• Title/Summary/Keyword: Scuba Diving

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Growth and Maturation of a Green Alga, Caulerpa okamurae Weber van Bosse (옥덩굴(CAULERPA OKAMURAE WEBER VAN BOSSE)의 생장과 성숙)

  • Hwang, Eun-Gyeong;Park, Chan-Seon;Han, Jeong-U;Sin, Won-Jun;Choe, Chang-Geun;Son, Cheol-Hyeon
    • ALGAE
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    • v.18 no.3
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    • pp.217-223
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    • 2003
  • Seasonal growth and maturation process of Caulerpa okamurae were investigated in natural populations and in culture. Monthly sampling was carried out by SCUBA diving at Baekunpo, Busan, southeastern coast of Korea from November 1999 to October 2001. Growth of erect branches depended mainly on the water temperature in the natural habitat. Maximum length of erect branches was 14.0 $\pm$ 1.4 cm in June 2001 when the water temperature was 19.7$^{\circ}C$ and minimum was 2.8$\pm$0.2 cm in April when the water temperature was 14.7$^{\circ}C$. Fresh weight of erect branches was 3.9 $\pm$ 0.5 g in June 2001 and 0.2 $\pm$ 0.04 g in September 2000. Biomass of the population was maximum of 922.5 g dw${\cdot}m^{-2}$ in July and minimum of 125.6 g dw${\cdot}m^{-2}$ in April. Gametangial network was observed on the ramuli when the water temperature was over 19$^{\circ}C$ in August 2000 and June 2001. In the culture regime of 4 temperatures (15, 20, 25 and 30$^{\circ}C$) and 3 irradiances (20, 50 and 80 $\mu$mol${\cdot}m^{-2}{\cdot}s^{-1}$) combination, the maturation of excised erect branches was mainly affected by temperature. Maturation was induced under all irradiance conditions at 20 and 25$^{\circ}C$; under 80 $\mu$mol${\cdot}m^{-2}{\cdot}s^{-1}$ at 15$^{\circ}C$; and under 20 $\mu$mol${\cdot}m^{-2}{\cdot}s^{-1}$ at 30$^{\circ}C$. The highest rate of maturation was 64% under 20 $\mu$mol${\cdot}m^{-2}{\cdot}s^{-1}$ at 25$^{\circ}C$. These results suggested that developmental initiations of C. okamurae occurred at higher than 13$^{\circ}C$ and maturation took about 270 degree-days.

The Fish Fauna of Little Munsom in Jeju-do, Korea (제주도 문섬(새끼섬) 주변의 어류상)

  • Choi, Youn;Kim, Bi;Lee, Heung-Heon
    • Korean Journal of Environmental Biology
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    • v.31 no.1
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    • pp.45-52
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    • 2013
  • The fish fauna of Munsom in Jeju-do, Korea, was investigated for a total of five times underwater from April 2009 to October 2010. Fish specimens were collected with a small net by SCUBA diving and fish specimens difficult to collect were photographed underwater using a underwater camera and a camcorder. The fish specimens collected from the sea around Munsom were identified as 91 species, belonging to 73 genera, 39 families, and 11 orders. Among them, the largest group was Order Perciformes, comprising 54 species and 21 families, consisting 59.3% in total number of species and the following 19 species of Order Scorpaeniformes was 20.8%. In this study Amblyeleotris sp. of family Gobiidae was discovered as new species by underwater photography in Korea. It was more the demersal fishes (55%) than the pelagic fishes (45%) and in social behavior pattern it was much more species swimming alone than schooling.

