Distribution of epipelagic biomass in Puget Sound over the summer
Presentation Abstract
Fishes often utilize multiple habitats over the course of their estuarine residence. Puget Sound, WA, provides epipelagic habitat to a variety of species, including declining populations of (Pacific herring, Clupea pallasi) and Endangered Species Act-listed Pacific salmon (Oncorhynchus spp). Currently, little is known about epipelagic habitat use by the fish community in Puget Sound. We used surface townetting, midwater trawling, and hydroacoustic data to characterize epipelagic fish distribution from April through October, 2011 in four basins of Puget Sound. Seasonal and spatial variability was evident in epipelagic biomass (fish and jellyfish). Biomass generally increased progressively during the summer and shifted to deeper depths. Biomass was observed more often in the offshore zone than in shelf and transition zones. Net catches indicated that herring and juvenile salmon species dominated the epipelagic fish community and exhibited considerable spatial and temporal overlap with one another. Spatial and temporal patterns in fish biomass sampled by surface townets generally reflected the patterns measured below the surface by acoustics. In July and September, when midwater trawl data were also available, acoustics and midwater trawls produced closer relative estimates to one another than to the surface townets. The spatial-temporal overlap among species and increase in biomass over the summer period create increased potential for species interactions, especially in the offshore zone.
Session Title
Session S-01D: Pelagic Ecology in the Salish Sea I
Conference Track
Species and Food Webs
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
1-5-2014 5:00 PM
End Date
1-5-2014 6:30 PM
Location
Room 6C
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 salmon--Washington (State)--Puget Sound--Geographical distribution; Pacific herring--Washington (State)--Puget Sound--Geographical distribution; Fish communities--Washington (State)--Puget Sound--Geographical distribution; Pacific salmon--Seasonal distribution--Washington (State)--Puget Sound; Pacific herring--Seasonal distribution--Washington (State)--Puget Sound; Fish communities--Seasonal distribution--Washington (State)--Puget Sound
Geographic Coverage
Salish Sea (B.C. and Wash.); Puget Sound (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
Distribution of epipelagic biomass in Puget Sound over the summer
Room 6C
Fishes often utilize multiple habitats over the course of their estuarine residence. Puget Sound, WA, provides epipelagic habitat to a variety of species, including declining populations of (Pacific herring, Clupea pallasi) and Endangered Species Act-listed Pacific salmon (Oncorhynchus spp). Currently, little is known about epipelagic habitat use by the fish community in Puget Sound. We used surface townetting, midwater trawling, and hydroacoustic data to characterize epipelagic fish distribution from April through October, 2011 in four basins of Puget Sound. Seasonal and spatial variability was evident in epipelagic biomass (fish and jellyfish). Biomass generally increased progressively during the summer and shifted to deeper depths. Biomass was observed more often in the offshore zone than in shelf and transition zones. Net catches indicated that herring and juvenile salmon species dominated the epipelagic fish community and exhibited considerable spatial and temporal overlap with one another. Spatial and temporal patterns in fish biomass sampled by surface townets generally reflected the patterns measured below the surface by acoustics. In July and September, when midwater trawl data were also available, acoustics and midwater trawls produced closer relative estimates to one another than to the surface townets. The spatial-temporal overlap among species and increase in biomass over the summer period create increased potential for species interactions, especially in the offshore zone.
