• Journal of Microbiology and Biotechnology
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• 제31권2호
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• pp.240-249
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• 2021

Phenotypic plasticity is a rapid response mechanism that enables organisms to acclimate and survive in changing environments. The Chinese mitten crab (Eriocheir sinensis) survives and thrives in different and even introduced habitats, thereby indicating its high phenotypic plasticity. However, the underpinnings of the high plasticity of E. sinensis have not been comprehensively investigated. In this study, we conducted an integrated gut microbiome and muscle metabolome analysis on E. sinensis collected from three different environments, namely, an artificial pond, Yangcheng Lake, and Yangtze River, to uncover the mechanism of its high phenotypic plasticity. Our study presents three divergent gut microbiotas and muscle metabolic profiles that corresponded to the three environments. The composition and diversity of the core gut microbiota (Proteobacteria, Bacteroidetes, Tenericutes, and Firmicutes) varied among the different environments while the metabolites associated with amino acids, fatty acids, and terpene compounds displayed significantly different concentration levels. The results revealed that the gut microbiome community and muscle metabolome were significantly affected by the habitat environments. Our findings indicate the high phenotypic plasticity in terms of gut microbiome and muscle metabolome of E. sinensis when it faces environmental changes, which would also facilitate its acclimation and adaptation to diverse and even introduced environments.

• 한국전자통신학회논문지
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• 제15권5호
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• pp.959-966
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• 2020

수산업의 중요성이 커지고 양식 산업이 급성장한 가운데 수산 양식 분야 ICT 융합을 통한 스마트 양식장에 대한 연구가 진행되고 있다. 양식장 현장에서 생육 환경 모니터링이 가능하도록 수중 드론의 구동부, 영상 수집 장치, 자세 안정화를 위한 통합 컨트롤러, 실시간 수중 영상을 통한 드론 조정 및 제어가 가능한 원격 관제 장치를 제안하고 설계, 개발 및 시험을 진행하였다. 수중 드론 활용을 통해 양식 산업에서 문제 되는 인력 수급 및 고비용 작업을 대체 할 수 있으며, 양식 폐사 확률을 줄여 안정적인 양식장 관리가 가능하다.

• ALGAE
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• 제29권1호
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• pp.35-45
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• 2014

Palmaria palmata was integrated with Atlantic halibut Hippoglossus hippoglossus on a commercial farm for one year starting in November, with a temperature range of 0.4 to $19.1^{\circ}C$. The seaweed was grown in nine plastic mesh cages (each $1.25m^3$ volume) suspended in a concrete sump tank ($46m^3$) in each of three recirculating systems. Two tanks received effluent water from tanks stocked with halibut, and the third received ambient seawater serving as a control. Thalli were tumbled by continuous aeration, and held under a constant photoperiod of 16 : 8 (L : D). Palmaria stocking density was $2.95kg\;m^{-3}$ initially, increasing to $9.85kg\;m^{-3}$ after a year. Specific growth rate was highest from April to June (8.0 to $9.0^{\circ}C$), 1.1% $d^{-1}$ in the halibut effluent and 0.8% $d^{-1}$ in the control, but declined to zero or less than zero above $14^{\circ}C$. Total tissue nitrogen of Palmaria in effluent water was 4.2 to 4.4% DW from January to October, whereas tissue N in the control system declined to 3.0-3.6% DW from April to October. Tissue carbon was independent of seawater source at 39.9% DW. Estimated tank space required by Palmaria for 50% removal of the nitrogen excreted by 100 t of halibut during winter is about 29,000 to $38,000m^2$, ten times the area required for halibut culture. Fifty percent removal of carbon from the same system requires 7,200 to $9,800m^2$ cultivation area. Integration of P. palmata with Atlantic halibut is feasible below $10^{\circ}C$, but is impractical during summer months due to disintegration of thalli associated with reproductive maturation.

