Presentation Abstract
Given the ongoing and potential increases in shipment of diluted bitumen (dilbit) out of the port of Vancouver, there is a need for toxicity data to assess the impact of catastrophic dilbit spillage on wildlife, particularly in the Salish Sea. Peer reviewed literature on dilbit toxicity is limited to teleost fish, despite the importance of coastal waters as habitat for a diverse bird fauna, including listed species. In this study we used the zebra finch (Taeniopygia guttata) as a tractable, avian model system for preliminary studies on Cold Lake blend dilbit. Objectives were to 1) determine appropriate methods of establishing dilbit toxicity to birds, 2) determine a range of lethal and sublethal doses, and 3) obtain meaningful physiological and behavioural endpoints. We conducted three 14-day exposure trials resulting in a LD100 (lethal dose resulting in 100% mortality) at 12 milliliters per kilogram body weight day (ml/kg bw day) and a LD50 (lethal dose resulting in 50% mortality) at 10 ml/kg bw day. Mortality was associated with significant mass loss, external oiling, increased non-enzymatic antioxidant capacity in plasma, and pectoral muscle wasting. In addition, we found evidence for sub-lethal effects at dilbit doses less than 10 ml/kg, such as elevated hepatic EROD activity. Further sub-lethal effects include changes in activity behaviours of treated birds on day 6 such as increased sleeping and decreased self-maintenance behaviours such as preening. Surprisingly, we found no effect of dilbit on hematocrit or hemoglobin levels even though anemia is a common endpoint reported in conventional crude oil avian dosing studies.
Session Title
Track: Contaminants, Plastics, Microplastics, Toxicology & Stormwater – Posters
Conference Track
Contaminants, Plastics, Microplastics, Toxicology & Stormwater
Conference Name
Salish Sea Ecosystem Conference (2020 : Online)
Document Type
Event
SSEC Identifier
2020_abstractID_4852
Start Date
21-4-2020 9:00 AM
End Date
22-4-2020 4:45 PM
Genre/Form
conference proceedings; presentations (communicative events)
Subjects – Topical (LCSH)
Bitumen--Environmental aspects--Salish Sea (B.C. and Wash.); Oil spills--Environmental aspects--Salish Sea (B.C. and Wash.); Zebra finch--Effect of pollution on--Salish Sea (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.)
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
Format
application/pdf
Included in
Fresh Water Studies Commons, Marine Biology Commons, Natural Resources and Conservation Commons, Terrestrial and Aquatic Ecology Commons
Effect of diluted bitumen on the survival, physiology, and behavior of the zebra finch (Taeniopygia guttata) and relevance to birds of the Salish Sea
Given the ongoing and potential increases in shipment of diluted bitumen (dilbit) out of the port of Vancouver, there is a need for toxicity data to assess the impact of catastrophic dilbit spillage on wildlife, particularly in the Salish Sea. Peer reviewed literature on dilbit toxicity is limited to teleost fish, despite the importance of coastal waters as habitat for a diverse bird fauna, including listed species. In this study we used the zebra finch (Taeniopygia guttata) as a tractable, avian model system for preliminary studies on Cold Lake blend dilbit. Objectives were to 1) determine appropriate methods of establishing dilbit toxicity to birds, 2) determine a range of lethal and sublethal doses, and 3) obtain meaningful physiological and behavioural endpoints. We conducted three 14-day exposure trials resulting in a LD100 (lethal dose resulting in 100% mortality) at 12 milliliters per kilogram body weight day (ml/kg bw day) and a LD50 (lethal dose resulting in 50% mortality) at 10 ml/kg bw day. Mortality was associated with significant mass loss, external oiling, increased non-enzymatic antioxidant capacity in plasma, and pectoral muscle wasting. In addition, we found evidence for sub-lethal effects at dilbit doses less than 10 ml/kg, such as elevated hepatic EROD activity. Further sub-lethal effects include changes in activity behaviours of treated birds on day 6 such as increased sleeping and decreased self-maintenance behaviours such as preening. Surprisingly, we found no effect of dilbit on hematocrit or hemoglobin levels even though anemia is a common endpoint reported in conventional crude oil avian dosing studies.
