• Journal of Ecology and Environment
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• 제46권1호
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• pp.41-53
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• 2022

Background: Due to the rapidly changing climatic conditions, South Korea faces the grand challenge of exotic species. With the increasing human movement, the influx of alien species to novel regions is prevalent across the globe. The latest research suggests that it is easy to prevent the introduction and establishment of alien species rather than controlling their spread and eradication. Like other countries, the Korean Ministry of Environment released a list (in 2018) of 45 potential risky exotic fish species considered likely to be invasive candidate fish species if they ever succeed in entering the Korean aquatic ecosystems. Results: The investigation into the invasion suitability traits showed that potential risky fish species could utilize those features in becoming invasive once they arrive in the Korean aquatic ecosystems. If the novel species establish viable populations, they are likely to incur higher economic costs, damage the native aquatic fauna and flora, and jeopardize the already perilled species. Furthermore, they can damage the installed infrastructure, decline overall abundance and biodiversity, and disturb the ecosystem services. Here we reviewed the list of fish species concerning their family, native origin, preferred aquatic biomes, main food items, current status in Korea, and potential threats to humans and the ecosystems. Data shows that most species are either already designated as invasive in the neighboring counties, including Japan, Vietnam, Thailand, and China, or originate from these countries. Such species have a higher climate match with the Korean territories. Conclusions: Therefore, it is exceptionally essential to study their most critical features and take regulatory measures to restrict their entry. The incoming fish species must be screened before letting them in the country in the future. The regulatory authorities must highlight the threatening traits of such species and strictly monitor their entrance. Detailed research is required to explore the other species, especially targeting the neighboring countries fish biodiversity, having demonstrated invasive features and matching the Korean climate.

• 대한수의학회지
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• 제47권2호
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• pp.191-195
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• 2007

This study reveals the unusual case reported for the first time on the selective non digestion of yellow mealworm (Tenebrio molitor) larvae by arowana fish. In January 2005, an Asian arowana (Scleropages formosus) (red variety), from Daesang Tropical Fish Corporation, Seoul, Korea, mortality was observed due to unknown cause. No putative causal factors were suggested by bacteriological and parasitological examinations. Internal examination of the dissected stomach showed some undigested debris with mandible parts of mealworms attached to the mucosal lining of stomach wall. Feeding experiment of yellow mealworm (Tenebrio molitor) was conducted on the silver arowana (Osteoglossum bicirrhosum). Result showed that on the test group, fish released vomitous material containing undigested mandibles of mealworm was observed on the 24th day of the feeding experiment. Histopathological examination of the cross section of the stomach wall layers of the test groups, showed detached parts of the mucosal layer and gastric pits around the damaged area with intact mucularis tissues. While the control group fed with mealworm larvae without head part showed intact stomach wall layers consisting of gastric pit, mucosa and mucularis tissues. Fish on both treatments survived until the termination of experiment. The removal of mealworm larvae head before feeding probably help or aid in the fast digestion of these insect larvae.

• 수산경영론집
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• 제36권1호
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• pp.121-138
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• 2005

This study was conducted to investigate the economic effect of the release of seed flounder to the central area of the West Sea, which was analyzed into both direct and indirect effects. The results showed that based on the data collected from partial area, the economic effect of flounder seed release reached 6.97 times, average catch proportion was 32.27$\%$, and recapture rate was 11.26$\%$, suggesting that economic effect was very high. In addition, it was observed that the recapture rate was greatly higher than 2.05$\%$, that of Break-Even-Point. It was noted that the increased catch by the release of seed flounder resulted in the increase in commission of sales and the increase in sports fishing. Another economic effect observed were diverse including the increase in income of fishing village, elevated spirit to proper management of fisheries resources, maintaining of willingness to live in fishing village through activation of local fishing village, prevention of illegal fishing including capture of juvenile fish, and the increase in the supply of sea food of high quality. It is emphasized that although the investigation was conducted in the same area, the results will vary by size at release, time at release and other factors. Finally, there is a need to expand species and area of study for more active economic analysis incorporating natural sciences.

