• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.1
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• pp.30-38
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• 2014

Hydro-acoustic survey was carried out to investigate the spatial characteristics of fish distribution near two artificial reefs (AO: large octagonal semi-sphere and AC: combined custom built) having different types in Jeju marine ranching area. The survey system consisted of scientific echo sounder (EK60), DGPS system, and ECDIS (Mecys). Field survey was conducted on August and October 2012 with star survey and line transect survey line method, and species composition was investigated from gill net fishing survey. The acoustic signals from individual fishes and small fish schools were mainly recorded around AO, but large and strong signals from large fish school were mainly detected in the top layer of and the water column near AC. The echogram suggest that the fish aggregation for the two types of AO and AC exist the significant difference in fish species and spatial distribution pattern.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.3
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• pp.232-238
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• 2010

The moving ranges and behavior of four wild abalones, Haliotis discus hannai, were measured by an acoustic telemetry technique. The shape of the sea bottom of the experimental area was surveyed by a bathymetry system and three self-recording type acoustic receivers were used for monitoring the behavior and measuring the movement range. The abalones (WA1-WA4) attached acoustic tags were released and measured the movement during ten months. Three abalones (WA1, WA3 and WA4) were successively detected around the released point during the experiment and were moved to the V2 area where water depth is deeper than the V1 area. The change of inhabitation depth was also detected from the depth sensor of WA4. As the result, abalones were moved to deeper water area accordance with the decrease of the water temperature. The moved ranges of abalones were approximately 200 - 400m from the release point.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.4
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• pp.331-339
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• 1996

It is most important to understand the behaviour of fish in case of the betterment of the current fishing gear and methods or the development of the conditioning by acoustic sound in marine ranching. This investigation has been attempted to provide for the prediction of the response action of fish to acoustic sound. The experimental fish was conditioned with sound and bait. As the acoustic sound for stimulus, the pure tone of sine waveform at the frequency of 200Hz was used. This pure tone was determined from previous investigation about hearing ability of walleye pollock Theragra chalcogramma. The fork length of walleye pollock used in this experiment was 385~450mm. The conditioning proceeding was recorded in the video tape recorder. Frequency of appearance in the feeding area was analyzed with computer and video tape recorder. The position of fish was tracked using the mouse cursor and picture mixed on the superimpose board. The response of conditioned fish to sound stimulus was appeared in the 8th day firstly. The conditioned fish remembered the stimulus sound for 4 days. Average frequency of appearance in the feeding area during the 30 seconds sound projection or 1 minute after the sound stimulus was 51%, and was higher than before it.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.1
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• pp.88-97
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• 1999

Auditory thresholds were determined by means of a conditioned response to sound stimuli at frequencies 80, 100, 200, 300, 500 and 800 Hz for a 10 black rock fish, Sebastes schlegeli. The conditioned response was a change of a cardiac rhythm. It was established through an electric shock as unconditioned stimulus, and could be monitored on an oscilloscope. A stable acoustic condition was obtained by suspending the fish in a small cage at fixed position in the test tank. The sensitive frequencies ranged from 80 Hz to about 800 Hz, showing the best frequency around 100 Hz where the mean threshold value was 90.5 dB. A gradual rise below 300 Hz and a relatively sharp turn above 500 Hz were indicated in the audiogram. The method presented here seemed to be useful for a rapid determination of the audiogram of fishes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.55 no.2
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• pp.105-120
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• 2019

The species composition and abundance variations of fishery resources in the adjacent marine ranching area, Tongyeong, Korea, were investigated by shrimp trawl, gill net, and longline during the period of July, September, and October in 2016. During the study period, the total catch were 8,522.9 kg with 34 species from the shrimp trawl, 32 species from the gill net, and nine species from the longline. The dominant species were different by gear, which were Hypodytes rubripinnis and Parapercis sexfasciata in the shrimp trawl, Platycephalus indicus and Raja kenojei in the gill net, and Conger myriaster and Scomber Japonicus in the longline. In terms of spatial distribution, Yongchodo showed the highest total catch in number as well as of in weight while Jukdo showed the lowest total catch in number and Bijindo showed the lowest total catch in weight. The amount of demersal fish resources in the survey area estimated as 301 ha, was 99,396 individuals which was converted to be 8,552.9 kg. The amount of demersal fish resources by gear were of trawling area, which area is 127 ha, were 76,251 and 3,489.5 kg, 74 ha in the gill net and longline survey area was 16,213 and 3,457.3 kg, and the other 100 ha area was 6,932 and 1,606.1 kg. In this study, the minimum resources for demersal fish is 61,687 and 4,265.2 kg, and the maximum is 149,439 and 14,197.9 kg.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.6 no.3
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• pp.141-147
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• 2013

