Contaminant exposure in marine foraging river otters from Southern Vancouver Island, British Columbia
Session Title
General contaminant toxicology in aquatic and terrestrial species
Conference Track
Fate and Effects of Pollutants
Conference Name
Salish Sea Ecosystem Conference (2016 : Vancouver, B.C.)
Document Type
Event
Start Date
2016 12:00 AM
End Date
2016 12:00 AM
Location
2016SSEC
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
North American river otter--British Columbia--Vancouver Island; Indicators (Biology)--British Columbia--Vancouver Island; Ecosystem health--British Columbia--Vancouver Island; Marine pollution--British Columbia--Vancouver Island; Environmental toxicology--British Columbia--Vancouver Island
Geographic Coverage
Salish Sea (B.C. and Wash.); Vancouver Island (B.C.)
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
Contaminant exposure in marine foraging river otters from Southern Vancouver Island, British Columbia
2016SSEC
Comments
Past industrial activities on Southern Vancouver Island, British Columbia, have resulted in localized polychlorinated biphenyl (PCB) contamination in the near shore marine environment. Previous studies have shown that PCB levels are particularly high in North American river otters (Lontra canadensis) residing in industrial/urban harbours, with some individuals displaying concentrations above the critical level of exposure. When an animal’s foraging area is more centralized in a contaminated area, their exposure risk concomitantly increases, which potentially leads to adverse health effects such as disruption of the endocrine system. Here, we investigated the degree of connectivity between otters in a contaminated (Victoria/Esquimalt Harbour) and two relatively uncontaminated areas (Oak Bay and Metchosin) by determining their home range and spatial movement through radio-telemetry. We also used scat and live animal sampling for three analysis: (i) evaluating subpopulation structure using multi-locus microsatellite genotyping; (ii) measuring concentrations of PCB, polybrominated diphenyl ether (PBDE), and organochchlroine pesticides; and (iii) assessing thyroid and reproductive hormone levels. Fixed kernel estimates revealed limited home range, with little to no overlap among otters of all three sites. Microsatellite analysis showed substantial genetic distance between the contaminated harbours and the uncontaminated Metchosin area (FST = 0.054). Mean PCB concentrations in otter blood and feces were significantly higher in harbours (38.94 and 6.35mg/kg lw, respectively) relative to Oak Bay (1.83 and 0.84mg/kg lw) and Metchosin (3.23 and 0.85mg/kg lw). Although there were differences in hormone measures among the sites, it is not clear whether the patterns were associated with contaminants. We conclude that in the harbour area, otters’ chronic exposure to PCB was attributed to their small home ranges and restricted gene flow with the adjacent uncontaminated sites. River otters are ideal biological indicators for aquatic ecosystem health and can be useful monitors for environmental and anthropogenic stressors on wildlife.