• 한국수산과학회지
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• 제36권6호
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• pp.661-668
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• 2003

Performance of an airlift bioreactor (ABR) containing the immobilized microorganisms was evaluated in an integrated pilot scale recirculating aquaculture system stocked with Nile tilapia (Oreochromis niloticus) at an initial rearing density of $5\%$ and compared to a rotating biological contactor (RBC) for 40 days. The TAN concentration of rearing tank for ABR and RBC were maintained at $0.4\;g/m^3$ and $0.5\;g/m^3,$ respectively, The nitrite nitrogen was completely removed by the ABR. The ABR's aeration was more stable than the RBC's. On the whole, the feasibility of ABR as an aquacultural water treatment unit was recognized.

• 한국어류학회지
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• 제34권2호
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• pp.113-118
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• 2022

이번 연구에 사용된 도루묵은 2020년 1월부터 2021년 12월까지 우리나라 동해에서 동해구외끌이저인망과 연안자망 어업을 통해 총 781개체를 채집하였다. 채집된 도루묵의 전장범위는 14.8~25.4 cm였다. 도루묵의 가장 중요한 먹이생물은 54.7%의 상대중요도지수비를 나타낸 단각류였으며, 그 다음으로는 각각 33.7%와 11.6%를 차지한 두족류와 난바다곤쟁이류였다. 그외 게류, 새우류, 어류, 갯지렁이류가 출현하였으나 그 양은 매우 적었다. 계절별 위내용물 조성을 살펴본 결과, 모든 계절에 단각류를 주로 섭식하였으며, 여름철에 두족류의 섭식비율이 가장 높았으며, 봄철에 난바다곤쟁이류의 비율이 가장 높았다. 크기군별 위내용물 조성을 살펴본 결과, 도루묵은 모든 크기군에서 단각류가 가장 중요한 먹이생물이었으며, 성장함에 따라 단각류와 난바다곤쟁이류의 비율은 감소하고 두족류의 비율은 증가하는 경향이 관찰되었다. 개체당 평균먹이생물 개체수는 유의한 차이를 보이지 않은 반면, 중량은 크기군이 증가함에 따라 증가하는 경향이 관찰되었다.

• 수산해양기술연구
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• 제57권2호
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• pp.117-126
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• 2021

Diet composition and trophic level of Trachurus japonicus were studied using 417 specimens collected by trawls, set nets and purse seine fisheries from March 2019 to February 2020 in the South Sea of Korea. The size of T. Japonicus ranged from 7.0 to 49.8 cm in total length. T. japonicus were a carnivore that fed mainly on euphausiids and pisces. In eddition, T. japonicus fed on small quantities of cephalopods, crabs etc. T. japonicus showed ontogenetic changes in feeding habits. The proportion of euphausiids decreased inversely proportional to body size whereas the consumption of pisces gradually increased. As body size of T. japonicus increased the mean number of prey per stomach and the mean weight of prey per stomach tended to increase, but the mean number of prey per stomach was not significantly different. As a result of the feeding strategy analysis, T. japonicus were specialized feeders with pisces and euphausiids as their dominant prey. The trophic level ranged between 3.57 ± 0.54 and 3.91 ± 0.65, and increased asymptotically with size of specimens. The average trophic level of the T. japonicus was 3.79 ± 0.61.

• 한국수산과학회지
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• 제54권1호
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• pp.73-79
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• 2021

The feeding habits of Chub mackerel Scomber japonicus were investigated using 329 specimens collected from coastal waters of the South Sea of Korea. S. japonicus is mainly a piscivore, consuming small fish such as Engraulis japonicus (%RI: 81.0 %). The diet of Chub mackerel also includes small quantities of thaliaceans, euphausiids, and amphipods. We calculated the trophic level as 3.92 for S. japonicus. The dietary composition of S. japonicus did not show significant differences with size, but differed with season. As the body size of S. japonicus increased, the mean weight of prey within the stomach (mW/ST) increased (One-way ANOVA, P<0.05).

