PHOTOCHEMICAL AND MICROBIAL PROCESSING OF DOM FROM PLANTS AND ESTUARINE WATERS IN PADILLA BAY IN THE PACIFIC NORTHWEST

Biogeochemical processing of DOM in productive ecosystems like salt marshes and estuaries at the land-ocean interface plays an important role in carbon cycling.  Padilla Bay is a dynamic estuary with large tidal variations and rich biodiversity, including one of the largest contiguous eelgrass meadows in North America. We are using optical techniques (absorbance, fluorescence, EEMs) and ancillary measurements (DOC, water quality parameters) to assess the sources and transformation processes of DOM in this ecosystem.  Our primary goal is identifying the characteristics of DOM from different sources, with a focus on eelgrass beds, salt grass (the dominant salt marsh plant), and slough inputs to mid-bay waters at high and low tides. Our secondary goal is to assess the lability of DOM from these different sources to biotic and abiotic processing. Results from time series of photochemical degradations and biological processing using samples inoculated with bay and slough water will be reported. This work enhances the understanding of biogeochemical processes at the land-ocean interface and may inform the development of sustainable strategies for salt marsh restoration in Padilla Bay.

Presentation Preference: Either

Primary Presenter: Lauren Karp, Western Washington University (karpl@wwu.edu)

Authors:

Lauren Karp, Western Washington University  (karpl@wwu.edu)

Catherine Clark, Western Washington University  (clarkc36@wwu.edu)

Warren de Bruyn, Chapman University  (debruyn@chapman.edu)