Chlorophyll a (chl a) has been used as an indicator for phytoplankton biomass in pelagic ecosystems due to the relative ease of measurement and selectivity for autotrophs in mixed plankton assemblages. However, the use of chl a as an indicator for phytoplankton biomass is restricted due to its inability to resolve taxonomic differences of phytoplankton and the highly variable relationship of chl a with phytoplankton. Here, we describe the analysis of High-Performance Liquid Chromatography (HPLC) photosynthetic pigment data using CHEMTAX, which is a matrix factorization program that uses chemical taxonomic indices (phytoplankton carotenoids) to quantify the abundance of phytoplankton groups. Compared to direct microscopic counting that can distinguish species within broad groups, the resolution of taxonomic groups by CHEMTAX is generally coarse. It can only distinguish between diatoms, dinoflagellates, cryptophytes, cyanobacteria, chlorophytes, prasinophytes, and haptophytes. However, CHEMTAX analysis is much faster and less expensive than microscopic counting methods. HPLC pigment observations were taken in the spring, summer, fall, and winter in 2005～2006 within Gamak Bay, South Korea. CHEMTAX results revealed that diatoms were the dominant taxonomic group in Gamak Bay. In inner Gamak Bay, the ratio between diatoms and cryptophytes was 75～80%, and the ratio between dinoflagellates and cryptophytes was 10～15%. In outer Gamak Bay, the ratio between diatoms and cryptophytes was 85～90%, and the ratio between dinflagellates and cryptophytes was only 1～5%. The population structure was seasonal. Relative diatom populations were less in the summer than the winter season.

This research was performed to simulate shellfish production systems and sales in Gamak Bay, South Korea. To study the way the shellfish system generates maxima, a numerical model was developed to simulate the model under a control and a number of different scenarios. The program calculates the EMERGY flows by multiplying the flows of energy and materials by the appropriate solar transformity. In this study, an energy systems model was built to simulate the variation of sustainability for oyster aquaculture. The results of the simulation based on 2005 data that as oyster production yield slightly increases, money and assets increase to a steady state. When the program is run control simulation, the system reaches carrying capacity after 8 years. The simulation of models with price of purchased inputs increased with 3.5% inflation rate per year showed maximum benefit of shellfish production occurs after 6 years but amounts are less than control simulation, and then decreases slightly in money and yield results. The results with 3.5% inflation and increase of oyster price annually showed steady and slightly increase of money and yield.

The objective of this research is to apply more scientific, quantitative methods and procedures of environmental investigation to the development of the natural environment and the improvement of the human environment during the establishment of a sewage treatment plant and special facilities using environmental accounting. This research was performed to develop a method of strategic environmental assessment on the operation of sewage treatment plant and reuse of shellfish seeding areas through the use of environmental accounting based on EMERGY evaluation. The result was applied to marine environment policy in order to evaluate the real wealth of the regional environment and economy for both the present phase and the proposed developed phase. Using results from the comparison of EMERGY indices between the present situation and future scenarios, cost benefit analysis was performed for three different scenarios: (1) construction of a new sewage treatment plant, (2) relocation and recovery of the shellfish seeding area , and (3) relocation and re-seeding of shellfish area and construction of a new sewage treatment plant. Cost-benefit ratios of the three scenarios are 1.88, 0.94, and 1.38, respectively.

This research outlines a new method for evaluation of shellfish production in Gamak Bay based on the concept of EMERGY. Better understanding of those environmental factors influencing oyster production and the management of oyster stocks requires the ability to assess the real value of environmental sources such as solar energy, river, tide, wave, wind, and other physical mechanisms. In this research, EMERGY flows from environment sources were 76% for shellfish aquaculture in Gamak Bay. EMERGY yield ratio, Environmental Loading Ratio, and Sustainability Index were 4.26, 0.31 and 13.89, respectively. Using the Emergy evaluation data, the predicted maximum shellfish aquaculture production in Gamak Bay and the FDA (Food and Drug Administration, U.S.) designated area in Gamak Bay were 10,845 ton/y and 7,548 ton/yr, respectively. Since the predicted shellfish production was approximately 1.3 times more than produced shellfish production in 2005, the carrying capacity of Gamak Bay is estimated to be 1.3 times more than the present oyster production.