To assess the possible effect of nodule mining on deep-sea environment, the
Indian deep-sea environment experiment (INDEX) was undertaken in the India
n Basin. The present investigation is a part of the disturbance and recolon
ization study. Pre- and post-disturbance sediment samples were collected fr
om 21 stations between 10 degrees 01 ' -10 degrees 03 'S and 75 degrees 59
' -76 degrees 02 'E at water depths of 5300-5350 m to assess the effect of
benthic disturbance. There was a significant change in the composition and
biomass of macrofauna after the disturbance. Post-disturbance vertical prof
iles indicated a 63% reduction in the numerical count in the top 0-2-cm lay
er and high aggregation of macrofauna in deeper (5-10-cm) sediment layer. T
he impact of the disturbance was severe, as the mean biomass of macrofauna
was significantly reduced in the disturbed area, probably due to the displa
cement and /or mortality caused by the benthic disturber. (C) 2001 Elsevier
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