• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.35 no.3
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• pp.227-236
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• 1999

Temperal and spacial analysis for catches have been drawing up a catch distribution chart and analysing catches and CPUE(Catch Per Unit Effort) using catch data with purpose of obtaining basic data to establish a selective method of effective fishing the tuna purse seine fishing ground.The temperature profile section and catch was surveyed to analyse the effect of catch in relation to the fishing ground environment.The results are as follows ;1. As for the catch variation between 1983 and 1984, the catch mainly took place on150^{\circ}E$, and after that it moved eastward enlarging the range of catch. In the monthly catch variation between January and February, the catches mainly happened on 135$^{\circ}$~ 150$^{\circ}$E, and then moved to the gradually westward. However, from July it moved to the South and from October Southeast.2. As to the eatch ratio for the school associated with the drifted object, the pelagic migrating school and the school associated with the biological objects, the catch ratio for the school associated with the drift objects was the highest. The catch ratio for the school associated with the drifted object was high in June, July and November whiles between January and March for the pelagic migrating school.3. SST(Sea Surface Temperature) was around 28~29^C$ on the observing line of 137^{\circ}E$ and the catches took place in the north equatorial counter-current situated on around $5^{\circ}~6^{\circ}N$. SST in the northern summer was 1^C$higher than winter and it was about 29~30^C$. The catch happened with the center of north equatorial counter-current. The reason why the catch mainly took place on the north equatorial counter-current is that main catch of tuna purse seine was the school associated with drift objects. It is thought that the fishing grounds are made in waters that have many drift objects like drift logs from the coast.

• The Plant Pathology Journal
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• v.35 no.6
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• pp.585-597
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• 2019

A disease forecast model for Marssonina blotch of apple was developed based on field observations on airborne spore catches, weather conditions, and disease incidence in 2013 and 2015. The model consisted of the airborne spore model (ASM) and the daily infection rate model (IRM). It was found that more than 80% of airborne spore catches for the experiment period was made during the spore liberation period (SLP), which is the period of days of a rain event plus the following 2 days. Of 13 rain-related weather variables, number of rainy days with rainfall ≥ 0.5 mm per day (L_day), maximum hourly rainfall (P_max) and average daily maximum wind speed (W_avg) during a rain event were most appropriate in describing variations in airborne spore catches during SLP (S_i) in 2013. The ASM, Ŝ_i = 30.280+5.860×L_day×P_max-2.123×L_day×P_max×W_avg was statistically significant and capable of predicting the amount of airborne spore catches during SLP in 2015. Assuming that airborne conidia liberated during SLP cause leaf infections resulting in symptom appearance after 21 days of incubation period, there was highly significant correlation between the estimated amount of airborne spore catches (Ŝ_i) and the daily infection rate (R_i). The IRM, ${\hat{R}}_i$ = 0.039+0.041×Ŝ_i, was statistically significant but was not able to predict the daily infection rate in 2015. No weather variables showed statistical significance in explaining variations of the daily infection rate in 2013.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.218-226
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• 2013

The objective of this study is to estimate the optimal net twine thickness of drift net for yellow croaker. The filed experiments of the fishing performance were conducted with three kinds of drift net with different monofilament diameters (No.3=0.284mm, No.4=0.330mm, No.5=0.370mm) the total eight times in the southwest coastal sea of Korea. And the physical properties tests on the monofilaments of experimental net were carried out to estimated breaking load and softness in dry and wet conditions, respectively. From the results, the No.3 mono. was the strongest break load per unit area in dry and wet conditions. And the softness showed that the No. 3 mono. was the most soft than another experimental monofilaments. The fishing performance was; the No. 3 drift net showed the most catches. Conversely, the catches of No. 4 and No. 5 drift net showed the half on the catches of No. 3 drift net. Consequently, the diameter of monofilament in the drift net for yellow croaker should carefully choose to consider the economic sides such as the amount of catches and the cost of catches.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.194-201
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• 2022

Purpose: This study investigated the relationship between climate factors and the catches in Korean offshore fisheries in recent three decades (1981 to 2010). Method: This study focused on seven types of fish species preferred in Korean cuisine. In the study, 10-year moving averages were used so that long-term trends could be easily identified. Results: Both air temperature and sea surface temperature (SST) on the coast of Korea rose in the period (p < 0.05). The rise in SST was significantly correlated with the rise in air temperature (p < 0.05), but not with precipitation. In the 2010s compared to in the 1981, catches of anchovy and squid greatly increased (p < 0.05), while catches of Alaska / walleye pollock has been almost extinct over the past 30 years. As such, cold-water fish species decreased or disappeared, and their fishing ground was replaced by warm-water fish species. Conclusions: These findings indicate that fish species caught in offshore fisheries of Korea have changed due to climate change, especially warming. This suggests that the warming of the Korean Peninsula may have a significant impact on the supply of fishery products and food security to Koreans in the near future.

