• The Journal of Fisheries Business Administration
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• v.31 no.1
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• pp.33-54
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• 2000

This study intends to examine the distribution channel of the most popular ten species caught in Korean coastal and off-shore fisheries with the aid of interviewing fish brokers and cooperative staffs in fish landing markets. This paper finds and emphasizes the following three suggestions, in order to improve the present scheme of fish distribution system. Firstly, annual catch of 10 kinds of fishes is successively decreasing in quantity from 1994 to 1998. Moreover annual catch shows larger variations than fish price and cooperative sales quantity. Except sea eel and sole, cooperative sales accommodates more than 90% of the fish landed, accounting for the small variation in cooperative sales, which invalidates the effectiveness of the free distribution system adopted by the government. Secondly, diversified distribution channels are exposed according to the nature of the fish, the method to harvest, and the quantity caught. Large retailers such as discount stores, super chains and home shopping institutions are actively involving themselves in direct purchase in fish landing markets. Through the analysis of distribution routes, the general distribution channel of fresh fish has been found such as producers longrightarrow fish brokers in landing markets longrightarrow fish brokers in central wholesale markets longrightarrow wholesalers longrightarrow retailers longrightarrow consumers. In order to reduce distribution margin through the analysis of distribution function and distribution margin, this paper presents a new distribution channel such as producers longrightarrow fish brokers in landing markets longrightarrow wholesalers longrightarrow retailers longrightarrow consumers. Thirdly, to improve the fish landing markets, this paper suggests the M&A of uneconomical fish landing markets or renovating toward wholesalers, introduction of processing services and improvement of processing facilities, subsidizing fish brokers in landing markets, revitalization of marketing divisions in cooperatives and improvement in fish auction system.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.6
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• pp.1055-1062
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• 2014

Hydroacoustic surveys were conducted for spatio-temporal distribution and size estimation of fish in the Yongdam reservoir, Korea, from April to July 2014. Acoustic data were collected along acoustic transects using a 120 kHz scientific echosounder. The received acoustic data were the in situ acoustic target strength (dB) and nautical area scattering coefficient ($m^2/mile^2$). Data on fish behavioral patterns and size were collected using a DIDSON acoustic camera at stationary stations. Fish were mainly distributed in the center channel and close to the outer Yongdam reservoir. Acoustic density of fish in the summer season were higher than in the spring season. The seasonal vertical distribution pattern of fish aggregations may be strongly related to the vertical temperature structure. The size distribution of fish obtained from an acoustic camera correlated well with the acoustic size of fish from an echosounder.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.44 no.4
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• pp.403-412
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• 2011

Hydroacoustic surveys were performed to clarify the density and spatial distribution of fish upstream and downstream of Changzhou Dam in the Pearl River, China, with regard to the condition of the spillways. Fish were densely distributed in the forebay of the upstream dam and the average fish density was 0.22 individuals/$m^3$ under open spillways on 24 June 2010, but when the spillways were closed on 25 June 2010, the fish in the upstream dam dispersed and the average fish density decreased to 0.007 individuals/$m^3$. Meanwhile, the average fish density in the downstream region was 0.28 individuals/$m^3$ before the spillway was opened on 24 May 2010, but it decreased to 0.08 individuals/$m^3$ on 26 June, just after the spillway was closed. The vertical distribution of fish upstream of the dam was not consistent. The target strength (TS) of fish upstream of the dam was larger than that of fish in the downstream region, although the distribution of TS was similar between the upstream and downstream regions. Therefore, we concluded that while numerous fish could swim to the upstream region while the spillways were open, closed spillways obstructed fish migrating upward from the downstream region.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.1
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• pp.80-89
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• 2021

In Korea, marine fish landed at ports are randomly sampled on a periodic basis (e.g., daily or weekly), and body sizes (e.g., lengths and weights) of those sampled fish are measured. The motivation for our study is whether or not such measurements reflect the size distribution, especially the length distribution of fish landed (= a population), because such length measurements are key data for a length-based assessment model. The current sampling method is to sample fish landed at ports by body size group (e.g., very small, small, medium, large, very large), using the sampling weights as the number of boxes by body size group. In this study, we showed that length composition data about fish sampled by the current method did not represent the length frequency distribution of the fish landed, and suggested that an alternative sampling method should be applied of using the sampling weights as the number of fish landed by body size group. We also introduced a method for determining an appropriate sample size.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.59 no.3
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• pp.242-252
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• 2023