An artificila fish-reef is a artificail structure installed at marine ranching under the littoral sea. The artificial fish-reefs provide the function of fish spawning ground, habitation, nursery ground, and enhance the productivity of fising industry devastated by environmental pollution. After the installation of artificila fish-reef, continuous monitoring is demanded to check the validity of artificila fish-reef plan. However, the support of follow-up management is impossible because of the lack of a huge budget and professional manpower. Therefore, the artificial fish-reef combined with IT devices can be controled IT devices through the IT artificial fish-reef management system, and collect the marine environment information for the fair management. This paper shows the example of systematization for the management of artificial fish-reef based on the marine rancing management system.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.138-146
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• 2006

The effects of night-lights on feeding by the black rockfish Sebastes inermis in the cage of the Tongyeong marine ranching area were investigated by analyzing the stomach contents of 200 individuals from July 2004 to August 2004. In night-lights groups, black rockfish consumed mainly copepoda, amphipoda and polychaeta; also those in control area fed on copepods, amphipods and polychaets. Copepods (57%) and amphipods (32%) were the major prey organisms for all study period in night-lights. While, major prey items in control area were copepods (88%). Growth of the black rockfish reared in night-lights conditions were significantly higher than that of those in control area.

• Korean Journal of Environmental Biology
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• v.24 no.2 s.62
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• pp.126-137
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• 2006

Effect of night-lights on zooplankton attraction has been studied in Tongyeong marine ranch area during the period from 12 July to 30 August, 2004. Each sampling has been carried out to collect zooplankton from both control area in natural waters experiment area of night-lights waters at night. A total of 43 taxa of zooplankton occurred during the study. Copepods showed the prosperity in species number with 15 species. Acartia erythraed and Copepodite occurred abundantly in night-lights waters. Zooplankton abundance appeared to increase in night-lights mainly due to the gathering of copepods and larvae through the study period. Average $3\sim166$ times of zooplankton abundance was recorded in night-lights when compared with that in control area of natural waters due to the gathering of copepods and larvae. Cluster analysis, based on monthly abundance data of the 13 most frequent species, showed that the species were seperated into two different groups: the photo-positive group and the photo-negative group.

• The Journal of the Acoustical Society of Korea
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• v.25 no.1
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• pp.7-13
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• 2006

Fisheries policy change from catching to farming requires more intensive consideration for aquaculture industry. The oceanic farm is a desirable cost effective aquaculture method. However. in odor to gather fish in the oceanic farm, eating sound or any attracting sound should be radiated through underwater loudspeaker. In this Paper, it has been found in literature that the frequency range responding to fish is about 16Hz to 13kHz but sensitive frequency range is about 150Hz to 2kHz and sound pressure level is about 100dB to 150dB reference $1{\mu}Pa$. Therefore, frequency range and output sound level of designed underwater loudspeaker has been specified as 150Hz to 3kHz and 100dB to 145dB reference $1{\mu}bar$. respectively To verify the stability and the endurance to the pressure of 40m water depth, manufactured underwater loudspeaker was examined before sea trial in manufactured water pressure tank which gives a maximum of 10 atmospheric Pressure. We experimented on acoustic characteristic with manufactured underwater loudspeaker under water depth of 10m.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.298-299
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• 2000

바다목장화 사업의 일환으로 치어의 방류효과 제고를 위한 기초적 연구로서 조피볼락을 대상으로 자연산 치어와 양식산 치어의 마취내성을 조사하였다. 어류에 미치는 스트레스는 마취, 저산소, 공기노출, 기아, 염분 등 여러 가지가 있겠지만, 이중 마취에 대한 내성의 측정은 어류의 마취제들이 마취작용뿐만 아니라 그 자체가 어류에 대하여 스트레스 요인으로도 작용하므로(Smit et al., 1979; Barton et al. 1982; 정준기 등, 1994), 어류의 건강도를 판정할 수 있는 간단한 방법으로 이용이 가능하다. 따라서 자원조성용으로 조피볼락 치어를 자연 생태계인 바다에 방류하였을 때, 새로운 수서 환경에 대한 적응 능력 판정의 척도로서 자연산 및 양식산 조피볼락 치어의 마취내성과 공기노출 내성 시험을 실시하였다. (중략)