• 수산경영론집
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• 제38권1호
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• pp.1-17
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• 2007

This study is aimed at investigating optimum level of payments in the direct payment program for aquaculture extruded pellets both theoretically and practically by analyzing the effects on production and income in accordance with Green Box conditions of WTO Agreement on Agriculture. In particular, by analyzing both effects on production and income, it evaluates and compares payments affecting to the level of production and income, respectively. Analysis results indicate that the optimum level of payments in the direct payment program for aquaculture extruded pellets is determined by the growth rate of farmed fish, farming period, price and volume of extruded pellets, and additional amount of cost increase and decrease. Suppose that growth rates of farmed fish by extruded pellets(EP) and raw fish - based moist pellets(MP) are the same, it reveals the optimum level of payment should be lowered from the current level of payment. However, when the growth rate of farmed fish by EP is lower than that by MP, the optimum level of payment should be raised from the current level and total amount of payments by area should be increased as well.

• 한국어병학회지
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• 제19권3호
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• pp.235-241
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• 2006

The effects of various temperature shifts on the kinetics of the humoral antibody response in oliver flounder, Paralichthys olivaceus, immunised with formalin-killed Edwardsiella tarda, were determined by measuring the antibody production in vivo and in vitro. When fish acclimated to a high temperature and immunised at that temperature were transferred to a lower temperature (22℃ to 12℃) at a various times after immunisation, the fish showed a weaker immune response than that achieved when the fish were kept at a high environmental temperature. However, in the converse experiment (12℃ to 22℃), the magnitude of the humoral immune response was recovered independent of the time of the transfer after immunisation at low temperature, even though the peak levels of each transferred group did not reach the level found in the positive control group that was maintained and immunised at a high environmental temperature. Hence, these studies provide some evidence that the potential for antibody production in B cells of oliver flounder immunized at high temperature is not impaired by subsequent exposure to low temperature.

• Asian-Australasian Journal of Animal Sciences
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• 제15권11호
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• pp.1617-1621
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• 2002

Two hundred and sixteen single comb white egg layers of the White Leghorn hens of 24 weeks of age were randomly allocated to 12 groups with three replications of six hens in each. Hens were fed in a factorial arrangement 2${\times}3{\times}$2, on diets containing either 16 or 18% crude protein with 0, 3 or 6% fish meal, replacing groundnut meal with soybean meal. Soybean meal incorporation improved (p<0.05) egg production, feed intake, feed conversion efficiency and egg weights. Egg quality traits of specific gravity, shape index, albumen index, yolk index and shell thickness remained unchanged. Laying performance was significantly (p<0.05) better at 18% than on 16% dietary protein level. Use of fish meal linearly improved egg production and feed conversion efficiency on diets supplemented with groundnut meal and fish meal incorporation showed quadratic improvement on feed conversion efficiency with SBM diets at 16% dietary protein level. Therefore, use of soybean meal as substitute of groundnut meal is recommended in layer diets, at 16% dietary protein level and fish meal incorporation could be beneficial for layers.

• 수산해양기술연구
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• 제50권2호
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• pp.131-138
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• 2014

The study aims at analyzing a species composition of the fish live in bottom of the coastal waters off Geomun island, Korea. To reach the goal of the study, a species composition and it's monthly fluctuation, a monthly fluctuation of the dominant species and it's appearance type was analyzed the fishes caught by the bottom trawl. The result obtained can be summerrized as follows; Fish caught in this area composes 14 orders, 34 families, and 47 species. The largest number of fish species was Perciformes (15 families and 19 species). The most dominant species in an number of fish was jhon dory, Zeus faber which was occupied at 22.5% from the whole number, the second most dominant species was horse mackerel, Trachurus japonicus which was occupied at 21.2%. Four groups were categorized based on appearance time period.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.191-196
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• 1994

Two experiments were conducted to study the effect of using Egyptian mallow leaf meal (EMLM) on growth performance and feed utilization of common carp (Cyprinus carpio L.) in experiment 1. Four diets containing 0, 5, 15 and 25% EMLM were included at the expense of berseem leaf meal and fed to fingerlings of common carp for 98 days. The results showed that the average daily gain, feed intake and feed coefficient ratio (FCR) were improved (p<0.05) with increasing the level of EMLM in the diet. Fish fed 25% EMLM were similar to control fish (30% berseem leaf meal) in the productive value (PPV%). In experiment 2, five diets were prepared to contain: 1) 30% berseem leaf meal, 2) 25% untreated EMLM, 3) 25% cooked EMLM 4) 25% treated EMLM with 0.5% NaOH and 5) 25% treated EMLM with 1% NaOH. The results showed that diet containing EMLM gave the best growth performance and feed utilization. However, diet containing 1% NaOH treated EMLM superior to the other diets in PPV% and energy utilization. Diets containing 0.5% NaOH-treated EMLM or cooked EMLM decreased the protein utilization compared to those containing EMLM.

