Observations and Measurements during the Monitoring of Deep Ocean Manganese Nodule Mining Tests in the North Pacific, March-May 1978

摘要

The objectives of the current phase of the project are to refine and modify predictive capabilities through the analysis of data acquired by monitorning tests of prototype mining systems. Although neither the volume nor the duration of the pilot-mining tests was directly comparable to proposed full-scale commercial mining, many of the data collected support the basic assessment for commercial mining. In the surface discharge, total particulate concentrations were much higher than ambient and formed the principle element of mining-related impact to the surface waters. Initial mixing of the surface discharge into the ambient surface was expected to lower concentrations of measured elements of the discharge. The dispersion of the discharged particulates was monitored for as long as a surface plume could be detected. The short duration of the pilot-mining tests hampered planned investigations of short-term effects of the surface plume on the biota. Results of those experiments indicate a small and short duration effect on diminishing primary production within the plume. A before/after sampling of benthic faunal populations was made to assess initial impact of the mining on the benthos. Complete analysis is incomplete, but significant differences are not obvious in preliminary analysis.