• International journal of advanced smart convergence
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• v.12 no.4
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• pp.208-216
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• 2023

The purpose of our study is to design datasets for Artificial Intelligence learning for cold sea fish farming. Salmon is considered one of the most popular fish species among men and women of all ages, but most supplies depend on imports. Recently, salmon farming, which is rapidly emerging as a specialized industry in Gangwon-do, has attracted attention. Therefore, in order to successfully develop salmon farming, the need to systematically build data related to salmon and salmon farming and use it to develop aquaculture techniques is raised. Meanwhile, the catch of pollack continues to decrease. Efforts should be made to improve the major factors affecting pollack survival based on data, as well as increasing the discharge volume for resource recovery. To this end, it is necessary to systematically collect and analyze data related to pollack catch and ecology to prepare a sustainable resource management strategy. Image data was obtained using CCTV and underwater cameras to establish an intelligent aquaculture strategy for salmon and pollock, which are considered representative fish species in Gangwon-do. Using these data, we built learning data suitable for AI analysis and prediction. Such data construction can be used to develop models for predicting the growth of salmon and pollack, and to develop algorithms for AI services that can predict water temperature, one of the key variables that determine the survival rate of pollack. This in turn will enable intelligent aquaculture and resource management taking into account the ecological characteristics of fish species. These studies look forward to achievements on an important level for sustainable fisheries and fisheries resource management.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.4
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• pp.291-300
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• 2007

The crayfish-shaped artificial bait for octopus drift line is manufactured, into which is made to insert ordinary bait. The effects of the artificial bait are confirmed through the analysis of octopus' behavior in the laboratory in comparison with the existing bait of pig-fat skin, and the investigation of the octopus catch on the sea, and in addition, the examination of the water quality in relation to the bait to be inserted into the artificial bait is done together. The artificial bait is red in color, 10.5cm in the length of the body, and 29g in weight. The octopus behavior in relation to the bait in the laboratory has shown a good result in which more than 30% of the octopuses rushed to the artificial bait. In the analysis of the octopus sitting time by the bait, the octopus stayed longer with the artificial bait(63.7%) than the pig-fat skin(25.1%). The octopus sitting time at the artificial bait inserted with frozen squid(48.8％, 44.6％) is shown to be longer than that of the pig-fat skin(36.9％) or boiled fish paste(21.2％). In the analysis of sitting frequency to the bait, the case of the artificial bait(total 17 times) was more than that of the pig-fat skin(total 3 times), and the case of the artificial bait with frozen squid attracted the octopuses more frequently than that of the pig-fat skin or the boiled fish paste. In the field experiment, the fishing boat A(Manseon-ho, 1.22tons) caught the total 93 octopuses, while the fishing boat B(Ilho-ho, 0.73tons) caught the total 154 octopuses, all of which weighed less than 9.0kg. In the comparison with the total catch, the case with the artificial bait was a little higher than that of the pig-fat skin($^{**}p\;<\;0.05$). In the analysis of the water quality in relation to the baits, the COD showed the descending order of frozen squid(0.57mg/g), boiled fish paste(0.18mg/g), and pig-fat skin(0.10mg/g), and the case with frozen squid was the highest and the case of the pig-fat skin, lowest. The total phosphorus, like the COD, showed the highest in frozen squid(0.02mg/g), and in case of the total nitrogen, unlike the COD, the pig-fat skin was shown to be the highest(0.006mg/g).

• Journal of Korean Society of Environmental Engineers
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• v.35 no.9
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• pp.666-674
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• 2013

Physical disturbance, which induces a lack of flow rate, frequently occurs in freshwater ecosystem. Due to this, it is required to provide a new fish shelter to resolve. We installed a pilot scale test-bed to scrutinize the relationship between water level and the influence of fish shelter. The proposed ADP (artificial deep pool) is a fish shelter which composed of concrete materials. From the monitoring results in test-bed, it was observed that the population of fish was the highest at the 0.5 m in depth from the water level of experimental pond. But it was more appropriate for shallow water level (<0.3 m) to conserve the total number of fish by increasing the number per unit area despite of lower inner temperature and DO than outer environment. Therefore, inner of ADP was more efficient lentic system for fish to live due to higher WCS, OS, SS, and TS. In addition, there was a relative abundance of WCS fish species such as Acheilognathus koreensis (A. koreensis), Carassius carassius (C. carassius). Considered these results, it is suggested that ADP is appropriate to use for fish shelter and habitat for the fishes in lentic ecosystem.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.3
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• pp.179-187
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• 1977

