9. Impact of ocean acidification benthic foraminifera – Ammonia beccarii A. tepida and A. dentata – in captive condition

Kannan Gunasekaran (1)*, Deivasigamani Selvam (1) and Ayyappan Saravanakumar (1)

1 Centre of Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University Parangipettai – 608 502, Tamil Nadu, India.

*Corresponding author: bk.guna18@gmail.com

Ocean has absorbed the one third of CO2 from the atmosphere that has resulted in decreasing the ocean pH, a phenomenon known as ocean acidification. Ocean acidification affects many marine calcifying organisms, however, less is known about its impact on marine benthic foraminifera.

To analyse the impact of ocean acidification on shell morphology of different types of benthic foraminifera (Ammonia beccarii, A. tepida A. dentata), we cultured them during 20 weeks at various acidified seawater pCO2 conditions (400, 750, 970 and 1200 µatm).

The present study investigates the functional morphology of benthic foraminifer’s using Scanning Electron Microscopy images and it shows that the deformation of test ornamentation, shell damage and reduction in teeth structure of all the three species. The average numbers of teeth were slightly differed between the (40 ± 2.4) control and (16 ± 2.1) treatment. All foraminifers’ teeth structure shape changed into conical to round shape; test surface cracked and aperture area also affected during the higher treatment.

Foraminifera act important role food chain hence current investigation found that these foraminifera species are affected in CO2 induced ocean acidification experiments as a result foraminifera has vulnerable to ocean acidification.

Key words: Ammonia beccarii, A. tepida A. dentata shell size, reduction ornamentation, CO2, SEM