Sustainable Utilization and Management Scheme in Wangdol-cho Surrounding Sea Area (동해 왕돌초 어장의 지속적 이용 및 관리 방안)

  • Lee, Kwang-Nam;Myoung, Jung-Goo
    • Ocean and Polar Research
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    • v.25 no.3
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    • pp.331-345
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    • 2003
  • The fishing ground surrounding Wangdol-cho is not only overexploited by the littering of dilapidated fishing net and equipment, but also by fishermen's overfishing, surpassing optimum fisheries resources. In addition, increasing fishing efforts (number of fishing vessel and fishing net, etc) contribute to the deterioration of fishing ground, and it is urgently required that schemes to tackle the problems should be taken. To effectively address the problems as such, this paper aims to propose sustainable utilization and management scheme of fishing ground through classification of fishing ground surrounding Wangdol-cho as one area which is less than 50m deep, measuring $13.66km^2$ and the other, permission fishing area of Gill Net fishery, measuring $347.23km^2$. The analysis shows that, for the water area less than 50m deep, implementation from a short-term perspective includes autonomous management fishery by gill net and trap fishery. For the permission fishing area of Gill Net fishery, implementation includes limit on fishing period, real name system of fishing equipment and limit on fishing equipment. Implementation from a medium and long-term perspective includes limit on scuba diving, designation of underwater sightseeing zone, sea farming, facilities of surveillance, adoption of approval system for the permission fishing area of Gill Net fishery and introduction of report system for fishing.

A Study about Reduction Rate of Wetsuit Patterns for Men in their 30's (국내 30대 남성용 웨트수트 패턴 축소율에 관한 연구)

  • Choi, Jin-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.9
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    • pp.1039-1048
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    • 2011
  • This research develops a basic design structure for scuba diving wetsuits suitable for the shape of Korean men in their 30's as well as enhances the reduction rate for underwater activity. The clothing pressure and fitness tests were performed using four different types of body suits. The usable data of the tests were coded for further statistical analysis that includes one way-ANOVA test and S-N-K Multiple Range Test by using SPSSWIN 17.0. An analysis of the results shows: (1) The results of the clothing pressure test (using a dummy) indicated that the larger the reduction rate, the stronger the clothing pressure gets (with an exception on the knee area). It has great impact on clothing pressure with regards to the different body parts. The different reduction rates should be applied to body parts accordingly. (2) In the case of test subjects, the overall mean values of the clothing pressure were lower than the ones with the dummy (attributable to the cushion function of body skin and muscle as well as the high stretch of the fabric). (3) In evaluating the subjective fit test of four types of body suits, a statistically significant difference was found in the relation between pattern reduction rates and all parts of the body. It was revealed that the reduction rate of 'B' pattern (X: 4%, Y: 3%) was the most suitable pattern and the 'B' pattern scored highest in the motion functional fit test performed by a test subject.

A Case of Bilateral Pneumoparotid Improved with Conservative Treatment (보존적 치료로 호전된 양측 이하선 기종 1예)

  • Oh, Yun Seok;Kim, Jeong Marn;Jung, Hahn Jin;Shim, Woo Sub
    • Korean Journal of Head & Neck Oncology
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    • v.33 no.1
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    • pp.43-45
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    • 2017
  • Pneumoparotid is defined as the presence of air within the parotid gland or duct. Pneumoparotid is an extremely rare cause of parotid gland swelling. Pneumoparotid can be induced by air insufflation from oral cavity into the intraparotid salivary ducts, in condition like nose blowing, blowing up balloons, during extubation after general anesthesia while receiving positive pressure, rapid decompression while scuba diving, chronic attempts to suppress cough, and glassblowers. It can also be self-induced, and the literature contains an increasing number of reports involving pediatric and adolescent patients who induce parotid insufflation to avoid school or gain attention. Here, we report a case of pneumoparotid caused by habitual cheek inflating and improved with conservative treatment.

Has the Restoration Project of Pseudopungtungia tenuicorpa (Pisces: Cyprinidae) in the Jojongcheon Stream, Hangang River Failed? (조종천에 재도입된 멸종위기어류 가는돌고기 Pseudopungtungia tenuicorpa (Pisces: Cyprinidae) 복원사업은 정말 실패하였는가?)

