• Title/Summary/Keyword: introduced fish

Search Result 172, Processing Time 0.023 seconds

Dynamics of in situ Bacterial Community Structure in the Nak-Dong River (낙동강에서의 세균군집구조의 역동성)

  • Park, Ji-Eun;Yeo, Sang-Min;Lee, Young-Ok
    • Korean Journal of Ecology and Environment
    • /
    • v.37 no.4 s.109
    • /
    • pp.363-367
    • /
    • 2004
  • For comparative analysis of the eubacterial community structure at 8 sampling sites throughout the Nak-Dong River, FISH (fluorescence in situ hybridization) method was employed. The total ratio of each determined eubacterial group such as ${\alpha}\;{\cdot}\;{\beta}\;{\cdot}\;{\gamma}-subclasses$proteobacteria and Cytophaga-Flavobacterium(CF) group to total counts(DAPI) at each site varied 9.3-42.5% with the highest value at uppermost part. And each ratio of determined eubacterial groups reached mostly under 10% except that of CF group (23%) at uppermost part. Furthermore, compared to lower part, upper part represented unexpectedly higher proportions of ${\gamma}-subclass$ proteobacteria comprised almost fast growing bacteria on degradable organics. Also the variations of ammonia-oxidizing bacteria ranged from $2.7{\times}10^4$ to $18.0{\times}10^4$ cells $mL^{-1}$ with the lowest value in lower part and the highest value in mid part whereas those of nitrite-oxidizing bacteria varied 5.2-7.7{\times}10^4$ cells $mL^{-1}$ without noticeable differences throughout the sites. Additionally, the ratio of nitrifying bacteria to total counts ranged from 1.0% to 13.6% with no differences between ammonia-oxidizing bacteria and nitrite-oxidizing bacteria. In conclusion, FISH method introduced in this study for monitoring, normally used for the quantitative analysis of bacteria, provided also good information on their environmental status in the Nak-Dong River.

Survey of drug resistance in Edwardsiella tarda isolated from diseased eels(Anguilla japonica) (뱀장어 병어로부터 분리한 Edwardsiella tarda의 약제내성)

  • Choi, Min-Soon;Choi, Sang-Hoon;Park, Kwan-Ha;Jang, Seon-Il;Yoon, Chang-Yong;Cho, Jeong-Gon;Song, Hee-Jong
    • Journal of fish pathology
    • /
    • v.9 no.2
    • /
    • pp.195-201
    • /
    • 1996
  • Ninety-six isolates of Edwardsiella tarda recovered from outbreaks of Edwardsiellosis in cultured eels(Anguilla japonica) in Kunsan, were examined for drug susceptibility, distribution and transferabilities of R plasmid. All of the E. tarda isolates examined were sensitive to gentamicin(GM), streptomycin(SM), norfloxacin(NF), and amikacin(AK). But most isolates were resistant to sulfadimethoxine(SD, 86 strains), ampicillin(AM, 84 strains), penicillin G(PM, 80 strains), nalidixic acid (NA, 67 strains), oxytetracycline(OT, 44 strains), and oxolinic acid(OA, 37 strains). Twenty different combinations of drug resistance patterns were observed : the frequently encountered pattern was SD-AM-PM-NA-OA(16 strains), SD-AM-PM-NA(14 strains), SD-AM-PM-NA-OT-OA(12 strains), SD-AM-PM-OT(10 strains), and SD-AM-PM-NA-OT(8 strains). Transferable R plasmids were found out to be carried in 78 out of 94 resistant strains, indicating that these isolates carry conjugally transferable R plasmids associated with single or multiple drugs. The frequently observed transferarble R plasmids were AM(8 strains), AM-PM-NA(8 strains), Am-SD(6 strains), PM(6 strains), and SD(6 strains) These results suggest that high dose of various antibacterials might have already been introduced to eel culture system leading to the acquirement of multi-drug resistance to wide range of antibacterials.