• Korean Journal Plant Pathology
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• v.11 no.3
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• pp.230-237
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• 1995

Airborne and waterborne ascospores and conidia of Botryosphaeria dothidea were collected in apple orchards at Suwon and Chunan in 1992 through 1994. Both waterborne and airborne spores were first detected in mid April to early May. Thereafter, spores were abundant in early June to late August and present until early December. Rainwater collections contained much more conidia than ascospores during the apple growing seasons. Airborne ascospores catches, which were also detected on humid days without measurable rainfall, were much more than airborne conidia catches. High amounts of ascospores were detected in early times of apple growing season, whereas most conidia catches occurred in later times of the season. The number of waterborne conidia and airborne ascospores was positively correlated with mean daily maximum, minimum, and average air temperatures during the trapping periods (p=0.01). However, no significant correlation was found between the number of spores and the total precipitation during the trapping periods.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.2
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• pp.197-207
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• 1996

The proportion of log-associated school catches by Korean tuna purse seiners in the western Pacific has shown a declining trend until recent years. During the period $1990\~1995$, log-associated school catches contributed $34.6\%$ to the total Korean tuna purse seine catch, representing quite a low level compared to the early phase of the purse seine fishery. Species compositions of both log-associated and free-school catches showed that skipjack, Katswonus pelamis, was dominant species and yellowfin, Thunnus albacares, followed, with the small amount of bigeye tunas, T. obesus, Yellowfin proportion was higher in free-school catches than in log-associated school catches. Log-associated school catches monitored during the scientific observation period were made of $60\%$ skipjack, $38\%$ yellowfin, and $2\%$ bigeye tunas, indicating the low skipjack and high yellowfin proportion compared with historical fisheries data based on logbooks. A total of 11 by-catch species were identified, of which sharks occurred together with tunas in all sets and yellowtail kingfish was the most abundant by-catch species. From the length distribution it was found that small yellowfin less than 70 cm mainly distributed around floating objects.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.909-917
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• 2017

In this study, we investigated the relationship between catches of yellowtail and water temperature at the set net fisheries of Gyeongsangbuk-do (Gyeongbuk) and Gangwon-do (Gangwon) off the east coast of Korea from May-November, 1980-2010. We also analyzed the water temperature and fluctuation of catches during the northward moving period (May-August) and southward moving period (September-November) using NOAA satellite images. Although the total catches fluctuated year by year, catches increased during the southward moving period when the water alongside the coast warmed. Yellowtail catches during the southward period in fall were higher than those during the northward period in spring or summer. The catch when the water temperature decreased was larger in Gyeongbuk than in Gangwon for all periods However, the catch when the water temperature increased was much larger in Gangwon than in Gyeongbuk. This indicates that high summer temperatures (> $25^{\circ}C$) affected the coast of Gangwon, with high water temperature ($20^{\circ}C$) maintained in the region during fall. Therefore, the increased catch in Gangwon was due to longer yellowtail presence caused by increased water temperature.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.33 no.2
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• pp.97-108
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• 1997

Variation of the catches and fishing grounds, and spawning ecology of Lophius litulon caught by large staw net were investigated from following as ; L. litulon caught through the year, and the peak in catches showed on January in winter, and the lowest catches showed on August in summer. The fishing grounds of L. litulon were located in the Yellow Sea and the East China Sea. And the main fishing ground was formed in the adjacent waters of Ilhyang-cho, where catches and CPUE were more than 50 M/T, 5 kg/haul, respectively, and the range of coefficient of variation(C.V) was 0.6~0.7. The spawning season of L. litulon was on March and April, when spawning area was formed in waters between Ilhyang-Cho and Cheju-Do. The fishing grounds distribution of L. litulon was obviously different with seasonal variation. Namely, in winter, the fishing grounds were mainly formed in the western waters of Cheju-Do, and on March and April( in spawning season), the fishing grounds were densely formed in the adjacent waters of Ilhyang-Cho, and after May, the fishing grounds were widely dispersed towards in the Yellow Sea and the East China Sea with temperature upgrade.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.1
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• pp.10-17
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• 2011

Biodegradable octopus pot was developed to reduce plastic pollution problem in the sea and fishing trouble between fishermen. It can be expect to recycle other wasted biodegrade fishing gear. Experimental fishing was carried out to understand the difference in fishing efficiency between Polyethylene (PE) octopus pots and biodegradable (Polybutylene Succinate and Polybutylene adipate-co-terephthalate) octopus pots which was tried to make in this study in the sea. There were caught by 237 numbers of fishing during the experimental period. Among the 237 numbers of fishing, 160 or 67.5% were PE pots which were more than the biodegradable pots. A comparison of the monthly catches between the PE pots and biodegradable pots shows that the catches were overall higher in the PE pots than in the other pots. The result is very similar with the comparison of total catches by each type of the pots. In terms of bycatch, the number of species, amount of catches and the number of fishing with bycatch were more significant in the biodegradable pots than in the PE pots.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.41 no.3
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• pp.179-187
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• 2005

This study was conducted in order to the experiment of bottom trawl fisheries in the sea mount of central northern pacific($30^{\circ}-40^{\circ}N$, $170^{\circ}-175^{\circ}E$), during the period of July 1 to August 25, 2004 by commercial trawl ship. Fishing experiment was carried out by bottom trawl, with the codend of 110mm mesh size. The number of 101 test fishing was done in the sea mount of central northern pacific during 56 days and the total catches were 198,593kg as 18 fish species, and CPUE/day and catches/day were 8.3 hours towing time and 3,546kg. Catch ratio according to each fishing ground was higher with the order of B, C, and E, and catches for B was 7,171.0kg during the towing time of 13.2 hours. Main target species were Pseudopentaceros richardsoni and Beryx splendens, there was 14.9% of damage ratio for fishing gears on catching the target fishes inhabiting on the rough sea bottom. Catches by water depth was the order of 300m below, 301-350m, 451-500m and 351-400m. It is thought that there was no problem on the mesh size because most of fishes caught from the experimental fishing was 30cm over.