This study intended to investigate the shape of the artificial fish reefs settled in the waters of Seogwipo, and the thronging of fish schools into them. The results obtained are summarized as follows : 1. Two types of artifical fish reef, circularized vertical type which is composed of Cryptomeria branches and parachute type, were put off the coast of Seogwipo at $33^{\circ}14'05'$ N Lat., $126^{\circ}34'40'$ E Long. The setting place is located 0.4 sea-mile away from natural fish reefs, at 25 m in depth. And its sediment is consisted of f. S. and Sh. 2. Maximum velocity of wind drift current was 15.28 cm/sec at 15 m depth. The Current direction was $20.5\%$n in the WSW. 3. Maximum fluid resistance of the circularized vertical type to current and wind waves showed about 890 kg, and the weight of sand bags attached to the fish reef totaling 1,200 kg was enough to sustain fish reef. 4. As maximum fluid resistance of the parachute type to current and wind waves was 106.3 kg, the retaining force of sand bags was enough to sustain the fish reef, but vinyl canvas and expansion materials were so poor that the fish reef was lost by the sea current and wind waves. 5. Sixteen species of fish among 53 usually caught in this area were thronged into the artificial fish reef. The fish catches comprized Porgy (Pagrosomus major) $23\%$, black kook fish (Sebastes (Mebarus) intermis) $13\%$, sand borer (Sillago sihama) $11\%$, Sebastes (Pteropodus) hubbsi $7\%$, and file fish (Monacanthus cirrhifer) $6\%$. According to the submarine observations by fivers, it was confirmed that a lot of fish larvae thronged in the middle part of the fish reefs.

• Ocean and Polar Research
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• v.41 no.1
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• pp.11-18
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• 2019

This acoustic experiment noted that fish species in Chilam-Gijang marine ranching area were more densely distributed in the pelagic zone during nighttime than daytime. In each season, the gill nets caught 15 different fish species and the estimated average target strengths were -44.0 dB and -44.4 dB for autumn and winter surveys, respectively. The estimated autumn fish biomass were 7.7 tons and 26.0 tons during daytime and nighttime, respectively. Winter biomass was 2.27 tons and 30.97 tons during daytime and nighttime, respectively. Different fish species form schools that exhibit different movements and behaviors, and thereby occupy varying water layers. These results explained the estimated fish biomass, and variation with seasons and time of the surveys around artificial reefs in Chilam Bay, Korea.

• Journal of Ecology and Environment
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• v.48 no.1
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• pp.32-48
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• 2024

Background: Longitudinal connectivity in river systems strongly affects biological components related to ecosystem functioning, thereby playing an important role in shaping local biodiversity and ecosystem health. Environmental DNA (eDNA)-based metabarcoding has an advantage of enabling to sensitively diagnose the presence/absence of species, becoming an efficient/effective approach for studying the community structure of ecosystems. However, little attention has been paid to eDNA-based biomonitoring for river systems, particularly for assessing the river longitudinal connectivity. In this study, by using eDNA we analyzed and compared species diversity and composition among artificial barriers to assess the longitudinal connectivity of the fish community along down-, mid- and upstream in the Hotancheon from the Geum River basin. Moreover, we investigated temporal variation in eDNA fish community structure and species diversity according to season. Results: The results of species detected between eDNA and conventional surveys revealed higher sensitivity for eDNA and 61% of species (23/38) detected in both methods. The results showed that eDNA-based fish community structure differs from down-, mid- and upstream, and species diversity decreased from down to upstream regardless of season. We found that there was generally higher species diversity at the study sites in spring (a total number of species across the sites [n] = 29) than in autumn (n = 27). Nonmetric multidimensional scaling and heatmap analyses further suggest that there was a tendency for community clusters to form in the down-, mid- and upstream, and seasonal variation in the community structure also existed for the sites. Dominant species in the Hotancheon was Rhynchocypris oxycephalus (26.07%) regardless of season, and subdominant species was Nipponocypris koreanus (16.50%) in spring and Odontobutis platycephala (15.73%) in autumn. Artificial barriers appeared to negatively affect the connectivity of some fish species of high mobility. Conclusions: This study attempts to establish a biological monitoring system by highlighting the versatility and power of eDNA metabarcoding in monitoring native fish community and further evaluating the longitudinal connectivity of river ecosystems. The results of this study suggest that eDNA can be applied to identify fish community structure and species diversity in river systems, although some shortcomings remain still need to be resolved.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.12
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• pp.5083-5088
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• 2010

An implementation of NPC AI(artifical intelligence) is similar with real world's flocking can increase fun factor of game. To this end, we design fish flocking patten of analyzed real world, implement using Ogre engine in this paper. To determine the usefulness of implemented fish flocking, we compare fish flocking in real world with implemented fish flocking. Implemented behavioral patterns of fish flocking show similar behavioral patterns of fish flocking in real world.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.859-877
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• 2012

