Initial characterization and comparison of beach sediment throughout Puget Sound
Presentation Abstract
An understanding of the sediment grain size distribution of a beach provides important information about its physical properties and ecological functions. Forage fish are a diverse assemblage of species that serve as an essential component to the marine food web. The ability of forage fish to produce viable spawn is dependent on the grain size present. Surf smelt Hypomesus pretiosus and Pacific sand lance Ammodytes hexapterus utilize sediment within a unique grain size range as a spawning substrate. Pacific herring Clupea pallasii are known to utilize native eelgrass Zostera marina as a spawning substrate, which grows in fine sediment-supported nearshore environments. Sediment grain size data can also provide information related to shoreline armoring impacts, feeder bluff activity, and the sediment budget of a littoral drift cell, which can help to inform land-use and resource management decisions. The Washington Department of Ecology Coastal Monitoring & Analysis Program employed a photogrammetric method to characterize sediment grain size along 10 drift cells throughout Puget Sound that have active feeder bluffs and are rich in high-value natural resources. Previously, grain size distributions were obtained using a laborious and time consuming sieve analysis technique, which requires the collection of sediment samples for lab analysis. The sieve technique cannot incorporate coarse gravel and cobbles, which are a significant constituent of Puget Sound beaches. By employing Daniel Buscombe’s digital grain-size analysis algorithm on photos taken using a “Cobble Cam” technique, we were able to perform in-situ grain size characterization of sediments. Photos of sediment were taken along cross-shore beach profiles to enable both cross-shore and longshore comparisons of grain size distributions. At each profile, sediment grain size was obtained at increments of 0.5m elevation, extending from the backshore to the shoreline, with the locations of samples recorded using real-time kinematic GPS equipment.
Session Title
General Habitat Topics
Conference Track
Habitat
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Location
2016SSEC
Type of Presentation
Poster
Genre/Form
presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Grain--Microbiology--Washington (State)--Puget Sound; Marine sediments--Washington (State)--Puget Sound--Analysis
Geographic Coverage
Puget Sound (Wash.); 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
Initial characterization and comparison of beach sediment throughout Puget Sound
2016SSEC
An understanding of the sediment grain size distribution of a beach provides important information about its physical properties and ecological functions. Forage fish are a diverse assemblage of species that serve as an essential component to the marine food web. The ability of forage fish to produce viable spawn is dependent on the grain size present. Surf smelt Hypomesus pretiosus and Pacific sand lance Ammodytes hexapterus utilize sediment within a unique grain size range as a spawning substrate. Pacific herring Clupea pallasii are known to utilize native eelgrass Zostera marina as a spawning substrate, which grows in fine sediment-supported nearshore environments. Sediment grain size data can also provide information related to shoreline armoring impacts, feeder bluff activity, and the sediment budget of a littoral drift cell, which can help to inform land-use and resource management decisions. The Washington Department of Ecology Coastal Monitoring & Analysis Program employed a photogrammetric method to characterize sediment grain size along 10 drift cells throughout Puget Sound that have active feeder bluffs and are rich in high-value natural resources. Previously, grain size distributions were obtained using a laborious and time consuming sieve analysis technique, which requires the collection of sediment samples for lab analysis. The sieve technique cannot incorporate coarse gravel and cobbles, which are a significant constituent of Puget Sound beaches. By employing Daniel Buscombe’s digital grain-size analysis algorithm on photos taken using a “Cobble Cam” technique, we were able to perform in-situ grain size characterization of sediments. Photos of sediment were taken along cross-shore beach profiles to enable both cross-shore and longshore comparisons of grain size distributions. At each profile, sediment grain size was obtained at increments of 0.5m elevation, extending from the backshore to the shoreline, with the locations of samples recorded using real-time kinematic GPS equipment.
