Validation of EIA sampling methods - bacterial and biochemical analysis

Abstract

Deep sea sediments from Central Indian Ocean Basin (CIOB) were sampled from 10 degrees .00'-10 degrees .10'S latitude and 75 degrees .55'-76 degrees .05'E longitude for assessing the potential environmental impact of polymetallic nodule mining under the Indian Experiment (INDEX) during September 1996 and June-Sept. 1997. Analysis were done for lipid, protein and carbohydrates, which comprise the labile organic matter (LOM), total organic carbon (TOC) and total bacterial counts (TC). Of the 5 variables tested, TC seemed to be relatively invariant. Analysis of variance (ANOVA) between grab and core samples showed that one could substitute the other for sampling only up to 10 cm depth. Varbability observed between samples for the two years could be due to temporal factors. Paired T-test between pre- and post-disturbance samples suggested that the above methods of sampling and variables like TC, protein and TOC could be used for monitoring disturbance.