In this study, we aimed to determine the seasonal distribution and biomass of fish in Samcheok marine ranching area (MRA) of Republic of Korea using the scientific echosounder. Fish trap and gillnets were used to identify fish species in the survey area, and dB-difference method was used to estimation the spatio-temporal distribution and density of fish. The results showed that the dominant species in Samcheok marine ranching area were Chelidonichthys spinosus, Sebastes inermis, Hexagrammos otakii and Tribolodon hakonensis. The spatio-temporal distribution of fish showed that fish had a relatively higher distribution at night than during the day. In addition, the density of fish by season was highest at night in July at 34.22 g/m² and lowest in April at 0.42 g/m².

• Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.276-282
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• 2024

The present study was conducted to investigate the behavior and distribution characteristics of fishes near an artificial reef close to the waters of Uljin marine ranch. A 200-kHz, dual-beam frequency transducer was attached to the side of a ship for acoustic measurements. The fish formed small groups in the bottom layer near the artificial reef around the afternoon-sunset period; at night, the fish did not form groups and remained individually scattered. During dawn-sunrise and morning, the fish formed groups again and were found near the upper and middle layers of the artificial reef. High density of fish occurred near the middle of the nautical zone during morning, afternoon-sunset, and dawn-sunrise, periods; at nighttime, the distribution was uniform across the entire zone. Moreover, the mean Nautical Area Scattering Coefficients (NASC, m²/nmi²) value was highest during dawn-sunrise at 400.2 m²/nmi², similar during night and morning (100.5 m²/nmi²), and lowest during afternoon-sunset (20.1 m²/nmi²). The present study is expected to provide the background for understanding the behavioral characteristics of fish living near artificial reefs and estimating the density and biomass of fish.

• The Journal of Fisheries Business Administration
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• v.36 no.1 s.67
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• pp.103-120
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• 2005

This study aims to examine the change of fish market(魚物市場) and inland brokers(客主, kaegju) on Gunsan(群山), (1899-1919). The increasement of productive capacity in the agriculture and the development of exchange economy in the late period of Chosun Dynasty activated the distribution of fishery products. As a result, the inland brokers who participated in the production and distribution of fishes grew largely. They made the basement of fishery modernization by providing the funds for the fisheries and making the national distribution network. But Japanese fishermen began to hold the domestic market as the Japan government supported legislatively and economically after the opening ports of Korea. On the contrary, the distribution of fishery products had the characteristics different from the production of some. The case of Gunsan which opened in 1899 showed these characteristics as Gunsan is a short distance from Kangkyung(江景), one of three biggest markets and was a base of fishery, That is to say, though the fishery merchants from Japan set up 'a fish market'(魚市場), they didn't hold the sales network on Gunsan, Because the inland brokers on Gunsan had a sales network and began the socio-economic movement. It goes without saying that the instability of price, the difficulties of charge and the racial taste difference in fish made the fish sales from Japan confronted with the difficulties. After Japanese Imperialism enforced the Company Law, the Market Regulation, the Chamber of Commerce Law before or after 1910, Korean inland brokers were disprited and Japanese 'fish market' began to grow largely. These phenomena appeared on Gunsan, too. Especially, the opening of a railway was the main factor which strengthened Japanese 'fish market'. After 1915, Japanese 'fish market' on Gunsan defeated the distribution network of inland brokers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.47 no.3
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• pp.283-291
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• 2014

