• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.31 no.1
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• pp.15-23
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• 1995

In order to investigate the relation between the phytoplankton and the catch fluctuation of set net fishing grounds located in the coastal waters of Yeosu, phytoplankton observations on the fishing ground were carried out by the training ship of Yeosu, Fisheries University from April to November in 1990, and the data obtained were compared with the catch data from the joint market of yeosu fisheries cooperative society in 1990. The results obtained are summarized as follows: 1) The phytoplanktons were more appeared in summer than in spring or autumn and their quantity was much in the shore of Dolsan-do, and little in the offshore waters distributed in the shores of Sori-do and Sejon-do, Thus, the quantity of the planktons could be used for estimating the distribution of watermass. 2) The fishes caught by the set net were arranged in the order of catch amounts as follows: Spanish mackerel > Hair tail > Common mackerel > Sardine > Anchovy > Horse mackerel > Yellow tail. The catches of anchovy and Sardine were high in April to May and Hair tail. Horse mackerel and Common mackerel were caught from June to October. But Spanish mackerel were caught during the whole period of fishing. 3) The catches by set nets showed a correlation with the quantity of phytoplanktons. The planktons appeared most in the inner waters. influenced largely by the inflow of land waters in summer. and the catches were high in summer when the offshore water was distributed least. Therefore, the most important factor influencing the catches were regarded to be the productivity of food organism in inner water into which abundant nutrients were supplied by the inflow of land waters. That is, the fluctuation of catches by set nets seemed to be influenced mainly by the productivity of food organism.

• 한국해양학회지
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• v.19 no.2
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• pp.217-227
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• 1984

Fish samples were collected by a trap net during 1981∼82 at the mouth of Cheonsu Bay to determine seasonal fluctuations in abundance and species composition. Examination of a series of trap net catches indicated that trap net data could be used, at least, for a qualitative analyses of a fish community and for a quantitative study of some pelagic fishes of Cheonsu Bay. Of the 64 species collected, a few temporal components predominated in abundance because of great seasonal fluctuations of water temperature. The early spring catch showed a low abundance value, and two cold weather seasonals, juvenile Enedrias fangi and Ammodytes personatus predominated in number and in weight. The number of species, abundance value in number and in biomass showed a peak in late spring when fishes move into bay for spawning and feeding after over-winterinig in the sea. Three pelagic species or warm weather seasonals, Harengula zunasi , Ammodytes personatus and Konosirus punctatus, predominated in abundance values. In this period night catch was significantly larger than day catch in terms of number of species, abundance in number and in weight Summer data showed a marked reduction of the number of species and abundance due to the loss of spawners probably by mortality or wide dipersion after spawning. A slight increase in abundance was observed in autumn by recruitment of the young-of-the-years. This catch was predominated by three juvenile fishes, H. zunasi, E. japonica and K. punctatus, which were the same species as in spring. The autumn catch showed no significant difference between day and night compositions.

• The Korean Journal of Malacology
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• v.28 no.2
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• pp.91-99
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• 2012

Corbicula japonica, belonging to Other Veneroida Family Corbiculidae, was distributed in the freshwater and brackish rivers, where was a sandy and shallow depth. Catch of C. japonica in the Seomjin River occupied at a large portion of the catch in Kyungnam Province, which was about 30% of total catch in Korea. C. japonica has little studied on biomass, scientific resources assessment and management, because of inaccurate catch report data in the Seojin River. In this study, we conducted scientific and systematic approaches under data limited situation with application of the potential fishery yield system for sustainable fisheries resources management. Estimation system of the potential fishery yield was consisted of 5 tier system. We have used to tier 1 and 2 which were demanded higher level of information than the other tiers. The potential fishery yields were estimated 77.66ton for tier 1 using commercial fishery-dependent data, and 129.82ton for tier 2 with fishery-independent survey data.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.15 no.1
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• pp.23-33
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• 1979

This paper was analysed based on the oceanographic and meteorological data complied from 1971 to 1977 for that search relationships among the fluctuation of sea condition and weather condition, and the catch of anchovy. In the year when heat loss from the sea surface in winter was maximum(in 1974, 658 Iy), temperature of midwater in summer was lower 2~4\ulcornerC than normal year. While heat loss was minimum (in1973, 487 Iy), temperature of mid water was higher 2\ulcornerC. When temperature of mid water of southern coast from June to August was higher than normal year, anchovy was caught good deal, but that was lower than normal year was bad fishing. When it had much precipitation (in 1973, 256mm), plankton was checked maximum (12cc) and also the catch of anchovy too (11, OOOm/t). While precipitation was minimum (in 1976, 123mm), plankton (3cc) and anchovy (2, 800m/t) was a litle. If we calcalate heat budget in winter, we can forecast temperature of mid-water in summer of following year. Therefore we may be able to forecast catch anchovy.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.2 no.1
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• pp.25-32
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• 1969

The estimated annual catch of river fishes in the lower part of the Naktong River was derived from the questionnaire, as a part of the fundamental investigation which was carried out for the development of fisheries In that region during the period of May 1967, to June 1968. The data were submitted by fishermen, and the area covered for the present investigation is shown in Fig.1. The annual catch of the region was estimated to be about 500 tons, excluding the mussel Cerbicula elatior. Prussian carp Carassius carassius was the largest in amount followed by com-mon carp Cyprinus carpio, and then goby Synechogobius hasta, Japanese eel Anguilla japonica, mullet Mugil cephalus, ect. and in that order. Major species of the fishes of this region belong to the carp family Cyprinidae, its species counting 23 from the collection during the observation period, and the total number of species was 40, these belonging to 14 families. But occasional severe drought heavily increase the salt content of the region, and at that time the major catch of fish becomes marine fishes such as Harengula zunasi, Clupanodon Punctatus, etc.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.30 no.4
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• pp.513-522
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• 1997

