Measurements of radium isotopes (224Ra, 228Ra and 226Ra) from spring field incubations (February through July 2019) detailing the release of radium from archived Deepwater Horizon oil and freshly-discharged oil recovered from the Gulf of Mexico during a cruise aboard the R/V Point Sur PS19_14

This dataset contains measurements of radium isotopes (224Ra, 228Ra and 226Ra) from spring field incubations (February through July, 2019) detailing the release of radium from archived Deepwater Horizon oil and freshly-discharged oil recovered from the Gulf of Mexico during a cruise aboard the R/V Point Sur PS19_14. 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 with 10 L of radium-free seawater was used 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. Some experimental variables were oil concentration, poison composition, and the addition of COREXIT 9527 dispersant. 10-L blanks for radium-free seawater (no oil) were 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.