Presentation Abstract
Bottom-up hypotheses predict that changes in primary production affect marine survival of species like Pacific salmon. Long term records of primary production would provide important data to test these predictions. However, direct observations of primary production (in situ fluorometers, water chemistry, and satellite observations of color back-scatter) have relatively short time series (< 30 years). We investigated whether growth increments of geoduck clams (Panopea generosa) are correlated with primary production in different sub-basins of greater Puget Sound. Geoduck are long-lived (older specimens live >100 years), widely distributed throughout the Salish Sea, and deposit annual growth rings in their shells. Shell samples from aged geoducks were by the Washington Department of Fish and Wildlife in four sub-basins within greater Puget Sound (Strait of Jan de Fuca, Southern Strait of Georgia, South Puget Sound, and Central Basin). Geoduck shells from Saratoga passage were provided by the Tulalip Tribe. Using growth indices, the known correlation of growth indices with sea surface temperature and other long-term measurements, and existing basin-level records of temperature and primary production, we modeled historical patterns of primary production in different regions of greater Puget Sound. Analyses show that the relationship between geoduck growth, temperature, and primary production varies between sub-basins, and stable isotope analysis suggests that geoducks may be more than just primary consumers. These issues make reconstruction of a historical record of primary production from growth increments challenging. Nevertheless, analyses suggest that residual growth (after accounting for temperature variation) can explain variation in annual marine survival of local coho and chinook salmon stocks. This indicates the method has promise for retrospective hypothesis testing.
Session Title
The Salish Sea Marine Survival Project: Bottom-up and Top-down Processes
Keywords
Geoduck, Growth increments, Primary production, Chlorophyll, Marine survival, Salmon, Salish Sea
Conference Track
SSE11: Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE11-442
Start Date
6-4-2018 8:30 AM
End Date
6-4-2018 8:45 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)
Pacific geoduck--Mortality--Salish Sea (B.C. and Wash.); Pacific geoduck--Salish Sea (B.C. and Wash.)--Growth ; Primary productivity (Biology)--Salish Sea (B.C. and Wash.)
Subjects – Names (LCNAF)
Washington (State). Department of Fish and Wildlife; Tulalip Tribes of Washington
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
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Reconstructing historical patterns of primary production in Puget Sound using growth increment data from shells of long-lived geoducks (Panopea generosa)
Bottom-up hypotheses predict that changes in primary production affect marine survival of species like Pacific salmon. Long term records of primary production would provide important data to test these predictions. However, direct observations of primary production (in situ fluorometers, water chemistry, and satellite observations of color back-scatter) have relatively short time series (< 30 years). We investigated whether growth increments of geoduck clams (Panopea generosa) are correlated with primary production in different sub-basins of greater Puget Sound. Geoduck are long-lived (older specimens live >100 years), widely distributed throughout the Salish Sea, and deposit annual growth rings in their shells. Shell samples from aged geoducks were by the Washington Department of Fish and Wildlife in four sub-basins within greater Puget Sound (Strait of Jan de Fuca, Southern Strait of Georgia, South Puget Sound, and Central Basin). Geoduck shells from Saratoga passage were provided by the Tulalip Tribe. Using growth indices, the known correlation of growth indices with sea surface temperature and other long-term measurements, and existing basin-level records of temperature and primary production, we modeled historical patterns of primary production in different regions of greater Puget Sound. Analyses show that the relationship between geoduck growth, temperature, and primary production varies between sub-basins, and stable isotope analysis suggests that geoducks may be more than just primary consumers. These issues make reconstruction of a historical record of primary production from growth increments challenging. Nevertheless, analyses suggest that residual growth (after accounting for temperature variation) can explain variation in annual marine survival of local coho and chinook salmon stocks. This indicates the method has promise for retrospective hypothesis testing.
