• Korean Journal of Environment and Ecology
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• v.34 no.5
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• pp.402-412
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• 2020

This study aims to examine the population characteristics of the fish and the bluegill (Lepomis macrochirus), designated as ecologically disturbing fish, living in four water dams in the Ulsan area and to provide basic data. The survey of fish living in 4 water dams and surrounding tributaries in the Ulsan area from 2016 to 2017 found a total of 1,987 individuals of 28 species of 9 families and identified 6 Korea's endemic species is (21.4% indigenous rate), 4 exotic species, and 2 ecosystem disturbing species. Based on the number of fishes identified, the dominant species was Lepomis macrochirus, and the subdominant species was Hemiculter eigenmanni. The investigation of the age structure of the L. macrochirus found in the 4 water dams in the Ulsan area showed a large population of 1 to 2 old, and the population was growing fast. Moreover, the analysis of the total length-weight relationship and obesity of the L. macrochirus population showed that the regression coefficient b of the total length-weight relationship was greater than 3.0, and the habitat of the L. macrochirus population was in good condition. Obesity had a positive slope, and the growth state was relatively good. The result of this study can be used as useful data to predict the trend of the L. macrochirus fauna inhabiting in 4 water dams in the Ulsan area.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.84-94
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• 2021

This study was conducted to elucidate the impact of invasive species, Micropterus salmoides and Lepomis macrochirus in Geumgyeji, Samgaji and Naejangji reservoirs of National Parks, Korea in 2020. In the Geumgyeji, 1,221 individuals of 11 species in 7 families were collected including M. salmoides (relative abundance, 96.3%) and L. macrochirus (0.3%), M. salmoides fed mainly on Rhinogobius brunneus (IRI, 37.2%), Odonata (25.6%), Megaloptera (11.6%), and M. salmoides (7.0%). In the results of Samgaji showed that 854 individuals of 10 species in 5 families were collected including M. salmoides (60.8%), and M. salmoides fed mainly on Decapoda (shrimp, 33.6%), Odonata (34.4%), R. brunneus (21.2%), and Zacco platypus (6.1%). In the Naejangji showed that 1,075 individuals of 13 species belonging to 7 families were collected including L. macrochirus (38.1%) and M. salmoides (9.5%), and L. macrochirus fed mainly on Branchiopoda (77.5%), Diptera (9.8%), Decapoda (4.0%) and M. salmoides fed mainly on R. brunneus (73.3%), Decapoda (21.2%). M. salmoides of Geumgyeji and Samgaji were apparently introduced more than a 10 years ago. The fish population declined rapidly since the introduction of M. salmoides. L. macrochirus of Naejangji was introduced more than 20 years ago, which increased its relative abundance to 40%. M. salmoides was introduced five to six years ago, and the fish species and population declined rapidly since the introduction of M. salmoides. Finally, we discussed the inhabitat status and management of M. salmoides and L. macrochirus in the National Park.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.543-550
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• 2020

This study aimed to identify the characteristics of fish inhabiting Hapcheon Dam and surrounding rivers and the Bluegill population, an invasive species, and provide basic data. The survey of fish living in Hapcheon Dam and surrounding tributaries in the Ulsan area from 2016 to 2017 identified a total of 1,785 individuals of 30 species of 10 families and identified 8 Korea's endemic species (21.8% indigenization rate), 3 exotic species, and 2 ecosystem disturbance species. The comparison of this study with the past survey showed that 36 species of 12 families were reported in the past survey, but 14 species of them were not found in this study. We believe that a more detailed survey of Lake Hapcheon should identify most of them. The analysis of the length-weight relationship for the Bluegill population, identified as the dominant species in the Hapcheon Lake, showed that a large number of populations was in the stage of rapid growth as a large number of populations aged 1 to 2 years was found. Since the obesity level and the length-weight relationship were confirmed to be in good condition, it was necessary to prepare a plan to control the Bluegill population. We expect that this study's results can be useful data for understanding the growth and trends of the Bluegill population inhabiting the Hapcheon Dam and surrounding rivers.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 1997.12a
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• pp.108-108
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• 1997

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.552-552
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• 2017

