가막만에 출현하는 동물플랑크톤을 계절별(2001년 4 월, 7월, 9월, 12월)로 Norpac 네트를 이용하여 수직 채집하였다. 우점적으로 출현한 분류군은 4월과 12월에 요각류, 7월에 요각류와 지각류, 9월에 야광충이었다. 출현 개체수는 22-17,197 indiv. m-3으로 시.공간적으로 변동폭이 매우 컸다. 요각류의 우점종은 4월에 Eurytemora pacifica, Acartia omorii, Centropages abdomina

In order to investigate the properties in distribution and movement of anchovy school catches by the lift net in the Kamak bay and their relation to the environmental factors, I. e., the amount of chlorophyll-a and turbidity were observed from June to August in 1997 and compared with the catch of anchovy by the lift net. The results obtained are summarized as follows;1) The amount of chlorophyll-a ranged from 4.0 to 12.0 mg/m3 on July and from 3.0 to 15.0 mg/m3 on August in horizontal distribution, the amount of chlorophyll-a ranged from 3.0 to 8.0mg/m3 on June, from 5.5 to 11.6 mg/㎥ on July, and from 6.0 to 11.1 mg/m3 on July and from 1.0 to 6.0ppm on August, respectively. 2) Anchovy school can be presurmed, they are come from north of bay, visited and distributed through east of bay at the middle of June. Moreover, they spreaded in all bay. Then gradually, when July arrive, they go to the south the nearest the coasts, and they are outflow through the south entrance of bay at the end of August.3) The catch of anchovy was highest on July, poor second on August, and lowest on June. The chlorophyll-a and the turbidity influenced remarkably on the distribution and movement of anchovy school and the influence of chlorophyll-a was alrgest.

In order to investigate the properties in distribution and movement of anchovy school catches by the lift net in the Kamak bay and their relation to the environmental factors, i.e., the water temperature and the salinity were observed form June to August in 1997 and compared with the catch of anchovy by the lift net. The results obtained are summarized as follows;1) The water temperature and salinity ranged form 20.0 to 27.0℃ and from 31.2 to 33.8‰, respectively. The water temperature and salinity at the fishing points ranged form 19.7 to 27.2℃ and, from 30.5 to 33.8℃ respectively.2) The water temperature influenced remarkably on the distribution and movement of anchovy school. But the salinity influenced little on the distribution and movement. 3) The catch of anchovy was highest on July, poor second on August, and lowest on June. Anchovy school can be presurmed, they are come from north of bay, visited and distributed through east of bay at the middle of June. Moreover, they spreaded in all bay. Then gradually, when July arrive, they go to the south th nearest the coasts, and they are outflow through the south entrance of bay at the end of August.

In order to find out the environmental factors influencing the catch of anchovy lift nets in kamakbay, the three oceanographic factors, i. e., the water temperature, the salinity, the amount of chlorophyll-a were observed respectively from August 1 to 12, 1995 and from September 20 to 26, 1995, and each of them was compared with the catch of anchovy by the lift net. The results obtained are summerized as follow : 1) The water temperature was ranged from 17.3 to 29.6℃ and its difference between the surface and bottom was 1 to 3℃. In the three areas, A, B and C, the area A was the hightest in temperature, the area B being a second, and the area C being the lowest. 2) The salinity was ranged from 32.20 to 33.47‰ and its difference between the surface and bottom was not significant. In the three areas, the area A was the highest in salinity, the area B being a second, and the area C being the lowest. 3) The amount of chlorophyll-a was ranged from 0.19 to 5.30mg/m supper(3) and its difference among the three areas was not significant. Daily variation of the amount was very irregulated because the position operated was changed daily. 4) A comparison of the water temperature, the salinity and the amount of chlorophyll-a with the catch gave that the water temperature and the amount of chlorophyll-a had large influence on the catch and the salinity did not so. However, the influence of the amount of chlorophyll-a was larger than that of the water temperature. 5) The catch of anchovy was large respectively during two hours after sun set and during two hours before sun rise.