• Asian-Australasian Journal of Animal Sciences
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• 제24권5호
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• pp.587-602
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• 2011

Improved efficiency in the use of natural resources, pragmatic production systems and environmental sustainability, justified by the need for improved land use systems and increased productivity, are discussed in the context of Asian integrated systems, diversification, and issues of sustainability. The importance of these are reflected by serious inadequate animal protein production throughout Asia, where available supplies cannot match current and projected human requirements up to 2050. Among the ruminant production systems, integrated tree crops-ruminant production systems are grossly underestimated and merit emphasis and expansion. As an example, integrated oil palm- based system is an important pathway for integration with ruminants (buffaloes, cattle, goats and sheep), and provides the entry point for development. The importance and benefits of integrated systems are discussed, involving animals with annual and perennial tree crops, integration with aquaculture, the significance of crop-animal interactions, stratification of the systems, production options, improved use of forages and legumes, potential for enhanced productivity, implications for improved livelihoods of the rural poor and the stability of farm households. The advances in research and development in South East Asia highlight demonstrable increased productivity from animals and meat offtakes, value addition to the oil palm crop, sustainable development, and distinct economic impacts. The results from 12 out of a total of 24 case studies concerning oil palm over the past three decades showed increased yield of 0.49-3.52 mt of fresh fruit bunches (FFB)/ha/yr; increased income by about 30%; savings in weeding costs by 47- 60% equivalent to 21-62 RM/ha/yr; and an internal rate of return of 19% based on actual field data. The results provide important socio-economic benefits for resource-poor small farmers. Potential increased offtakes and additional income exist with the integration of goats. Additionally, the potential for carbon sequestration with tree crops is an advantage. The reasons for low adoption of the syatems are poor awareness of the potential of integrated systems, resistance by the crop- oriented plantation sector, and inadequate technology application. Promoting wider expansion and adoption of the systems in the future is linked directly with coherent policy, institutional commitment, increased investments, private sector involvement, and a stimulus package of incentives.

• 한국전자통신학회논문지
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• 제13권6호
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• pp.1379-1386
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• 2018

양식장에서 사용되는 기존의 수중 카메라는 제한된 구역만 촬영할 수 있으며, 수중 오염으로 인해 훼손되기 쉽다. 또한 양식장 그물망에 사료 공급에 따른 잉여 찌꺼기가 퇴적되어 양식장을 오염시키는 문제점이 있다. 이에 본 논문은 양식장 수중 모니터링과 그물망 청소를 위한 수중 드론을 제안한다. 수중 드론을 이용한다면 수중 영상 촬영, 모니터링과 양식장 그물망 청소가 가능하다. 이를 활용하면 양식장 환경 변화를 감지해 데이터를 수집할 수 있고 그 데이터를 기반으로 양식장 내에서 발생하는 변화에 대응할 수 있다. 더불어 통합관제 시스템을 구축하게 되면 이를 통해 효율적이고 안정적인 스마트 양식장 구축이 가능할 것이다.

• 환경생물
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• 제40권4호
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• pp.374-386
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• 2022

Phytoplankton communities, with emphasis on picoplankton and nanoplankton, were investigated in Gamak Bay, South Korea, where freshwater input and coastal water intrusion shape ecosystem functions. Shellfish farms and fish farms are located in the inner bay and outer bay, respectively, and tides translocate uneaten food and urine production from aquaculture farms toward the inner bay. Water masses were distinctly different based on a significantly different density between the surface and bottom layer and among three water masses, including the inner bay, outer bay, and Yeosu Harbor. Phytoplankton communities were quantified using flow cytometry and size-fractionated chlorophyll-a (chl-a) was measured. Salinity was a principal variable separating phytoplankton communities between the surface and bottom layer, whereas Si(OH)₄ controlled the communities in the inner bay, and NH₄⁺ and PO₄^3- governed the outer bay communities. While phycocyanin-containing (PC) cyanobacteria dominated in the outer bay, phycoerythrin-containing (PE) cyanobacteria dominance occurred with cryptophyte dominance, indicating that nutrients affected the distribution of pico- and nanoplankton and that cryptophytes potentially relied on a mixotrophic mode by feeding on PE cyanobacteria. Interestingly, picoeukaryotes and eukaryotes larger than 10 ㎛ were mostly responsible for the ecological niche in the western region of the bay. Given that chl-a levels have historically declined, our study highlights the potential importance of increased small phytoplankton in Gamak Bay. Particularly, we urge an examination of the ecological role of small phytoplankton in the food supply of cultivated marine organisms.