  • Han, Mee-Sook;Choi, Kwang-Seek;Ko, Myeong-Hun
    • Korean Journal of Ichthyology
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    • v.32 no.3
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    • pp.182-190
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    • 2020
  • The endangered Pseudopungtungia tenuicorpa were reintroduced to the Jojongcheon Stream in the Hangang River 2011~2012 as part of the restoration project. Since then, the restoration project has been evaluated as a failure because the P. tenuicorpa were not collected from the discharge site 2014~2016. This study was conducted 2017~2019 to verify that the P. tenuicorpa restoration project failed. Six locations were selected, including the discharge site, and the fish collection method used skimming nets, cast nets, long bag set nets, and scuba diving. In the survey results, 13 individuals were collected in a 0.5 km section, including the discharge station. The P. tenuicorpa habitat was approximately at a water depth of 0.5 m to 2 m in run water flow with the boulders and rocks. The age of the collected P. tenuicorpa were 0+ to 3-years-old, and the generation alternation was occurring stably. Thus, the P. tenuicorpa restoration project was evaluated as partially-successful, as the P. tenuicorpa, re-introduced to the Jojongcheon Stream, settled in its habitat with stable generation alternation.

Feasibility of Enhancing Fishing Household Income Through Leports-fishing Development (레포츠피싱을 통한 어가소득 증대에 관한 연구)

  • Park, Seong Kwae;Kim, Soo Jin;Kim, Young Ja
    • Journal of Fisheries and Marine Sciences Education
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    • v.19 no.2
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    • pp.180-196
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    • 2007
  • This study aims at analyzing the potential of leports-fishing for improving fishing household income. Leports-fishing is a composite concept which is combined with those of leisure, sports and fishing. Korean on-shore resources have also a composite characteristic. The properties of the east, west and south coastal waters are quite different in geography, biology and ecology. There is a array of leports-fishing development potentials of utilizing their characteristics. At present, angling forms a main activity of leports-fishing, but coastal seas would be an emerging space for the public. In order for them to be a ground of fun, enjoyment and festivals, it would be necessary to supply a wide range of activities and facilities including angling, scuba diving, fish barbecue, ecological experience, fishing experience, cruise, and so forth. As seen in the survey results, the participants have strong desire for fun and enjoyment through leports-fishing activities. The proportion of people participating in one or two times a year amounts to 40 percent. Most coastal places visited are close to medium/large cities and two-days leports-fishing/tourism accounts for some 77 percent. However, it turned out that conflicts between leports-fishing participants and fishermen are not serious. The results of expenditure function estimation appear that the elasticity of per capita income is very high with 1.2660 and that there are negative relationships between leports-fishing expenditure and transportation/food/lodging costs. Assuming the annual national economic growth rate of 4 percent, it is anticipated that Korean leports-fishing population will increase to 3.18 million in 2010 and 4.07 million in 2015. Korean leports-fishing market potential in 2015, which is calculated based on per capita expenditure on leports-fishing, appears to amount to 1,400 billion won~1,600 billion won. The contribution of such market potential to the fishing households is expected to be 62.3~74.2 percent(934.5 billion won~111.3 billion won).

Seasonal variation and species composition of fishes communities in artificial reef unit at marine ranching area in the coastal waters off Jeju island, Korea (제주바다목장 해역 내 인공 어초군에 서식하는 어류군집의 종조성 및 계절변동)

  • Oh, Taeg-Yun;Cha, Hyung-Kee;Chang, Dae-Soo;Hwang, Choul-Hee;Nam, Yun-Ju;Kwak, Seok-Nam;Son, Min-Ho
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.46 no.2
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    • pp.139-147
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    • 2010
  • This study monitored a variety of marine fish communities in artificial reefs unit of the total 5 types (Dice type, Octagonal turtle type, Two-stage tube type, Gazebo type, Tetrapod type) which are located in the marine ranching at Jeju island by scuba diving in May, July, October and December 2009. Underwater photographing was accomplished at total 3 phases (condition of artificial reefs photographing, concentric circle movement photographing and line transect photographing). The preservation condition of artificial reefs facility was very good, and the dominant species were Chromis notatus, Sebastes thompsoni, Oplegnathus fasciatus and Halichoeres poecilopterus. Fish abundance was high in May and June, and low in October and December, 2009. Chromis notatus was dominant at the all types of artificial reefs, Halichoeres poecilopterus for Gazebo type and Tetrapod type of artificial reefs, and Sebastes thompsoni for Dice type, Octagonal turtle type and Two-stage tube type of artificial reefs.

