Benthic communities associated with ferromanganese nodules from the Central Indian Ocean

Abstract

Micro- meio- and macrobenthic associations with Ferromanganese nodules collected from the Central Indian Ocean were evaluated. The area of nodules ranged from 13.58 to 21 cm super (2). The density of abyssal macrobenthos varies from 22-110 no. m super(2) (mean=58 + or - 33 SD, n=17). Density of sediment meiobenthos ranged between 02 to 11 no. 10cm super(-2) (mean=7 + or - 3 SD, n=9) and was dominated by nematodes. Significant difference was observed in meiobenthic density associated with nodules and sediment (p less than 0.05). Microbenthic abundance in association with nodules ranged between 2647 to 9680 no.10cm super(-2) (4531 + or - 11981 SD, n=9) and was mainly comprised of benthic Coscinodiscus sp. The nodule surface provides favorable substrate for grazers, shelter for burrowers and sessile organisms as well as protection for mobile fauna. It is concluded that benthic organisms like nematodes, polychaetes and foraminiferas may have strong influence on nodule formation and growth.