In this study, Echo-sounder($E_s$) monitoring methodology was applied to test environmental impacts of artificial weirs(SCW and JSW) in the Yeongsan River on fish community and habitat structures at first time, and was compared with conventional fish sampling methodologies($C_s$). For the Es monitoring in the fields, parallel transect methods was employed in determining the survey distance interval with every 125 m within the upper-lower 2 km of the weirs. Four different fish sampling gears such as casting nets, kick nets, fyke nets, and gill nets were used for applications of $C_s$ monitoring methodology. According to the Echo-sounder monitoring, fish density, expressed as a number of individuals per square meter, along the longitudinal axis of the weir was significantly greater(JSW, t = 3.506, n = 30, p < 0.001) in the down-river reach of the weir than in the up-river reach. Also, fish density along the vertical water column was highest at mid-depths of Seungchon weir, which has simple habitat substrates, while fish density was highest at hypolimnetic depth of Juksan weir. According to fish sampling by the $C_s$ methodology, the fish compositions decreased as the river goes upward, and significant differences(JSW, t = 0.248, n = 30, p < 0.05) in the compositions of fish species occurred between up-reach and down-reach of the weirs. The dominant species near the two weirs were Opsarichthys uncirostris amurensis, Hemiculter eigenmanni and Coilia nasus. Overall, our fish and habitat data, based on $E_s$ and $C_s$ monitoring methodologies, suggest that the weirs disturbed the rivers due to initial habitat disturbances by the weir constructions as well as the barrier roles of weirs on fish passage and migrations. More long-term scientific and systematic fish impact monitoring and assessments($E_s$ and $C_s$) are required in the future to predict changes of ecological structures and functions on the constructions of the weirs.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.4
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• pp.295-303
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• 2004

In order to estimate the effect of ceramic artificial reefs on the fisheries resources enhancement, we have studied the variation of catch and species, which were caught by trammel net on the three fishing grounds of ceramic artificial reef, natural reef, and control(non-reef)in the coast of Geomun-do, Korea from 2001 to 2003. Catch per unit effort (CPUE ; g/panel) of fishing ground with the ceramic artificial reef area was 1,621.9g, it was about 67.9% higher than the natural reef area 333.3% higher than the control area. The catch of fish with the ceramic artificial and the natural reef area was not significantly different based on statistical analysis of Tukey test, whereas the relationship between the ceramic artificial reef and the control area was significantly different (p<0.05). Monthly mean number of species caught by the artificial reef area, the natural reef area and the control area was no difference by ANOVA test. The catch of fish was highest in November and lowest in May, whish was associated with the natural reef and the control area. The dominant species were demersal fishes living around rock such as Pagrus majir, Thamnaconus modestus, Stephanolepis sirrhifer, Pleuronichthys curntus, and Ostracion cubicus in the artificial reef area, but demersal of migratory fishes in the natural reef and the control area.

• Parasites, Hosts and Diseases
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• v.51 no.1
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• pp.107-114
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• 2013

Fishborne trematode (FBT) metacercariae were investigated in fish from 3 Provinces of Lao PDR. Total 242 freshwater fish of 40 species were collected in local markets of Luang Prabang (59 fish of 16 species), Khammouane (81 fish of 19 species), and Saravane (97 fish of 14 species), and each of them was examined by artificial digestion method. Four species of metacercariae (Opisthorchis viverrini, Haplorchis taichui, Haplorchis yokogawai, and Centrocestus formosanus) were detected. O. viverrini was detected in 35 fish (14.5%), and their density was 252 per infected fish (Luang Prabang, 88 metacercariae in 5 fish; Khammouane, 187 in 6 fish; Saravane, 303 in 24 fish). H. taichui was found in 102 fish (42.1%), and their density was 485 per infected fish (Luang Prabang, 260 metacercariae in 38 fish; Khammouane, 1,084 in 23 fish; Saravane, 359 in 41 fish). H. yokogawai was detected in 92 fish (38.0%), and their density was 222 per infected fish (Luang Prabang, 362 metacercariae in 17 fish; Khammouane, 126 in 20 fish; Saravane, 214 in 55 fish). Metacercariae of C. formosanus were found in 8 fish (3.3%), and their density was 3 per infected fish. In the present study, it has been confirmed that FBT metacercariae, in particular, H. taichui, H. yokogawai, and O. viverrini, are highly prevalent in fish from Luang Prabang, Khammouane, and Saravane Province, Lao PDR.