• 한국수산과학회지
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• 제49권3호
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• pp.376-384
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• 2016

Seasonal catch distributions of large purse seines and daily landings of coastal set nets were analyzed to understand the migration path of the Spanish mackerel Scomberomorus niphonius around Korean waters. The Spanish mackerel start to move toward the coastal region in the South and West Sea in May for spawning and stay until July, when spawning finishes. Afterwards, they start to migrate to the East China Sea and the southern East Sea and are found irrespective of the onshore and offshore regions. Therefore, they disappear from the offshore region during the spawning season in June and July, and a new recruitment population of age 0 begins to inflow into the coastal fishing grounds in the South Sea and West Sea in August, one month earlier than in the Japanese coastal region of the East Sea.

• 한국환경과학회지
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• 제30권10호
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• pp.811-820
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• 2021

The population variation of Spanish mackerel (Scomberomorus niphonius) according to its major prey abundance was analyzed using monthly catches of coastal set net fisheries in the southern waters off Gyeongsangnam-do and eastern waters off Gyeongsangbuk-do of Korea from 2006 to 2019. The abundance of Spanish mackerel and its prey species fluctuated almost simultaneously with time lags of +2 to -2 months between the set net fisheries in the southern and eastern waters. The generalized additive model revealed that the abundance of Spanish mackerel was influenced by its prey species such as hairtail and anchovy in southern waters, and common mackerel and horse mackerel in eastern waters. The model deviance explained 49% and 42% of Spanish mackerel abundance in southern and eastern waters respectively. These results suggest that the abundance of Spanish mackerel is affected by seasonal migratory prey fish species in the coastal areas and can be linked to their northerly migration.

• 대한조선학회논문집
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• 제58권1호
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• pp.32-39
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• 2021

Korean coastal fishery suffers from profitability degradation due to a decrease in fisheries resources, pollution in coastal waters, fuel coast increase, and market opening for aquaculture products. The next generation Korean fishing vessel aims at the improvement of energy efficiency, enhancement of crew welfare, and safety. These purposes can be accomplished by adopting a new standard hull form with improved resistance performance and a modernized residence facility on the deck. In order to improve resistance performance, this study attempts to optimize design variables for stern flaps for three kinds of fishing vessels - coastal multi-purpose, coastal trap, and dredged nets. A series of model tests for these fishing vessels was carried out in the towing tank of Pusan National University. The results indicate that for some cases, the stern flap caused the stern trim of the vessel to decrease, leading to the resistance reduction.

• 수산경영론집
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• 제25권1호
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• pp.37-59
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• 1994

Many studies to cope with the present problems of Korean coastal and offshore fisheries has been performed, but these were done partly in necessities and general studies for Korean inshore and offshore fisheries are in early stage. Most of these studies adopted analytical way of approach for each fishery individually and they could not reflect the effect of correlated interaction among fisheries on the several common species/stocks, and thus optimal effort allocation was impossible. To consider general fisheries and optimal effort allocation among competing mixed species, a linear programming (LP) approach is applied in this study and introduced into 16 important inshore and offshore fisheries with 13 constraining species which were chosen by annual yield order. This study is not based on the biological interaction among species (i.e., prey - predator system) but the technological interaction between species and fishing efforts. For the application of LP model in these fisheries, the standardization of fishing efforts through different fishing gears could not be successful and a new way of effort standardization through CPUE for vessel tonnage was originated. Total standardized fishing effort on a particular species i, Ei, is computed as the linear summation of standardized fishing effort generated by each fishery j. That is, (equation omitted) where $f_{j}$ is the total vessel tonnage of fishery j and aij is the coefficients contributing to the standardized fishing effort per ton for species i taken in fishery j. The total fishing effort level on species i due to both directed fishing and by - catch can thus be accounted in the aij's. Optimal effort allocation among the j fisheries may be considered a minimizing problem (minimize $\Sigma$ $f_{j}$), subject to the constraints that standardized fishing effort levels on particular species are maintained at, above, and below certain predefined levels. Fishing effort goals for individual species can be based on various biological and/or economic criteria, i.e., fishing effort level generating maximum sustainable yield and/or maximum economic yield. But in this study the $F_{0.1}$ criteria which was accepted as an approximate level for $F_{mey}$ by Outland and Boerema's (1973) study. The findings of this study are, (1) LP model can be applied to the Korean inshore and offshore fisheries giobally. (2) Through a new way of combining multiple different fisheries' efforts for a particular species together generating standardized fishing effort, Schaefer curve could be applied to the complex system successfully. (3) The results of this study for total reduction scale were mostly the same as those of prior studies, but different much from the individual scales of reduction. This study showed the necessities for exploitation of more concrete parameters to put into consideration of profitability of fisheries and social factors, and this model can be modified according to the actual constraints. Also, considering the age structure of stocks, this model can be developed into better one for better fisheries management.ent.

