• 한국해양생명과학회지
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• 제6권2호
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• pp.106-116
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• 2021

태화강에서 방류한 연어(Oncorhynchus keta) 치어의 성장, 생존 및 어류상 등의 모니터링를 통한 생태학적 기초 자료를 확보하고자, 방류 후 연어 치어의 지점별 포획개체수, 성장 및 어류상 특성을 조사하였다. 태화강 상류로부터 총 4개 지점[선바위교(St.1), 구영교(St.2), 삼호교(St.3), 명촌대교(St.4)]에서 2년간 조사를 실시하였다. 2017년 연어 치어 방류 후 전장은 평균 10 mm, 체중은 평균 0.8 g의 증가를 나타내었다. 2018년 연어 치어 방류 후 평균 전장 10 mm, 체중 0.5 g의 증가를 나타내었다. 연어 치어를 포식할 수 있는 어식성 어류는 St.1에서 6종(동사리, 숭어, 배스, 꺽지, 황어 및 끄리), St.2에서 5종(동사리, 황어, 배스, 꺽지 및 끄리), St.3에서 6종(큰가시고기, 가물치, 날망둑, 배스, 황어, 끄리) 및 St.4는 8종(큰가시고기, 베도라치, 문절망둑, 날망둑, 풀망둑, 강준치, 점농어 및 황어)이 출현하였다. 본 연구결과 연어 치어는 체중의 증가보다 전장 및 체장의 성장에 집중하는 것으로 나타났다. 또한, 적정 방류지역은 포식생물의 서식이 적고 수심, 유속, 염분 등의 변화가 적은 St.1과 St.2 지점이 적절할 것으로 판단되며 방류 시기는 끄리 및 배스 등의 포식어류의 먹이활동이 활발하지 않은 1월 초순 혹은 포식 활동이 적은 야간이나 새벽시간에 방류하는 것이 적절할 것으로 판단된다.

• 생태와환경
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• 제55권4호
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• pp.368-375
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• 2022

보구치는 어류와 요각류가 공통 먹이원으로 분석되었다. 광양만에서 채집한 보구치가 가장 많이 먹은 먹이원은 단각류로 ASV 빈도가 62.5%로 나타났으며 여수 어시장에서 구입한 보구치는 어류의 ASV 빈도가 16.6%로 가장 많았다. 광양만에서 채집한 참조기의 우점 먹이원은 십각류로 ASV 빈도가가 99.9%로 나타났으며 어시장의 참조기는 어류의 ASV 빈도가 51.2%로 조사되었다. 광양만과 어시장의 자주새우 우점 먹이원은 각각 요각류로 92.6%와 100%로 조사되었다. 광양만에서 채집한 꼴뚜기는 요각류(91.4%)를 가장 많이 먹었으나 어시장에서 구입한 갑오징어는 어류(96.6%)를 가장 많이 섭식하였다. 계층적 군집 분석 결과, 꼴뚜기 및 채집한 자주새우와 구입한 자주새우는 먹이원이 유사하였으며 보구치와 참조기, 갑오징어와는 차이가 있는 것으로 조사되었다. 네트워크 분석 결과, 요각류는 참조기를 제외한 모든 수서 생물과 연결되어 있어 가장 중요한 먹이원인 것으로 조사되었다. 먹이원 폭 분석 결과 광양만에서 채집한 참조기의 먹이원 폭 값은 0.001로 낮았으나 어시장에서 구입한 참조기의 먹이원 폭 값은 0.886으로 먹이원 다양성이 가장 높았다. 영양단계 분석 결과, 어류를 주로 섭식했던 갑오징어가 3.98로 가장 높았으며, 광양만에서 채집한 보구치가 2.0으로 영양단계가 가장 낮은 것으로 조사되었다. 이를 통해 위 내용물의 DNA 메타바코딩을 활용한 먹이원 분석 연구는 육안을 통한 먹이원 분석 사이에서 상호보완하여 섭식생태 연구에 활용할 수 있을 것이다.

• 수산해양기술연구
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• 제26권4호
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• pp.326-332
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• 1990

인공추출물을 조제하여 유인활성을 검토하였으며 9종의 아미노산과 2종의 핵산 관련물질을 표준품으로 현장에서 omission test를 실시한 결과는 다음과 같다. 1. 생멸치 및 냉동정어리의 에탄올 추출물과 잔사의 유인활성을 검토한 결과, 에탄올 추출물에서 강한 유인활성을 나타내었다. 2. 생멸치의 구성성분과 같은 농도로 인공합성품을 조제하여 현장실험을 한 결과, 유인활성이 생시료의 에탄올 추출액보다 약했으나 아미노산 합성물질과 핵산 관련 물질이 다른 물질들보다 유인활성이 강한 것으로 나타났다. 3. 9종의 아미노산에 대하여 omission test를 실시한 결과 L-글루타민산, L-글리신, 타우린 및 L-메티오닌은 붕장어에 대하여 유인활성이 강한 것으로 나타났으며, L-라이신이나 DL-폐닐알라닌은 기피활성이 있는 것으로 나타났다. 4. 2종의 핵산 관련물질중 IMP는 유인활성이 있었으나 하이포산틴은 없었다.