This study assessed dominant fish species, and the characteristics and spatio-temporal distribution of fish schools using acoustic and catch data in the marine ranching area (MRA) of Yeosu in July and August 2013. Acoustic data were collected using a 200-kHz dual beam transducer, and catch data were analyzed through auction data generated by a set net installed in the MRA. More fish schools were detected by acoustic methods in July than in August. The temporal distribution of fish schools differed between July and August, but, many schools demonstrated a high mean volume scattering strength (SV) around artificial reefs. Additionally, the characteristics of fish schools detected by echograms and the species caught by set nets differed between July and August. The dominant fish species were Engraulis japonicus, Pampus argenteus, Scomberomorus niphonius, and Pampus echinogaster in July, and approximately 85% of the catch in August consisted of Scomberomorus niphonius. Therefore, hydro-acoustic tools are useful for estimating fish school characteristics in large areas over a short period. To determine species, it is important to conduct net sampling surveys during the acoustic surveys. However, if a database of fish school characteristics organized by species is constructed through continuous study, it could be possible to identify fish species through acoustic methods alone.

• The Journal of Fisheries Business Administration
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• v.34 no.2
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• pp.91-107
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• 2003

Distribution of fish products from Tongyoung Marine ranching can be classified by three routes such as street-stall, live fish transportation vehicles, and wholesale markets neighboring unloading ports. These methods of distribution, however, have been restricted by limited distribution right, difficulties to differentiate fish prices from other surfaces, simple marketing channels. The ratio of cultured live fish circulated in market is increasing while naturally caught live fish is decreasing and the fresh fish shows a little of increasing rate. Consumers purchasing routes mainly depend on the live fish transportation merchants. For fresh fish traditional market plays an important role in trade. Convenience for consumers and quality of products are main factors in making decision of purchases. Bargaining power, however, belongs to the live fish transportation merchants. The demand of special markets for live fish was very strong, and the convenience and quality are relatively important required factors. Catch from Tongyoung Marine ranching has very good reputation as the possibility of being a good brand. Expecting possibility of quality differentiation was higher than price differentiation specially. The possible conclusion of a contract of a supply was suspicious however. Preliminary quality evaluation revealed that the catch is better than the cultured but worse than naturally grown fish. A merchandising is to be in a better position in the formation of prices by giving $\ulcorner$brand image$\lrcorner$ to potential consumers. The target markets are retail stores such as restaurants for raw fish and final consumers. The staple markets are retail stores. Possible items of products are live fish, fresh fish for cook, and fresh fish for raw fish. It is necessary for the catch to be informed as new functional products that have been improved in safety and quality, since the product positioning is similar but not well known to consumers. To secure a brand it is required to register a trademark, eco-label product design or packing, use real name in tranction, introduce recall system, and put label. Price higher than naturally grown live fish should be targeted. Establishing broad distribution channel, wholesale market, franchise are required. To secure enough catch and control shipment of products facilities of containing live fish are necessary. Instead of dealing with live fish only, it would be better to. sell fresh fish and live fish simultaneous. Strategically promotion focuses on advertisement of Marin ranching at first and then focuses on the catch from the marine ranching.

• Journal of Korean Society on Water Environment
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• v.33 no.6
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• pp.626-639
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• 2017

Based on an ecological monitoring in a Korean stream (Gapyeong), Habitat Suitability Index (HSI) of nine fish species was developed for three physical habitat factors : current velocity, water depth and substrate. The species were chosen based on their abundance and frequency in the fish community of the Gapyeong stream. The Weibull model was used as the probability density function to analyze the distribution and number of each fish species according to the three identified physical factors, which showed good results. This HSI equation has advantages because it statistically expresses habitat preferences of fish species simply and clearly. From that, we can quantitatively deduce the central tendency and variation of environmental factors for fish distribution. The selected fish species showed different preferences for each habitat factor respectively. Although there are some exceptions, the distribution and abundance of individual species of nektonic fish (Zacco koreanus, Zacco platypus, Microphysogobio longidorsalis and Pungtungia herzi) were positively skewed to deep water and fine substrate while riffle-benthic fish (Koreocobitis rotundicaudata and Coreoleuciscus splendidus) were normally distributed at the shallow and coarse substrate zone. It seems that the species showing the positively skewed distribution to the current, Z. koreanus, Z. platypus, M. longidorsalis and P. herzi have adapted themselves to the fast current and have expanded their niche.