• Fisheries and Aquatic Sciences
• /
• v.5 no.3
• /
• pp.212-218
• /
• 2002

The response behavior of a fish school to an approaching vessel was observed using scanning sonar. The evaluation using six parameters, which signify characteristics of school shape and behavior by sonar image processing, was proposed. Ten fish schools were analyzed and among them, three fish schools were identified for their changing shape, swimming direction, and swimming speed. Moreover, by tracing fish schools on stack of sonar images, these fish schools were seen to exhibit an apparent change of school shape and behavior. Therefore, the evaluation method of fish school behavior using six characteristic parameters indicating fish school shape and behavior by sonar image processing is useful.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.35 no.3
• /
• pp.237-241
• /
• 1999

It was investigated that the condition of fishing ground gave what kind of effect school type in relation to the property for the target school after the vertical temperature profile and school type were observed when tuna purse seiner for tuna purse seine was operated in the western pacific Ocean around the equator between December 12, 1993 and January 26, 1994. The results are as follows;1. This study divided fish schools associated with drift objects, a one targeted-operation, and the pelagic migrating fish schools that are another one for the property. The total of 23 operations were complected including 6 that targeted fish schools associated with drift objects and 17 that targeted pelagic migrating fish schools. It was known that the main operation was conducted on pelagic migrating fish school.2. Average and standard deviation of the depth of the surface mixing layer was 86.0m and 13.8m for fish schools associated with drift objects. 61.6m and 13.0m for pelagic migrating fish schools, respectively. The average depth of the surface mixing layer of the pelagic migrating fish schools was lower when compared to the fish schools associated with drift objects however the concentration of standard deviation was higher than those fish schools associated with drifted objects. Accordingly, it was assumed that the effect of vertical temperature profile for pelagic migrating fish school was higher than the fish schools associated with drift objects.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.22 no.1
• /
• pp.11-18
• /
• 1986

Schooling behavier to a fishing gear and estimation of the volume of fish school in set net have ~ been studied by making use of such techniques as visual observations, underwater cameras, under- water televison. However, all of these observation techniques are subject to restrictions caused by illumination, underwater visibility, underwater transparent and sea conditions. For the above mentioned reasoa, one of the most effective method by this time become generally known a method using fish finder. In this paper, in order to control the fishing ground of set net effectively and to develope the telemetric fish finder, the experiments for the target strength, underwater shape of fishing gear, schooling behavier and volume of fish school with fish finder were performed at Galgott fishing ground of set net located Keouje Island, 15th-24th July and 18th-20th October in 1985. The results of these experiment showed that a method using fish finder in fishing grOlllld of set net is available for estimating distribution and school size, fish behavier in relation to a fishing gear and underwater shape of fishing gears.

• Journal of the Korean Society of Food Culture
• /
• v.26 no.1
• /
• pp.53-62
• /
• 2011

The middle school subjects were 65.8% girls and 34.2% boys. Seniors were most abundant at 56.3%. The most abundant location was Gyeonggi-do (54.7%), and 69.3% of subjects were living with 4?5 family members. Approximately 56% of the mothers had graduated from high school, and 58.1% were unemployed. The mother most often prepared the food (78.4%), fish was eaten mostly in the home, and taste was the most important factor (62.6%). The preferred home food menu was fish because it is healthy, and the main cause for disliking the school meal service was poor quality dishes compared to a home cooked meal. The acceptance and type of fish were proportional. Rice was the most favored dish to eat with fish and scored 3.97, the highest rank. Approximately 50% answered that fish was nutritious, and a significant difference was observed regarding the mother's educational background (p<0.05). Students who never had a lecture about fish answered that fish was not nutritious, which showed a significant difference with education (p<0.05). Approximately 44% of students ate fish 2?3 times per week, and male students showed a significantly higher intake of fish than female students (p<0.05). The poorly educated disliked fish the most, and the higher frequency intake of fish resulted in a significantly higher percentile (p<0.001).

• Kosin Medical Journal
• /
• v.33 no.3
• /
• pp.415-421
• /
• 2018

Cases showing complications such as esophageal injury, deep neck infection, and mediastinitis caused by accidental ingestion of fish bone are common. But ingestion of fish bone rarely causes perforation of the gastrointestinal tract or an intra-abdominal abscess. We report herein a case of a 78-year-old man with a periumbilical mesenteric abscess caused by fish bone which was ingested unconsciously. The fish bone was found in the terminal ileum and it was removed by colonoscopy. The patient improved and he was discharged after systemic antibiotic therapy. Occasionally, when patients swallow fish bone without a foreign body sensation, clinicians should suspect perforation caused by fish bone in case of an intra-abdominal abscess of unknown cause.

