standardization of environmental data and information - International ...

3.3.2. Water column
As the operation of any equipment would involve traversing the
entire water column, physico-chemical conditions such as currents,
temperature, salinity, oxygen and chemical composition of the water at
various depths, and their seasonal variation, would be important
considerations in the design of subsurface components.
3.3.3. Near-bottom waters
Most of the activities, such as the operation of the nodule collector,
filtering of sediments, separation of nodules, storage and pumping from the
buffer, and release of suspended matter would be concentrated in waters
close to the bottom (about 100 to 200 metres above the seafloor).
Therefore, the baseline conditions of this area must be known in order to
assess the impact of mining activity.
3.3.4. Seafloor
As the nodules lie loose on the seafloor, partially buried under the
sediment, seafloor characteristics such as topography, sediment type,
thickness, grain size, chemical composition and engineering characteristics
will influence the performance of the nodule collector. In addition, the
redistribution of sediment over the area would change the bio- and
geochemical conditions that sustain the megabenthos, macrobenthos,
meiobenthos and microbes, which form essential components of the
environment that will be disturbed by nodule mining.
3.4. Parameters for environmental data collection
Baseline studies are essential for environmental impact
assessment, as they provide:
i. Reference information for comparison with post-perturbation
data, and
ii. Inputs for planning, design and execution of mining operations.
These studies should therefore be conducted at all sites, both
experimental sites for simulation of impact as well as potential mining sites,
in order to determine the existing environmental conditions in the area.
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