저서성 단각류 Pontogeneia rostrata의 종내 대상분포와 주야-조석주기

유옥환,서해립,서호영,YU Ok Hwan,SUH Hae-Lip,SOH Ho Youn 한국수산과학회 1998 한국수산과학회지 Vol.31 No.4

돌산도 모래해안 쇄파대에서 1993년 1월 소조와 대조때 1조석주기 동안 채집한 저서성 단각류 시료를 가지고. 주야와 조석주기에 따른 Pontogeneia rostrata의 종내 대상분포를 조사했다. p. rostrata의 밀도는 대조보다는 소조때 높았다. 개체군을 성체 암$\cdot$수컷과 미성체로 나누어 보면. 미성체와 수컷의 밀도가 각각 소조와 대조때 가장 높았다. 체장빈도 자료에 따르면. 겨울철에 미성체의 사망이 큰 것 같다. 야간 표층에서 소조때는 미성체 그리고 대조때는 성체암$\cdot$수컷이 유의하게 많았다. 이것은 미성체와 성체의 수직이동 양상이 조석에 따라 다르게 나타난 것으로 여겨 진다. 대조 밀물때 평균해수면 (MSL) 위에 나타난 p. rostrata의 $90\%$ 이상이 성체였다. MSL 위에서 암컷/수컷의 비율이 감소했고. 암컷의 체장은 변동이 없었지만 수컷의 체장은 증가했다. 이것은 몸이 큰 수컷의 활발한 이동습성을 가리킨다. 이런 행동은 큰 수컷의 분포역 확장으로 이어지고, 교미와 섭식경쟁에 있어 큰 수컷에게 유리할 것으로 여겨진다. 성체가 대조 야간에 MSL 위 100cm에서 채집되기도 하지만. 나머지 기간에 p. rostrata 개체군은 대부분 MSL 아래에 머물렀다. 분포중심은 MSL 아래 50cm에서 200cm 사이였다. Using a sledge net, the benthic amphipods were taken over one cycle of the neap and spring tides in January 1993 at the sandy shore surf zone of Dolsando, southern Korea. From these samples, we investigated the diel and tidal effects on the intraspecific zonation of Pontogeneia rostrata. The density of p. rostrata was higher during neap tide than spring. Of three categories (adult males and females and juveniles), juveniles and males attained to its highest density during neap and spring tides, respectively. Length- frequency data show that the high mortality of juveniles seemed to occur in winter. In the surface at night, it is significant that juveniles were significantly more abundant during neap tide than spring, whereas both adult males and females were more abundant during spring tide than neap. This suggests that the vortical migration patterns of juveniles and adults vary with the type of tides. During flood of spring tide, more than $90\%$ of population collected at the area above the mean sea level (MSL) were adults. With a decrease of female/male ratio, size of males increased there but that of female did not change, indicating an active migration of large males. This behavior can provide an extension of distribution area far large males, and also give a competitive advantage to large male against small one for mate and feeding. Although adult p. rostrata was collected at 100 cm above MSL at night during spring tide, a major portion of population as usually present on the shore below MSL. The center of zonation was restricted from 50 cm to 250 cm below MSL.

인공구조물에 따른 조간대 대형저서동물 군집변화

유옥환,이형곤,이재학,Yu Ok-Hwan,Lee Hyung-Gon,Lee Jae-Hac 한국수산과학회 2006 한국수산과학회지 Vol.39 No.2(특별호)

Artificial structures have been designed as pilot structures to promote the creation and restoration of tidal flats. However, little information is available as to whether such artificial construction affects the macrobenthic community structure. We monitored the variation of the macrobenthic community structure and species composition near natural and artificial structures (seaweed and a timber fence) on the tidal flats near the Iwon Dike, Korea. In total, 137 macrobenthic species were recorded during this study, predominantly crustaceans (47%), polychaetes (18%), and molluscs (27%). Polychaetes comprised over 50% of the total density, followed by gastropods (38%) and crustaceans (11%). Macrobenthic species composition in the artificial and natural areas, was initially similar, but it differed after 7 months. The gastropod Umbonium thomasi, the most dominant species, was present at both sites in the first month after the start of the experiment, but disappeared at the artificial sites within 7 months, suggesting disturbance by the environmental factors. The number of species and diversity (H') varied significantly within sites at the beginning of the experiment, but no difference was observed after 7 months. Multivariate analysis (multidimensional scaling) revealed significant differences in community structure between the artificial and the natural areas from 7 months after the start of the experiment, except from 18 to 21 months. The community structures were mainly influenced by U. thomasi. Community structure at the artificial sites was affected by environmental variables, such as carbon, COD/IL sulfide, loss of ignition, kurtosis and silt, which changed over time. We observed no significant correlations between environmental variables and the dominant species, except in the case of Spio sp. and Macrophthalmus dilatatus, suggesting that the biological interactions and temporary disturbances such as typhoon, as well as the effects of artificial structures may also be important regulating factors in this system.