• The Journal of Fisheries Business Administration
• /
• v.51 no.2
• /
• pp.1-13
• /
• 2020

The purpose of this study is to analyze consumer preference for fish farm HACCP certification using conjoint analysis. This study used raw flatfish product to evaluate the fish farm HACCP. In this study, 500 consumers were surveyed using panel survey and stratified sampling. In the recognition analysis, the farm HACCP certification system was found to be highly recognized by consumers. It can be seen that the brand assets accumulated by existing food and agricultural HACCP certification were transfered to the fish farm HACCP and absorbed. Consumers perceived fish farm HACCP certification as similar one with existing food and agricultural HACCP. Conjoint analysis evaluated three levels factors. The attributes and levels evaluated were : price(25,800 won, 28,400 won, 31,000 won), certification(fish farm HACCP, seafood traceability, and non certified), and origin(domestic, JEJU, and WANDO). The important levels were in order of price(40.8%), certification(30.2%) and origin(29.0%). We found that consumers give higher utility to fish farm HACCP certification compared with non certified and seafood traceability certification. Market simulation results showed that the fish farm HACCP product has 12%p higher market share than non certified products. Seafood traceability certification showed 4.6%p higher market share than non certified products.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.34 no.1
• /
• pp.6-12
• /
• 1998

The moving behaviour of Yellowtail Seriola quinqueradiata schools in the main-net of a large scale set-net was investigated in relation to the catching function of the funnel-net by a scanning sonar. The investigation was took place in the Kishihata set-net fishing ground located in Nanao city Ishigawa prefecture, Japan from Nov. 9 to Nov. 13, 1992. The obtained results are summarized as follows; 1. Fish schools showed the greatest number at the playground in the morning and at the bag-net in the afternoon. The fish schools remained long time in the main-net. 2. The rate of fish school through the funnel-net was smaller than that of fish school which is though the playground and bag-net. Because the Yellowtail school changed the shape of school in passing the funnel-net. 3. The rate of entering the bag-net was 24%, among the fish school heading to the outer funnel-net. But, the rate of escaping to the playground was 27%, among the fish school heading to the inner funnel-net. It seems that the structure of the outer funnel-net was not enough to lead the fish to the bag-net. However, the structure of the inner funnel-net was very effective at preventing escape. 4. It is appropriate to haul the net in the morning in considering the number of accumulated fish in the bag-net during the survey.

• Parasites, Hosts and Diseases
• /
• v.56 no.5
• /
• pp.509-513
• /
• 2018

Present study was performed to survey infection status of digenetic trematode metacercariae in 2 alien fish species, Micropterus salmoides (largemouth bass) and Lepomis macrochirus (bluegill), in 2 rivers draining Chungcheongbuk-do, Republic of Korea. A total of 107 largemouth bass and 244 bluegills were caught in Daecheong-ho (ho=lake) and Musim-cheon (a branch of Geum-gang), in Chungcheongbuk-do April-July 2015. Additionally, 68 native fish of 5 species, i.e., Zacco platypus, Hemibarbus longirostris, Carassius auratus, Pseudogobio esocinus and Puntungia herzi, were caught from the same water bodies. All of the fish collected were examined by artificial digestion method. The metacercariae of Centrocestus armatus, Clinostomum complanatum, Metagonimus sp. and Diplostomum spp. were detected from 4 out of 5 native fish species in Daecheong-ho. However, any metacercariae were not found from 87 M. salmoides and 177 L. macrochirus in Daecheong-ho. In Musim-cheon, metacercariae of Exorchis oviformis and Metacercaria hasegawai were detected from 78% Z. platypus and 34% L. macrochirus, but any metacercariae not found in M. salmoides. We report here that the 2 alien fish species were less infected with the metacercariae than the native ones. Surveys on the metacercariae in the alien fish species in geographically various rivers should be undertaken for better understanding on the role of alien fish species in the trematode infections in Republic of Korea.

• Fisheries and Aquatic Sciences
• /
• v.5 no.3
• /
• pp.206-211
• /
• 2002

The aim of this study was to obtain the basic data on the fish school behavior change to approaching vessel and fish species identification by means of their swimming speed. The surveys were carried out for the juvenile southern blue fin tuna and other fish schools off Esperance, western Australia from January to March 1999. We observed changes of fish school behavior in response to the approaching vessel using 360-degree scanning sonar. The results showed that, a horizontal direction index used to quantify a change of fish school behavior did not identify dependence of a radial distance and a swimming speed. A Mann­Whitney test conducted using the horizontal swimming speed of both species identified by sonar specialists, did not reveal a significant difference.

• Journal of Institute of Control, Robotics and Systems
• /
• v.21 no.10
• /
• pp.924-929
• /
• 2015

In this paper, we suggest a phase difference algorithm inspired by weakly electric fish. Weakly electric fish is a fish which generates electric field though its electric organ in the tail. The weakly electric fish search for prey and detect an object by using electrolocation. The weakly electric fish have Jamming Avoidance Response (JAR) to avoid jamming signal. One of pulse-type weakly electric fish Gymnotus carapo also have JAR to reduce the probability of coincidence of pulses. We analyze this response signal and design the phase difference algorithm. We expect that simple algorithm inspired by weakly electric fish can be used in many engineering fields.