• 한국패류학회지
• /
• 제17권2호
• /
• pp.95-104
• /
• 2001

To determine optimal conditions for measurement of the clearance rate in feeding experiment of an intertidal bivalve Glauconome chinensis, effects of starvation, extent of mixing at subsampling, and initial prey concentration were assessed. Experiments were conducted separately for each condition with different treatments. Two-way ANOVAs showed that there were significant differences in clearance rates among different starvation periods (p<0.001), extents of mixing (p = 0.005), and prey concentrations (p < 0.001). Starvation for 1 or 2 days gave rise to 2 to 3-fold increase in the clearance rate. After starvation for 5 days, the clearance rate decreased seriously, implying loss of physiological status. It is suggested that animals should be fed during acclimation. The differences of the clearance rates between gentle and vigorous mixings were significant, but the differences were smaller than that among different incubation times. It was found that vigorous mixing is not necessary. The effect of initial prey concentration was great. However, optimal prey concentration could not be determined at any fixed value. Experiments with multiple concentrations of algal prey are recommended. Optimal incubation time for measurement of the clearance rate of G. chinensis was determined to be 2-4 hours.

• 수산해양기술연구
• /
• 제52권3호
• /
• pp.271-275
• /
• 2016

Recently, pollution problem in coastal water has become more serious and pollution including red tide serves as a main reason for reduction of fishes resources. Particularly, nutrients such as nitrogen and phosphorus are the most serious pollutants. Normally, biological wastewater treatment process is used in removing such nutrients. However, it is difficult to adopt the biological wastewater treatment process to a small-scale fish processing factory in case of using seawater as wash water. Thus, removing nutrients through struvite crystallization is investigated in this study for treating shrimp processing wastewater. Experiments were conducted by varying molar ratio of $Mg^{2+}:NH^4-N:PO^4-P$ from 1:1:1 to 2:1:1. It can be concluded that optimum molar ratio is 1:1:1. Struvite crystallization process is compared with chemical coagulation process using PAC and struvite crystallization process is proven as the more effective process in removing nutrients from wastewater. In view of results obtained from these experiments, struvite crystallization process is a promising method in removing nitrogen and phosphorus from wastewater; however, not so good in removing organics. Thus, struvite crystallization process is suitable as the pre-treatment process in treating shrimp processing wastewater and additional biological process is needed to remove organics.

• 한국재난정보학회:학술대회논문집
• /
• 한국재난정보학회 2016년 정기학술대회
• /
• pp.426-427
• /
• 2016

본 논문에서는 Unmaned Aerial Vehicle(UAV)를 이용하여 양식어장에 유입될 수 있는 적조 모니터링에 대한 연구를 실시하였다. 적조는 한반도 주변 해역을 포함한 전 세계 연안 지역에서 물고기의 집단 폐사, 해안구조물에 대한 물리적 손상등과 같이 사회 경제적인 피해를 야기 시켜왔고, 최근 해수면 온도상승과 같은 기후 변화에 의한 영향으로 증가되고 있는 실정이다. 특히 남해안과 같이 생활하수가 다량 유입되고 저층에 퇴적된 영양물질이 용출되는 곳에서 상습적으로 발생한다. 1995년에 발생한 코클로디니움에 의한 적조는 764억원의 기록적인 피해를 입히면서, 적조에 대한 신속한 대응과 효과적인 방제작업의 필요성이 대두되었다. 이렇게 양식어장 운영에 다양한 문제가 발생이 된 후 대응하는 것보다 모니터링을 통해 사전에 유입을 차단하고 대처하는 연구가 필요하고 판단된다. 원격탐사를 활용한 적조 탐지 및 모니터링 연구는 UAV에서 취득한 RGB color 영상을 통한 적조 추출 및 분석, 시계열 분석을 위한 영상자료 수집, 현장관측 자료와 위성영상에서 추출한 클로로필 농도 비료글 통해 이루어 졌다. 또한 매년 발생하는 적조생물에 관한 속성정보를 통해 적조발생지역에 대한 적조생물종과 국내 연안에서 발생한 적조의 발생 범위 등의 정보를 지리정보기반에 의한 공간분석을 실시하였다.

• 한국수산과학회지
• /
• 제14권4호
• /
• pp.227-232
• /
• 1981

1981년 하계중 진해만에서는 3차에 걸친 대규모의 적조가 있었다. 이들 적조는 그 규모나 원인종, 농도, 머문기간에 있어 남해안궤서 그 유예가 없었던 악성적조었다. 그로 인한 수산물 피해액만도 약 17억3천4백만으로 추정되었다. 1차 적조는 7월 18, 19일부터 시작되어 7월말까지 계속되었으며, 2차는 8월중순에 그리고 3차는 9월초순에 있었다. 주 원인종은 와편모조의 일종인 Gymnodinium sp.로서 외부형태로 보아 1963년 일본 대촌만에서 있었던 적조의 원인종인 Gymnodinium 65년도형과 유사하였으나 확인할 수는 없었다. 적조시의 수색은 암갈색이었고 세포양은 주로 표면에서 수심 악 2m층까지 농밀하여 심한 경우 투명도는 0.1 m이었다. 최고세포수는 약 20만cells/ml 이었고 이때 클로로필-a양은 약 $1,000mg/m^3$ 이었다. 용존산소양은 $2\sim3ml/1$인 경우가 많았고 최하 1ml/l이 발견되었다. 1차 적조 후기핀 양식굴 및 흥합의 폐사가 나타났고 2차 적조가 사라진8월 16, 17일에는 게. 고동. 새우유 등과 양태류, 볼락, 까나리 등의 사체가 조류에 밀려 해안에서 발견되었다. 금번 적조의 특징은 원인종이 악성인 Gymnodinium sp. 이고 내년에도 재발할 수 있는 가능성이 있다는 점이다. 발생원인은 일본 대촌만 적조의 경우처럼 다우후 고온의 지속과 저이중 다양의 유화물이 주요인자라 추측된다.

