Measurements of radium isotopes (224Ra, 228Ra and 226Ra) from fall field incubations (September and October 2018 ) detailing the release of radium from Deepwater Horizon archived oil and from freshly-discharged oil recovered from the Gulf of Mexico during a cruise aboard the R/V Point Sur PS19_05

This dataset contains measurements of radium isotopes (224Ra, 228Ra and 226Ra) from field incubations (September and October 2018) detailing the release of radium from Deepwater Horizon archived oil and from freshly-discharged oil recovered from the Gulf of Mexico during a cruise aboard the R/V Point Sur PS19_05. The goal of these incubations is to assess the degree of radium isotope release as a function of various degradation processes. 1 g of oil was incubated with 10 L of radium-free seawater to replicate surface sheen ('Surface') and submerged plume ('Deep') degradation. The surface sheen incubations were stored outside in ambient sunlight, with some incubations left unamended to allow both photodegradation and microbial degradation, and others serving as a kill control using chemical poisons to only allow photodegradation. The submerged plume simulations were stored in a dark refrigerator (2 deg. C), with some incubations left unamended (to allow microbial degradation) and others poisoned to serve as a kill control. Each of the treatments underwent destructive analysis at various time points (from 0 days up to 3 weeks) to determine the radium isotope (Ra-224, Ra-226, and Ra-228) activities in the aqueous phase through time. The experimental variables were oil concentration, poison composition, and poison concentration. 10-L blanks for radium-free seawater (no oil) was used alongside the surface (i.e., outside) incubations. Any radium detected in these blanks would be due to atmospheric contamination and are subtracted from the measured activity for the surface incubations.