• 월간피드저널
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• 제4권8호통권36호
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• pp.108-113
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• 2006

양돈장에서 번식돈은 농장의 시작이자 마지막이라 과언이 아닐 것이다. 그만큼 중요한 돼지이며 번식돈 관리만 철저히 해도 소모성 질병으로부터의 피해를 어느 정도는 줄일 수 있다고 생각한다. 이렇게 중요한 번식돈 관리가 모두가 알고 있는 것처럼 여름철에는 매우 힘들다. 힘든 여름철 번식돈 관리의 핵심은 사료 섭취량에 있다. 사람도 여름철이되면 입맛이 떨어지고 차가운 물만 찾는 것과 마찬가지로 돼지도 그렇다. 덥기 때문에 사료 섭취량은 자연적으로 감소하게 되고 포유돈의 경우 줄어든 사료 섭취량은 모유 분비량에 직접적인 영향을 미치기 때문에 이유 제충이 감소하게 되고 이는 농장 총 육성률에 영향을 미치게 된다. 다시 말해서 여름철 포유돈 사료 섭취량 감소는 이유 체중, PSY(연간 모돈 두당 이유자돈수), MSY(연간 모돈 두당 출하두수) 그리고 WSY (연간 모돈 두당 출하체중)에 결정적인 영향을 미친다 해도 과언이 아닌 것이다. 여름철 번식돈 관리 방안을 논하기에 앞서 대한민국 여름철은 어떤 특징을 갖고 있는지 생각해보자. 여름철 날씨를 대중 목욕탕 사우나에 비교해서 설명해 보겠다. 대중 목욕탕에 가보면 사우나가 있는데, 이 사우나를 대한민국 여름철과 비교해 볼 수 있다. 사우나에는 건식과 습식 사우나가 있는데, 이 두 사우나실의 온도를 보면 건식보다 습식사우나실의 온도가 10~20℃ 정도 더 낮은 것을 볼 수 있다. 그러나 실제로 사람이 느끼는 온도는 습식 사우나실에 들어갔을 때 더 뜨겁게 느낀다. 상대적으로 낮은 온도임에도 불구하고 습식 사우나실이 더 뜨겁다고 느끼는 이유는 습도에 의한 것이다. 대한민국 여름철은 바로 습식 사우나실과 같은 환경인 것이다. 지금부터는 습식 사우나실과 같은 고온 다습한 대한민국 여름철 환경에서 번식돈이 받을 수 있는 고온스트레스의 정도와 고온 스트레스가 번식돈 생산성에 미치는 영향을 설명하고자 한다.

• 수산해양기술연구
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• 제55권3호
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• pp.206-216
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• 2019

This study is aimed to compare stock assessment models depending on how the models fit to observed data. Process-error model, Observation-error model, and Bayesian state-space model for the Korean Western coast fisheries were applied for comparison. Analytical results show that there is the least error between the estimated CPUE and the observed CPUE with the Bayesian state-space model; consequently, results of the Bayesian state-space model are the most reliable. According to the Bayesian State-space model, potential yield of fishery resources in the West Sea of Korea is estimated to be 231,949 tons per year. However, the results show that the fishery resources of West Sea have been decreasing since 1967. In addition, the amounts of stock in 2013 are assessed to be only 36% of the stock biomass at MSY level. Therefore, policy efforts are needed to recover the fishery resources of West Sea of Korea.

• 수산해양기술연구
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• 제49권4호
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• pp.432-439
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• 2013

This study was performed to assess the current stock condition of elkhorn sculpin along the Uljin area in the East Sea of Korea. To assess the state of the stock, yield-per-recruit (YPR) and spawning biomass-perrecruit (SBPR) analyses were performed. Estimates of $F_{max}$ and $F_{0.1}$ were 2.10/year and 0.48/year, respectively, and those of $F_{35%}$ and $F_{40%}$ were 0.66/year and 0.54/year, respectively. Current fishing mortality was estimated at 0.63/year and the current age at first capture was 2.41years. $F_{40%}$ was set as the target reference point of the stock. SBPR at $F_{40%}$ and current SBPR were estimated to be 41.85g and 37.77g, respectively. Estimated FOTY which is the fishing mortality for the overfished threshold yield was 0.49/year. The ratio of SBPR/$SBPR_{MSY}$ was calculated as 0.90 and that of $F/F_{OTY}$ was 1.05. The ratio of $t_c/t_{c\;opt}$ was calculated as 1.15 and that of $F/F_{OTY}$ was 1.17. Therefore, the current stock condition of elkhorn sculpin along the Uljin area of Korea has not been overfished, however, it indicates that a light overfishing is going on this stock.