• 한국환경과학회지
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• 제19권11호
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• pp.1397-1405
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• 2010

Mass mortalities of cultivated organisms have occurred frequently in Korean coastal waters causing enormous losses to cultivating industry. The preventive measures require continuous observation of farm environment and real-time provision of data. However, line hanging aquaculture farm are generally located far from monitoring buoys and has limitations on installation of heavy equipments. Substituting battery pack for solar panels and miniaturizing size of buoy, newly developed system can be attached to long line hanging aquaculture farm. This system could deliver measured data to users in real-time and contribute to damage mitigation and prevention from mass mortalities as well as finding their causes. The system was installed off Gijang and Yeongdeck in Korea, measuring and transmitting seawater temperature at the sea surface every 30 minutes. Short term variation of seawater temperature, less than one day, in Gijang from June to July 2009 corresponded tidal period of about 12 hours and long term variation seemed to be caused by cold water southeast coast of Korea, particularly northeast of Gijang. Seawater temperature differences between Gijang station and the other station that is about 500 m away from Gijang station were $1^{\circ}C$ on average. This fact indicates that it is need to be pay attention to use substitute data even if it is close to the station. Daily range of seawater temperature, one of crucial information to aquaculture, can be obtained from this system because temperature were measured every 30 minutes. Averages of daily range of temperature off Gijang and Yeongdeok during each observation periods were about $2.9^{\circ}C$ and $4.7^{\circ}C$ respectively. Dominant period of seawater temperature variation off Yeongdeok was one day with the lowest peak at 5 a.m. and the highest one at 5 p.m. generally, resulting from solar radiation.

• 한국산학기술학회논문지
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• 제14권1호
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• pp.478-484
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• 2013

최근 해양관련 레저 활동 및 관광의 활성화로 연안역에서의 안전사고 위험은 더욱 증가하고 있다. 그러나 현재 안전사고를 방지하기 위한 안전시설의 기술적 측면이나 관리적 측면에 대한 규정이 부재하여 연안역 안전사고 대책이 안전사고의 증가속도에 적절하게 대응하지 못하고 있는 실정이다. 연안역의 지리적, 환경적 조건은 육역과 해역의 특성이 혼재되어있으며 또한, 다양한 많은 활동(어업, 항만업, 관광, 레저)이 존재하므로 안전사고를 방지하기 위한 안전시설을 설치하는 경우에는 육역 및 해역의 특성과 어부/항만노동자/관광객/레저활동자들의 행동특성이 적절히 고려되어야 한다. 본 논문에서는 국내 및 국외(홍콩, 마카오) 실태조사를 실시하였으며, 이로부터 국내 연안역의 안전시설에 대한 현안 문제점을 제시하였다. 또한 안전시설에 대한 개선방향을 제안하였다.

• 수산해양기술연구
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• 제54권1호
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• pp.32-37
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• 2018

The aim of this study is to investigate influence of moon light to the fishing of squid jigging fishery in the southwest Atlantic Ocean based on analyses of date taken from 127 vessels in Falkland fishing ground by squid jigging fishery from 2010 to 2015. Catch and CPUE were analyzed between the new moon and full moon phases. Catches of the new moon phase were higher than those of the full moon phase by 7.6% and CPUE expressed in mt/day-vessels and mt/line-day were also higher by 18.2%, 18.2% respectively. However, as a result of statistical analysis at a significance level of p > 0.05, no significant statistical differences in catch, mt/day-vessels and mt/line-day were found between the new moon and the full moon as a result of statistical analysis at a significance level of p > 0.05.

