• 수산해양교육연구
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• 제12권1호
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• pp.98-121
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• 2000

The Korean fishery encountered a difficulty situation, due to the new regime of the Exclusive Economic Zone (EEZ) and the decreasing fisheries resources in Korean waters. In addition, the coastal areas are deteriorated by industrial wastes, sewage, farming wastes and pollution from aquaculture. In this situation, it is necessary to study the TAC (total allowable catch) - based management system, the development of fishing gears and appropriate fishing methods for stock conservation, and the automation system of fishing gears for improving the efficiency of fisheries. The objective of this study is to look for an appropriate system in marine production and resource management under the new UNCLOS (United National Convention for the Law of the Sea) regime for subjects in fishing gears and methods, production system, and information, and fisheries resources management. The results of this study could be used as scientific information to maintain and develop the Korean fisheries and to establish fisheries policy for the management of fisheries resources in Korean waters.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권12호
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• pp.4866-4888
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• 2020

One major and time-consuming task in fish production is obtaining an accurate estimate of the number of fish produced. In most Nigerian farms, fish counting is performed manually. Digital image processing (DIP) is an inexpensive solution, but its accuracy is affected by noise, overlapping fish, and interfering objects. This study developed a catfish recognition and counting algorithm that introduces detection before counting and consists of six steps: image acquisition, pre-processing, segmentation, feature extraction, recognition, and counting. Images were acquired and pre-processed. The segmentation was performed by applying three methods: image binarization using Otsu thresholding, morphological operations using fill hole, dilation, and opening operations, and boundary segmentation using edge detection. The boundary features were extracted using a chain code algorithm and Fourier descriptors (CH-FD), which were used to train an artificial neural network (ANN) to perform the recognition. The new counting approach, based on the geometry of the fish, was applied to determine the number of fish and was found to be suitable for counting fish of any size and handling overlap. The accuracies of the segmentation algorithm, boundary pixel and Fourier descriptors (BD-FD), and the proposed CH-FD method were 90.34%, 96.6%, and 100% respectively. The proposed counting algorithm demonstrated 100% accuracy.

• Fisheries and Aquatic Sciences
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• 제26권4호
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• pp.256-267
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• 2023

The suitability of any fish species for successful aquaculture requires basic information on its reproduction and growth. This study investigated some facets of the reproductive biology of Synodontis shall (Mochokidae) from River Siluko in Nigeria. Fish samples were collected forth-nightly for a duration of fourteen (14) months-March 2015 to April, 2016 with the assistance of artisanal fishermen. Fishes were identified using taxonomic guides and standard techniques were used for determination of sex ratio, gonad maturation and fecundity. Linear regression method was used to define the correlation between fecundity and fish length, body weight and ovary weight. Results showed that sex ratio did not indicate a significant divergence (p > 0.05) from the 1 male to 1 female distribution ratio (1:1.41). Gonad morphology revealed paired gonads. Testes and ovaries were classified into four maturity stages: immature, resting, ripening and ripe. Gonadosomatic index ranged from 0.04 to 5.68 (males) and 0.03 to 20.19 (females). Absolute fecundity ranged from 1,014 to 4,520 eggs (mean = 2,592 eggs) and did not correlate significantly (p > 0.05) to ovary weight. This study has contributed to existing data on the biology of freshwater fish species in Nigeria and provided valuable information for fishery management tools in the conservation and utilization of this valuable freshwater fish species.

• 수산경영론집
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• 제54권3호
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• pp.29-43
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• 2023

The United States is Korea's important trading partner, ranking third (13.7%) in exports of fishery products in Korea. The impact on exports to the United States is expected to be significant if the seafood import provisions under the MMPA are implemented in 2024 accordingly. It is expected that documents proving production information will be required for all items when exporting to the U.S. Therefore, this study attempted to examine the current status of exports and exporters in order to understand the actual conditions of major fishery products exported to the United States. Besides, there are currently no official system and procedures in Korea to prove production information for all fishery items, so we tried to suggest implications by examining distribution channels for major export items to the U.S. In this study, five items including seaweed and halibut as domestic aquaculture items, tuna and squid as deep-sea fishing items, and fish cake using imported raw materials were selected as the target items for distribution channel investigation. In addition, this study is meaningful in that it investigated the routes from production to processing, distribution, and export of each item and identified detailed distribution channel for major items exported to the U.S.

