Presentation Abstract
The Salish Sea is a globally significant location for marine birds. However, forage fish declines, legacy contaminants, and increasing industrial activity are ongoing concerns for wildlife and humans here. Glaucous-winged gulls (Larus glaucescens) are effective biomonitors of long-term shifts in marine food-webs and contaminant trends. Over the past 150 years, they have increasingly relied on terrestrial prey and urban areas to forage and nest. Simultaneously, Glaucous-winged gulls (GWGU) have experienced lower reproductive success and significant population declines. Currently, Environment and Climate Change Canada (ECCC) has a mandate through the Ocean’s Protection Plan to assess threats to wildlife posed by new and proposed industrial projects, including the Trans-Mountain Pipeline expansion which will increase crude oil tanker traffic in the Salish Sea by approximately seven-fold. Canada has a regional stewardship responsibility to GWGUs, and ECCC has identified a gap in knowledge of wintering gull habitat use, diet, contaminant exposure, and health. To address these gaps, we deployed satellite tags on 31 birds and collected blood samples from 164 wintering gulls in 2020 and 2021. Initial findings indicate that 14.8% of GWGU migrated out of the Salish Sea preceding the breeding season (n = 4 of 27). Broadly, gulls appear to have established home ranges, but will make short-distance, temporary migrations to access seasonal resources. Movement patterns among individuals are highly variable, but some appear to specialize on particular anthropogenic habitat types. Additionally, gull health varies regionally within the Salish Sea. Diet and contaminant analyses are on-going but will be used to build a food-web to contaminants model linked with health. This work will help identify important wintering habitat for GWGUs and highlight potential risks posed by anthropogenic and industrial activities. Finally, this research will provide information key to managing the health of coastal seabird populations and the Salish Sea Ecosystem at large.
Session Title
Birds
Conference Track
SSE3: The Circle of Life
Conference Name
Salish Sea Ecosystem Conference (2022 : Online)
Document Type
Event
SSEC Identifier
SSE-traditionals-437
Start Date
28-4-2022 8:30 AM
End Date
28-4-2022 10:00 AM
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
The health and habitat use of Glaucous-winged gulls wintering in the Salish Sea
The Salish Sea is a globally significant location for marine birds. However, forage fish declines, legacy contaminants, and increasing industrial activity are ongoing concerns for wildlife and humans here. Glaucous-winged gulls (Larus glaucescens) are effective biomonitors of long-term shifts in marine food-webs and contaminant trends. Over the past 150 years, they have increasingly relied on terrestrial prey and urban areas to forage and nest. Simultaneously, Glaucous-winged gulls (GWGU) have experienced lower reproductive success and significant population declines. Currently, Environment and Climate Change Canada (ECCC) has a mandate through the Ocean’s Protection Plan to assess threats to wildlife posed by new and proposed industrial projects, including the Trans-Mountain Pipeline expansion which will increase crude oil tanker traffic in the Salish Sea by approximately seven-fold. Canada has a regional stewardship responsibility to GWGUs, and ECCC has identified a gap in knowledge of wintering gull habitat use, diet, contaminant exposure, and health. To address these gaps, we deployed satellite tags on 31 birds and collected blood samples from 164 wintering gulls in 2020 and 2021. Initial findings indicate that 14.8% of GWGU migrated out of the Salish Sea preceding the breeding season (n = 4 of 27). Broadly, gulls appear to have established home ranges, but will make short-distance, temporary migrations to access seasonal resources. Movement patterns among individuals are highly variable, but some appear to specialize on particular anthropogenic habitat types. Additionally, gull health varies regionally within the Salish Sea. Diet and contaminant analyses are on-going but will be used to build a food-web to contaminants model linked with health. This work will help identify important wintering habitat for GWGUs and highlight potential risks posed by anthropogenic and industrial activities. Finally, this research will provide information key to managing the health of coastal seabird populations and the Salish Sea Ecosystem at large.