Study on the wetsuit manufacturing status in Korea and future research task (국내 습식 잠수복 생산 업체의 생산실태 조사 및 향후 연구과제)

  • Shin, Hyun-Suk;Choi, Inyoung
    • Journal of the Korea Fashion and Costume Design Association
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    • v.23 no.3
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    • pp.99-108
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    • 2021
  • The present study examines the overall manufacturing status of local wetsuit makers, problems in the manufacturing process, and future research tasks. The study revealed that most manufacturers use neoprene fabric of varying thickness, depending on the body part. Normally, 3 mm-thick fabric is utilized for high-activity body parts and 5 mm-thick fabric is used for high-activity areas requiring thermal insulation. In terms of the manufacturing method, the tools and manufacturing processes used by companies were found to be similar. However, because of the nature of wetsuits requiring a more complicated manufacturing method than that of general clothing, there were some differences in the manufacturing method processes from company to company, such as bonding and ease treatments. According to wetsuit manufacturers, they make incisions in consideration of the body's curvature and the overall shape and design of the wetsuit when developing patterns. For example, most answered that they preform the wrist and ankle parts, where the body's curvature is obvious. On the question regarding the "difficult manufacturing process", the most frequent response was the "bonding" process. Most manufacturers were found to focus on designs that can improve mobility and clothing fit, and commonly experienced low-order quantity as an operational difficulty. As for the question on the wetsuit-related technology needed in the future, the "development of various designs" was the most frequent answer, followed by the "development of lightweight and diverse materials".

Characteristics of Marine Algal Communities in the Spring at Gijang-gun, Busan (부산시 기장군 연안의 춘계 해조 군집 특성)

  • Jung, Seung-Wook;Choi, Chang-Geun
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.2
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    • pp.175-185
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    • 2020
  • Quantitative and qualitative surveys were conducted during scuba diving activity between May 2017 and June 2017 in order to analyze spring marine algal community structure at Gijang-gun, Busan. A total of 121 species including 13 (10.7 %) Chlorophyta, 18 (14.9 %) Phaeophyta, and 90 (74.4 %) Rhodophyta were identified. The species count in the subtidal zone (110 species) was twice as high as in the intertidal zone (56 species). In terms of regions, 88,76, and 75 species were found in Mundong, Gongsu, and Daebyeon, respectively. Mean biomass for the whole study area was 1,501.5 g·m-2, higher for the subtidal zone (1,869.4 g·m-2) than for the intertidal zone (1,133.5 g·m-2). Mean biomass by region values were 2,234.0 g·m-2, 1,228.1 g·m-2, and 1,044.4 g·m-2 for Mundong, Gongsu, and Daebyeon, respectively. Ulva australis, Sargassum thunbergii, and Corallina pilulifera had high biomass in the intertidal zone, while Sargassum macrocarpum, Undaria pinnatifida, and Phycodrys fimbriata had high biomass in the subtidal zone. The composition ratio of marine algal functional forms suggests that the entire study area had 'Low' status, and all sites fell within 'Low' to 'Moderate' status. Results indicate that opportunistic species are widely distributed throughout the Gijang-gun coast, hence potential effects of disturbance and environmental pollution should be considered. Seaweed farming in particular - a major activity along the Gijang-gun coast -, together with effects of other anthropogenic activities such as national fishing port development and the coastal improvement project, could have long-term effects on marine algal communities. Therefore, long-term monitoring and management plans for marine algal communities will be required.