• Title/Summary/Keyword: scuba diving

Search Result 160, Processing Time 0.023 seconds

Report of Additional Molluscan Species from Rocky Inter- and Subtidal Area of Dokdo Island, Korea (독도 연체동물상에 대한 추가 종 보고)

  • Hong, Byung-Kyu;Son, Min-Ho;Seo, In-Soo;Kim, Mi-Hyang;Lee, Hae-Won;Choi, Young-Min;Chun, Yong-Yull
    • The Korean Journal of Malacology
    • /
    • v.24 no.3
    • /
    • pp.199-203
    • /
    • 2008
  • Thirty one marine molluscan species were added to the malacofauna of Dokdo Island, Korea based on the samples collected from April 2006 to August 2008 with SCUBA diving. As a result, one hundred six marine molluscan species were recorded from Dokdo Island hitherto.

  • PDF

Variation of Community Structure of Decapods by Season and Depth near Oryuk Islets off Busan, Korea (오륙도 주변해역 십각류의 계절별 수심별 종조성과 군집구조)

  • PARK, Hyun-Jung;PARK, Won-Gyu;CHOI, Jung-Wha;LEE, Bo-Ram
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.29 no.1
    • /
    • pp.257-269
    • /
    • 2017
  • The occurrence variations of decapods by season and depth off Oryuk Islets, Busan were investigated at seven stations in April and October 2009, July 2010 and January 2011. Decapods were collected by SCUBA diving at 5 m and 10 m depths. 46 species belonging to 18 families in 3 orders were identified. Pilumnus minutus, Pugettia intermedia, Pachycheles stevensii, and Paguristes japonicus were dominant species, comprising 73.0% of total decapods. P. minutus and P. intermedia were abundant in all seasons (except summer) while P. stevensii and P. japonicus were abundant in fall and summer. Dominant species were divided into three groups (resident species, seasonal species and temporary species) on the basis of their occurrence patterns. P. minutus and P. intermedia were resident species while P. stevensii, P. japonicus were temporary species. The species number, density and biomass of decapods were fluctuated by seasons. They were highest in fall and lowest in winter. This study implied that the variations of species number and density of decapods were significantly related with seasonal change of water temperature.

Composition and Structure of Macrofouling Communities on Ocean-going Ships in the Far East Sea Basin

  • Moshchenko, Alexander V.;Zvyagintsev, Alexander Y.
    • Ocean and Polar Research
    • /
    • v.23 no.2
    • /
    • pp.63-75
    • /
    • 2001
  • Species composition and community structure of the fouling found on the hulls of 28 ships traveling through 6 main shipping routes (SR)in the Far East Sea Basin were analyzed using statistical methods. Samples obtained during 1976-1990 expeditions of the Institute of Marine Biology were used for the analyses. These samples were taken from the ships anchored in the harbor by SCUBA diving and in dry-docks of the Vladivostok ship-repairing yard. Similar composition of the fouling communities occurred on the ships travelling the same SR. In five cases, fouling was dominated by different Cirripedia communities. And, in one case, a community of the mussel Mytilus trossulus was found. In most cases the results of the factor analyses showed extremely low level of the relationships among different animals and algal species in fouling communities. Each ocean-going ship had an original structure of the fouling. Spatially disconnected animal associations of tropical and boreal origin may simultaneously coexist at the same ship. This paper testified to the originality of the zone of anthropogenic substrata as a benthos concentrator in the pelagic regions of the world ocean. The fouling from different zones showed that each zone possesses peculiar features and regularities of the composition and relationships between organisms dwelling here.

  • PDF

Four New Records of Two Genera Balanophyllia and Cladopsammia (Anthozoa: Hexacorallia: Scleractinia: Dendrophylliidae) from Korea

