• Animal Systematics, Evolution and Diversity
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• v.22 no.2
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• pp.169-177
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• 2006

Some hyromedusae were collected from Korean waters with Issacc-Kidd Midwater trawl net or by SCUBA diving during the period from May 2001 to Nov. 2005. They were identified into 14 species of 11 families in six orders. Of these, the following six species are new to Korean fauna: Olindias formosa (Goto, 1903) and Proboscidactyla stellata (Forbes, 1846) of the order Limnomedusae; Aglantha digitale ($M\ddot{u}ller$, 1776) and Rhopalonema velatum Gegenbaur, 1854 of the order Trachymedusae; Solmundella bitentaculata (Quoy and Gaimaud, 1833) and Aegina citrea Eschscholtz, 1829 of the order Narcomedusae. The order Narcomedusae and the families Rhopalonematidae and Aeginidae are first recorded in Korean waters. As a result of the present study, the Korean hydromedusae consist of 26 species of 19 families in six orders so far.

• Animal Systematics, Evolution and Diversity
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• v.39 no.3
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• pp.127-132
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• 2023

Aquilonastra doranae, a newly recorded sea star, was collected from the southern coast of Jejudo Island by a trimix SCUBA diving survey in May 2021. The newly collected specimen is distinguished from a previously known Aquilonastra species in South Korea by having a fissiparous body form with six arms. Results of pairwise genetic distance analysis showed that the new specimen was identical or close to A. anomala from Hawaii (0.0%), Australia (3.1%), and Samoa (3.3%). However, morphological characteristics of the Korean Aquilonastra specimen corresponded with the original description of A. doranae, not that of A. anomala, including the number of inferomarginal spines, the absence of pedicellariae, and the inhabit locality. Thus, this study agrees with the original morphological study of A. doranae and presents this specimen as the first record of A. doranae in South Korea.

• Animal Systematics, Evolution and Diversity
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• v.39 no.4
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• pp.218-247
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• 2023

In our ongoing efforts to explore the species diversity of the harpacticoid fauna in Korea, we present findings on four newly identified species from family Tegastidae Sars, 1904. Although this family is frequently encountered in phytal communities, the diversity of tegastid copepod species within Korean waters largely remains to be elucidated. Drawing from our collections of tegastid harpacticoids from Chuja-do and Geomun-do Islands, we provide morphological descriptions for Tegastes lobus sp. nov., T. tresetosus sp. nov., T. pilosus sp. nov., and Syngastes acutus sp. nov., and propose their taxonomic relationships in relation to other species within the genus. Finally, we update the list of tegastid harpacticoids found in Korea and provide a key for identifying the six confirmed species from this region.

• Korean Journal of Ichthyology
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• v.22 no.3
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• pp.168-178
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• 2010

Fish assemblages associated with rock reef and non-rock reef were studied using specimens collected at three sites in Geomun Island waters of the Southern Sea, Korea, in February, May, August and October, 2006. Two survey methods for the study were followed: collection by a gill net, and video observation by scuba diving. The gill-net survey was conducted during the night, the scuba-diving observations were conducted during the day. From the gill-net survey, a total of 40 species, 380 inds. and 71,426.9 g was caught at the three sites. The dominant species was Trachurus japonicus; other species were Raja kenojei, Dasyatis akajei, Stephanolepis cirrhifer, Narke japonica, Pagrus major, Sebastes inermis, and Sphyraena pinguis. At the rock-reef site, a total of 26 species, 264 inds. and 46,776.7 g was caught by gill net, and the dominant species was T. japonicus. A total of 17 species, 45 inds., 10,535.1 g was caught at the flat-bottom 1 site, and 19 species, 71 inds. and 14,115.1 g were caught at the flat-bottom 2 site. The scuba-diving survey resulted in 13 species and 1,749 inds. observed at the three sites through the survey period. The main observed fishes were rock-dwelling species such as Chromis notatus, Microcanthus strigatus, S. cirrhifer, Ditrema temmincki, Evistias acutriostris, Girella punctata, Halichoeres poecilopterus, Hexagrammos agrammus, Prionurus scalprum, Sebastes inermis, and Semicossyphus reticulatus. Seven species and 1,739 inds. observed at the rock-reef site comprised 99.4% of the inds. of the three sites. Therefore, the fish community in Geomun Island waters included many rock-reef. species, but a few were migratory species like T. japonicus and Scomber japonicus. The abundance of fish at the rock-reef site was high in comparison with those at two non-rock reefs. The dominant species were very different between the day and the night, although rock-reef species comprised the main part of the fish community. We conclude that the high abundance of fish in Geomun Island waters is most closely related to physical structure, such as rock reefs, which is the main habitat of many fishes.