  • PDF

The Medicinal Effects of Seafoods in ${\ulcorner}$Lim-Won-Sib-Rheuk-Ji${\lrcorner}$ ("임원십육지(林園十六誌)"에 수록된 어패류의 향약성(鄕藥性)에 관한 연구)

  • 최영진;백숙은
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.14 no.3
    • /
    • pp.187-195
    • /
    • 2004
  • This study was conducted to figure out the nutritional nature of seafoods categorized according to the medicinal effects and the usages introduced in Lim-Won-Sib-Rheuk.-Ji, one of the well-known encyclopedias published during the Chosun Dynasty. They were compared with those introduced in other cooking books in order to find out how they were used in the diet of real-life. The seafoods of the book were first categorized into the fish 20, the mollusk 5, the crustacea 4, and the shellfish 7, and reptile according to the biological taxonomy, and then each one was reviewed in terms of the taste and the food-nature. Generally, the fishes had the sweet taste; the crustacea and the shellfish the salty or sour in addition to the sweet taste; none of them were bitter or hot. Most of them had the mild nature; seven of them were regarded as warm; four as cool; one as cold from the standpoint of the traditional medicine. The food-nature of seafoods was closely related with the medicinal effects on the human body. These seafoods were characteristically used in daily dietary life as well as the medical applications; used as the side-dishes rather than the main-dishes. The cooking methods of boiling, steaming, and baking were preferred to drying and stewing. The preservation methods favored were the fermentation, drying and salting. These cooking and preservation methods were believed to reflect the nature of the seafoods to manifest the medicinal effects.

  • PDF

Comparative Study of Cooking Methods in 「Suwoonjabbang」 vs. 「Eumsikdimibang」 (「수운잡방」과 「음식디미방」에 나타난 조리법 비교)

  • Chung, Hae Kyung;Yoon, Kyung Soo;Kim, Mi Hye
    • Journal of the Korean Society of Food Culture
    • /
    • v.30 no.1
    • /
    • pp.41-53
    • /
    • 2015
  • This study aimed to examine the cooking methods used in the Joseon Dynasty using cooking books. We chose "Suwoonjabbang" (1500's) and "Eumsikdimibang" (1610) as the subjects of this study. Cooking methods from these two recipe books were categorized into staples, side dishes, rice cakes, Korean traditional sweets and cookies, drinks, fermented foods, seasonings, and storage methods. Firstly, "Suwoonjabbang" contains a total of 121 cooking methods divided into two volumes. In contrast, "Eumsikdimibang" includes 146 cooking methods. There are 18 methods for noodles and dduks, 74 methods for fish and meat, and 54 methods for drinks and vinegars, and others. Secondly, "Suwoonjabbang" written by Yu Kim in Chinese characters can be described in simple terms. It provides caution against indulging in the taste of food. In contrast, "Eumsikdimibang" by Kye Hyang Jang contains detailed cooking methods that have disappeared. Thirdly, "Eumsikdimibang" introduced more diverse cooking methods for noodles, dumplings, side dishes, rice cake, Korean traditional sweets and cookies, and fermented foods as compared to "Suwoonjabbang". In conclusion, unique cooking methods introduced in these two cooking books, which are rare these days, are expected to be further applied and developed.

Visualization Tool Design for Searching Process of Particle Swarm Optimization (Particle Swarm Optimization 탐색과정의 가시화를 위한 툴 설계)

  • 유명련
    • Journal of Korea Multimedia Society
    • /
    • v.6 no.2
    • /
    • pp.332-339
    • /
    • 2003
  • To solve the large scale optimization problem approximately, various approaches have been introduced. Recently the Particle Swarm Optimization has been introduced. The Particle Swarm Optimization simulates the process of birds flocking or fish schooling for food, as with the information of each agent is skated by other agents. The Particle Swarm Optimization technique has been applied to various optimization problems whose variables are continuous. However, there are seldom trials for visualization of searching process. This paper proposes a new visualization tool for searching process of Particle Swarm Optimization algorithm. The proposed tool is effective for understanding the searching process of Particle Swarm Optimization method and educational for students. The computational results can be shown tiny and very helpful for education.