• 한국음향학회지
• /
• 제24권8호
• /
• pp.447-453
• /
• 2005

수중 초음파 (5, 10, 15 MHz)를 사용하여 적조 플랑크톤 Cochlodinium polykrikoides (식물 플랑크톤, 편모조류)의 후방산란 특성을 파악하기 위한 음향 실험을 실시하였다 적조 산란체의 적조주의보 (300 cells/a) 보다 적은 양의 개체 수 변화를 탐지하였고, 개체군 밀도와 후방 산란신호와의 상관관계를 시간영역에서와 주파수 영역에서 확인하였다. 또한, fluid-sphere model[1]을 이용한 이론적인 체적 산란강도를 계산하여 실측 체적 산란강도와 비교한 결과가 잘 일치하였다.

• Fisheries and Aquatic Sciences
• /
• 제11권4호
• /
• pp.205-208
• /
• 2008

The mixotrophic dinoflagellate Cochlodinium polykrikoides was reported to be linked to major fish kills in Korea and Japan since the 1990s. Rapid and sensitive detection of microalgae has been problematic because morphological identification of dinoflagellates requires light microscopic and scanning electron microscopic observations that are time consuming and laborious compared to real-time PCR. To address this issue, a real-time PCR probe targeting the ITS2 rRNA gene was used for rapid detection and quantification of C. polykrikoides. PCR inhibitors in water column samples were removed by dilution of template DNA for elimination of false-negative reactions. A strong association between cell quantification using real-time PCR and microscopic counts suggests that the real-time PCR assay is an alternative method for cell estimation of C. polykrikoides in environment samples.

• 수산경영론집
• /
• 제47권3호
• /
• pp.35-52
• /
• 2016

This paper analyzed economic feasibility of aquacultural construction which of large-scale. The results of the economic analysis, cage cultural and water recycling cultural by post-water treatment were analyzed that NPV is 2,083,685 thousand won and -14,105,896 thousand won and B/C ratio is 0.590 and 0.855, respectively. These were shown economic infeasibility. But, running water culture by pre-water treatment(small scale) and running water culture by pre-water treatment(large scale) were analyzed that the one is 5,555,747 thousand won and 15,048,589 thousand won and the other is 1,154 and 1,1221, respectively. these were shown economic feasibility. In addition, measurement of B/C ratio through a sensitivity analysis on running water cultural by pre-water treatment(small scale) and running water cultural by pre-water treatment(large scale) is economic feasibility in all cases. However, these were analyzed when the selling price was falling to 20 percent, it has shown economic infeasibility and when the selling price rises to 20 percent, water recycling culture by post-water treatment has economic feasibility. The significance of the study analyzed a sensibility as well as economic feasibility by methods and scales. It is expected that used as basic materials when constructing and operating of land aquaculture in order to minimize the damage from natural disasters.

• 한국환경보건학회지
• /
• 제9권1호
• /
• pp.49-62
• /
• 1983

Evaluation of water quality of Yeong San river and Seomjin river by using of newly simplified MBOD method was performed. Of course, thought that there is some differences between nutrient demands of heterotrophic bacteria and those of Algae which obtain it by photosynthesis, but it has little influence on evaluation of Algae Growth potential. The result of this study were as follows: 1) In both river, the value of Chemical analysis and MBOD method of inorganic salts reveals as nearly same result. 2) Though organic pollution of Seomjin river is less than that of Yeongsan but inorganic contamination is somewhat advanced BOD 2.8 ppm. and MBOD 340 ppm. in Seomjin river but BOD 22 ppm. and MBOD 480 ppm. in Yeongsan river. 3) Both river have tendency to reveal higher Nitrogen value is MBOD=MBOD -P

• 한국해양공학회:학술대회논문집
• /
• 한국해양공학회 2002년도 추계학술대회 논문집
• /
• pp.251-255
• /
• 2002

Eutrophic matters accumulated on the bottom of sea, river and lake cause red tide phenomenon in ocean and outbreak green algae in river and lake. Systems are developed to remove the noxious deposit. But the existing systems remove not only the eutrophic matters but also natural materials, sand, pebbles etc. that should remain at the bottom. This paper describes a new system that can safely, and economically take away the noxious deposit in underwater. High pressure water jet is used to induce vortices in the triangular suction section, and air-lifting pump to lift up the deposit. The mixture of the water and deposit is filtered through the drum filters. An under camera shows the under water situation along the moving direction of the system that is controlled by a remote operator. This remote controlled moving system obliterate the necessity of the diver that usually costs high. The experimental results show the effectiveness of the suggested system.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2019년도 춘계학술대회
• /
• pp.403-405
• /
• 2019

스마트 농업에 대한 기준 모델, 서비스 능력, 네트워크 능력에 대한 기술 표준화 과정을 추진해 오는 과정에서 현안으로 떠오르는 내용이 병충해, 전염병과 같은 위기상황이 가져올 수 있는 영향에 대한 우려였다. 동물의 감염요인인 구제역, 조류 인플루엔자 등의 위기요인들은 경제적 손실은 물론 인간의 사회활동에도 많은 제약을 가져와 국가경제에 막대한 영향을 끼치게 되었다. 본 논문에서는 이러한 인적요인, 자연재해 및 동물 감염 등의 위기로 인한 ICT 해결 방안인 네트워크 기반에서의 위기완화 서비스의 표준화 로드맵을 제시하여 표준기술을 적용 이러한 문제를 해결하는데 긍정적 요소로 작용할 것으로 판단된다.