• 수산해양교육연구
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• 제26권5호
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• pp.935-940
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• 2014

점농어, Lateolabrax maculatus 암컷의 GSI변화는 실험개시시에 $0.51{\pm}0.05%$였고, 사육 90일 후인 실험종료시에는 대조구(자연광주기)에서 $1.07{\pm}0.09%$인데 비해 9L:15D구에서 $1.93{\pm}0.06%$로 가장 높았으며, 15L:9D에서 $0.32{\pm}0.07%$로 가장 낮은 값을 보였다. 수컷의 GSI변화는 실험개시시에 $0.16{\pm}0.05%$였으며, 실험종료시에는 대조구의 경우 $0.75{\pm}0.05%$인데 비해 9L:15D에서 $1.89{\pm}0.12%$ 가장 높았으며, 15L:9D에서 $0.22{\pm}0.06%$로 가장 낮은 값을 보였다. 암컷의 혈중 E2 변화는 실험개시시에 $125.8{\pm}9.5pg/ml$였으나 실험종료시에 대조구에서 $226.0{\pm}13.62pg/ml$였으며, 9L:15D에서 $296.3{\pm}15.0pg/ml$로 가장 높았고 15L:9D에서 $138.5{\pm}7.9pg/ml$로 가장 낮은 값을 보였다. 혈중 testosterone은 실험개시시에 $172.5{\pm}14.5pg/ml$였으나, 실험종료시에 대조구에서 $194.3{\pm}23.6pg/ml$였으며, 모든 실험구에서 대조구보다 낮은 값을 보였다. 혈중 $17a20{\beta}OHP$ 농도는 실험개시시에 $174.0{\pm}28.5pg/ml$였으나 실험종료시에 대조구에서 $193.5{\pm}13.4pg/ml$였으며, 대조구가 나머지 실험구에 비해 높은 값을 보였다. 혈중 testosterone의 농도는 실험개시시에 $125.0{\pm}5.1pg/ml$였으며 실험종료시에 대조구에서 $259.3{\pm}33.1pg/ml$였으며, 9L:15D에서 $370.5{\pm}27.5pg/ml$로 가장 높았고 15L:9D에서 $112.3{\pm}8.7pg/ml$로 가장 낮은 값을 보였다. 수컷의 혈중 $17a20{\beta}OHP$ 농도는 실험개시시에 $205.3{\pm}15.1pg/ml$였으며, 실험종료시에 대조구에서 $196.3{\pm}17.0pg/ml$였으며, 다른 실험구에 비해 가장 높은 값을 보였다.

• 한국컴퓨터정보학회논문지
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• 제17권10호
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• pp.61-69
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• 2012

삼면이 바다인 우리나라의 연안에 번식력과 포식성이 매우 강한 아무르불가사리의 개체수가 매년 급증하고 있다. 더욱이 아무르불가사리는 살아있는 어패류를 먹기 때문에 양식 어민들의 피해가 매우 크다. 따라서 불가사리를 구제하거나 불가사리의 개체수의 변화 및 이동 경로 파악 등을 위하여 수중 영상에서 불가사리 개체를 인식하는 기술은 매우 중요하다고 할 수 있다. 본 논문에서는 아무르불가사리의 형태적 특징 분석을 이용한 개선된 인식 방법을 제안하였다. 제안한 인식 방법은 아무르불가사리의 형태적 특징인 오목과 볼록에 대한 추출 정보가 부족한 경우를 위해 제안된 개선된 인식 방법이다. 바다 속에서 촬영되는 불가사리의 영상에서 불가사리의 형태적 특징을 모두 추출하는 것은 매우 어렵다. 따라서 제안하는 인식 방법은 다양한 아무르불가사리 영상에서 개체를 인식하는데 효과적이다. 실험결과, 제안한 기법의 인식률은 92.5%로 기존 기법보다 우수한 성능을 보였다.

• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.475-482
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• 2011

In this research, we have attempted to estimate the water quality of fish farms in terms of parameters such as water temperature, dissolved oxygen, pH, and salinity by employing observational data obtained from a coastal ocean observatory of a national institution located close to the fish farm. We requested and received marine data comprising nine factors including water temperature from Korea Hydrographic and Oceanographic Administration. For verifying our results, we also established an experimental fish farm in which we directly placed the sensor module of an optical mode, YSI-6920V2, used for self-cleaning inside fish tanks and used the data measured and recorded by a environment monitoring system that was communicating serially with the sensor module. We investigated the differences in water temperature and salinity among three areas - Goheung Balpo, Yeosu Odongdo, and the experimental fish farm, Keumho. Water temperature did not exhibit significant differences but there was a difference in salinity (significance <5%). Further, multiple regression analysis was performed to estimate the water quality of the fish farm at Keumho based on the data of Goheung Balpo. The water temperature and dissolved-oxygen estimations had multiple regression linear relationships with coefficients of determination of 98% and 89%, respectively. However, in the case of the pH and salinity estimated using the oceanic environment with nine factors, the adjusted coefficient of determination was very low at less than 10%, and it was therefore difficult to predict the values. We plotted the predicted and measured values by employing the estimated regression equation and found them to fit very well; the values were close to the regression line. We have demonstrated that if statistical model equations that fit well are used, the expense of fish-farm sensor and system installations, maintenances, and repairs, which is a major issue with existing environmental information monitoring systems of marine farming areas, can be reduced, thereby making it easier for fish farmers to monitor aquaculture and mariculture environments.

