Influence of environmental drivers on satellite-derived chlorophyll a in the Strait of Georgia from 2003-2016
Presentation Abstract
The Salish Sea is a dynamic region with substantial temporal and spatial variability at lower trophic levels. This variability, in turn, may directly impact resident and migratory fish populations that are of major economic importance. Here, we examine the relationships between environmental drivers (e.g. SST, wind, river input) and patterns of satellite-derived chlorophyll a (chl a) from 2003-2016 in the Northern and Central Strait of Georgia. Average spring bloom start date in the Salish Sea occured in late March. Strong positive chl a anomalies in spring 2005 and 2015 resulted in the early spring blooms (mid-February). Anomalously high chl a concentrations ([greater than] 20 mg m-3) were also observed in autumn 2008 in the Central region, which was twice as high as the maximum values typically observed in autumn throughout our time series. In contrast, later than average (late April) spring blooms occurred in 2007 and 2008. Results from analysis of the environmental drivers showed positive SST anomalies predominated between 2003-2006 and 2013-2016, with the highest anomalies occurring in spring 2015. Strong positive anomalies in Fraser River discharge, coupled with strong negative wind anomalies, occurred in both spring 2005 and 2015. Chl a in the Northern region was most highly correlated with SST and PAR (r = 0.328, p<0.0001 and r = 0.347, p<0.0001, respectively), whereas chlorophyll a in the Central region was most highly correlated with Fraser River discharge (r = 0.264, p[greater than]0.0001). Similar analyses on anomaly data revealed that chl a anomalies in both the Northern and Central regions were highly correlated with SST and PAR anomalies. Ultimately, results from this study will be paired with zooplankton data to provide insight into how changes in the seasonal patterns of lower trophic levels may influence the growth, survival, and overall return strength of salmon populations in the region.
Session Title
The Salish Sea Marine Survival Project: Phytoplankton and Zooplankton
Conference Track
SSE11: Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE11-238
Start Date
5-4-2018 4:00 PM
End Date
5-4-2018 4:15 PM
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)
Fish populations--Monitoring--Georgia, Strait of (B.C. and Wash.); Chlorophyll--Georgia, Strait of (B.C. and Wash.); Ecological disturbances--Georgia, Strait of (B.C. and Wash.)
Geographic Coverage
Georgia, Strait of (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
Influence of environmental drivers on satellite-derived chlorophyll a in the Strait of Georgia from 2003-2016
The Salish Sea is a dynamic region with substantial temporal and spatial variability at lower trophic levels. This variability, in turn, may directly impact resident and migratory fish populations that are of major economic importance. Here, we examine the relationships between environmental drivers (e.g. SST, wind, river input) and patterns of satellite-derived chlorophyll a (chl a) from 2003-2016 in the Northern and Central Strait of Georgia. Average spring bloom start date in the Salish Sea occured in late March. Strong positive chl a anomalies in spring 2005 and 2015 resulted in the early spring blooms (mid-February). Anomalously high chl a concentrations ([greater than] 20 mg m-3) were also observed in autumn 2008 in the Central region, which was twice as high as the maximum values typically observed in autumn throughout our time series. In contrast, later than average (late April) spring blooms occurred in 2007 and 2008. Results from analysis of the environmental drivers showed positive SST anomalies predominated between 2003-2006 and 2013-2016, with the highest anomalies occurring in spring 2015. Strong positive anomalies in Fraser River discharge, coupled with strong negative wind anomalies, occurred in both spring 2005 and 2015. Chl a in the Northern region was most highly correlated with SST and PAR (r = 0.328, p<0.0001 and r = 0.347, p<0.0001, respectively), whereas chlorophyll a in the Central region was most highly correlated with Fraser River discharge (r = 0.264, p[greater than]0.0001). Similar analyses on anomaly data revealed that chl a anomalies in both the Northern and Central regions were highly correlated with SST and PAR anomalies. Ultimately, results from this study will be paired with zooplankton data to provide insight into how changes in the seasonal patterns of lower trophic levels may influence the growth, survival, and overall return strength of salmon populations in the region.
