Effects of barrier island salt marsh restoration on marsh bird occurrence in the Northern Gulf of Mexico

Restoration Ecology
By: , and 

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Abstract

In the Northern Gulf of Mexico, salt marshes are threatened by sea level rise, erosion, and loss of protective barrier islands. These barrier islands provide critical habitat for wildlife, including globally significant populations of marsh and shorebirds. We investigated salt marsh restoration on two Louisiana barrier islands using presence of 8 marsh bird species as an index to evaluate restoration success. Land loss was extensive for both islands prior to restoration, with submerged marsh restored by backfilling sediment into the marsh platform. Restoration methods were similar between the two islands, although Raccoon Island was built to a higher elevation (1.1 m) than Whiskey Island (0.8m). Avian presence was estimated via passive acoustic monitoring and point counts. To evaluate restoration success, we modeled influence of habitat covariates on index species presence in restored and reference (intact) sites over three breeding seasons and modeled occupancy for 6 species. On Whiskey Island, index richness was higher in restored sites. Marsh specialists Seaside Sparrows (Ammospiza maritima ) and Least Bitterns (Ixobrychus exilis ) had higher occupancy in restored areas on Whiskey, while generalist species showed no response to site. These results are likely due to a strong association between habitat and vegetation type, with restored sites dominated by Spartina alterniflora and reference sites by Avicennia germinans . On Raccoon Island, species richness was low across all sites. Our results suggest that restoration efforts were successful in creating salt marsh habitat on Whiskey but not Raccoon as of the time of our study.

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Publication type Article
Publication Subtype Journal Article
Title Effects of barrier island salt marsh restoration on marsh bird occurrence in the Northern Gulf of Mexico
Series title Restoration Ecology
DOI 10.1111/rec.13222
Volume 28
Issue 6
Year Published 2020
Language English
Publisher Wiley
Contributing office(s) Wetland and Aquatic Research Center
Description 11 p.
First page 1610
Last page 1620
Country United States
State Louisiana
Other Geospatial Isles Derniers, Raccoon Island, Whiskey Island
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