Sediment ballast accelerates sinking of Alaska North Slope crude oil measured ex situ with surface water from Cook Inlet

Abstract Oil spilled into the ocean interacts with suspended matter forming aggregates that transport oil into subsurface layers and towards the bottom. We conducted a series of laboratory experiments to explore aggregation of oil with natural phytoplankton assemblages from Cook Inlet, Alaska at thr...

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Bibliographic Details
Published in:Environmental Research Communications
Main Authors: Ross, Jesse, Kinner, Nancy, Saupe, Susan, Ziervogel, Kai
Other Authors: Coastal Response Research Center, Cook Inlet Regional Citizens Advisory Council, Kenai, AK
Format: Article in Journal/Newspaper
Language:unknown
Published: IOP Publishing 2024
Subjects:
Online Access:http://dx.doi.org/10.1088/2515-7620/ad6125
https://iopscience.iop.org/article/10.1088/2515-7620/ad6125
https://iopscience.iop.org/article/10.1088/2515-7620/ad6125/pdf
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Summary:Abstract Oil spilled into the ocean interacts with suspended matter forming aggregates that transport oil into subsurface layers and towards the bottom. We conducted a series of laboratory experiments to explore aggregation of oil with natural phytoplankton assemblages from Cook Inlet, Alaska at three times during a spring bloom. Oil and phytoplankton formed marine oil snow (MOS) that remained positively buoyant with a small fraction of MOS sinking to the bottom of our experimental bottles. Seawater treatments amended with suspended sediments formed oil-mineral aggregates (OMAs) with an oil capacity similar to MOS (∼20% of aggregate area was covered with oil). OMAs accelerated oil sedimentation in our bottles relative to MOS sedimentation underlining the significance of suspended matter as ballast for sinking oil. Our results reveal potential transport mechanisms of oil in Cook Inlet which apply to other coastal systems with high productivity and sediment loads.