• Korean Journal of Applied Biomechanics
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• v.17 no.2
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• pp.11-21
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• 2007

The study was undertaken to present the quantitative materials available in underwater industries, underwater rehabilitation & physical training through comparison & analysis of effects contributing to propulsion of COG by types of fin-kick in underwater activities. For this 3D cinematography was performed for the skilled subjective and conclusions obtained on the basis of analysis of kinematic variables were as follows. In temporal variable the delay in the order of flutter>side>dolphin kick in elapsed time by total & phase resulted in longer sliding phase by larger fin kick of extension & flexion of both leg and thus more contributed in propulsion of COG. than those of the otherwise. In linear variable the contribution ratio to the result of propulsion of COG in both propulsive(mean $35.39{\pm}7.93cm$ in Y axis) and sliding phases(mean $66.36{\pm}11.01cm$ in Y axis)was shown to be order of flutter>dolphin>side fin kick. the maximum velocity of COG in Y direction was showed in both propulsive and sliding phases, and the contribution ratio to the propulsion of COG was in the order of flutter$\geq$dolphin>side fin kick. In angular variable the Significant difference in angle of leg joint by types of fin kick in both leg was showed but no routine order. The Significant difference in angular velocity of leg joint by types of fin kick in both leg was showed in the order of flutter>dolphin$\geq$side fin kick in propulsive but no in sliding phase. The Fluid resistance by tilting angle of trunk in both propulsive and sliding phase was decreased in the order of flutter>dolphin$\geq$side fin kick and tilting angle of trunk of the skilled was smaller than that of the unskilled in difference of maximum mean 7.97degree and minium mean 2.06degree. In summary of the above, It will desirable fin kick type because of more contribution to COG propulsion by the velocity & displacement in Y-axis and less fluid resistance by tilting angle of trunk and larger angular velocity in the case of more delayed in elapsed time of propulsive phase than that of the otherwise.

• Journal of Marine Life Science
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• v.4 no.2
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• pp.81-85
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• 2019

This study was carried out to observe the changes of seaweed community in artificial reefs installed in September, 2016 in Namae-ri, Yangyang-gun, and Seokbyeong-ri, Pohangsi, Korea. Field surveys were conducted by SCUBA diving once a season in February, May, August, and November of 2017, and quantitative survey and qualitative survey were carried out in parallel. In this study, a total of 94 species, including 11 green algae, 15 brown algae and 68 red algae were appeared. 66 species (8 green algae, 9 brown algae, 49 red algae) and 65 species (7 green algae, 9 brown algae, 49 red algae) were collected and identified in Yangyang and Pohang. In dominant species, Yangyang was dominant species of Saccharina japonica and subdominant species of Ulva australis. Pohang dominated in order of Colpomenia sinuosa and Gelidium elegans. In both coastal areas, Ulva spp., Colpomenia sinuosa were grown at the early stage of reforestation, and perennial seaweeds such as Saccharina japonica, Ecklonia cava and Gelidium elegans were grown. In order to clarify the clustering relation through flora change, it is necessary to monitor the transition process until the seaweed community is stabilized by observing the long-term change through continuous monitoring.