  • PDF

Price Volatility, Seasonality and Day-of-the Week Effect for Aquacultural Fishes in Korean Fishery Markets (수산물 시장에서의 양식 어류 가격변동성.계절성.요일효과에 관한 연구 - 노량진수산시장의 넙치와 조피볼락을 중심으로 -)

  • Ko, Bong-Hyun
    • The Journal of Fisheries Business Administration
    • /
    • v.40 no.2
    • /
    • pp.49-70
    • /
    • 2009
  • This study proviedes GARCH model(Bollerslev, 1986) to analyze the structural characteristics of price volatility in domestic aquacultural fish market of Korea. As a case study, flatfish and rock-fish are analyzed as major species with relatively high portion in an aspect of production volume among fish captured in Korea. For analyzing, this study uses daily market data (dating from Jan 1 2000 to June 30, 2008) published by the Noryangjin Fisheries Wholesale Market which is located in Seoul of Korea. This study performs normality test on trading volume and price volatility of flatfish and rock-fish as an advanced empirical approach. The normality test adopted is Jarque-Bera test statistic. As a result, first, a null hypothesis that "an empirical distribution follows normal distribution" was rejected in both fishes. The distribution of daily market data of them were not only biased toward positive(+) direction in terms of kurtosis and skewness, but also characterized by leptokurtic distribution with long right tail. Secondly, serial correlations were found in data on market trading volume and price volatility of two species during very long period. Thirdly, the results of unit root test and ARCH-LM test showed that all data of time series were very stationary and demonstrated effects of ARCH. These statistical characteristics can be explained as a reasonable ground for supporting the fitness of GARCH model in order to estimate conditional variances that reveal price volatility in empirical analysis. From empirical data analysis above, this study drew the following conclusions. First of all, from an empirical analysis on potential effects of seasonality and the day of week on price volatility of aquacultural fish, Monday effects were found in both species and Thursday and Friday effects were also found in flatfish. This indicates that Monday is effective in expanding price volatility of aquacultural fish market and also Monday has higher effects upon the price volatility of fish than other days of week have since it has more new information for weekend. Secondly, the empirical analysis led to a common conclusion that there was very high price volatility of flatfish and rock-fish. This points out that the persistency parameter($\lambda$), an index of possibility for current volatility to sustain similarly in the future, was higher than 0.8-equivalently nearly to 1-in both flatfish and rock-fish, which presents volatility clustering. Also, this study estimated and compared and model that hypothesized normal distributions in order to determine fitness of respective models. As a result, the fitness of GARCH(1, 1)-t model was better than model where the distribution of error term was hypothesized through-distribution due to characteristics of fat-tailed distribution, was also better than model, as described in the results of basic statistic analysis. In conclusion, this study has an important mean in that it was introduced firstly in Korea to investigate in price volatility of Korean aquacultural fishery products, although there was partially a limited of official statistic data. Therefore, it is expected that the results of this study will be useful as a reference material for making and assessing governmental policies. Also, it is looked forward that the results will be helpful to build a fishery business plan as and aspect of producer, and also to take timely measures to potential price fluctuations of fishery products in market. Hence, it is advisable that further studies related to such price volatility in fishery market will extend and evolve into a wider variety of articles and issues in near future.

  • PDF

Using the Red Pepper in Korean Traditonal Cuisine (우리나라 전통조리에서 고추의 활용)

