Review of Biological Processes within Oceanic Water Columns Relevant to the Assessment of the Safety of Disposal of Waste, Notably Radioactive Isotopes, on or within the Seabed

摘要

Pelagic biological processes and their connotations in the assessment of dispersal mechanisms of contaminants released on the deep oceanic seabed are reviewed. Biological gradients tend to be from the surface down so the search is for processes which run counter to these general gradients. Observed profiles off standing crop of plankton and micronekton show that below 2000 m biological activity has to be exceptionally dynamic to have an influence even within an order of magnitude of the dispersive effect of physical mixing. Examination of all forms of known migration mechanisms fails to reveal such dynamic activity. No critical pathways within the present or foreseeable pattern of exploitation of the oceans are identified. However, a major gap in knowledge is whether the pattern of these biological processes changes substantially in the region of continental slopes.