해역이용협의에 따른 협의서 검토현황과 연안이용형태를 분석한 결과, 공유수면 점 사용은 공작물설치와 해수 취배수, 공유수면 매립은 산업단지조성, 항만 어항개발과 도로건설의 점유율이 높았고, 점 사용은 서해에서 그리고 매립은 남해에서 우세하였다. 지역별로는 전남, 경남지역과 인천 경기지역에서 이용행위가 많았다. 해역이용협의 검토량은 2008년이 전년도에 비해 약 200건 이상 증가하였고, 협의과정에서 준설토 해양투기, 매립, 준설, 해수 취배수, 바다골재채취와 규사채취에 대해 보완요청이 주로 이루어졌다. 연안이용은 대부분 해양환경기준 I등급 또는 II등급의 지역에서 집중되었고, 특히, 법령상 해양 규제지역인 특별관리해역에서는 항만 어항개발과 관련된 매립과 공작물설치, 국립공원에서는 공작물설치와 호안정비가 많았다. 또한, 수산자원보호구역에서는 호안정비, 공작물설치와 해수의 취배수 행위가 많이 이루어진 것으로 평가되었다. 해역이용협의제도의 제반적인 합리성과 신뢰성을 높이는 방법 등 개선방안을 제도운영 및 정책적인 측면과 협의서 작성과 관련한 해양환경영향평가 측면으로 구분해서 정책제언을 제시하였다.

본 논문은 수산자원보호구역의 효과적이고 합리적인 관리방향에 대한 정책수립 지원라 체계적인 어장환경실태조사 시스템 구축을 위한 사전 진단적 연구접근으로서 수산자원보호구역에서 계절별로 장기적으로 모니터링된 국가해양환경측정망 등의 자료를 이용해서 어장환경의 실태와 변화를 분석하고 평가하였다. 어장환경은 오염이 진행되었거나 진행 중인 것으로 진단되었는데, 각 영역별로 수질과 저질 오염특성이 다소 다르게 나타나서 오염원과 이용실태 및 지형적 특성 등 제반 환경요소를 고려한 맞춤형 수질관리방안 수립이 요구되었다. 또한, 보호구역의 지정면적은 점차적으로 변화되어 왔는데, 2003년도와 처음 시정시의 면적을 비교해 볼 때, 총 면적변화는 -22.9~2.4% 범위로 완도 도암만은 약 2.4% 정도 미미한 증가를 보였지만, 전체 구역은 평균 약 6.4%가 감소하였고, 한산만이 가장 큰 비율로 감소하였다. 전체 면적 중 육역이 약 6.1%, 해역이 약 6.6%가 감소되었지만, 2008년 시 군별로 고시된 상황을 종합적으로 고려하면 지정면적의 감소는 대부분 육역인 것으로 사료 되었다. 보호구역의 환경을 양호하게 유지하고 효과적인 관리정책을 수립하기 위해서는 실효적인 수질관리방안 뿐만 아니라 개발 및 이용실태 파악을 위한 조사와 데이터(정보)관리가 체계적으로 이루어지고 해역별로 종합 관리할 필요가 있을 것이다. 아울러 각종 관련 법률을 정비 보완해서 조사, 평가, 협의 등 관리방향과 관련된 요소를 일관성있고 체계적으로 정립할 필요가 있다고 판단된다.

본 연구는 연안의 수질개선과 오염제어의 관점에서 효율적인 수질관리의 원리와 기법, 연안오염총량관리제 및 선진사례를 검토하였고, 현재 오염총량 산정시 나타나는 문제점 및 개선사항을 지적하였다. 또한, 오염총량제와 환경용량과의 관계, 해양환경 예측 모델로 활용되고 있는 생태계모델의 연구접근에서 중점적으로 검토해야 하는 사항을 토의하고, 나아가서 연안수질 관련 제도와 정책에서 반영하고 흡수해야 할 수질관리 내용과 개선방안을 제시하였다. 연안오염총량제의 대상이 되는 연안에서는 환경영향평가와 사전환경성검토에서 해당하는 개발사업이나 계획 중 신규 오염원에 대해서는 오염부하삭감량과 할당량을 산정해서 평가서에 구체적으로 제시할 필요가 있고, 연안관리지역계획에서는 환경관리계획에 좀 더 중심을 옮겨 기본적으로 관할 해역으로 유입하는 오염원과 오염부하량 자료를 구축할 필요가 있다. 특별관리해역 등 향후 연안오염총량제 적용대상이 되는 지자체에서는 하수도관리계획 등 도시계획을 수립할 때 이러할 점을 고려해서 장기적이고 일관성있는 하수도정책이 수립되어야 할 것이다. 연안오염총량제도는 다른 환경관리해역으로 점진적으로 확대 시행되어야 할 것이로, 그 외의 지역은 지자체장이 주부장관과의 협의를 통해 자발적으로 시행하고 인센티브를 주는 것도 검토해야 할 것이다. 해역의 수질개선을 위해서는 생태계모델링에 의한 환경용량(수질적 차원의 총허용오염부하량) 산정이 필수적이며, 이와 관련한 적용모델의 신뢰성과 과학적 타당성 확보는 환경영향평가 관련 협의시 매우 중요한 검토항목으로 고려되고 있다 연안 육역에 존재하는 오염원에 대해서는 연안환경을 관리하는 주무부처가 주도적으로 감시 감독하고 관리체제에 환한 법적 거를 마련하거나 관련 법률을 정비해서 통합 운영해야 할 것으로 사료되었다.