본래 식용으로 들여온 외래어종은 우리나라 하천에서 토착 어류의 생태계를 교란시키며, 빠르게 서식처를 확산하고 있다. 일반적으로 알려져 있는 외래어종인 배스와 블루길 이외에도 무지개 송어 및 향어도 외래어종으로 분류된다. 본 연구는 외래어종 중 배스와 블루길을 대상으로 여러 환경적 요인에 따른 서식처 형성을 관찰하고 외래어종의 생태활동 변화를 분석하는 것을 목적으로 수행하였다. 여러 연구에 따르면 수온과 용존산소가 담수 어류의 서식환경 구축을 결정하는 매우 중요한 인자임을 알 수 있다. 이에 따라, 외래어종의 서식처 형성에 영향을 미치는 여러 환경적 요인 중 수온을 주요 인자로 선정하여 실험실 실험을 수행하였다. 연구를 수행하기 위해 하천 및 농업용 저수지로부터 배스와 블루길을 채집하였다. 채집된 외래어종을 길이 12 m, 깊이 0.6 m, 폭 1 m의 하천과 유사한 자연적 환경이 갖추어진 수조에 이식하였다. 수조 내 환경은 독립변인인 수온을 제외하고 모두 동일하게 구성하였다. 수조를 3개의 구역으로 구분하여 양 끝단에 냉수대와 온수대를 조성하였으며, 중간부의 평균 수온대를 기준으로 냉수대와 온수대의 수온 차는 약 $1^{\circ}C$이상 유지되도록 설정하였다. 현재까지의 실험 결과에 따르면, 외래어종은 온수대에 서식처를 형성하였다. $1^{\circ}C$의 수온 차에도 매우 민감하게 반응하며, 냉수대에는 서식처를 형성하지 않는 것 또한 확인되었다. 이를 통해 수온이 외래어종의 서식처 형성에 매우 중요한 영향을 미치는 요인인 것으로 판단된다. 연구 과정에서 추가적으로, 먹이 금붕어가 부재할 경우 동종 어식을 하는 것이 관찰되었다. 수조 내 수온에 따른 구역의 구분을 위해 공통으로 설치된 가림판 부근에 외래어종의 군락이 형성된 것을 통해, 향후에는 외래어종의 서식처 형성과 장애물과 같은 지형적인 요인이 미치는 영향에 관한 연구가 필요할 것으로 판단된다. 춘계는 수온의 증가로 외래어종이 더욱 왕성한 활동을 하는 시기이다. 수온이 외래어종의 서식처 형성에 지배적인 영향을 미치는 것이 실험을 통해 확인하였으나, 수온에 대한 민감도에 관한 연구 또한 필요하다. 더불어 외래어종의 계절에 따른 먹이활동 및 생장량 또한 지속적으로 관찰할 것이다.

• Proceedings of the Korea Water Resources Association Conference
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• 2018.05a
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• pp.482-482
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• 2018

우리나라의 대표 생태계 교란 외래어종인 배스와 블루길은 본래 식용 목적으로 유입되어 하천에서 빠르게 확산되고 있다. 그로 인해 우리나라 토종 어류의 개체수가 감소하고 토종 어류의 서식지가 사라지고 있다. 따라서 본 연구는 배스와 블루길을 대상으로 여러 환경적 요인에 따른 서식처 형성 특징을 관찰하고 분석하여 최종적으로 외래어종의 확산을 차단하는 것을 목적으로 수행하였다. 실험실 연구를 통해 외래어종이 서식처를 형성할 때 주변 환경을 관찰한 결과 특정 반응에 민감하고 장애물과 같은 지형적 요소를 선호하는 행동 특성을 발견하였다. 이에 따라 발견된 특성을 중점으로 하여 지형인자와 조명에 관련된 실험실 연구를 진행하고 분석하였다. 연구를 수행하기 위해 자연 상태에서 채집한 배스와 블루길을 길이 12 m, 깊이 0.6 m, 폭 1 m의 하천과 유사한 자연적 환경이 갖추어진 수조에 이식하였다. 첫 번째로 장애물에 대한 반응 실험은 세 가지 종류의 장애물을 환경 조건이 동일한 수조에 설치하여 어떤 장애물을 더 선호하는지를 관찰하는 방식으로 진행되었다. 그 결과 외래어종은 어류의 위쪽 시야를 차단하는 즉, 상단 벽 장애물을 가장 선호하였으며 이 장애물 밑에 주로 서식처를 형성하였다. 그 이유로는 자연 상태의 외래어종에게는 조류가 가장 큰 천적이므로 조류를 경계하는 습성에 의한 서식처 형성으로 판단된다. 또한 외래어종이 서식처를 형성할 때 크게 고려하는 수온과 장애물 중 어떤 독립변인에 더 민감하게 반응하는지도 관찰되었다. 실험은 춘계에 먼저 수온의 차이를 두어 외래어종이 서식처를 형성하게 만든 후, 서식처로 자리 잡지 않은 곳에 장애물을 설치하여 형성된 서식처를 옮기는지 지켜보았다. 그 결과 앞선 연구로 발견된 외래어종의 서식처 형성에 적당한 수온 $20{\sim}24^{\circ}C$가 아니어도 장애물이 설치된 곳 밑에 서식처를 형성하는 것을 발견하였다. 두 번째로 조명에 관한 실험에서는 외래어종이 수조 전체에 설치된 상단 조명의 아래에는 위치하지 않았으며, 외래어종이 자리 잡은 서식처에 간이 조명을 설치하여 비추거나 하면 피하는 특성을 보였다. 하지만 실험실이 아닌 실제 하천의 환경은 매우 다양한 변수를 포함하고 있어 실험실 수조와의 환경과는 다른 양상을 보일 수 있다. 이와 같은 실제 생태계와 실험실 수조의 환경 차이에서 오는 불확실성에 대한 개선을 위해 실험실에서 진행된 실험 결과를 바탕으로 향후 외래어종의 서식 환경 특성을 고려한 외래어종 확산 차단물을 설계하여 실제 자연 환경에서 외래어종이 어떻게 반응하는지에 관한 연구가 필요할 것으로 판단된다.

