• The Journal of Fisheries Business Administration
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• v.39 no.3
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• pp.111-137
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• 2008

Fisheries resources living in inland have continuously reduced due to over-fishing and development thoughtless for the environment. Inland fisheries that target the fisheries resources have been also confronted by several problems such as insufficiency of inland fisheries management systems, inconsistent fisheries management system, inferior infrastructure of inland fisheries, and decreasing fishermen's real income. These problems have demotivated fishermen who want to focus on fishing and farming activation. Therefore, this paper provides alternatives of reorganization for turning to sound and healthy inland fisheries industries by reviewing Korean inland fisheries management systems. The reorganization should be preferentially granted resource management by water system considering geographical conditions, seed release, and establishment of fisheries order for maintenance of sound and healthy inland fisheries. Also, the reorganization should be moved toward the competitive strengthening of "company unit" for inland fisheries, the nourishment of fisher-oriented fisheries management system, strong relationship among inland fishermen, the systematic management of inland fisheries, the strengthening of guidance service for inland fisheries, the extension of infrastructure related to fisheries production, the development of inland fisheries policy including public people, and the improvement of inland fisheries system and law reflecting various users of inland fisheries.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.1
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• pp.54-64
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• 2018

The age and growth of Pleurogrammus azonus in the coastal of Gangwon-do, East Sea were determined, from monthly samples of commercial catches, caught by the gill net and set net fishery from January to December in 2008. Gonadosomatic index (GSI) began to increase in September, and reached the maximum between November and December. After spawning GSI began to decrease from January. The annuli of P. azonus are formed once a year, with the boundary between opaque and translucent zones forming from December to January. The relationships between fork length (FL) and body weight (BW) were $BW=0.005FL^{3.240}$($R^2=0.963$) for females and $BW=0.006FL^{3.238}$($R^2=0.946$) for males. The FLs at annuli formation in otoliths were back-calculated from the otolith-length relationship and were adjusted to von Bertalanffy growth curves to $FL_t=70.54(1-{\exp}^{(-0.099(t+1.188))})$ for females and $FL_t=51.87(1-{\exp}^{(-0.135(t+1.697))})$ for males. Until the age of 3 years, males grew faster than females; however, from the age of 4 years, females grew faster than males. In the future, we want to study the relationship between early growth and water temperature changes in the East Sea.

• The Journal of Fisheries Business Administration
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• v.31 no.2
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• pp.1-9
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• 2000

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.50 no.4
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• pp.583-594
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• 2014

This study was performed to estimate biomass and provide management guidance through population ecological characteristics, including growth parameters, instantaneous coefficients of natural and fishing mortalities, and age at first capture of the starry flounder, Platichthys stellatus and olive flounder, Paralichthys olivaceus of Korea. For describing growth of this species, a von Bertalanffy growth model was adopted. The von Bertalanffy growth parameters estimated from a non-linear regression for starry flounder were $L_{{\infty}}=48.25cm$, K=0.16/yr, and $t_0=-1.48$, respectively and those for olive flounder were $L_{{\infty}}=86.46cm$, K=0.26/yr, and $t_0=-0.29$, respectively. Biomass of Platichthys stellatus was estimated by direct biomass estimation method was 2.6 M/T, that was estimated by indirect method was 13.4 M/Tt. Those of Paralichthys olivaceus were estimated as 10.1 M/T, 19.3 M/T, respectively. An yield per recruit analysis showed that the current yield per recruit on Platichthys stellatus was about 48.2 g with F=0.646/yr and the age at first capture ($t_c$) 1.35yr, that on Paralichthys olivaceus was about 167.6 g with F=1.121/yr and the age at first capture ($t_c$) 1yr.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.42 no.4
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• pp.210-216
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• 2006

The circle hook experiments were conducted to compare the catch rates of target and bycatch species between J hook and circle hooks in the tuna longline fishery of the eastern Pacific Ocean between $1^{\circ}48'S-7^{\circ}00'S\;and\;142^{\circ}00'-149^{\circ}13'W$ from July 15 to August 12, 2005. In the target species group no significant differences among 3 types hook, between size 4.0 traditional tuna hooks(J-4) and size 15 circle hooks(C15), and between C15 and size 18 circle hooks(C18) were revealed, but significant differences were found between J-4 and C18. In the bycatch species group significant differences were found among 3 types hook, between J 4 and C15, and between J-4 and C18, but no significant differences were revealed between C15 and C18. Large circle hook(C18) had the lowest catch rate for tunas and for other fishes, and the small circle hook(C15) had lowest rate for billfishes and sharks. The length distributions for bigeye tuna are very similar for the 3 hook types. There were very slight differences in length size between hook types in the bycatch species.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.45 no.1
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• pp.22-33
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• 2009

