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

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.

Language

English

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Apr 21st, 9:00 AM Apr 22nd, 4:45 PM

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.