This study estimated response of water quality and pollutant behavior according to the discharge and reuse of treated wastewater by three-dimensional eco-hydrodynamic model, and suggest plan that water quality management and environmental restoration in the coastal area including urban stream of Yeosu, Korea. Dispersions of low-saline water and COD by treated wastewater loads (design facility capacity, about 110,000 m3/d) were very limited in near of effluent site. Nutrients, however, increase compared to the other water quality factors, especially total nitrogen was very sensitive to input loads. When reuse some of treated wastewater to Yeondeung stream, nitrogen was big influence on estuarine water quality. Although current characteristics of treated wastewater such as discharge and water quality were negligible to the change of marine environment, effluent concentration of COD, TN and TP, especially 40% of TN, are reduced within the allowable pollutant loads for satisfy environmental capacity and recommended water quality criteria. Also, controls of input point/non-point sources to Yeondeung stream and base concentration of pollutants in coastal sea itself are very necessary.

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.

It is very important to interprete and simulate the variation of phytoplankton maximum region for the prediction and control of red tide. This study was composed of two parts, first, the hydrodynamic simulation such as residual current and salinity diffusion, and second, the ecological simulation such as phytoplankton distribution according to freshwater discharge and pollutant loads. Without the Nakdong river discharge, residual current was stagnated in inner side of this estuary, and surface distribution of salinity was over 25psu. On the contrary, with summer mean discharge, freshwater stretched very far outward and some waters flowed into Chinhae Bay through the Kadok channel, and low salinity extended over coastal sea and salinity front occurred. From the result of contributed physical process to phytoplankton biomass, the accumulation was occurred at the west part of this estuary and the Kadok channel with the Nakdong river discharge. When more increased input discharge, the accumulation band was transported to outer side of this estuary. The frequently outbreak of red tide in this area is caused by accumulation of physical processes. The phytoplankton maximum region located inner side of this estuary without the Nakdong river discharge and with mean discharge of winter, but it was moved to outer side when mean discharge of the Nakdong river was increased. The variation of input concentration from the land loads was not largely influenced on phytoplankton biomass and location of maximum region. When discharge was increased, phytoplankton maximum region was transferred to inner side of the Kadok channel. On the other hand, when discharge was decreased, phytoplankton maximum region was transferred to inner side of this estuary and chlorophyll a contents increased to over 20㎍/L. Therefore, if any other conditions are favorable for growth of phytoplankton, decrease of discharge causes to increase of possibility of red tide outbreak.

The estuary of Nakdong river is very influenced by the freshwater contained nutrients and organic materials. The response results of these influences are eutrophication and red tide outbreak in this region. Concentration of chlorophyll a was 0.78∼62.55㎍/L in February, 1.20∼21.29㎍/L in April, 1.88∼188.35㎍/L in June, and 0.78∼11.21㎍/L in August, respectively. The decrease of chlorophyll a is considered that residence time is shorten by increase of freshwater discharge, and unfavorable growth condition of phytoplankton is created by diffusion of low salinity and increase of turbidity. The phytoplankton maximum region located inner side of this estuary during winter season, whereas it was moved to outer side when mean discharge of the Nakdong river was increased. Therefore, the variation of phytoplankton maximum region was affected by input discharge from the Nakdong river basin.

From the environmental aspects, primary productivity of phytoplankton plays the most important role in enhancement of marine culture oyster production. This study may be divided into two branches; one is estimation of maximum oyster meat production per unit facility(Carrying Capacity) under the present environmental conditions in Kamak Bay, the other is improvement of carrying capacity from increase of primary productivity by changing the environmental conditions that cause not to form an unfavorable environment such as the formation of oxygen deficient water mass using the eco-hydrodynamic model. By simulation of three-dimensional hydrodynamic model and ecosystem model, the comparison between observed and computed data showed good agreement. The results of sensitivity analysis showed that phytoplankton maximum growth rate was the most important parameter for phytoplankton and dissolved oxygen. The estimation of mean primary productivity of Wonpo, Kamak, Pyongsa, and Kunnae culture grounds in Kamak Bay during culturing period were 3.73gC/㎡/d, 2.12gC/㎡/d, 1.98gC/㎡/d, and 1.26gC/㎡/d, respectively. Under condition not to form the oxygen deficient water mass, four times increasing of pollutants loading as much as the present loading from river increased mean primary productivity of whole culture grounds to 4.02gC/㎡/d. Sediment N, P fluxes that allowed for 35% increasing from the present conditions increased mean primary productivity of whole culture grounds to 3.65gC/㎡/d. Finally, ten times increasing of boundary loadings from the present conditions increased mean primary productivity of whole culture grounds to 3.95gC/㎡/d. The maximum oyster meat production per year and that of unit facility in actual oyster culture grounds under the present conditions were 6,929ton and 0.93ton, respectively. This 0.93ton/unit facility is considered to be the carrying capacity in study area, and if the primary productivity is increased by changing the environmental conditions, oyster production can be increased.