• Journal of the Korean Society of Marine Environment & Safety
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• v.25 no.2
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• pp.212-219
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• 2019

This study was conducted to investigate marine algal community characteristics and the status of barren ground in the summer at study sites on Jeju Island, Korea. Sampling was carried out from July to September 2017 using a qualitative and quantitative survey (including coverage of non-geniculated coralline algae and density of grazer) by scuba diving. A total of 121 species were identified, including 11 (9.1 %) green algae, 24 (19.8 %) brown algae, and 86 (71.1 %) red algae. Hyeongjeseom had the greatest diversity, with 60 species, and Harye the least, with 18 species. The mean biomass at the study sites was $1,503.0g{\cdot}m^{-2}$, while the mean for the neighboring islets ($3,268.7g{\cdot}m^{-2}$) was higher than that of the main island ($914.7g{\cdot}m^{-2}$). Also, dominant species was identified: Sargassum macrocarpum at the neighboring islets, and Ecklonia cava at the main island, with differences showing not only in biomass but also species composition. In conclusion, the marine algal community status in summer at the study sites was evaluated based on the algal community characteristics (species composition, biomass, biomass ratio of kelp species), coverage of non-geniculated coralline algae, and density of grazer. As a result, both Hyeongjeseom and Marado require preservation and management to maintain their excellent marine algal communities, and other sites on the main island require the creation and/or restoration of marine algal communities. In addition, as the generation of barren ground accelerates, it is urgent not only to grasp existing monitoring research but also to identify the status of the marine algal community where it is not known at present.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.379-388
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• 1983

The subtidal benthic algal communities of Dolsan-island in the southern coast of Korea were surveyed by means of SCUBA diving. The vertical zonation is recognized into three groups; upper, middle and lower subtidal zones. The representative species in each group throughout the year are Ulva pertusa, Codium fragile, Chondria crassicaulis and Gigartina tenera in the upper, Myagropsis myagroides and Sargassum tortile in the middle, and Plocamium telfairiae, Callophyllis japonica and Symphyocladia linearis in the lower zone. According to the normal association analysis by $2{\times}2$ contingency table and chi-square calculation among 29 quadrats, the algal communities are divided into 9 groups which are dominated by Sargassum tortile, Myagropsis myagroides, Chondria crassicaulis, Codium fragile, Pterocladia tenuis, Gigartina tenera, Gracilaria textorii. The thallus length and standing crops of Myagropsis myagroides show the highest value in spring and the lowest in summer.

• Animal Systematics, Evolution and Diversity
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• v.21 no.2
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• pp.243-250
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• 2005

A taxonomic study on the marine sponges was conducted with materials which were collected from Ulleung Island and Chuja Island, Korea by SCUBA diving during the period of July 2000 to May 2005. Among them, two species, Mycale (Aegogropila) jukdoensis n. sp. and Mycale (Mycale) chujaensis n. sp. are new to science. M. (A.) jukdoensis n. sp. seems closely to M. grandis based on the shape of spicules, but our new species has two categories of subtylostyles and also larger sigmas and raphides than those of M. grandis. And anisochelae I of M. (A.) jukdoensis n. sp. is smaller than that of M. grandis. M. (M.) chujaensis n. sp. is similar to M. sulgata in the growth form and size of microscleres. However, the new species has two categories of subtylostyles instead of one type in M. sulgata.

• The Korean Journal of Malacology
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• v.31 no.3
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• pp.165-170
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• 2015

The presence of predators (excluding starfishes) of disk abalone, Haliotis discus hannai was directly investigated by nine SCUBA divings during February-December 2014 at the coastal areas of Yangjeong, Jukjin and Bongpyeong, Uljin, Korea, where the young disk abalone seedlings were artificially released. The results revealed that a total of six individuals of Neptunea cumingii that were feeding on the young disk abalone were observed within the water depth 10m at the coastal area of Jukjin, of which bottom substrate consists of the relatively high composition rate of rocks (60.3%). Though N. cumingii is well known as a carnivorous predator of diverse marine invertebrates such as live mussels (Mytilus spp.) it is the first report that this predator also feeds on the disk abalones. Thus, our results strongly suggest that the future artificial release projects around Korean coasts necessitate extermination works of predators including newly observed N. cumingii in this study as well as previously known starfishes prior to the releases of young Pacific abalone seedlings.