POSTER SESSION 1
15:30–17:30, Monday, September 14
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1198 | POSTER 181
COMPARISON OF HYPERSPECTRAL, CHEMOTAXONOMIC AND CYTOMETRIC METHODS TO CHARACTERIZE PHYTOPLANKTON COMMUNITY COMPOSITION IN DYNAMIC COASTAL WATERS
Phytoplankton community composition can vary over small spatial and temporal scales in coastal marine waters, exerting a significant influence on biogeochemical cycling. Characterizing such fine-scale taxonomic variability requires high-frequency data collection, which has been facilitated in recent years by automated measurement approaches, including hyperspectral optics and particle imaging instruments. These methods each target different signatures of phytoplankton taxonomic variability, with distinct strengths and limitations. Here, we present a direct comparison of these automated methods, alongside discrete pigment analysis and flow cytometry, applied to spring-time phytoplankton assemblages around Vancouver Island, BC, and a nutrient and light-controlled field incubation experiment. Ship-based hyperspectral absorption, PACE-derived remote sensing reflectance, and particle imaging all yielded consistent representations in phytoplankton community structure, at both broad spatial scales and across fine-scale oceanographic features. Compared with pigment-based and hyperspectral optical approaches, particle imaging provided greater taxonomic resolution and yielded genus-level phytoplankton size distributions. However, particle imaging could not resolve variability in the abundance of smaller, yet ecologically important, phytoplankton groups, such as Prasinophytes and Cyanobacteria. Phytoplankton size structure varied significantly across our sampling region, and the fraction of total biomass captured by imaging methods ranged from approximately 0% to 100%, as determined through combined flow cytometry and particle imaging analyses. Results from our incubation experiment show differing sensitivities of each method to phytoplankton photoacclimation, potentially driven by taxon-specific decoupling of Chla and carbon biomass. We discuss the implications of our results for characterizing phytoplankton community structure across a range of oceanic environments.
Sacchidanandan Pillai*, University of British Columbia, [email protected], https://orcid.org/0000-0003-4858-9435
Paul Covert, Fisheries and Oceans Canada (DFO), [email protected], https://orcid.org/0000-0002-7434-4995
Cameron Kraft, Fisheries and Oceans Canada (DFO), [email protected], https://orcid.org/0009-0009-6389-835X
Lori-Jon Waugh, University of British Columbia, [email protected], https://orcid.org/0000-0002-7829-0808
Jason Graff, Oregon State University, [email protected], https://orcid.org/0000-0003-0029-3299
Philippe Tortell, University of British Columbia, [email protected], https://orcid.org/0000-0003-0212-2151
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