• Journal of Ecology and Environment
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• 제44권3호
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• pp.185-195
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• 2020

Background: The flathead grey mullet Mugil cephalus has the widest distribution among mugilid species. Recent studies based on mitochondrial DNA sequences showed that the species comprises at least 14 different groups, three of which occur in the northwest Pacific. We analyzed the otolith microchemistry of M. cephalus at several locations in Korea to improve understanding of migration pattern and population origin. Results: We collected 123 sagittal otoliths from seven locations and determined their concentrations of eight elements (⁷Li, ²⁴Mg, ⁵⁵Mn, ⁵⁷Fe, ⁶⁰Ni, ⁶³Cu, ⁸⁸Sr, and ¹³⁸Ba) using laser ablation inductively coupled plasma mass spectrometry. Mean otolith elemental ratios differed significantly among the locations. The Sr:Ca, Fe:Ca, and Ba:Ca ratios were significantly higher than others, and useful chemical signatures for investigating the habitat use of M. cephalus populations. We identified five diverse and complicated migration patterns using the otolith data that we collected: estuarine resident (type I), freshwater migrant (type II), estuarine migrant (type III), seawater resident (type IV), and seawater migrant (type V). A canonical discriminant analysis plot revealed separation of two groups (type II in the Yellow Sea vs. other types in remaining locations). Two locations on Jeju Island, despite their close proximity, had fish with quite different migration patterns, corroborating previous molecular studies that distinguished two groups of fishes. Conclusion: We successfully showed that the migration patterns of the Korean mullet varied by location. Only fish from the western sector of Jeju had a unique migration pattern, which is likely confined population in this area. Among the eight otolith elements measured, the Sr:Ca ratio was found to be the best indicator of migration pattern and population origin.

• 한국수산과학회지
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• 제48권5호
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• pp.621-630
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• 2015

This study investigated the concentration of total mercury in 17 species of commonly consumed fishes and assessed the risk to human health from provisional tolerable weekly intakes PTWI% as affected by migratory characterization, such as migration and vagility. The measured mean concentrations of total mercury in these 17 species of commonly consumed fishes suggest that mean concentrations of total mercury in 10 species of migratory fishes (largehead hairtail, chub mackerel, Pacific saury, skipjack tuna, Pacific cod, anchovy, Alaska pollack, brown croaker, Japanese Spanish mackerel, yellow croaker and Pacific herring) were low compared to those in 7 species of demersal fishes (red stingray, brown sole, bastard halibut, conger eel, blackmouth angler, rockfish and filefish). Based on the mean concentrations, the PTWI% of total mercury among commonly consumed migratory fishes was 3.393%, which was higher than that of commonly consumed demersal fishes (2.710%).

• 한국물환경학회지
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• 제22권5호
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• pp.796-804
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• 2006

The objective of this research was to develop ecological multi-metric models using natural fish assemblages for a diagnosis of current stream health condition, and apply the model to nationwide lotic ecosystems of the Geum River, the Youngsan River, and the Sumjin River. The ecological stream health model was based on the index of biological integrity (IBI), which was originally developed in North American streams by Karr (1981), and the Rapid Bioassessment Protocol (RBP), which was scientifically established by the US EPA (1999). The metric numbers and metric attributes were partially changed for the regional applications, so the scoring criteria was modified for the assessment. Overall, metric values, based on the IBI calculations, reflected conventional water quality characteristics, based on nutrient regime, and agreed with results of staticeco-toxicity tests. Some stations impaired in terms of stream health were identified by the IBI approach, and also major key stressors affecting the stream health were identified by additional evaluations of physical habitats. Our preliminary results suggested that biological integrity in stream ecosystems was largely disturbed by habitat degradation as well as chemical pollutions. This new approach would be used as a key tool for ecological restorations and species conservations in the degraded aquatic ecosystems in Korea and applied for elucidating major causes of ecological disturbances. Ultimately, this approach provides us an effective management strategy of stream ecosystems through establishments of ecological networks in various watersheds.

