Lab tests on the biodegradation of chemically dispersed oil should consider the rapid dilution that occurs at sea

Biodegradation of dispersed oil in natural seawaters from Western Greenland and a Norwegian fjord

“…Once the oil is chemically dispersed, rapid dilution will occur in the water column. Environmental concentrations of dispersed oil over the period of biodegradation is expected to be below 1 mg L −1 (Lee et al 2013). It has also been argued that the use of dispersants may be of advantage in the Arctic, since the chemicals can be applied by plane and are therefore less logistically challenging than mechanical treatment (Lewis and Prince 2018).…”

Biodegradation of dispersed Macondo crude oil by indigenous Gulf of Mexico microbial communities

“…Oil droplets ≥ 70 μm in diameter are subject to buoyant forces and rapidly rise to the surface, while droplets ≤50 μm in diameter are predicted to remain below the surface for extended periods of time (North et al, 2011). Eighty percent of the droplets measured at depths of 1000 m to 1400 m in the month following the accident were estimated to be b70 μm (Lee et al, 2013). The only available field data obtained from in-situ optical measurements of "droplets" by laser scattering and transmissometry (LISST) at depth during the DWH accident were reported to be of approximately 20 μm in average diameter (Lee et al, 2011).…”

Concentrations of viable oil-degrading microorganisms are increased in feces from Calanus finmarchicus feeding in petroleum oil dispersions

“…2A) (Delvigne, 1993;Lee et al, 2013). These droplet diameters overlap with the diameter of the feed algae (R. baltica, $7 lm, Fig.…”

“…In the present experiment, copepods were exposed to oil dispersions at concentrations and droplet sizes designed to mimic dilute oil dispersions (Lee et al, 2013). Feeding activity of the copepods was quantified as clearance rates and feces production.…”