This is a brief review paper to introduce the Marino-Forum 21 project for creating new fishing ground by enhancement of marine primary production using artificial upwelling. The first term was performed from 2000 through 2004 to develop a prototype ocean nutrient enhancer. In the first part of this paper, the building and installation processes and the states of the operation and maintenance are summarized. In the second part of this paper, the research plan of the second term, which started in April 2005 and aims to confirm the effect of enhancement of marine primary production and to establish the technology for practical use of ocean nutrient enhancer, is introduced.


Security of food has always been one of the most important subjects for human society. Fish catches, which support human food mainly as animal protein, is also decreasing because of over-fishing and environmental deterioration of habit of fish by various human activities (Takahashi, 2000). These low productivities in marine environments are mainly resulted from limited nutrient availability in the euphotic zone, where photosynthetic production is carried out by primary producer such as phytoplankton. Primary productivities in the most of ocean are then expected to be enhanced if nutrient availability for primary producer is improved (Takahashi and Ikeya, 2004). Deep ocean water (DOW) is cold, nutrient-rich and pathogen-free seawater found at depth of several-hundred meters or lower. The DOW has attracted special interest as a renewable resource for energy and marine primary production (Otsuka, 2001). Especially, an artificial upwelling of DOW to the euphotic zone has a great potential for drastically enhancing marine primary production (Liu, 1999). The high potential of artificial upwelling is supported by the results of many researches on natural upwelling, e.g. Ryther's classical report (1969).

This content is only available via PDF.
You can access this article if you purchase or spend a download.