A studies on the pattern of sea water circulation was carried out by using drogue experiments, tidal current measurement and hydrographic data in Kamak Bay which has two channels. At the flood, the water inflowed from the northern narrow channel flows mostly to the southward then the westward because Daekyung-island located at the flow path, at the same time the water from the southern channel of bay directed strongly to the north with a spine centered at around Gunnaeri. And these waters converged at the area between eng-Island and Deakyung-Island in the bigining of the flow, and placed at less southern part than the area at the late. The water of the north west inner bay having concave bottom topography inflows to Najin inlet with a spin of anti-clockwise. At the ebb, those waters in the bay turn back to two channels respectively, but most of waters directed to the southern channel of the bay. The directions of residual current of two channels are the southward mainly, and the current of inner area are influenced by the prevailing wind. The north-west inner bay which has the weak tidal current less than 10 cm/sec shows a similar upwelling by off-shore wind in winter, and the stratification in summer, respectively.

The concepts of residence time and flushing time can be used to explain the exchange and transport of water or materials in a coastal sea. The application of these transport time scales are widespread in biological, hydrological, and geochemical studies. The water quality of the system crucially depends on the residence time and flushing time of a particle in the system. In this study, the residence and flushing time in Gamak Bay were calculated using the numerical model, EFDC, which includes a particle tracking module. The average residence time was 55 days in the inner bay, and the flushing time for Gamak Bay was about 44.8 days, according to the simulation. This means that it takes about 2 months for land and aquaculture generated particles to be transported out of Gamak Bay, which can lead to substances accumulating in the bay. These results show the relationships between the transport time scale and physical the properties of the embayment. The findings of this study will improves understanding of the water and material transport processes in Gamak Bay and will be important when assessing the potential impact of coastal development on water quality conditions.

The environmental changes related to hypoxic water mass were investigated at Gamak bay in summer times, June, July and August 2006. The hypoxic water mass was found, in first, at the northern area of Gamak bay on 27 June. This water mass has been sustained until the end of August and disappear on 13 September. In Gamak bay, the hypoxic water mass was closely related to geography. During the formation of oxygen deficiency, changes in dissolved nutrients was studied and found that on surface layer and lower layer, DIN were 0.80 μM~19.8 μM(6.03 μM) and 1.13 μM～60.83 μM(10.66 μM), and DIP were 0.01 μM～0.92 μM(0.24 μM), and 0.01 μM～3.57 μM(0.49 μM), respectively, far higher distribution on lower layer of the water where hypoxic water mass was occurred. The configuration of phosphorus was analyzed to figure out the possibility of release of phosphorus from sediments. It was found that the Labile-Phosphorus, which is capable of easy move to water layer by following environmental change was found more than 70%. Therefore, in Gamak bay, it was found that the possibility of large amount of release of soluble P into the water, while hypoxic water mass was occurred in deep layer was higher. It is suggested that DIP in the northern sea of Gamak bay mainly sourced from the soluble P from lower layer of the waters where hypoxic water mass was created more than that from basin. However, existence form of phosphorus in sediments during normal times, not during creation of hypoxic water mass, needs further study.