• 수산경영론집
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• 제47권3호
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• pp.53-69
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• 2016

The purpose of this study is to explore the ecosystem service and benefit indicators of natural seaweed beds. Ecosystems of natural seaweed beds provide a wide range of services and benefits to human society including provisioning services, regulating services, supporting services, and cultural services. Indicators for each of the ecosystem services are chosen by marine plants ecologists and as follows. Ecosystem indicators of natural seaweed beds for provisioning services are well-being food(amount of seaweed harvested/amount of fish landed, fish biomass, area of natural seaweed beds, the number of species, contribution to the second production), raw materials(amount of biomass by breed, amount of aquaculture feed), genetic resources(amount of genetic material extracted, amount of genetic material contained by age and habitat), and medicinal resources(amount of medicinal material extracted). Ecosystem indicators of natural seaweed beds for regulating services are air purification(amount of fine dust/NOx or $SO_2$ captured), climate regulation(amount of $CO_2$ sequestered), waste treatment(amount of N, P stored, biochemical degradation capacity COD), and costal erosion prevention(length and change of natural coast line, amount of sediment prevented). Ecosystem indicators of natural seaweed beds for supporting services are lifecycle and maintenance(primary production, contribution to the second production) and gene pool protection(amount of compositional factors in ecosystem, introduced species). Ecosystem indicators of natural seaweed beds for cultural services are recreation and tourism(the number of visits of an area) and information for cognitive development(amount of time spent in education, research and individual learning about ecosystem of natural seaweed beds).

• Fisheries and Aquatic Sciences
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• 제22권6호
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• pp.12.1-12.8
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• 2019

Background: Wild fish populations stock is continuously diminishing in the Indo-Ganges river basin, and the population status of most fishes is unidentified. The identification of the population status and the conservation of commercially important and endemic wild fish populations in this region are crucial for the management. The aim of this paper was to identify the population status of Cirrhinus reba, a promising aquaculture but vulnerable species in the Indo-Ganges river basin in Bangladesh. Methods: C. reba samples were collected from four isolated populations of the Brahmaputra (n = 30), the Padma (33), the Karatoya (31), and the Jamuna Rivers (30) in Bangladesh, and the population status was evaluated using morphometric and landmark comparisons. Data were analyzed with the Kruskal-Wallis test, univariate analysis, discriminant function analysis, and the formation of a dendrogram. Results: Three meristic characters (Pectoral fin rays, caudal fin rays, scale in lateral lines), four morphometric characters (head length, pre-orbital length, post-orbital length, maximum body depth), and truss measurement (4-7) were significantly different among the stocks. The step-wise discriminant function analysis retained 15 variables from morphometric and landmark measurements that significantly differentiated the populations based on the constructed DFI and DFII. Discriminate function analysis also showed that 91.2% of the original groups were classified into their correct samples. The cluster analysis of Euclidean distances placed the Jamuna population in one cluster and the Brahmaputra, the Padma, and the Karatoya populations in the second one. Conclusion : Morphological differences among the stock were probably due to different ancestral origin. This is the first report about population status of C. reba in their natural habitat of the Indian subcontinent. Further genetic studies and the evaluation of environmental impact on C. reba populations in Bangladesh are suggested to support our findings.

• 한국어류학회지
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• 제31권1호
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• pp.54-61
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• 2019

꼬치동자개 Pseudobagrus brevicorpus의 일주기활동과 식성에 관한 연구를 낙동강 지류인 대가천에서 실시하였다. 일주기 활동은 일몰 직후와 일출 전에 2회에 걸쳐 일어났다. 주로 하천의 중층대에서 활동을 하며 먹이생물이 발견하면 접근하여 흡입하는 행동을 취했다. 연령은 3개 그룹으로 구분되었고 위내용물 중 상대중요성지수 (index of relative importance, IRI)가 1%를 초과하는 먹이생물은 하루살이목 (Ephemeroptera) 80.8%, 파리목 (Diptera) 8.6%, 날도래목 (Trichoptera) 8.5% 순으로 나타났다. 또한 모든 연령군에서 하루살이목이 매우 중요한 먹이생물이었고, 성장함에 따라 먹이생물의 크기가 증가하였다.

• 한국수산과학회지
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• 제55권3호
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• pp.345-352
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• 2022

In this study, the dietary habits of the spinyhead sculpin Dasycottus setiger were investigated based on 156 specimens collected seasonally between May 2018 and February 2019 from the East Sea off the Korean coast. In terms of the weight contribution (%W), the main food items of the spinyhead sculpin were found to be teleosts (33.5%), followed by carid shrimps (13.8%), amphipods (13.3%), cephalopods (12.0%), and polychaetes (7.1%). Dietary analyses based on the weight contribution of different prey taxa in the diet of the spinyhead sculpin revealed considerable variation in the dietary composition in terms of the sampling region and fish size implying intra-specific dietary segregation. The spinyhead sculpin showed a size-related trends in dietary shift from amphipods to carid shrimps and teleosts in northern region, and from carid shrimps and mysids to teleosts and cephalopods in middle eastern coast. Multivariate analyses of dietary changes revealed that the dietary composition of spinyhead sculpin is significantly associated with the sampling site, but not the fish size. Amphipods contributed more to the diets of the northern population, while mysids typified the diets of spinyhead scuplin inhabiting the middle eastern coast, indicating differences in available food resources between the two study regions.