Bioavailability and Toxicity of Oil Trapped in River Sediments by Hyporheic Flows
Loading...
Authors
Adams, Julie
Date
Type
thesis
Language
eng
Keyword
Oil spills , Toxic effects , Hazard/risk assessment , Dilbit , Fluorescence spectroscopy , Chemically enhanced water accommodated fraction , EROD , Embryotoxicity , PAC , Oiled substrate , Diluted bitumen , Droplets , Hyporheic flows , Oil , Bioavailability
Alternative Title
Abstract
Transportation of large volumes of oil in Canada increases the likelihood of inland oil spills and river contamination. In oil spills to rivers, turbulence may disperse floating oil into the water column and hyporheic flows may carry oil droplets through the bed sediments, including sediments utilized by fish for reproduction. Research is needed to measure the toxicity of oil stranded on and trapped within sediments to fish, including assessment of diluted bitumen (dilbit) products that are frequently transported across Canada. The objectives of this thesis were to measure the toxicity of dilbits to rainbow trout with commonly used laboratory toxicity test methods; to develop laboratory methods to model oil droplet entrainment in hyporheic flows; and to measure oil droplet trapping in gravel by hyporheic flows, dissolution of oil into water, and bioavailability to rainbow trout.
Research to address these objectives found that: Chemically dispersed dilbit and water flowing through gravel coated with dried films (dried oil films: DOF) of dilbit were chronically embryotoxic to rainbow trout alevins. Existing DOF methods were modified to assess oil droplet trapping in river gravels by hyporheic flows (trapped oil droplets: TOD). Increased oil mass loaded to or trapped in gravel (more trapping of higher viscosity oils) and increased oil surface area resulted in higher hydrocarbon concentrations in effluent. In DOF and TOD experiments, the concentration of hydrocarbons in water decreased over time, but the hydrocarbons were highly bioavailable to juvenile trout and were sustained at maximal levels over weeks of water flow.
These findings contribute to the understanding of the fate of oil in rivers and the exposure of organisms that inhabit the hyporheic zone. Embryo-larval fish chronically exposed to oil trapped in river sediments could cause lethal or sublethal effects that reduce the number of fish that survive to adult stages and successfully reproduce. Population reductions in subsequent years could threaten the sustainability of fisheries. It is recommended that the potential fate of oil in the hyporheic zone be included in risk assessments and oil spill response to prevent and mitigate oil contamination of river sediments.
Description
Citation
Publisher
License
Queen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canada
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.
ProQuest PhD and Master's Theses International Dissemination Agreement
Intellectual Property Guidelines at Queen's University
Copying and Preserving Your Thesis
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.