지중해담치 Mytilus galloprovincialis는 대서양연안, 지중해, 홍콩 및 일본 남부증지에 분포하며, 한국에서는 동, 서, 남해안 그리고 제주도와 울릉도에서 채집된다 (Choe et al., 1999). 전남 여수시 가막만에서 양식되고 있는 지중해담치는 6～8월 동안 자연채묘하여 중간양성을 거친 후 이듬해 5～6월에 본양성을 위하여 시설되며, 그해 11월부터 수확이 시작된다. 조개류의 생식주기에 관한 연구는 주로 기초 생물학적 연구와 자원증대 및 양식기술 개발을 위한 기초자료를 제공하기 위하여 수행되어 왔다. 그 가운데 우리나라에 서식하는 조개류의 생식에 관한 연구로는 바지락, Ruditapes philippinarum의 생식소 발달과 연령 및 성장 (Chung et al., 1994), 대복, Gomphina veneriformis의 생식소 발달과 생식주기 (Park et al., 2003), 백합, Meretrix lusoria의 성 성숙과 배우자형성 (Chung and Kim, 2000) 및 개조개의 생식소발달과 생식주기(Shin et al., 2007)등 다수가 발표되고 있으나, 현재 양식 생산량이 많으며, 주요 양식대상종임에도 불구하고 국내에서 지중해담치의 생식생리에 관한 보고는 찾아보기 힘들다. 이매패류의 성 성숙 및 생식주기에 미치는 영향요인들 가운데 수온은 외인성 요인으로 여러 요인들 가운데 가장 중요하게 작용하는 요인이며 (Mackie, 1984), 수온은 주로 위도와 지리적 조건에 따라 달라진다. 최근 기후변화에 따라 연안 수온의 상승 및 강우량의 증가에 의해 연안에서 양식되고 있는 생물의 산란시기가 불규칙하여 자연 채묘 및 생산량의 변동이 초래되고 있는 실정이다. 본 연구는 여수시 가막만에서 양식되고 있는 지중해담치를 대상으로 생식생태학적 기초 자료인 성비, 생식소 발달, 생식소 지수, 비만도의 월 변화와 생식주기를 조사하여 산란시기 추정에 따른 채묘시기를 예측하고, 생산량 증가를 위한 적정양식시설의 재배치 및 적정생산량 산정을 위한 기초자료 제공을 위해 실시되었다. 본 연구에 사용한 지중해담치는 2009년 6월부터 2009년 12월까지 전남 여수시 가막만 해역에서 수하연 중간부분의 개체를 매월 30～40개체씩 채집하였다. 채집한 개체는 각장, 각고, 전중량 및 육중량 등의 측정형질을 계측한 후, 생식소가 포함된 내장낭의 일부를 Bouin's solution에 일정시간 고정한 후 파라핀 절편법으로 두께 4 ㎛의 조직표본을 제작하였다. 염색은 Mayer's hematoxylin과 0.5% eosin 비교염색을 행하였다. 생식소 발달단계는 회복 및 초기활성기I (Re & EaⅠ: recovery and early active stageⅠ), 초기활성기Ⅱ (EaⅡ: early active stageⅡ), 후기활성기 (La: late active stage), 완숙기 (R: ripe stage), 방출기 (S: spent stage)의 5단계로 나누었다. 담치의 비만도는 조사지역(원포, 소호)에서 암․수 모두 6월에 가장 높은 정점 (암: 0.046, 수: 0.050)을 나타냈다. 성비는 원포지역의 경우 1:0.94(암:수), 소호지역은 1:1.2(암:수)로 나타났으나 유의적인 차이는 없었다(P>0.05). 생식소 발달은 원포지역과 소호지역 모두 7월부터 산란 및 방정을 시작하여 12월까지 지속되었다. 생식소지수는 원포지역의 경우 암컷과 수컷 모두 6월에 가장 높은 값을 나타낸 후 감소하여 10월에 다시 증가하는 경향을 보여주고 있었고, 소호지역 역시 8월을 제외하고 원포지역과 동일한 경향을 나타내었다. 두 지역 모두 주 산란기는 7～9월로 추정되었다. 그러나 소호지역은 원포지역보다 생식소의 발달이 다소 느리며, 퇴화․흡수 후 휴지기에 들어가는 개체들의 비율이 낮게 관찰되었다.