• 생태와환경
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• 제45권4호
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• pp.403-411
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• 2012

수중음향측정 방식은 어류이동에 대한 연속적인 자료를 확보하기 위해 사용되는 방식으로, 대형하천이나 하구에서 이동하는 어류의 이동에 용이하게 활용된다. 낙동강은 남한에서 가장 긴 하천으로 연속적인 보의 설치로 인하여 하천의 변형이 이루어지고 있다. 본 연구에서는 국내에 서식하는 잉어과 어류인 강준치를 대상으로 하여 수중음향측정방식을 적용, 서식처범위(home range)와 이동거리, 이동패턴에 대한 모니터링을 시행하였다. 연구는 낙동강 하구둑부터 창녕함안보까지의 약 80 km 구간을 대상으로 총 14개체의 강준치를 3지점에 방류하여 모니터링을 수행하였다. 하구둑(N02)에서 방류한 8개체들은 방류지점으로부터 15.9 km 상류지점까지를 서식처 범위로 하여 이동하였고, 삼랑진(N07)에서 방류한 4개체들은 신호가 사라진 E12개체를 제외하고 하류로 이동하였으며, 9.7 km 구간을 서식처 범위로 활용하였다. 2개체가 방류된 창녕함안보(N10)에는 모두가 하류로 이동 하였으며, 이 중 E14개체는 32일 동안 가장 긴 누적감지거리(36.7 km)를 이동하였다. 강준치의 체장과 누적감지거리, 서식처 범위와는 상관성이 없는 것으로 확인되었다(Spearman rank correlation, p>0.05). 비록 본 연구 방식이 담수어류의 이동에 유용하지만 좀 더 자세한 결과를 확보하기 위해서는 수신기의 수와 적용하는 발신기의 수를 증가시킬 필요성이 있다.

• 한국식품영양과학회지
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• 제7권1호
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• pp.43-52
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• 1978

It is well known that water holding capacity plays an important role in processing such meat products as frankfurter-type sausage and fish meat paste products as kamaboko and fish sausage. Consumer qualities of meat products, such as appearance, flavor, as well as drip and shrinkage on cooking, depend greatly on the degree of water binding. In this paper, the water holding capacities of fish paste and salt added paste of white corvenia, Argyrosomus argentatus and file fish, Novodon modestus were measured by centrifuging and press method before and after cooking. And the effects of the addition of phosphates and starch to enhance water binding and stabilize gel formation were also discussed. In addition, the experimental conditions which are suitable to determine the water binding of fish meat paste product were suggested. The results were expressed in percent of water absorbed by the filter paper when pressed or released by pressor or centrifuge to the weight of sample. From the results. a proper condition to measure the water holding capacity of fish meat paste was that 3.0 g of sample which was previously added with 10 percent water was centrifuged at 13,400 G or 12,000 rpm for 15 minutes for the centriguging method and for press method, 0.3 g sample with 10 percent of water added was extracted by an oil pressor at $30\;kg/cm^2$ for 1 minute. Water holding capacity of fresh paste of white corvenia was relatively higher than that of file fish and the difference between species of fish was greater than the difference between measurments by two methods. Sodium chloride had a great effect on enhancing the water holding capacity of fish meat paste giving better effect when 3.0 percent of salt was added. Phosphates used except calcium phosphate revealed a certain enhancement in water binding, yielding best effect at 0.3 percent addition, and metaphosphate seemed to be more effective in order. The addition of corn starch, however, appeared to be not so effective for enhancement of water binding in fresh-salt-added fish meat paste but in cooked fish paste which might be attributed to absorption of water by starch grain and swelling during the heating and consequently enforced gel strength of cooked fish paste. And the water holding capacity of cooked fish paste was proportionally related to its gel strength.

• 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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• 제51권4호
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• pp.450-455
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• 2018

We examined correlations of the density of fish farms with the distributions of indicator bacteria (Escherichia coli, fecal streptococci) and a bacterial fish pathogen (Streptococcus parauberis) off the coastline of Jeju Island. Seawater samples were collected at four coastal sites on the Island [Aewol (control), Gujwa, Pyoseon and Daejeong] in June, August and October 2016. The indicator bacteria were generally more frequently isolated from samples taken in August when water temperatures and human activities on nearby beaches were highest. Although fish farms were least common at Daejeong, the numbers of isolated fecal indicator bacteria were highest in the seawater and effluent water collected from this site. Hence, fish farms were not likely major contributors of indicator bacteria at Daejeong. We found discrepancies between the isolated bacterial counts and the predicted bacterial copy numbers deduced from our qPCR results, indicating that this pathogen may exist in a viable but non-culturable (VBNC) state in seawater. Thus, livestock wastewater and chemical fertilizer loading off Jeju Island may negatively impact seawater quality more than the effluent released from fish farms does.

