MEPS 736:181-187 (2024)  -  DOI: https://doi.org/10.3354/meps14574

ABSTRACT: Spatiotemporal observations are data rich and offer insights into links between ecological patterns and underlying processes. We present fine-scale autonomous observations from repeated ferry transects in the Strait of Georgia (British Columbia, Canada) during the 2020 spring bloom period using a FerryBox system (temperature, salinity, chlorophyll a fluorescence) and a digital inline holographic microscope. Despite instrument cleaning interruptions related to COVID-19 restrictions, 3 periods from late winter (February) to springtime (March and April) contained 14 days of high-quality holograms (>70000) capturing >10500 identifiable micro- to mesoplankton using automatic object detection. The ferry set-up provided automatic data storage through Ocean Networks Canada, which also automatized data flagging and guaranteed remote access. The highest-quality holograms repeatedly covered the central and eastern Strait and showed aspects of bloom succession. Fast-growing diatoms (Skeletonema sp.) emerged first, followed by a diverse assemblage including Chaetoceros spp., Ditylum spp., and Eucampia spp., and by April, larger centric cells prevailed. The combined approach captured local suppression of chlorophyll a fluorescence and diatom concentrations in Fraser River plume waters during the freshet, suggesting fine-scale spatial patterns in seasonal planktonic community composition. This work is among the first of its kind to autonomously generate in situ imaging and physicochemical data with spatiotemporal resolution.

KEY WORDS: Automated ferry sampling · Holographic imaging · Plankton · FerryBox · Strait of Georgia · Salish Sea

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Cite this article as: MacNeil L, Costa M, LaRoche J (2024) Glimpsing the 2020 spring bloom in the Strait of Georgia (Canada) with autonomous ferry-based sensors. Mar Ecol Prog Ser 736:181-187. https://doi.org/10.3354/meps14574 Export citation Share:    Facebook - - linkedIn