Formation and fate of oil-related aggregates (ORAs) in seawater at different temperatures

TitleFormation and fate of oil-related aggregates (ORAs) in seawater at different temperatures
Publication TypeJournal Article
Year of Publication2020
AuthorsHenry IA, Netzer R, Davies EJ, Brakstad OGunnar
JournalMarine Pollution Bulletin
Volume159
Pagination111483
Date Publishedoct
ISSN0025326X
KeywordsAggregation, biodegradation, Dispersed oil, Marine snow, Microbial communities, RCC4289, Sinking
Abstract

In this study, the formation and fate of oil-related aggregates (ORAs) from chemically dispersed oil in seawater (SW) were investigated at different temperatures (5 °C, 13 °C, 20 °C). Experiments in natural SW alone, and in SW amended with typical marine snow constituents (phytoplankton and mineral particles), showed that the presence of algae stimulated the formation of large ORAs, while high SW temperature resulted in faster aggregate formation. The ORAs formed at 5 °C and 13 °C required mineral particles for sinking, while the aggregates also sank in the absence of mineral particles at 20°. Early in the experimental periods, oil compound accumulation in ORAs was faster than biodegradation, particularly in aggregates with algae, followed by rapid biodegradation. High abundances of bacteria associated with hydrocarbon biodegradation were determined in the ORAs, together with algae-associated bacteria, while clustering analyses showed separation between bacterial communities in experiments with oil alone and oil with algae/mineral particles.

URLhttps://doi.org/10.1016/j.marpolbul.2020.111483 https://linkinghub.elsevier.com/retrieve/pii/S0025326X20306019
DOI10.1016/j.marpolbul.2020.111483