  • 한복진
    • Journal of the East Asian Society of Dietary Life
    • /
    • v.12 no.2
    • /
    • pp.173-186
    • /
    • 2002
  • Red pepper have affected traditional cuisines through various ways since they were first introduced in Korea over 400 years. But we on easily determine that red pepper powder and red pepper paste were not used daily dishes until 1940 as we look into traditional cookbooks. Chinese pepper and black pepper were used for hot spices before red pepper was introduced in Korea. It is estimated that red pepper was introduced during the last of 1500s the Japanese invasion of Chosun dynasty, but it was first used to make Sunchang red pepper paste in $\boxDr$Sumunsasul(수문사설)$\boxUl$(1740), and to make Kimchi in $\boxDr$Jeungbo Sanlimkungje(증보 산림경제)$\boxUl$(1766), and it became a general spice for vegetables in the middle of the 1800s. Pepper is mostly used to make Kochujang(red pepper paste), Kimchi, Jutkal(salted flesh) and Jangaji(salited very.) etc as fermentable cuisines. The attribute of using pepper was developed fur fermentable spices, and to give spicy flavor to cuisines. The types of peppers using traditional cuisines are various such as unripened pepper, red pepper, red pepper powder, red pepper paste, and pepper leaves. Traditional dishes with vegetables mostly use red peppers. Fish dishes(soup, stew, bracing, roasting, steaming) also use red peppers. Soup '||'&'||' stew with meat item partly use red pepper but steaming, roasting dishes with meat item not use pepper. roasted pork, pork ribs, steamed chicken of spicy meat cuisines in the 1930s did not use pepper. Kochujangbokkum(고추장볶음) is one of the oldest cuisines for using red pepper paste in the 1800s. Sliced red peppers and red pepper powder are mostly used for garnishing of cuisines.

  • PDF

Regulatory Reform Proposals for the Korean Deep Sea Fishing Industry (원양어업(遠洋漁業)에 대한 정부규제(政府規制)의 개선방안(改善方案))

  • Kim, Jong-seok
    • KDI Journal of Economic Policy
    • /
    • v.12 no.1
    • /
    • pp.93-110
    • /
    • 1990
  • The basic purpose behind the Korean government's policy toward the Korean deep sea fishing industry is to limit growth of the industry. Therefore, the regulations on the industry are generally restrictive and interventionist. The policy is intended to maintain high domestic fish prices in order to protect the domestic coastal fishing industry. Some regulations have also been introduced to maintain "industrial order." Each fishing vessel must obtain a government permit for operation. The permit specifies the kind of fish it can catch, the area of sea in which it can operate, and the port at which it can unload its catches. The number of permits government issues each year is based on the estimates of the demand increase calculated by government officials, and the government traditionally has been fairly conservative in its estimation, reflecting its concern for fish price stabilization, which actually implies a gradual increase of the prices. There is also a restriction on importing vessels from abroad. This regulation is intended to protect the domestic shipbuilding industry. However, this regulation has resulted in an unusually high average age of Korean fishing vessels, causing fishing costs to rise. These regulations and the inflexible response of the regulators to changing circumstances have resulted in many problems: i) high domestic fish prices, which are, to some extent deliberately, inflated to three or four times the level of international prices, resulting in huge consumer welfare losses; ii) over-exploitation of coastal fish resources; iii) provision of a hospitable environment for inefficient firms to survive, which is especially evident from the fact that, despite the high fish prices in Korea, most of the firms in the industry do not enjoy high profitability. It also must be pointed out that the actual beneficiaries of the high fish prices are the large operators, who are protected from competition and provide most of the fish for domestic consumption, rather than the low-income fishing households and small coastal operators whom the policy was originally designed to help. This study proposes a set of regulatory reforms and policy changes which could Promote competition and equity within the industry and allow firms to reduce costs and increase productivity. Such changes can make the industry more efficient and internationally competitive. Major proposals are, among others: minimization of bureaucratic discretion in issuing fishing permits and maintaining transparency in the governments' decision-making processes; reduction of the government permit specifications and simplification of the operational categories within the industry; and removal of the restrictions on importing foreign fishing vessels.