The short-term variations of the mesozooplankton community structure were investigated in Gamak Bay during summer season, 2006. The study was based on a comprehensive survey constituting from 12 stations on June 19, July 28, August 4, and August 29, respectively. Mean of temperature and chlorophyll a concentrations in the surface layer were significantly higher than those in bottom layer, and those concentrations were significantly higher in the inner bay than those in the outer bay. A total of 40 taxa including 19 copepods were observed in Gamak Bay during summer season. Mean abundance of total mesozooplankton varied from 1,859 to 26,111 indiv. m-3. The dominant species were Noctiluca scintillans, Penilia avirostris, Evadne tergestina, Paracalanus parvus s. l., Acartia omorii and Cirriped nauplii and cyprii in Gamak Bay, and they contributed 90% of mean abundance of total mesozooplankton. Noctiluca scintillans was high after the rainfall. Cluster analysis showed that the mesozooplankton community could be divided into 4 distinct groups, indicating rapid change of the community in the short-term of this survey. The relative contribution of each group of the N. scintillans, P. avirostris, E. tergestina, and P. parvus s. l. showed differences during the phytoplankton bloom period. The mesozooplankton community compositions were highly associated with water temperature, and salinity in physical conditions, and food organisms affect short-term variations in mesozooplankton composition. Interestingly, protozoa N. scintillans, and Cladocera appeared to be one of the key organisms to extinguish the phytoplankton bloom. Therefore, this study suggests that N. scintillans, and Cladocera could be a key player to control the mesozooplankton community structure during summer season, 2006.

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.

To investigate correlation between the distribution of marine bacteria and environmental characteristics in the surface sediments of Kamak Bay, chemical oxygen demand(COD), acid volatile sulfide(AVS), ignition loss(IL), total organic carbon(TOC), and total organic nitrogen(TON) were measured and analyzed at 7 stations in winter and summer. In winter, COD and AVS ranged from 13.45 mg/g to 30.06 mg/g(average: 23.58 mg/g) and from 0.03 mg/g to 1.04 mg/g(average: 0.63 mg/g), respectively. IL, TOC, and TON ranged from 8.03% to 11.41%(average: 9.41%), from 1.17% to 2.10%(average: 1.62%), and from 0.09% to 0.18%(average 0.15%), respectively. In summer, COD, AVS, IL, TOC, and TON ranged from 14.06 mg/g to 32.19 mg/g(average: 24.71 mg/g), from 0.03 mg/g to 1.11 mg/g(average: 0.66 mg/g), from 9.00% to 12.15%(average: 10.96%), from 1.27% to 2.12%(average 1.77%), and from 0.12% to 0.19%(average: 0.16%), respectively. These values were relatively higher than those in winter. Kamak Bay had high C/N ratio that might be resulted from the input of terrestrial sewage and industrial wastewater. The number of marine viable bacteria was 8.9 × 104 cfu/g in winter and 9.7 × 105 cfu/g in summer. The most abundant species were Pseudomonas spp., Flavobacterium spp., and Vibrio spp. in the surface sediments of Kamak Bay. It was found that the concentration of organic matters and viable bacterial cells in the inner part were relatively higher than those in the outer of Kamak Bay. The distribution of viable bacterial cells was closely influenced by environmental factors.

The eco-hydrodynamic model was used to estimate the environmental capacity in Gamak Bay. It is composed of the three-dimensional hydrodynamic model for the simulation of water flow and ecosystem model for the simulation of phytoplankton. As the results of three-dimensional hydrodynamic simulation, the computed tidal currents are toward the inner part of bay through Yeosu Harbor and the southern mouth of the bay during the flood tide, and being in the opposite direction during the ebb tide. The computed residual currents were dominated southward flow at Yeosu Harbor and sea flow at mouth of bay. The comparison between the simulated and observed tidal ellipses at three station showed fairly good agreement. The distributions of COD in the Gamak bay were simulated and reproduced by an ecosystem model. The simulated results of COD were fairly good coincided with the observed values within relative error of 1.93%, correlation coefficient(r) of 0.88. In order to estimate the environmental capacity in Gamak bay, the simulations were performed by controlling quantitatively the pollution loads with an ecosystem model. In case the pollution loads including streams become 10 times as high as the present loads, the results showed the concentration of COD to be 1.33～4.74㎎/ℓ(mean 2.28㎎/ℓ), which is the third class criterion of Korean standards for marine water quality. In case the pollution loads including streams become 30 times as high as the present loads, the results showed the concentration of COD to be 1.38～7.87㎎/ℓ(mean 2.97㎎/ℓ), which is the third class criterion of Korean standards for marine water quality. In case the pollution loads including streams become 50 times as high as the present loads, the results showed the concentration of COD to be 1.44～9.80㎎/ℓ(mean 3.56㎎/ℓ), which is the third class criterion of Korean standards for marine water quality.

