• Korean Journal of Ichthyology
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• v.28 no.2
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• pp.79-86
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• 2016

Stomach contents of Amblychaeturichthys hexanema and A. sciistius (Perciformes: Gobiidae) from southeastern waters off Korea were analyzed to determine dietary habits and the presence of any inter- and intra-specific partitioning of food resources. These two species were bottom-feeding carnivores that consumed mainly benthic crustaceans, and other demersal invertebrates and planktonic organisms were also important in their diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on gravimetric contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences; i.e. partitioning of food resources between the two species. Size-related changes, however, were not significant for their diets. Differences in the types and range of prey ingested by the two species could often be related to differences in the feeding behaviors. Our results of stomach contents analyses provide clear evidence of niche segregation between co-occurring A. hexanema and A. sciistius in southeastern Korean waters, which would reduce the likelihood of inter-specific competition for food resources.

• Korean Journal of Environment and Ecology
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• v.19 no.1
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• pp.46-54
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• 2005

The change of fish community in the Wonju-stream was investigated from May to November, 2004. During the period,24 species belonging to 6 families were collected. There were 10 Korean endemic species$(41.7\%)$, including Pseudopungtungia tenuicorpa, Coreoleuciscus spiendidus, Squalidus gracitis majimae, Squalidus japonicus coreanus, Microphysogobio yaluensis, Microphysogobio longidorsalis, Iksookimia koreensis, Koreocobitis rotundicaudata, Liobagus andersoni and Odontobutis interrupts. The dominant species was Zacco Platypus$(54.7\%)$, and the subdominant species was Rhynchocypris oxycephalus$(16.7\%)$. Also, Carassius auratus$(5.4\%)$, I. koreensis$(3.4\%)$, Orthrias toni$(3.3\%)$, and Pungtungia herzi$(3.0\%)$ appeared. According to the fish species compositions, the fish community was divided into 2 groups by an unweighted pair group method using arithmetic averages(UPGMA). The comparison of the fish community showed that benthic fish species were decreased, while, the number of water-column species, resistant 1,o substrate changes and water pollution were increased.

• Korean Journal of Ichthyology
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• v.30 no.4
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• pp.224-231
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• 2018

Dietary niches can support the coexistence of sympatric species in marine ecosystems, which can lead to the presence of greater abundances of those species. Stomach contents of silver croaker (Pennahia argentata) and Japanese sillago (Sillago japonica) inhabiting the Nakdong River estuary, Korea were analyzed to determine diet compositions and the presence of any size-related and inter-specific feeding relationships. These species were bottom-feeding predators that consumed mainly benthic crustaceans and mollusks, but polychaetes were also important in the S. japonica diets. Non-metric multidimensional scaling (nMDS) ordination and multivariate analyses based on weight contributions of the different prey taxa to stomach contents revealed significant inter-specific dietary differences. Size-related change was also significant for P. argentata diets, but not for S. japonica. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. The results from this study provide clear evidence of niche segregation between co-occurring P. argentata and S. japonica in the Nakdong River estuary, which would reduce the likelihood of inter-specific competition for food resources.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.5
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• pp.535-548
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• 1994

Community structures and fish densit were investigated on three different types of artificial reefs, dice, turtle artificial reef and tubes, constructed in the Korean waters. Variations of fish fauna according to type of artificial reef and the proper artificial reef in each area for optimizing harvest were discussed. Fish were captured by trammel gill net during May, June, September and November, 1988 and both identified and counted. Fourty-five fish species were found in the artificial reefs. Of these, Sebastes spp., Hexagrammos otakii, Pleuronectidae, Navodon modestus and Stephanolepis cirrhifer showed high occurrence-frequency. The dominant species groups were coastal settlement, demersal or rock fishes such as Pleuronectidae, Rajiformes, Stephanolepis cirrhifer, Navodon modestus, Hexagrammos otakii and Sebastes spp. in all of the Artificial reefs except the oceanic area of southern waters. Scomber japonicus was predominant in the oceanic area of southern waters. Composition of demersal, rock and pelagic fishes were different depending on the types of artificial reef. Dice artificial reefs were occupied by rock fish, on the other hand turtle artificial reefs were dominated by dermersal fish. Fish density was high at the dice artificial reef in all survey areas except the middle area of Eastern waters, with high fish density evident in the Tube artificial reef. Fish community structures were remarkably different between Dice and Turtle artificial reefs. The Tube artificial reef showed intermediate characteristics between the above two types of artificial reefs. The coastal areas of Southern waters and the middle and southern areas of Western waters revealed similar fish fauna. Results from the oceanic areas of Southern waters were well associated with the middle and southern areas of Eastern waters.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.413-414
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• 2001

우리나라 동해는 남해나 서해와는 달리 수심이 깊고 해안선이 단조로우며 급경사를 이루는 곳이 많은 지형적 특징을 가지고 있으며, 연안역은 생산성이 높은 해역으로 수 많은 해양생물이 산란, 생육 및 섭식의 장소로 이용하고 있어 어장으로서 가치가 매우 높은 곳이다. 특히 동해 중부연안은 동한난류와 북한한류의 영향을 동시에 받는 해역으로서 한ㆍ난류성 어류 및 표 저층성 어류 등 다양한 어종이 서식하고 있는 곳으로 알려져 있다. (중략)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.3
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• pp.244-253
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• 1990

