Effect of oxygen manipulations on benthic foraminifera: A preliminary experiment

235-239Three sediment cores were collected at 50 m water depth on the west coast of India, off Ratnagiri, and were subjected to oxygen manipulations maintaining natural temperature and salinity. The objective was to understand foraminiferal response to changed oxygen conditions. After a fortnight, the experimental cores were sub-sectioned and analyzed for their live foraminiferal content. This data was compared with background field data obtained from the non-experimental core. The data indicate that any change in natural oxygen conditions causes lowering of foraminiferal numbers. It is clearly evident that Fursenkoina and Nonions are more adaptive to changed oxygen conditions in contrast to Bolivinids and Rotalids, which quickly die out. This study clearly demonstrates the change in foraminiferal distribution in response to oxygen changes. This experimental study further can help develop foraminifera as a proxy to decipher the past fluctuations in the OMZ in the past, including assessment of their anthropogenic origin