of phytoplankton type distributions. However, using optical measurements allows us to estimate the presence of different phytoplankton types by measuring the color of the water (i.e. the intensity of light at different wavelengths), which can change due to the presence of various photosynthetic pigments found in different phytoplankton. Our data include near-surface absorption and reflectance properties of the visible light spectrum that are measured from ships throughout the world’s oceans, and these measurements provide much greater spatial and temporal resolution compared to discrete water samples. Here we present a comparison of these optical measurements to phytoplankton pigments determined from water samples, as well as the abilities and limitations of using optical measurements to understand more about where and when different phytoplankton types are found in the ocean. This work has implications for the use of hyperspectral satellite data to discern phytoplankton composition from space. The high spectral-resolution radiometric measurements made in-water and used in our work are comparable to ocean color measurements made by future hyperspectral satellites, following removal of atmospheric effects. Improvement of our knowledge of phytoplankton composition at broad spatial and temporal scales will advance our understanding of current ocean ecosystems, and will improve inputs into biogeochemical ocean models that predict phytoplankton composition in future climate scenarios.

Presentation Type:  Poster

Session:  Theme 3: Future research direction and priorities: perspectives relevant to the next decadal survey   (Mon 4:30 PM)

Associated Project(s): 

• Related Activity: Related Activity or Previously Funded CC&E Activity not listed ...details

Poster Location ID: 195