For the purpose of the investigation on the selective action of trawl net, a series of fishing experiments carryed out in M. S. Pusan 402 during the years of 1986~1987, by using a set of trawl net with a few pocket nets in each part of the bagnet. The author analyzed these experimental data and derived the following results. 1. 58 species of aquatic animals were caught in totally 43 times of trawl operation and 33 species of them did not escape at all through the barrier of netting in the bagnet. 2. Sardinops melanosticta, Harengula zunasi, Thrisa kamalensis, Englausis japonicus, little size of Tracurus japonicus, Sphyraena pinguis, Trichirus lepturus, and Psenopsis anomala escaped easily through the barrier of netting after being caught inside of the codend. Especially, Englusis japonicus escaped well not only through the netting of the codend but also through the netting of the square and the baiting. 3. In the case of mesh size of 60mm in the codend, Pampus argentus, Doderleinia bercoides and Tracurus japonicus were caught all in the size of less than 10cm.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.188-195
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• 2005

The dynamics of the fish community in the Lake Hoengseong region, Korea, were investigated from April 2000 to November 2004. During the surveyed period 39 species belonging 10 families were collected, and there were 17 Korean endemic species (43.59%) including Rhodeus pseudosericeus. Dominant species were Acheilognathus lanceolatus (20.10%), Zacco platypus (15.94%), Z. temmincki (6.92%), Carassius cuvieri (6.33%), A. rhombeus (6.18%), Pungtungia herzi (5.13%), and Pseudorasbora parva (4.93), In the comparison community of fish according to ecotype by each studied years, benthic fished are gradually decreasing and pelagic fishes creasing. Also, according to the fish distribution, the fish community of each studied years was divided into 3 groups by UPGMA. Being based on the fish community, similarity analysis results of each artificial lakes and this lake were divided 2 groups by water system, and divided again 3 groups in the same water system. Fish Community of the Lake Hoengseong was similar with that of the Lake Chuncheon and Cheongpyeong of the Bukhan-River.

• Korean Journal of Ecology and Environment
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• v.46 no.2
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• pp.154-165
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• 2013

The species composition of the fish community was studied in four streams where fish kills have previously occurred in recent years; Worun Stream, Seo Stream, Jangnam Stream, and the Anyang Stream. The number of fish species varied from 22 to 86% compared to the number of fish species pre-fish kill. The recovery of fish populations in the streams seems to be determined by water quality and the presence of artificial structures in the streams. The Jangnam Stream, where alkaline pH caused a fish kill, showed a high recovery of fish species due to improvements in water quality. Anyang Stream had a low number of species, possibly because dissolved oxygen concentrations were intermittently low. Artificial structures in streams had a negative impact the recovery of fish species, particularly for benthic fish species. It appears that fish populations can recover rapidly when water quality improves or the movement of fish community is unimpeded. However, water quality and artificial structures in many streams in Korea still present adverse conditions for fish survival, deterring the recovery of fish populations. To conserve fish populations in streams, habitat all owing unimpeded movement for fish and controls on pollutant inputs are needed.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.40 no.4
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• pp.295-303
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• 2004

In order to estimate the effect of ceramic artificial reefs on the fisheries resources enhancement, we have studied the variation of catch and species, which were caught by trammel net on the three fishing grounds of ceramic artificial reef, natural reef, and control(non-reef)in the coast of Geomun-do, Korea from 2001 to 2003. Catch per unit effort (CPUE ; g/panel) of fishing ground with the ceramic artificial reef area was 1,621.9g, it was about 67.9% higher than the natural reef area 333.3% higher than the control area. The catch of fish with the ceramic artificial and the natural reef area was not significantly different based on statistical analysis of Tukey test, whereas the relationship between the ceramic artificial reef and the control area was significantly different (p<0.05). Monthly mean number of species caught by the artificial reef area, the natural reef area and the control area was no difference by ANOVA test. The catch of fish was highest in November and lowest in May, whish was associated with the natural reef and the control area. The dominant species were demersal fishes living around rock such as Pagrus majir, Thamnaconus modestus, Stephanolepis sirrhifer, Pleuronichthys curntus, and Ostracion cubicus in the artificial reef area, but demersal of migratory fishes in the natural reef and the control area.

• Korean Journal of Ecology and Environment
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• v.38 no.4 s.114
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• pp.482-493
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• 2005

The objective of this research was to evaluate an sampling effect of fish species and individual number on sampling techniques of electrofishing and conventional capture methods of cast net and kick net in 38 stream sites sampled during June - September, 2005. For the study, sampling gears were categorized as three types of electrofishing method (EM), conventional sampling technique (CM), and the combined technique (CT) of the electrofishing and the conventional method to compare statistical differences. Major differences of species composition between the CM and EM method were found in some benthic species of Misgurnus mizolepis and Iksookimia koreensis along with lithophilic species of Pungtungia herzi. These species were predominated in the EM rather than the CM, indicating that conventional sampling can underestimate the abundance of benthic or lithophilic species. In contrast ,individual number of typical water column species such as Zacco platypus and Zacco temmincki were more sampled by the CM, so that these fish populations were community overestimated. Also, t-tests on the types of sampling gear from various watersheds of Chogang Stream, Yugu Stream, Daejeon Stream, and Gap Stream showed that total individual numbers and species number in each stream were significantly (t values = 2.806-6.896, p values<0.05, n = 5-14) greater in the CT than the CM. Similar statistical significance (p<1.001, n = (10-24) on sampling seasons were observed during the monsoon and postmonsoon. These results indicate that if the electrofishing is not added to the conventional gears, the abundance of fish population and community can be underestimated and some benthic or lithophilic species may be excluded from the analysis, resulting in overall errors including sampling, fish fauna, and final judgement of community abundance. Overall our results strongly suggest that new application of electrofishing method along with the conventional sampling gears reduce sampling bias on underestimation of the real fish populations and communities.