Presentation Abstract

Most predatory fish, marine mammals, and birds that eat salmon rely primarily vision to feed. Natural processes and anthropogenic change affect visual conditions underwater which in turn profoundly affect the magnitude of predation risk on juvenile and adult salmon as well as forage fishes and other species in shoreline and pelagic environments. I will discuss the implications of how natural and anthropogenic changes in water transparency and artificial light pollution have significantly increased the predation threat environment for juvenile salmon in the Salish Sea and relate these to some of the major infrastructure projects in the Pacific Northwest. High levels of artificial light pollution are pervasive throughout Puget Sound and the southern portion of the Strait of Georgia. Over the past 30-40 years, increasing light pollution in Lake Washington, a useful surrogate for the greater Salish Sea, has expanded the peak twilight predation periods of juvenile salmon predators from just dusk and dawn to predation increasing throughout the night. Moreover, changing hydrology and water quality due to dams, climate, and land-water use have changed the magnitude, timing, and spatial patterns in water transparency from sediment plumes and plankton blooms. Collectively, these changes in underwater light penetration and transparency have fundamentally changed the predation environment with important implications for marine survival of salmon, functional sustainability of forage fish populations and the services they provide to the broader ecosystem.

Session Title

Big Objects Need Big Solutions: Addressing the Environmental Effects of Major Infrastructure Around the Salish Sea

Keywords

Visual predation, Artificial light at night

Conference Track

SSE1: Habitat Restoration and Protection

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE1-543

Start Date

6-4-2018 2:15 PM

End Date

6-4-2018 2:30 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

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

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Apr 6th, 2:15 PM Apr 6th, 2:30 PM

Effects of large infrastructure on the underwater visual environment and heightened predation on salmon in the Salish Sea

Most predatory fish, marine mammals, and birds that eat salmon rely primarily vision to feed. Natural processes and anthropogenic change affect visual conditions underwater which in turn profoundly affect the magnitude of predation risk on juvenile and adult salmon as well as forage fishes and other species in shoreline and pelagic environments. I will discuss the implications of how natural and anthropogenic changes in water transparency and artificial light pollution have significantly increased the predation threat environment for juvenile salmon in the Salish Sea and relate these to some of the major infrastructure projects in the Pacific Northwest. High levels of artificial light pollution are pervasive throughout Puget Sound and the southern portion of the Strait of Georgia. Over the past 30-40 years, increasing light pollution in Lake Washington, a useful surrogate for the greater Salish Sea, has expanded the peak twilight predation periods of juvenile salmon predators from just dusk and dawn to predation increasing throughout the night. Moreover, changing hydrology and water quality due to dams, climate, and land-water use have changed the magnitude, timing, and spatial patterns in water transparency from sediment plumes and plankton blooms. Collectively, these changes in underwater light penetration and transparency have fundamentally changed the predation environment with important implications for marine survival of salmon, functional sustainability of forage fish populations and the services they provide to the broader ecosystem.