Annual variations In main fishing grounds of common squid with different angling and their fishing conditions in Korean waters were studied by analyzing catch and water temperature data. The main fishing grounds of squid angling fishery started to moved to the north in April and to the south in September in the last Sea of Korea. The catch of squid was related to the direction of thermal fronts. The catch was high when the thermal front was formed in the east-west direction, while there was low catch when the thermal front was formed in the south-north direction which runs parallel to the roast.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.11 no.1
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• pp.15-20
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• 1975

The catch per unit effort and the migration of Alaska pollack Theragra chalcogramma were deduced from the catch data of 1, 208 hauls of a stern trawler operated on and around the continental shelf east of the Kamchatka Peninsula and Kurile Islands from October 1974 to December 1975. Alaska pollack occupied more than ninety per cent of the total catch of approximately 17, 760 metric tons, while the cuttle and flat fishes occupied less than five percent. Beside those fishes, approximately 131 metric tons of Alaska pollack roe were produced during the voyage from February to April 1975. The mean catch per unit effort in each sub-area of fishing ground was approximately 15.5 metric tons and the peak of the CPUE occured in January and August. The CPUE in the continental shelf east of Kamchatka Peninsula ($50^{\circ}- 52^{\circ} N$ Lat) showed the maximum of 25-34 metric tons in August. The main fish school is thought to migrate southward speedily in August-September along the continental shelf from the Kamchatka Peninsula to the east of Kurile Islands. The CPUE on the continental shelf east of Kamchatka Peninsula was higher than that on the steeper continental slope. However, the CPUE on the steeper flank of the bank east of Paramushiru Island and Onekotan Island was remarkably higher than that on the relatively flat top of the bank. The small-sized fishes of less than thirty centimeter in fork length began to recruit in the fishing ground since August 1965.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.1
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• pp.48-55
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• 2016

The species composition and distribution of catches by dredge gear in the Yeongil Bay, Korea were investigated on a seasonal basis from February to November, 2015. Total catches consisted of 44 species and 35 families. They were 13 species of fish, 10 species of crustacea, 5 species of echinodermata, 5 species of gastropoda, 4 species of cephalopoda and 3 species of bivalvia. Major catch species was shellfish and had seasonal variations in catch. In spring and winter, the catch of ark shell (Scapharca broughtonii) was increased. Adversely, the catch of admas venus clam (Callithaca adamsi) increased in sunmmer and autumn. Species diversity indices was high as the value of 1.99 in spring, and low to the value of 0.34 in summer. In addition, multi dimentional scaling (MDS) indices also was high in spring as the value of 1.99. In summer, the index was low as the value of 0.34. Similarity analysis based on species data was transformed by fourth root. With the result of cluster analysis and MDS analysis, species was divided into two groups. The first group as Group A consists of winter and spring species and another was Group B made of species in summer and winter.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.56 no.4
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• pp.277-291
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• 2020

In order to understand characteristics on bycatch of Korean tuna purse seine fishery, especially operations associated with Fish Aggregating Device (FAD) in the Indian Ocean, we conducted analyses related to bycatch by school association type (unassociated school, FAD associated school and log associated school) using the data collected by scientific observers from 2016 to 2018. The FAD used by Korean tuna purse seine fishery in the Indian Ocean was a drifting FAD, which belongs to non-entangling FADs according to the category proposed by the International Seafood Sustainability Foundation (ISSF). The target species of Korean tuna purse seine fishery are skipjack, yellowfin and bigeye tunas, accounting for 99% of the total catch. The ratio of bycatch was 0.97% in total catch and the discard accounted for less than 1%, indicating that most catch was retained on board. In terms of bycatch ratio by school association type, it accounted for 0.12% for unassociated school, 1.09% for FAD associated school and 1.25% for log associated school. As for the catch proportion of shark species by school association type, it accounted for 0.01% for unassociated school, 0.11% for FAD associated school and 0.10% for log associated school, which showed that unassociated school type was the lowest to affect bycatch of non-target and shark species. Given the proportion of bycatch compositions, however, it is considered that FAD associated school of Korean tuna purse seine fishery has less caught bycatch species of non-target and shark, compared to other fleets operating in the Indian Ocean.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.52 no.6
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• pp.685-695
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• 2019

To assess the state of Todarodes pacificus fisheries, we examined changes in major fishing and ecological characteristics by comparing jigging fishery data between high (HCLP, 1996-2000) and low (LCLP, 2013-2017) catch level periods. The peak catch occurred in October during the HCLP compared with December during the LCLP. The average catch per unit effort was higher during the HCLP (1.3 tons/jigging vessel) than LCLP (1.0 ton/jigging vessel). During the HCLP, fishing grounds were highly concentrated in the southwestern East Sea and Yamato bank, whereas during the LCLP, the distribution of grounds extended to the South Sea, West Sea, and northern East Sea (near Russian waters) at a low density. Water temperatures in the main fishing ground in the southwestern East Sea were higher at 0, 50, and 100 m depths during the LCLP than HCLP. Meanwhile, the average mantle length of catches decreased from 23.5 cm during the HCLP to 22.21 cm during the LCLP. The mantle length at 50% maturity also decreased between the two periods from 22.06 (HCLP) to 18.77 cm (LCLP). These findings will help guide future management strategies for T. pacificus.