Comparison of bottom-up processes in Canadian subregions of the Salish Sea
Presentation Abstract
The Salish Sea is a complex coastal region wherein annual variations in prey availability for salmon have changed over time. Specific areas within this region have distinct physical oceanographic features and thus may play an important role in seasonal and interannual variability of lower trophic levels. As part of the Salish Sea Marine Survival Project we are investigating how bottom-up processes differ between regions within the Canadian areas of the Salish Sea, in part to determine if variations in prey availability in these subregions affect the health and/or foraging success of young herring and salmon. Environmental drivers (SST, PAR, wind), oceanographic conditions (from CTD data), in addition to phytoplankton and zooplankton community composition will be compared across the different subregions. Hotspot analyses on mean monthly phytoplankton and zooplankton biomass will provide information as to which areas are more productive. In addition, a simultaneous data-driven approach based on taxonomic composition will indicate how well our defined subregions represent natural spatial distributions of phytoplankton and zooplankton communities. Preliminary results of satellite-derived chlorophyll a from 2015 show that the Juan de Fuca and Tidal Mixed regions had consistently lower phytoplankton biomass throughout all seasons. Analysis of in situ phytoplankton samples revealed similar results with relatively low cell densities occurring in the Tidal Mixed region throughout the year. In contrast, the Central region had the highest phytoplankton biomass in the spring, whereas the highest biomass in the summer was observed in the Northern region. Variations were also observed in monthly anomalies of zooplankton biomass, with the highest positive anomalies occurring in Baynes Sound. Results from this work will ultimately be combined with juvenile salmon studies to address whether variations in prey availability within these different subregions affect the health and survival of juvenile salmon in the northern Salish Sea.
Session Title
The Salish Sea Marine Survival Project: Bottom-up and Top-down Processes
Conference Track
SSE11: Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE11-455
Start Date
6-4-2018 8:45 AM
End Date
6-4-2018 9:00 AM
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Salmon--Food--Salish Sea (B.C. and Wash.); Salmon--Effect of predation on--Salish Sea (B.C. and Wash.); Phytoplankton--Salish Sea (B.C. and Wash.)--Geographic distribution; Zooplankton--Salish Sea (B.C. and Wash.)--Geographic distribution
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Comparison of bottom-up processes in Canadian subregions of the Salish Sea
The Salish Sea is a complex coastal region wherein annual variations in prey availability for salmon have changed over time. Specific areas within this region have distinct physical oceanographic features and thus may play an important role in seasonal and interannual variability of lower trophic levels. As part of the Salish Sea Marine Survival Project we are investigating how bottom-up processes differ between regions within the Canadian areas of the Salish Sea, in part to determine if variations in prey availability in these subregions affect the health and/or foraging success of young herring and salmon. Environmental drivers (SST, PAR, wind), oceanographic conditions (from CTD data), in addition to phytoplankton and zooplankton community composition will be compared across the different subregions. Hotspot analyses on mean monthly phytoplankton and zooplankton biomass will provide information as to which areas are more productive. In addition, a simultaneous data-driven approach based on taxonomic composition will indicate how well our defined subregions represent natural spatial distributions of phytoplankton and zooplankton communities. Preliminary results of satellite-derived chlorophyll a from 2015 show that the Juan de Fuca and Tidal Mixed regions had consistently lower phytoplankton biomass throughout all seasons. Analysis of in situ phytoplankton samples revealed similar results with relatively low cell densities occurring in the Tidal Mixed region throughout the year. In contrast, the Central region had the highest phytoplankton biomass in the spring, whereas the highest biomass in the summer was observed in the Northern region. Variations were also observed in monthly anomalies of zooplankton biomass, with the highest positive anomalies occurring in Baynes Sound. Results from this work will ultimately be combined with juvenile salmon studies to address whether variations in prey availability within these different subregions affect the health and survival of juvenile salmon in the northern Salish Sea.