  • Choi, Eunae;Song, Jun-Im
    • Animal Systematics, Evolution and Diversity
    • /
    • v.30 no.3
    • /
    • pp.183-190
    • /
    • 2014
  • The four species of the family Dendrophylliidae are newly recorded in Korea: Balanophyllia (Balanophyllia) cumingii Milne Edwards and Haime, 1848, Balanophyllia (Balanophyllia) vanderhorsti Cairns, 2001, Cladopsammia eguchii (Wells, 1982), and Cladopsammia gracilis (Milne Edwards and Haime, 1848). The two genera of Balanophyllia and Cladopsammia, to which the four species belong, are newly recorded in Korea. They were collected from the subtidal zones in Jeju-do Island, Korea by SCUBA diving from 1987 to 2012. This study aims to identify the four dendrophyllid species based on external and internal morphological characters including growth form, size, budding, and color of colonies, shape and size of corallites, columella, theca, and septa. Balanophyllia (Balanophyllia) cumingii is distinguished by its solitary growth form, small and low subturbinate corallite with enlarged calice, and expanded basal part, exsert first and second septa, and Pourtal$\acute{e}$s plan. Balanophyllia (Balanophyllia) vanderhorsti is characterized by its quasi-colonial growth form, subturbinate corallites with compressed calice, thick theca, and Pourtal$\acute{e}$s plan. Cladopsammia eguchii is characterized by its phaceloid growth form of compressed corallites basally united with common coenosteum, flat spongy columella, thick theca, and Pourtal$\acute{e}$s plan. Cladopsammia gracilis is distinguished by its phaceloid growth form of corallites basally united with common coenosteum, and pronounced Pourtal$\acute{e}$s plan forming flower patterns.

Correlation between Community Structure of Herbivore and Succession of Macro-algal Flora in the Subtidal Area of East Coast of Korea - Focusing on the herbivorous gastropods - (동해 남부해역 조하대 조식동물 군집구조 변화와 대형 해조군락 천이와의 상관성 - 조식성 복족류를 중심으로 -)

  • Kwon, Jung-No;Jung, Min-Ji;Kim, Dae-Ik;Son, Min-Ho
    • The Korean Journal of Malacology
    • /
    • v.26 no.3
    • /
    • pp.185-199
    • /
    • 2010
  • Correlation between community structure of herbivore and succession of macro-algal flora was examined in subtidal area of Dang-Sa Province, eastern coast of Korea from April 2008 to December 2009. For examination, the authors hypothesized that there are significant correlation between the foregoing two variables. Samplings were conducted every two months quantitatively with SCUBA diving at -3, -6 and -10 depth in the two line transects (barren and forest grounds). As results, rhodophyts was predominated in the algal flora based on the number of species and biomass; molluscs was predominated in the herbivores based on the number of species and echinoderms was predominated in that based on the biomass. There was no significant correlation between the foregoing two variables in the whole survey area and barren/forest grounds. Consequently, the hypothesis was rejected. The authors proposed that examination of correlation between the foregoing two variables should focus on the specific herbivore group(s) (e.g., amphipods) afterward.

A new record of larger benthic foraminifera from Jeju Island (South Korea)

  • Somin Lee;Fabrizio Frontalini;Wonchoel Lee
    • Journal of Species Research
    • /
    • v.13 no.1
    • /
    • pp.89-99
    • /
    • 2024
  • Larger benthic foraminifera (LBF) are a group of marine organisms that inhabit oligotrophic subtropicaltropical photic zones, commonly possess relatively large shells (i.e., tests) with a complex internal structure and host photosynthetic endosymbionts. In this study, we provide a new report of a LBF species belonging to the genus Sorites Ehrenberg, 1839, with a brief description and images of the test. The sediment samples were collected by SCUBA diving from the east coast of Jeju Island (South Korea). The discoidal test shape and annular series of chamberlets with a single row of apertures surrounded by rim indicate that these specimens belong to the genus Sorites, and this is the first record of the genus in Korea. The arrangement of early chamberlets, septular disposition, and the aperture details suggest that the specimens can be assigned to Sorites orbiculus(Forsskål in Niebuhr, 1775). Only three LBF species, including the present species, have been reported from Korean waters. The present study provides additional information for the evaluation of foraminiferal diversity including LBF in Korea and suggests the necessity of continuous investigations to understand the diversity of Sorites species in Korea.

Risk Analysis of Alcohol Consumption During Underwater Activity Using the Risk Assessment and Analysis Method (리스크 평가 및 분석 기법을 활용한 알코올 섭취에 따른 수중활동 시 리스크 분석)

  • SEO, Sang-Woo;KANG, Shin-Beum;KANG, Sin-Young
    • Journal of the Korean Society of Marine Environment & Safety
    • /
    • v.25 no.2
    • /
    • pp.159-168
    • /
    • 2019
  • This study was designed to investigate the physiological response of humans to alcohol during underwater activity and to complete related risk analysis. After comparing human responses to alcohol during underwater activity, we analyzed physiological changes and risk level using a new risk analysis method developed in this study, 'Risk Assessment and Analysis (RAA)'. RAA is a modified method based on an internal control frame work. It has 3 steps, the first of which is to analyze risk correlation. The second step is to quantify risk and build a risk database. The last step is to analyze the diagramed risk map. Using RAA, the risk levels of alcohol use underwater were calculated and diagramed. The diagramed risk map was then used to analyze the difference between risk levels underwater before and after alcohol use. As a result, it was found that risk level underwater increased after alcohol use. This study shows alcohol use increases the ratio of high risk groups during underwater activity. It also indicates that risk levels can be quantified according to the likelihood and impairment scale, which can potentially help in identifying high risk groups for intensive management underwater.