• 수산해양기술연구
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• 제53권1호
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• pp.60-66
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• 2017

This study researched the population of ecological characteristics of the goldeyes rockfish Sebasetes thompsoni sampled by gill net in the Ulleungdo area from February 2013 to February 2014 in order to assess the current stock status and provide scientific advice for management implementation. The instantaneous coefficient of total mortality (Z) was 0.78/year and the survival rate (S) was 0.459. The instantaneous coefficient of natural mortality (M) was 0.461/year. Based on the estimates of Z and M, the instantaneous coefficient of fishing mortality (F) was 0.318/year. The age at first capture ($t_c$) was 4.41/years. Current Yield-per-recruit (YPR) was 30.83 g, and fishing mortality at maximum YPR ($F_{max}$) and fishing mortality corresponding to 10% of the maximum slope in YPR curve ($F_{0.1}$) were 3.257/year and 0.673/year, respectively. $F_{35%}$ and $F_{40%}$, indicating fishing mortalities at 35% and 40% of maximum Spawning biomass-per-recruit (SBPR), were 0.619/year and 0.509/year, respectively. Based on the biological reference points, fishing mortality at overfished threshold yield ($F_{OTY}$) was calculated as 0.509/year. Current $SBPR/SBPR_{MSY}$ was 1.313 above 1.0, which means 'not overfishe,' while current $F/F_{OTY}$ was 0.629 below 1.0, which indicates 'not overfishing.' In conclusion, the current status of goldeyes rockfish was located in green zone (i.e., not overfished and not overfishing) according to the revised Kobe plot.

• 한국수산과학회지
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• 제22권4호
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• pp.196-200
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• 1989

최근 몇 년간 제주도의 소라 생산량이 급감하고 있는바, 그 원인 규명을 위한 목적으로 노력당 어획고의 변동 및 최대지속생산량을 추정하기 위하여, 1968년에서 1986년까지의 제주도 소라어획통계자료와 1984년에서 1986년까지의 동귀리(복제주군 애월읍) 어촌계의 작업일지를 분석하였으며, 그 결과는 다음과 같다. 동귀리 어촌계의 경우, 소라 어획량은 제주도 총 소라 어획량의 $1\%$에 지나지 않으며, 실제 조업한 해녀수는 등록된 해녀수의 $53.4\%$인 63명이었다. 그리고 어획노력량으로서는 작업일수 보다 해녀수를 선정함이 양호하다. 제주도의 연간 최대지속생산량은 $2,500\~2,800$톤으로 추정되었으며 1982년에서 '85년까지의 어획량은 $3,100\~3,650$톤으로 과잉의 어획시기였고, 그로 인해 1986년은 매우 감소한 1,400톤이었다. 이전 상태로 어업을 지속할 경우 매우 심각한 상태에 도달할 것으로 예상된다.

• 농업과학연구
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• 제42권3호
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• pp.223-229
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• 2015

This study was conducted to investigate the changes in the pig productivity after ban of antibiotics growth promoter in commercial pig farms. A total 74 pig farms that herd size is from less than 100 sows to more than 500 sows were selected for survey. Changes of pig productivity before/after ban of antibiotics were analyzed by comparing with our survey results and report of KPPA (Korean Pork Producers Association, 2013). In the results, no difference on pig productivity was observed by herd size among our survey farms. Live born piglets have been raised as time passes since 2003, and then it reach to 10.6 head per sow in 2012. The numbers of weaning piglet tended to increase, but sow turnover ratio was found to be a tendency to decrease after ban of antibiotics in our survey results. There was no effect of using antibiotics on mortality of pre- and post- weaning. Marketing per sow per year (MSY) does not be improved because the post-weaning mortality was maintained at a high level, despite live pig born and weaning piglet have increased after 2003. In conclusion, a ban of antibiotics growth promoter does not directly affect to pig productivity, but it needs the efforts to reduce the mortality of post-weaning for improvement of pig productivity. We suggest that this data will be useful to swine industry as the fundamental information.