• Ocean and Polar Research
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• 제26권1호
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• pp.102-111
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• 2004

Recirculating aquaculture system (RAS) consists of different treatment compartments that maintain water quality within the ranges commonly recommended for fish cultures. However, common RASs still exert considerable environmental impact since concentrations of organic matter and nutrients in their effluents are high. Compared with the traditional RAS, the model RAS developed here use a sedimentation basin for digestion purposes and then use the released volatile organic matter to stimulate a denitrification process. Different treatment compartments for solids, total ammonia nitrogen, and nitrate removal have been reviewed. This paper provides the basic information on designing different treatment compartments as well as the engineering criteria in closed seawater RAS, consisting of circular tanks for fish cultures; dual drain systems, sedimentation basins and foam fractionators for removal of solids; nitrification biofilters for TAN removal; denitrification biofilters for nitrate removal; and aerators for aeration. The main purpose is to outline a common procedure in designing of closed RAS for marine fish culture with an emphasis on easy management and low expense, as well as reduction of the environmental impact.

• 한국수산과학회지
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• 제36권6호
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• pp.669-675
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• 2003

To increase fishery resources in coastal waters, juvenile fish and bivalves are artificially released every year in Korea. This study provides a methodology to estimate an optimal release quantity based on the carrying capacity of the receiving basins. Carrying capacity was defined by E.p. Odum's theory of ecosystem development as the upper limit of biomass, where total system respiration equals total primary production. The Ecopath trophic ecological model was used to determine carrying capacity in the surfzone ecosystem of Bangjukpo on the southern coast of Korea. Using a top-down control method, various biomasses of fish groups were given to the simulation, with primary production constant and no catch. The results showed that biomass of selected fish groups increased by two orders of magnitude, yielding a five-fold increase in overall consumer biomass. The resultant values are 10 times higher than those estimated in open seas. This can be explained by higher primary production in the Bangjukpo surfzone ecosystem. This method can be used for strategic releases and ecosystem management, particularly when based on an ecological background.

• 생태와환경
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• 제45권4호
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• pp.482-489
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• 2012

어류는 수체 내에 서식하기 때문에 시각적으로 행동이나 이동을 연구하는 데에는 어려움이 있다. 원격측정방식 중 하나인 수중음향측정 방식(acoustic telemetry)은 수생 생물 특히, 어류에 효과적으로 적용되는 방식으로 이동경로 및 거리, 패턴의 분석에 효과적이다. 본 연구에서는 국내에 서식하는 잉어과 어류인 눈불개를 대상으로 하여 수중음향측정방식을 적용, 서식처범위(home range)와 이동패턴에 대한 모니터링을 시행하였다. 연구는 금강 하구둑부터 백제보까지의 약 70 km 구간을 대상으로 총 9 개체의 눈불개를 하구둑(Sc1-3)과 백제보(Sc4-9)에서 각각 방류하여 모니터링을 진행하였다. 하구둑에서 방류한 개체들은 방류지점으로부터 12.7 km 상류지점까지를 서식처 범위로 하여 이동하는 패턴을 나타냈고, 백제보에서 방류한 개체들은 가장 하류까지 이동한 Sc6 (방류지점에서 직선거리로 53.4 km 하류까지 이동)을 제외하고 대부분 방류지점에서 7.2 km 하류 지역을 서식처 범위로 이용하고 있었다. 상대적으로 크기가 작은 Sc7, 8, 9 개체는 큰 이동을 보이지 않았다. 눈불개의 총 이동거리는 개체의 체장의 크기와 관련이 있는 것으로 나타났고($r_s$=0.715, p=0.03), 또한 이동 개체와 이동하지 않은 개체 비교 시 이동 개체들의 체장이 통계적으로 유의하게 큰 것으로 확인되었다(Mann-Whitney U test, p=0.024). 따라서 눈불개의 이동 범위는 크기와 관련이 있고, 체장이 커질수록 총 이동거리가 늘어나는 것으로 나타났다. 비록 모니터링 개체수가 많지 않았지만 대상종의 이동과 관련된 의미 있는 자료들의 수집이 가능하였으며, 연구방식이 전반적으로 국내의 다양한 어류에 안정적으로 적용이 가능하기 때문에 향후 어류의 이동을 모니터링을 하는데 있어서 활용가치가 높을 것으로 판단되었다.