• Fisheries and Aquatic Sciences
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• 제27권8호
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• pp.525-532
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• 2024

The strategy of cultivating healthy fish by manipulating their gut microbiota composition using probiotics is crucial for establishing sustainable fish farms. Information on the gut microbiota composition of healthy fish is important for the efficient development of probiotics and the aquaculture strategies that would apply them. This study assessed the gut microbiota composition of farmed olive flounder according to the growth stage to provide useful information for the development of probiotics. The fish were classified according to their weight, and the intestines of five juveniles weighing less than 100 g and five subadults weighing between 400 and 800 g were used for analysis. The results of alpha diversity analysis confirmed higher richness and diversity in the subadult group than in the juvenile group. Beta diversity analysis revealed clear boundaries and distances between the groups; however, individuals within each group were similar. The two groups showed marked differences in their gut microbiota composition. Phylum-level analysis revealed that the most abundant phylum was Proteobacteria in the juvenile group and Firmicutes in the subadult group. Notably, genus-level analysis revealed that Vibrio accounted for more than 50% of the total composition in the juvenile group. Linear discriminant analysis effect size revealed that the genera Vibrio, Photobacterium, and Leuconostoc were representative of the juvenile group, whereas 19 genera, including Lactococcus and Vagococcus, were representative of the subadult group. Thus, information on the representative microorganisms abundantly present in the intestines of healthy olive flounder can be considered for the selection and development of a probiotic genus for olive flounder farming.

• Animal Systematics, Evolution and Diversity
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• 제29권4호
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• pp.272-278
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• 2013

Accurate identification of fish and fish products, from eggs to adults, is important in many areas. Grey mullets of the family Mugilidae are distributed worldwide and inhabit marine, estuarine, and freshwater environments in all tropical and temperate regions. Various Mugilid species are commercially important species in fishery and aquaculture of many countries. For the present study we have chosen two Mugilid genes with different phylogenetic signals: relatively variable mitochondrial cytochrome oxidase subunit I (COI) and conservative nuclear rhodopsin (RHO). We examined their diversity within and among 9 Mugilid species belonging to 4 genera, many of which have been examined from multiple specimens, with the goal of determining whether DNA barcoding can achieve unambiguous species recognition of Mugilid species. The data obtained showed that information based on COI sequences was diagnostic not only for species-level identification but also for recognition of intraspecific units, e.g., allopatric populations of circumtropical Mugil cephalus, or even native and acclimatized specimens of Chelon haematocheila. All RHO sequences appeared strictly species specific. Based on the data obtained, we conclude that COI, as well as RHO sequencing can be used to unambiguously identify fish species. Topologies of phylogeny based on RHO and COI sequences coincided with each other, while together they had a good phylogenetic signal.

• 한국어병학회지
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• 제28권2호
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• pp.99-107
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• 2015

Despite its economic importance as an aquaculture species, the molecular and genetic information regarding physiologically important elements in rock bream (Oplegnathus fasciatus) is not completely understood. Rab proteins play a vital role in cellular mechanisms and immunity as one of the key regulators of membrane trafficking. In this investigation, a Rab gene, named as RbRab-5C-like, was identified from Oplegnathus fasciatus. RbRab-5C-like protein exhibited high homology with Rab proteins of other species and possessed signature characteristics of Rab proteins with four conserved cysteine residues. Phylogenetic analysis showed that RbRab-5C-like clustered with other fish counterparts. The RbRab-5C-like genomic sequence possesses six exons and five introns. Transcriptional analysis revealed that RbRab-5C-like was ubiquitously expressed in all examined tissues with the highest expression occurring in the liver. While the structural and homologic characteristics of RbRab-5C-like suggest a strong conservation of this element in different species, its mRNA distribution implies a wide range of biological significance in rock bream.