Assessing the effects of seawall armoring on fish in Elliott Bay, Washington
Presentation Abstract
Seawall armoring is ubiquitous along developed shorelines worldwide, but its effects on fish and crabs are poorly understood. In related studies, we compared habitat use between three nearshore sites that were modified by seawalls and three unarmored reference beaches with minimal anthropogenic structure in Elliott Bay, Washington. Snorkel surveys at the surface and scuba surveys at the bottom of the water column suggested that seawall armoring affects the species assemblage structures of fish and crabs in intertidal and shallow subtidal areas. Flatfish in particular were negatively impacted by seawall presence and occurred in lower densities at seawall sites than reference beaches. Additionally, all observations of larval fish and black rockfish Sebastes melanops occurred at the reference beach Olympic Sculpture Park. Diet sampling from juvenile Pacific salmon Oncorhynchus spp. captured at these sites suggested that seawall armoring also influences diet composition, especially by reducing benthic and epibenthic prey consumption. These results suggest that seawall armoring can influence the use of nearshore habitats by fish in Puget Sound.
Session Title
Session S-06H: Puget Sound Shorelines and the Impacts of Armoring: State of the Science 2014
Conference Track
Shorelines
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
1-5-2014 1:30 PM
End Date
1-5-2014 3:00 PM
Location
Room 607
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)
Shore protection--Environmental aspects--Washington (State)--Elliott Bay; Fishes--Effect of habitat modification on--Washington (State)--Elliott Bay; Benthic animals--Effect of habitat modification on--Washington (State)--Elliott Bay
Geographic Coverage
Salish Sea (B.C. and Wash.); Elliott Bay (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
Assessing the effects of seawall armoring on fish in Elliott Bay, Washington
Room 607
Seawall armoring is ubiquitous along developed shorelines worldwide, but its effects on fish and crabs are poorly understood. In related studies, we compared habitat use between three nearshore sites that were modified by seawalls and three unarmored reference beaches with minimal anthropogenic structure in Elliott Bay, Washington. Snorkel surveys at the surface and scuba surveys at the bottom of the water column suggested that seawall armoring affects the species assemblage structures of fish and crabs in intertidal and shallow subtidal areas. Flatfish in particular were negatively impacted by seawall presence and occurred in lower densities at seawall sites than reference beaches. Additionally, all observations of larval fish and black rockfish Sebastes melanops occurred at the reference beach Olympic Sculpture Park. Diet sampling from juvenile Pacific salmon Oncorhynchus spp. captured at these sites suggested that seawall armoring also influences diet composition, especially by reducing benthic and epibenthic prey consumption. These results suggest that seawall armoring can influence the use of nearshore habitats by fish in Puget Sound.
