Effects of large-scale and local anthropogenic habitat modifications on aquatic bird communities in an urban estuary
Presentation Abstract
The abundance of several marine bird and waterfowl species in Puget Sound and adjacent waters has declined markedly in recent decades. The causes of these declines are not well understood, but they likely include a variety of local and large-scale influences. While individual species and species groups are monitored throughout the greater Puget Sound, few analyses of local natural and anthropogenic influences on taxonomic composition have been done. We combined data from annual winter aerial bird surveys and GIS layers of physical shoreline structure and land cover to explore changes in marine bird and waterfowl assemblage composition across years, oceanographic sub-basins, and simple urbanization metrics in Puget Sound. Twenty-one years of annual winter surveys (1994-2014) were combined with data layers of land use/land cover adjacent to the shoreline. The best models using large-scale factors (year, oceanographic sub-basin), and local factors (% armoring or % urbanization) were generated through multiple model comparisons. Declines over time in some key groups (diving invertivores, diving piscivores, opportunistic omnivores) had added effects of sub-basin and local urbanization. These results document declining diversity in marine bird and waterfowl assemblages across greater Puget Sound and demonstrate that local anthropogenic factors can also influence bird density, presumably by affecting availability of food, foraging areas, or nesting sites. Examining these relationships will not only improve our understanding of local bird populations, but will also improve our understanding of the greater Puget Sound ecosystem and assist in the development of improved monitoring and assessment tools.
Session Title
Transboundary Monitoring of Marine Birds and Mammals in the Salish Sea
Conference Track
SSE7: Monitoring: Species and Habitats
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE7-205
Start Date
4-4-2018 2:00 PM
End Date
4-4-2018 2:15 PM
Type of Presentation
Oral
Genre/Form
presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Water birds--Effect of human beings on--Washington (State)--Puget Sound; Water birds--Monitoring--Washington (State)--Puget Sound
Geographic Coverage
Puget Sound (Wash.); 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
Effects of large-scale and local anthropogenic habitat modifications on aquatic bird communities in an urban estuary
The abundance of several marine bird and waterfowl species in Puget Sound and adjacent waters has declined markedly in recent decades. The causes of these declines are not well understood, but they likely include a variety of local and large-scale influences. While individual species and species groups are monitored throughout the greater Puget Sound, few analyses of local natural and anthropogenic influences on taxonomic composition have been done. We combined data from annual winter aerial bird surveys and GIS layers of physical shoreline structure and land cover to explore changes in marine bird and waterfowl assemblage composition across years, oceanographic sub-basins, and simple urbanization metrics in Puget Sound. Twenty-one years of annual winter surveys (1994-2014) were combined with data layers of land use/land cover adjacent to the shoreline. The best models using large-scale factors (year, oceanographic sub-basin), and local factors (% armoring or % urbanization) were generated through multiple model comparisons. Declines over time in some key groups (diving invertivores, diving piscivores, opportunistic omnivores) had added effects of sub-basin and local urbanization. These results document declining diversity in marine bird and waterfowl assemblages across greater Puget Sound and demonstrate that local anthropogenic factors can also influence bird density, presumably by affecting availability of food, foraging areas, or nesting sites. Examining these relationships will not only improve our understanding of local bird populations, but will also improve our understanding of the greater Puget Sound ecosystem and assist in the development of improved monitoring and assessment tools.
