Abstract
The cleanliness and stability of Muroto deep seawater were examined throughout the year. Surface and deep seawater samples were collected monthly from January 2000 to December 2000 on the surface or from a depth of 320 m off the coast of Cape Muroto at the Kochi Prefectural Deep Seawater Laboratory. The numbers and sizes of suspended particles in the seawater samples were analyzed using a particle analyzer. In the deep seawater, the numbers of particles with diameters of 1-50 μm were 334-844/ml (yearly average of 549/ml) and those with diameters of 10-50 μm were only 10-28/ml (yearly average of 19.4/ml). Particle numbers of the deep seawater varied slightly from month to month, but no seasonal variations were observed. On the other hand, the numbers of particles with diameters of 1 -50μm in the surface seawater samples were 1445-7289/ml (yearly average of 4416/ml) and showed clear seasonal variations. The particle numbers of the surface seawater were high in spring and summer, but low in winter. These results demonstrate that the Muroto deep seawater is cleaner and more stable in suspended particles contained than the surface seawater, and therefore it is better use for industrial uses, particularly for those having filtration processes.