Investigation of Dice Artificial Reef Stability Installed (1981-2004 years) on Pohang Coast of the East Sea (경상북도 포항시 해역에 시설된(1981-2004년) 사각형 어초의 상태조사)

  • Cho, Yong-Chul;Kim, Wan-Ki;Lee, Chae-Sung;Kim, Nam-Il
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.34 no.1
    • /
    • pp.177-182
    • /
    • 2010
  • Sediment transport around artificial habitat which is induced by the change of flow due to installation of the structure plays a role not only as a defect function of subsidence and burial but also bottom-environment control function. Using Side Scan Sonar (SSS), Differential Global Positioning System (DGPS) and Scuba diving equipment, we investigated a facility condition of a dice reef installed on Pohang coast of the East Sea. Investigation result, at total 139 place, 10,526 dice reef was discovered. As the level which affects function of the above 0.5m, the case 4 place of burial (0.5~1.2m, 2.9%), scour appeared with 3 place (0.5m, 2.2%) and broken was appeared with 183 artificial reefs (1.74%). As a result, dice reef installed Pohang coast appeared to mostly stable.

Investigation of conservation state of two types artificial reef on physical factors, immersed in Gang won coastal waters of the East Sea (해양 물리적 영향에 따른 강원도 해역에 시설된 2가지 인공어초의 보존상태 조사)

  • Lee, Ji-Hyun;Kim, Wan-Ki;Ahn, Jung-Mi;Lee, Chae-Sung
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.34 no.1
    • /
    • pp.168-176
    • /
    • 2010
  • Stability and durability of the artificial reefs (ARs) for wildstock enhancement have been a key issue. We surveyed the side scan sonar (SSS), multi beam echo sounder (MBES) and scuba diving surveys confirmed that the ARs stability was age and type-dependent. A case of the stability of 8,438 ARs (60 group ARs) installed at 4 sites (Yangyang, Gangeung, Donghae and Samcheok) along the Gangwon coast of the East Sea (Sea of Japan). And a confirmation amount to 85.4% ARs remained safe, the rest 14.6% being influenced by a physical parameter of the waters. The representative influences by their circumstances were of breakage (6.3%). capsizing (8.3%). A group of a ARs to 61.7% ARs remained safe, the rest 38.3% being influenced by a physical parameter of the waters. The representative influences by their circumstances were of buried.

Evaluation of the effect of cubic artificial reefs in Kyonggi Bay, west coast of Korea by using fish trap (통발 어구를 이용한 서해 경기만 사각형어초 시설의 효과 평가)

  • Yoo, Jae-Won;Lee, Man-Woo;Lee, Chang-Gun;Kim, Chang-Soo;Kim, Jung-Soo;Hong, Jae-Sang
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.43 no.2
    • /
    • pp.126-139
    • /
    • 2007
  • In the autumn of 2000 and spring of 2001, field surveys were conducted to estimate the effectiveness of artificial reefs (type cube, $2{\times}2{\times}2m^3$) that were established in the four islands of Bangnyeong, Socheong, Daeyeonpyeong and Ganghwa in Kyonggi Bay, the west coast of Korea during 1995 and 1996. The condition of reefs was examined through SCUBA diving and a side-scan sonar. Much of the reefs in Daeyeonpyeong and Ganghwa area were buried in bottom sediment. Despite an intensive search in Bangnyeong area, even a cluster of reefs was not found and most of them seemed to be buried by sand waves. Thus an appropriate investigation on the sediment transport should be included in pre-assessment for the expected performance and protection of artificial reefs. Distribution of average CPUE in natural fishing ground (control) was estimated by bootstrapping simulation and possible comparison of CPUE between control and reef areas (treatment) were made in Bangnyeong and Socheong (Experiment I). Positive reef effect was detected in Socheong but CPUE of treatment in Bangnyeong was varied between or lower than the 99% CPUE confidence intervals of the control. Control/treatment abundance and biomass of fishes and invertebrates were tested by paired t-test and sign test (Experiment II). Only four cases among 22 showed significant positive effect. Based on the results, the cube artificial reef in Socheong was inferred as an affirmative one. Floor type was hypothesized to be one of the probable agents in determining the effectiveness of artificial reefs.