Changes in habitat availability for outmigrating juvenile salmon (Oncorhychus spp.) following estuary restoration

Restoration Ecology
By: , and 

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Abstract

The restoration of the Nisqually River Delta (Washington, U.S.A.) represents one of the largest efforts toward reestablishing the ecosystem function and resilience of modified habitat in the Puget Sound, particularly for anadromous salmonid species. The opportunity for outmigrating salmon to access and benefit from the expansion of available tidal habitat can be quantified by several physical attributes, which are related to the ecological and physiological responses of juvenile salmon. We monitored a variety of physical parameters to measure changes in opportunity potential from historic, pre-restoration, and post-restoration habitat conditions at several sites across the delta. These parameters included channel morphology, water quality, tidal elevation, and landscape connectivity. We conducted fish catch surveys across the delta to determine if salmon was utilizing restored estuary habitat. Overall major channel area increased 42% and major channel length increased 131% from pre- to post-restoration conditions. Furthermore, the results of our tidal inundation model indicated that major channels were accessible up to 75% of the time, as opposed to 30% pre-restoration. Outmigrating salmon utilized this newly accessible habitat as quickly as 1 year post-restoration. The presence of salmon in restored tidal channels confirmed rapid post-restoration increases in opportunity potential on the delta despite habitat quality differences between restored and reference sites.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Changes in habitat availability for outmigrating juvenile salmon (Oncorhychus spp.) following estuary restoration
Series title Restoration Ecology
DOI 10.1111/rec.12333
Volume 24
Issue 3
Year Published 2016
Language English
Publisher Wiley
Contributing office(s) Pacific Coastal and Marine Science Center
Description 12 p.
First page 415
Last page 427
Country United States
State Washington
Other Geospatial Puget Sound
Online Only (Y/N) N
Additional Online Files (Y/N) N