• 수산경영론집
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• 제27권1호
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• pp.47-56
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• 1996

The pollution in the coastal sea is being aggravated because of frequent happening of red tide and oil leakage from tankers. The Exclusive Economic Zone is being drawn in the seas surrounding Korean Peninsula. Therefore, the fisheries in Korea is under a great change in their production base. On the other hand, the fisheries have been considered as a part of agriculture in policy making and financial support. The thesis compares agriculture with fisheries in the fund demands and financial supports. It tries to find a way in the efficient allocation of fund for the two industries. The fund demand of a typical fishing household is greater than that of a typical farm household. The fund used by a fishery household is more dependent on debt than that of a farm household. Therefore, the internal financing ability of a fishery household is weaker than that of a farm household. The repaying ability of a fishery household is weaker than that of a farm household because a fishery household's income is less than a farm household's. When we analyze the uses of fund, the fishing industry has some disadvantage in fund uses. The financial support for the fisheries' structural change is weaker than that for agriculture. The fishing industry has some disadvantage in the investment and subsidy rates. Also, the loan period for fisheries is shorter on average than that for agriculture. When we analyze the sources of the fund, the fisheries' banking sources are greater than the government's sources, which is relatively stable. Therefore, the fisheries will be more heavily affected by the liberalization of banking industry and system than the agriculture will. The government needs to change the shortcomings in the sources and uses of fund. First, it needs to use the fund, considering the characteristics of the industry and producers' financing ability. Second, it needs to adjust the sources of fund to the liberalization of financial system.

• 한국수산과학회지
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• 제43권1호
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• pp.78-82
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• 2010

Vessel numbers and fuel consumption by South Korea's offshore and coastal fisheries have continuously declined since 2000. Using the 2006 Intergovernmental Panel on Climate Change Guidelines, $CO_2$ emissions by South Korea's fishery industry (fishing and aquaculture, excluding deep-sea fishing) were calculated by the default $ CO_2$ emission factor and fuel consumption by fuel type, Emission of $CO_2$ was estimated to be 3.22 million $tCO_2$/year in 2007 for fisheries (excluding deep-sea fishing); when including deep-sea fishing, the estimated value increased to 4.11 million $tCO_2$/year. Fuel consumption per tonne of fishery production was 498 L, and the amount of $CO_2$ emission per tonne of production was 1.62 $tCO_2$. To calculate $CO_2$ emission more exactly, we must develop a system to compile energy balance statistics and introduce life-cycle assessment for the fishery industry.

• 한국해양생명과학회지
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• 제3권1호
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• pp.22-30
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• 2018

본 연구는 울릉도 수산자원 감소 문제를 해결하기 위한 방안 중 하나로서 정치성 구획어업의 도입을 위한 시험 연구를 수행하였다. 시험용 어구인 삼각망은 울릉도 해역의 환경, 운영 및 관리 비용, 소형 어선 및 인력이 운영할 수 있는 조건을 고려하여 선정하였다. 2017년 4월부터 5월까지 삼각망을 이용하여 11회 어획 조사한 결과, 총 개체수는 2,735개체, 중량은 983.4 kg으로 계측되었으며, 우점종은 참돔, 방어, 넙치, 한치, 전갱이, 쥐치류 등으로 조사되었다. 조사기간 중 유용 수산자원은 어류의 경우 조피볼락(Sebastes schlegelii), 볼락(S. inermis), 개볼락(S. pachycephalus), 쑤기미(Inimicus japonicus), 노래미(Hexagrammos agrammus), 농어목 어류 붉바리(Epinephelus akaara), 참돔(Pagrus major) 그리고 말쥐치(Thamnaconus modestus)로 분류되었으며, 두족류인 한치(Uroteuthis chinensis)의 어획량이 많은 것으로 분석되었다. 울릉도의 주요 수산자원 중 하나인 살오징어의 생산량이 지속적으로 감소할 경우, 삼각망과 같은 소형 정치성 구획어업의 도입은 어민 수입 창출의 대체 수단으로 유용할 것으로 판단된다.