• Ocean and Polar Research
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• 제43권2호
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• pp.89-98
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• 2021

The seagrass habitats are a highly productive marine ecosystem which provides nursery ground and shelter for many fish and invertebrate species. Pholis nebulosa (Temminck & Schlegel, 1845) is one of the most abundant seagrass fishes in the coastal waters of Korea. The estimation of fish production is key for devising conservation measures and ensuring fish resources sustainability. A total 894 P. nebulosa ranging from 3.83 to 26.5 cm total length (TL) were collected monthly in 2006 with a small beam trawl in a seagrass bed of southern Korea. Growth parameters of P. nebulosa were estimated using the von Bertalanffy growth model, and production was estimated using a general equation which relates daily fish production to ash-free dry weight (AFDW), biomass, and water temperature. The von Bertalanffy's growth equation was estimated as: L_t = 28.3823(1-e^{-0.7835(t+0.9864)}). The densities, biomass, daily, annual production, and P/B ratio were 0.069±0.061/m^-2, 1.022±0.621 g/m², 0.005±0.004 g AFDW/m²/day, 1.676 g AFDW/m²/yr, and 1.641, respectively. Monthly variation in production of P. nebulosa peaked during March and April 2006 (0.0139 and 0.0111 g AFDW/m²/day), whereas the lowest value of 0.0005 g AFDW/m²/day was in December. Monthly change in production of P. nebulosa was positively correlated with biomass and condition factor. Our results will contribute to the conservation of seagrass ecosystems, which are still undisturbed in the study area.

• 수산해양교육연구
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• 제27권6호
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• pp.1610-1618
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• 2015

This study is aimed to estimate price interactions between wild caught fish and farmed fish on the Korean seafood market, using multivariate cointegration analysis. Major commercially important four wild caught fish (chub mackerel, hairtail, yellow croaker and spanish mackerel) and two farmed fish(oliver flounder and black rockfish) are selected as analytical target fish species. Between 2000 and 2013, monthly production and price data are used in this study. The results of cointegration test showed that there would be a long-term equilibrium relationship among 4 wild caught fish and 2 farmed fish. However, the results of exclusion test indicated that farmed fish might not contribute significantly to the long-run relationship, suggesting that farmed fish might be only a weak substitute for wild caught fish, but no significant interaction could be found.

• 한국식품위생안전성학회지
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• 제14권4호
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• pp.408-414
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• 1999

자연계에 오염되어 있는 수많은 화학 물질들은 정상적인 내분비 기능을 교란한다. 내분비 교란 물질은 수계에 오염되면 야생동물과 사람에게 건강에 미치는 영향이 크다. 본 연구는 오염물질이 생체의 내분비계를 교란시키므로서 생성되는 난황 전구체 단백질로서 환경오염의 생물체의 지표로서 비트로게닌의 생성을 유도하는 내분비 교란 물질에 대하여 고찰하였다. 수계의 환경에서 서식하고 있는 물고기는 내분비계 교란 물질에 의하여 암컷에서는 번식률과 난백의 생산이 감소되고 수컷에서는 정소의 왜소화 및 암컷화로 유도되기도 한다. 여성호르몬 작용을 하는 화학물질에 노출된 수컷은 비트로게닌의 생성을 촉진하고, 암컷에 있어서 비트로게닌의 생성은 난백을 형성하는 동안 에스트로겐의 함량을 증가시켜 정상적인 활동을 제한하기도 한다. 따라서 수컷에서의 비트로게닌은 환경에 오염된 내분비교란 물질의 오염에 의하여 생성되게 된다. 결과적으로 수컷의 물고기에서 생성된 비트로게닌은 환경에 오염된 내분비 교란물질이 어느 정도 노출되어 있는가를 결정하는 생물학적 지표로 사용할 수 있다. 특히 치어의 경우 극미량의 내분비 교란물질에 노출되어도 믿을 만한 생물지표로서 이용될 수 있다.

• 한국수산과학회지
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• 제38권4호
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• pp.265-275
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• 2005

A prerequisite for deriving the abundance estimates from acoustic surveys for commercially important fish species is the identification of target strength measurements for selected fish species. In relation to these needs, the goal of this study was to construct a data bank for converting the acoustic measurements of target strength to biological estimates of fish length and to simultaneously obtain the target strength-fish length relationship. Laboratory measurements of target strength on 15 commercially important fish species were carried out at five frequencies of 50, 70, 75, 120 and 200 kHz by single and split beam methods under the controlled conditions of the fresh and the sea water tanks with the 389 samples of dead and live fishes. The target strength pattern on individual fish of each species was measured as a function of tilt angle, ranging from $-45^{\circ}$ (head down aspect) to $+45^{\circ}$ (head up aspect) in $0.2^{\circ}$ intervals, and the averaged target strength was estimated by assuming the tilt angle distribution as N $(-5.0^{\circ},\;15.0^{\circ})$. The TS to fish length relationship for each species was independently derived by a least-squares fitting procedure. Also, a linear regression analysis for all species was performed to reduce the data to a set of empirical equations showing the variation of target strength to a fish length, wavelength and fish species. For four of the frequencies (50, 75, 120 and 200 kHz), an empirical model for fish target strength (TS, dB) averaged over the dorsal sapect of 602 fishes of 10 species and which spans the fish length (L, m) to wavelength (\Lambda,\;m)$ ratio between 5 and 73 was derived: $TS=19.44\;Log(L)+0.56\;Log(\Lambda)-30.9,\;(r^2=0.53)$.

• 수산해양기술연구
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• 제50권1호
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• pp.30-38
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• 2014

Hydro-acoustic survey was carried out to investigate the spatial characteristics of fish distribution near two artificial reefs (AO: large octagonal semi-sphere and AC: combined custom built) having different types in Jeju marine ranching area. The survey system consisted of scientific echo sounder (EK60), DGPS system, and ECDIS (Mecys). Field survey was conducted on August and October 2012 with star survey and line transect survey line method, and species composition was investigated from gill net fishing survey. The acoustic signals from individual fishes and small fish schools were mainly recorded around AO, but large and strong signals from large fish school were mainly detected in the top layer of and the water column near AC. The echogram suggest that the fish aggregation for the two types of AO and AC exist the significant difference in fish species and spatial distribution pattern.