  • PDF

A Study of Fish Community on Up and Downstream of Hwabuk Dam Under Construction in the Upper Wie Stream. (위천 상류에 건설 중인 화북댐 상 하류 어류군집에 관한 연구)

  • Seo, Jin-Won;Kim, Hee-Sung
    • Korean Journal of Ecology and Environment
    • /
    • v.42 no.2
    • /
    • pp.260-269
    • /
    • 2009
  • Hwabuk Dam has been under construction to reduce flood damage in Nakdong River watershed and to supply stable water for middle area of Gyeongbuk Province. Therefore, fish investigation in up and downstream of the dam was conducted from 2004 to 2008 in order to determine any negative effect on fish community due to dam construction and to use as fundamental data for conserving species diversity and maintaining stream health. According to data analysis on water quality, temperature, dissolved oxygen, pH, suspended solids, and total E-coli had seasonal variation, but they did not significantly differ in sites. However, biological and chemical oxygen demand, chlorophyll-a, nitrogen, and phosphorus representing organic matter and nutrient concentration were higher in upper site and decreased to lower site so that they differed by site. Concentration of arsenic among the heavy metals was less than 0.05 mg $L^{-1}$, which is regulated for protection of human health in water quality standard, except for 0.092 mg $L^{-1}$ in June 2005. During the study period, the total number of fish caught from the 6 sites was 10,263 representing 7 families 19 species. Among them, dominant and subdominant species were Korean chub (Zacco koreanus, 62.5%) and Chinese minnow (Rhynchocypris oxycephalus, 10.6%) which inhabit mostly in mid and upper streams, Korea. Among the 19 species, Korean endemic species were 9 species (47.4%) including Korean slender gudgeon (Squalidus gracilis majimae), Korean dark sleeper (Odontobutis platycephala), and Korean shiner (Coreoleuciscus splendidus). There was several individuals of the $1^{st}$-class endangered species, Naktong nose loach (Koreocobitis nahtongensis), caught in 2005${\sim}$2007, and no introduced species of fish was found in entire sampling period. According to result of community analysis, dominance index decreased toward lower site, but diversity and richness indices increased toward lower site. The equation of length-weight relationship on the dominant species was TW=0.000003$(TL)^{3.2603}$. The parameter b in the equation was greater than 3.0 indicating good nutritional condition in the populations. Compared to populations of Korean chub in other streams, the population in Hwabuk Dam watershed had higher mean of condition factor by size indicating better growth rate. With fish fauna and multi-metric health assessment model in each sampling attempt, index of biotic integrity (IBI) was evaluated and it resulted mostly in good (26${\sim}$35) and excellent (36${\sim}$40) condition in all sites, and the mean of IBI was the highest in site 5. The results indicate that it is very important to study not only environmental impact assessment with fish composition but also stream health assessment in order to conserve healthy aquatic ecosystem.

Fish Fauna and Weight-Length Relationships for 9 Fish Species in Andong Reservoir (안동호의 어류상과 9개 어종의 길이-무게 상관관계에 관한 연구)

  • Han, Seung-Cheol;Lee, Hak-Yeong;Seo, Eul-Won;Shim, Jae-Hun;Lee, Jong-Eun
    • Journal of Life Science
    • /
    • v.17 no.7 s.87
    • /
    • pp.937-943
    • /
    • 2007
  • The fish fauna and weight-length relationship in Andong reservoir were investigated from May 2005 to March 2006. During surveyed period, 2,540 individuals 20 species belonging to 7 families were collected. Dominant species were Hemibarbus labeo(19.6%) and sub-dominant species were Carassius cuvieri (19.2%). The korea endemic species were Hemiculter eigenmanni(7.1%), Squalidus chankaensis tsuchigae (0.1 %), Corroperca herzi (0.1 %) and introduced fishes were Carassius cuvieri (19.21 %) Lepomis macrochirus (4.2%), Micropterus salmoides (0.2%). Dominace, species diversity, species richness, species even-ness were 0.39, 3.16, 2.42, 0.73 respectively. The values of the exponent b in the weight-length relation-ship $W=aL^{b}$ ranged from 2.9162(H. labeo, $R^{2}$=0.9567) to 3.2509(Zacco pla쇼pus, $R^{2}$=0.9928) and the median value was 3.1079, whereas 50% of the values ranged between about 3.05 to 3.20. The Condition factor(K) showed good state of health in the surveyed species (excepts H. labeo and Cyprinus carpio).