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of COD (chemical oxygen demand) and net supply(or decomposition) rate of COD in Kamak Bay to find proper management plan for oxygen demanding organic matters. The estimation results of the physical process in terms of COD showed that transportation of COD is dominant in surface level while accumulation of COD is dominant in bottom level. In the case of surface level, the net supply rate of COD was 0～0.50 mg/m2/day. The net decomposition rate of COD was 0～0.04 mg/m2/day in middle level(3～6m) and 0.05～0.15 mg/m2/day in bottom level(6m～bottom). These results indicates that the biological decomposition and physical accumulation of COD are occurred predominantly at the northern part of bottom level. Therefore, it is important to consider both allochthonous and autochthonous oxygen demanding organic matters in the region.

The three-dimensional eco-hydrodynamic model was applied to estimate the physical process in terms of nutrients and net uptake(or regeneration) rate of nutrients in Kamak Bay for scenario analysis to find proper management plan. The estimation results of the physical process in terms of nutrients showed that transportation of nutrients is dominant in surface level while accumulation of nutrients is dominant in bottom level. In the case of dissolved inorganic nitrogen, the results showed that the net uptake rate was 0～60 mg/m2/day in surface level(0～3m), and the net regeneration rate was 0.0～10.0 mg/m2/day in middle level(3～6m) and above 10 mg/m2/day in bottom level(6m～below). In the case of dissolved inorganic phosphorus, the net uptake rate was 0.0～3.0 mg/m2/day in surface level, and the net regeneration rate was 0.5～1.5 mg/m2/day in middle level and 1.0～3.0 mg/m2/day in bottom level. These results indicates that net uptake and transport of nutrients are occurred predominantly at the surface level and the net generation and accumulation are dominant at bottom level. Therefore, it is important to consider the re-supplement of nutrients due to regeneration of bottom water.

The objective of this study is understanding and evaluation of temporal and spatial variation of pollutant loads by input sources for water quality management in Kamak Bay. Flow rate of rivers and ditches ranges from about 2,592-63,072㎥/d in October to 864-55,296㎥/d in January. In particular, the R2 predominated flow rate among input sources. Total COD, BOD, DIN and DIP loadings in January were about 896kg/d, 718kg/d, 2,152kg/d, and 154kg/d, respectively, which exceeded those of October. Lower POC/TOC levels are estimated in R2, and also in October. Temporal variation of pollutant loads were closely related to the human activity. Total discharging loadings of BOD, TN and TP by unit loading estimation were 4,993.0kg/d, 2,558.7kg/d, and 289.2kg/d, respectively, and were mainly affected by the population. Runoff ratio of BOD was about 0.14 in January. Mean NH4+-N and PO43--P loadings from sediment were 16.23㎎/㎡/d and 7.26㎎/㎡/d, respectively. For the improvement of water quality in this area, not only pollutant loads of rivers and ditches but also benthic flux from sediment should be reduced within the limits of the environmental capacity.

In order to study on the variational characteristics of water quality and chlorophyll a concentration, the water samples were collected daily or three times a week during the period from April 1990 to November 1991 at Kukdong port located in the Northern Kamak bay of Southern Korea I made an analysis on biological factor as chlorophyll a concentration as well as physico-chemical factors such as water temperature, salinity, sigma-t, dissolved oxygen, nutrients (ammonia, nitrite, nitrate, phosphate, and silicate), N/P ratio and chemical oxygen demand. In Northern Kamak bay seasonal variations in physical factors such as water temperature, salinity and sigma-t were very marked. On the other hand, chemical factors such as nutrients concentration and COD were not so. Chemical factors, in particular, silicate were influenced by input of freshwater. And the roles of silicate on the seasonal succession of phytoplankton species composition was very low. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round, and it was controlled by the combination of several factors, especially of N/P ratio determined by dissolved inorganic nitrogen.