Development of evaluation tools for countermeasure technologies harnessing marine ecosystem

点击翻译按钮获取中文摘要

A coupled physical-biological model was developed to simulate the nitrogen and carbon cycles to evaluate the technologies harnessing marine ecosystems. The model is focusing on the degradation of particulate organic matter (POM), because the process should much affects on the efficiency of the biological pump which transport carbon from the surface to the deep layer. The employed ecosystem model is based on KKYS which is one of the most popular nitrogen cycle model, but some new compartments such as Bacteria (BAC), Semi-Refractory POM (SR-POM) and dissolved inorganic carbon (DIC) are also considered. The model is tuned by the laboratory experimental data in which the seawater sampled at the target site was used. The performance of the developed model is compared to that of the original KKYS to discuss the availability of the model. Then, the model is applied to simulate the ecosystem behaviour in the target area where the artificial upwelling generator is installed. The long-term carbon budget is also estimated by vertical one-dimensional ecosystem model using the parameters determined from the results of the three-dimensional model. It is clarified that CO2 budget gradually changes because the vertical profile of C/N ratio is affected due to the decomposition of refractory organic matters.A food economic model including fishery products is also developed by expanding IFPSIM which was originally made for analyzing agricultural economic polices. Fishery products are introduced by categorizing fish species according to patterns of supply and demand, modeling production and demand for typical fish species, and then extending the model to all fishery products. In simulations using the developed model, it is demonstrated that self-sufficiency in fishery products, which do not rely on feed grain, would make a substantial contribution to overall self-sufficiency in sources of essential animal protein.