• Korean Journal of Environment and Ecology
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• v.29 no.3
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• pp.401-409
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• 2015

The fish community and introduced fish were surveyed at eight stations of Lake Soyang from March to October, 2013. A total of 41 species of twelve families were collected from the survey stations and among them, two species: Hemibarbus mylodon and Siniperca scherzeri (albino type) were identified as natural monument. There were fifteen Korean endemic species (36.6 %) including Acheilognathus yamatsutae. When compared with previous data (2003), A. yamatsutae, Pseudorasbora parva, Sarcocheilichthys nigripinnis morii, Sarcocheilichthys variegatus wakiyae, Orthrias nudus, Leiocassisuss ussuriensis, Oncorhynchus mykiss, and Micropterus salmoides appeared new in the lake. Dominant species were Hypomesus olidus (St. 1, 3, 6, 7, 8), Lepomis macrochirus (St. 2, 4) and Zacco platypus (St. 5). Of the 12 introduced species fishes in Lake Soyang, Anguilla japonica, Hemiculter eigenmanni, H. nipponensis, Rhinogobius giurinus and Tridentiger brevispinis were introduced and released from other native river water zones in Korea but Cyprinus carpio (Israeli type), Carassius cuvieri, O. mykiss, Ictalurus puntatus, L. macrochirus, and M. salmoides originated from foreign countries.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.559-565
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• 2014

The fish and attached fish eggs by artificial floating island in lake Soyang was investigation from May to June 2013. The observed fish at the floating island during the survey period were Zacco platypus (5.2 %), Siniperca scherzeri (1.0 %), Lepomis macrochirus (90.8 %) and Micropterus salmoides (3.0 %) at the Cheongpyeong-ri, Cyprinus carpio (0.4 %), Z. platypus (54.6 %), L. macrochirus (20.3 %) and M. salmoides (24.7 %) at the Ungjin-ri. The collected species at the neighboring facility were 22 species belonging the seven families. Among them, exotic species such as Carassius cuvieri, L. macrochirus and M. salmoides. Also, Z. platypus (30.4 %), L. macrochirus (18.9 %), Opsariichthys uncirostris amurensis (15.4 %) and Hemibarbus labeo (9.3 %) were numberous. Attached fish eggs number were 708,800 (800 per $m^2$) at the Cheongpyeong-ri and 974,500 (1,100 per $m^2$) at the Ungjin-ri. The fish eggs number were 504,920 of the Carassius auratus (212,640 at the Cheongpyeong-ri, 292,280 at the Ungjin-ri) and 1,178,380 of the C. carpio (496,160 at the Cheongpyeong-ri, 682,220 at the Ungjin-ri). The hatched eggs number were 350,505 of the C. auratus(102,067 at the Cheongpyeong-ri, 248,438 at the Ungjin-ri) and 811,222 of the C. carpio (238,157 at the Cheongpyeong-ri, 573,065 at the Ungjin-ri).

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.76-83
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• 2017

Fish respond sensitively to light, so it is possible to develop fish management technology using this feature. In this study, we developed a light-based fish barrier and analyzed itsblocking effect using the difference in illuminance for the major fish species in Korea, bass and bluegill. The light was generated by a light emitting diode and the facility was installed vertically from the bottom. Considering the fish's ability to travel upstream, the flow rate was divided into three stages (0.2, 0.1, and 0.05 m/s). To prevent the learning effect, an experiment was carried out with fish that had rested for more than one day in a rearing tank. The experiment was carried out in such a way as tocompare the number of fish which travelled upstream after the introductionof the fish barrier and that of the fish which travelled upstream after itsremoval. It was also carried out after sunset to increase the effectiveness of the barrier. According to the results of the experiment, the fish blocking effect depending on the difference in illuminance was high and, overall, the blocking rate for bass was lower than that for bluegill. Based on the total size of the experimental population, the blocking rates for bass and bluegill were 96.33% and 99.00%, respectively. Based on the number of fish that travelled upstream, the blocking rates for bass and bluegill were 91.73% and 98.73%, respectively.

• Korean Journal of Ichthyology
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• v.24 no.4
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• pp.278-286
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• 2012

This study was examined for information of management of bluegill, Lepomis macrochirus which is disturbance species of underwater ecosystem in Korea. Research of bluegill population was investigated spring-summer and autumn periods in the Han river system from 2009 to 2012. Bluegill inhabited mostly lakes, and restrictedly lived at still area in downstream. The range of relative abundance were 0.2~18.2% in individual number and 0.2~40.0% in biomass and it was subdominant or superiority species for the most part of the lakes. Population structure were analyzed r-strategy in Lake Soyang and Paldang and K-strategy in Lake Uiam and Cheongpyeong. But Lake Chungju was estimated transition period from K-strategy to r-strategy. Condition factor and body weight-total length relations were presented favorable condition. For the nesting, bluegill was formatted the group. And the water depth and the distance from shore were mean 56.3 cm and 191.9 cm respectively in nesting ground. Diameter and depth of nests were mean 42.4 cm and 9.7 cm respectively. These results are available for research of population dynamics and reproductive ecology of bluegill.