Ecological risk assessment(ERA), developed in Australia, can be used to estimate the risk of target, bycatch and protected species from the effects of fishing using limited data for stock assessment. In this study, we employed the ERA approach to estimate risks to tunas, billfishes, sharks, sea turtles and other species by the Korean tuna longline fishery in the Western and Central Pacific Ocean using productivity and susceptibility analyses of the ERA based on low(<1.30), medium(1.30-1.84) and high risk(>1.84). Albacore, bigeye, yellowfin, skipjack and bluefin tunas were generally evaluated in the medium risk. The susceptibility of tuna species, however, had higher risks than the productivity. Billfishes were also at medium risk, while sharks were at high risk by the tuna longline fishery. The risk of productivity was generally high, because most sharks caught by the tuna longline fishery have high longevities, i.e., over 10 years, including ovoviviparous species. Susceptibility, which is related with the selection of fishing gear, was also high, because the longline fishery has no gear modifications to prevent bycatch of protected species. Not only target tuna species were influenced by the tuna longline fishery in the Western and Central Pacific Ocean, but also nontarget species, such as pomfret, mackerels rays, sea turtle were done. Ecosystem-based fishery assessment tools, such as productivity and susceptibility analysis(PSA), have the ability to provide broad scientific advice to the policy makers and stakeholders.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.6
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• pp.740-746
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• 2010

This study standardized the catch per unit effort (CPUE) of bigeye tuna (Thunnus obesus) caught by the Korean longline fishery in the Pacific Ocean. The study used a general linear model (GLM) to standardize the CPUE using catch and effort data aggregated by year, month, and $5{\times}5$ degrees of latitude and longitude in the tropical Pacific Ocean from 1982 to 2008 (except for 1988 and 1989). Explanatory variables in the GLM analysis included year, month, subtropical area, and number of hooks between floats (HBF). The study area and HBF were subdivided into three subtropical areas and six classes, respectively. During the study period, the standardized CPUE was significantly related to the nominal CPUE. The standardized CPUE declined sharply, as compared to the nominal CPUE, after the mid 1990s. In particular, the decline in the standardized CPUE in all subtropical areas in the 2000s was clearer than that of the nominal CPUE.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.430-440
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• 2010

To investigate the catches of jack mackerel fishery, a series of fishing experiments was conducted in the high seas of the southeastern Pacific Ocean ($30^{\circ}S-38^{\circ}S,\;82^{\circ}W-95^{\circ}W$) during the period of 9 August to 18 December, 2003 by commercial fishing vessel and research vessel. The number of 205 tows fishing was carried out in the southeastern Pacific Ocean. The total catch was 1,988 ton and CPUE was 2.4 ton/hour. CPUE showed high values in the frontal zone during the survey. Main target species caught from the experimental fishing were the jack mackerel, Trachurus murphyi (98.1%) and chub mackerel, Scomber japonicus (1.9%) as bycatch. Body length of the jack mackerel was different between female and male. The high mean catch per unit effort of jack mackerel was showed when the fishing ground of jack mackerel fishery was over the $110^{\circ}W$ in the southeastern Pacific Ocean. But the fluctuation of the catch per unit effort in the western part of fishing ground was not matched with those year. Reliable physical and oceanographical information will be useful for the efficiency of fishing activity. According to the result of monthly movement of center of fishing ground, the fishing activity of jack mackerel fishery was performed northward in the southeastern Pacific Ocean as time passes.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.43 no.4
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• pp.329-338
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• 2007

Data collected by on-board observers and from experimental surveys during 2004-2006 were analyzed to figure out the status of shark bycatch in Korean tuna longline fishery. Results obtained from 10 surveys indicated that 14, 13 and 1 species of shark were incidentally caught in Korean tuna longline fishery operated in the Pacific, Indian and Atlantic (Mediterranean) Ocean, respectively, and that shark bycatch accounted for about 29-31% of the total catch. Sharks brought aboard were processed in 3 ways; out of 1,127 sharks observed, 575 sharks (51.0%) were discarded after finning, 299 sharks (26.5%) were stored frozen after finning for future use and 253 sharks (22.4%) were released into the sea immediately after caught. The fin to body weight ratio of sharks was estimated to be about 4.7% which is similar to the guideline of 5% established by the international fisheries organizations. The underestimate of shark bycatch in Korean tuna longline fishery was significant because it was general practice that fishermen on-board did not count the discarded shark as a catch.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.4
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• pp.344-348
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• 2006

The ecological characteristics and stock biomass of the Shiba shrimp, Metapenaeus joyneri, in Korean waters were determined, using fishery data from the Ministry of Maritime Affairs and Fisheries (MOMAF) and available length frequency data. The instantaneous coefficient of total mortality (Z) of M. joyneri was estimated to be 4.191year, and the annual survival rate (S) was 0.015. The estimated instantaneous coefficient of fishing mortality (F) for recent years was calculated to be 1.94/year. The age at first capture of M. joyneri was 0.71 years. Based on these parameters, the annual biomass of the M. joyneri stock was estimated using a biomass-based cohort analysis and data on the annual catch in weight at age for 1993-2004 in Korean waters. During the study period, the biomass of the shrimp peaked in 1994 at about 9,082 metric tons. Subsequently, it decreased to 500 metric tons in 1998.