• 수산해양교육연구
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• 제11권2호
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• pp.150-183
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• 1999

Korea-Japan Fisheries Agreement concluded in 1965 made a contribution to the stable development of fisheries relationship for both countries until the year of 1980. From the time on thereafter a series of respectable fishery disputes occurred throughout the period of fisheries self-regulation in accordance with alteration of home and abroad conditions. And both countries marched into a cooperation era by enforcement of the new fisheries agreement from the 23 January 1999, because the Fisheries Agreement system of 1965 had many limitations to settle the fundamental fisheries problems. In this paper, the author carried out the legal interpretation, arrangement of historical facts and evaluation of actual results of the Korea-Japan Fisheries Agreement of 1965. The key contents of the Fisheries Agreement were the establishment of 12-nautical mile exclusive fishery zone and the joint-control fishery zone under the principles of maintenance of MSY for fishery resources, freedom of high seas and mutual cooperation. The legal foundation of the conclusion of the Fisheries Agreement were the San Francisco Peace Treaty of 1952 and the four International Conventions on the Law of the Sea of 1958. During the 33 years, the fisheries power of Korea made a rapid stride, on the other hand that of Japan was almost stagnated. And in the meantime, there were very important development on the international law of the sea, for instant, the settlement of 12-nautical mile territorial sea regime and the establishment of 200-nautical mile exclusive economic zone regime. Annual meetings of the Joint Fisheries Committee were not successful to fill the role for conservation of fishery resources. The Fisheries Self-Regulation Agreement concluded in 1980 was also insufficient to accept the new international regime on the law of the sea, for that reason it was terminated on 23 January 1999. But it is true that the Fisheries Agreement of 1965 made a contribution to normalization of fisheries relationship between both countries and fisheries development of Korea.

• 수산해양기술연구
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• 제55권2호
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• pp.95-104
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• 2019

This study is aimed to take a stock assessment of blackthroat seaperch Doederleinia seaperch regarding the fishing effort of large-powered Danish Seine Fishery and Southwest Sea Danish Seine Fishery. For the assessment, the state-space model was implemented and the standardized catch per unit effort (CPUE) of large powered Danish Seine Fishery and Southwest Sea Danish Seine Fishery which is necessary for the model was estimated with generalized linear model (GLM). The model was adequate for stock assessment because its r-square value was 0.99 and root mean square error (RMSE) value was 0.003. According to the model with 95% confidence interval, maximum sustainable yield (MSY) of Blackthroat seaperch is from 2,634 to 6,765 ton and carrying capacity (K) is between 33,180 and 62,820. Also, the catchability coefficient (q) is between 2.14E-06 and 3.95E-06 and intrinsic growth rate (r) is between 0.31 and 0.72.

• 한국수산과학회지
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• 제53권6호
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• pp.925-933
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• 2020

This study is aimed to compare stock assessment models which are effective in assessing red snow crab Chinonoecetes japonicus resources and to select and apply an effective stock assessment model in the future. In order to select an effective stock assessment model, a process-error model, observation-error model, and a Bayesian state-space model were estimated. Analytical results show that the least error is observed between the estimated CPUE (catch per unit effort) and the observed CPUE when using the Bayesian state-space model. For the Bayesian state-space model, the 95% credible interval(CI) ranges for the maximum sustainable yield (MSY), carrying capacity (K), catchability coefficient (q), and intrinsic growth (r) are estimated to be 10,420-47,200 tons, 185,200-444,800 tons, 3.81E-06-9.02E-06, and 0.14-0.66, respectively. The results show that the Bayesian state-space model was most reliable among models.

• 한국수산과학회지
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• 제55권2호
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• pp.183-188
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• 2022

It is a difficult task to estimate parameters in even a simple stock assessment model such as a surplus production model, using only data about temporal catch-per-unit-effort (CPUE) (or survey index) and fishery yields. Such difficulty is exacerbated when time-varying parameters are treated as random effects (aka state variables). To overcome the difficulty, previous studies incorporated somewhat subjective assumptions (e.g., B₁=K) or informative priors of parameters. A key is how to build an objective joint prior of parameters, reducing subjectivity. Given the limited data on temporal CPUEs and fishery yields from 1999-2020 for common squid Todarodes pacificus, we built a joint prior of only two parameters, intrinsic growth rate (r) and carrying capacity (K), based on the resilience level of the population (Froese et al., 2017), and used a Bayesian state-space production assessment model. We used template model builder (TMB), a R package for implementing the assessment model, and estimating all parameters in the model. The predicted annual biomass was in the range of 0.76×10⁶ to 4.06×10⁶ MT, the estimated MSY was 0.13×10⁶ MT, the estimated r was 0.24, and the estimated K was 2.10×10⁶ MT.