허베이유류오염 영향에 따른 모래조간대 대형저서동물군집의 장기 변화

유옥환(Ok Hwan Yu),이형곤(Hyung-Gon Lee),박흥식(Heung-Sik Park) 한국해양환경·에너지학회 2015 한국해양환경공학회 학술대회논문집 Vol.2015 No.5

발향장치를 이용한 가상현실에서의 향 미디어 서비스

유옥환 ( Ok Hwan Yu ),김민구 ( Min Ku Kim ),김정도 ( Jeong-do Kim ) 한국센서학회 2018 센서학회지 Vol.27 No.6

To augment emotion and immersion in virtual reality (VR), technological research based on scent displays have increased in recent years. The results of extensive studies have enabled the development of methods to interface head mounted displays (HMDs) with scent devices, and the possibility of VR applications of this development was identified via several demonstrations in actual VR environments. Despite all these efforts, more practical methods and conditions for scent display in VR environments are yet to be developed. To efficiently interface VR and scent, this study proposes three ways to set the position for scent display and scent conditions. The first is scent display using local positioning in the VR engine, the second is scent display using the relative distance and orientation between user and object in VR environments, and the third is scent display using time setting. In this study, we developed scent devices using a piezo actuator to validate the proposed method and successfully conducted demonstrations and experiments.

방조제 건설이후 아산만 대형저서동물 군집 구조에 영향을 주는 환경요인

유옥환 ( Ok Hwan Yu ),이형곤 ( Hyung Gon Lee ),이재학 ( Jae Hac Lee ) 한국환경생물학회 2011 환경생물 : 환경생물학회지 Vol.29 No.4

Although anthropogenic disturbance of 20 years duration affects benthic habitats, few studies have examined its effects on the macrobenthic communities of a bay. The aim of this study was to determine the influence of environmental variables on the macrobenthic communities after the construction of the Hwaong dike. Macrobenthos were collected at 22 sites using a Smith McIntyre grab (0.1 m2) in August 2007 and February 2008. Total organic content was very low around the Hwaong dike. Sediment grain size increased from the Hwaong dike to the outer bay. In total, 317 species of macrobenthic fauna were collected and the mean density was 1,155 ind. m 2, both of which were higher than the results of previous studies. The dominant species, Hetermastus filiformis, known to be a potential pollution indicator, was more abundant near the Hwaong dike. Conversely, species sensitive to organic pollution, such as the polychaete Ampharete arctica and the ophiuroid Amphioplus squamata, exhibited higher mean densities in areas distant from the dike. A cluster analysis indicated that the macrobenthic community was divided into two distinct groups: group I near the dike and group II in the outer bay, which were affected by sediment grain size and total organic content. This study suggests that variations in sediment grain size and organic content after dike construction are important factors controlling the macrobenthic community in Asan Bay.

돌산도 모래해안 쇄파대에 사는 저서성 단각류의 겨울철 대상분포

서해립,유옥환,SUH Hae-Lip,Yu Ok-Hwan 한국수산과학회 1997 한국수산과학회지 Vol.30 No.3

1993년 1월 소조와 대조때 썰매네트로 돌산도 모래해안 쇄파대 1m 수심의 표층과 저층과 바닷가에서 옆새우 단각류를 채집해서 우점하는 세 종의 대상분포를 비교했다. 단각류는 표층보다는 저층과 바닷가에 많이 나타났다. Pontogenera rostrata와 Allorchestes anusta의 밀도는 저층과 바닷가에서 대조보다 소조때 높았으나, Synchelidium lenorostralum은 소조때 더 낮았다. P. rostrata는 밀물과 썰물에 따라 수평이동을 했으나, S. lenrostralum과 A. angusta는 수평이동을 하지 않았다. 다른 두 종과 달리 P. rostrata는 낮보다는 밤에 유의하게 많이 나타나, 밤에 활발히 이동하는 듯하다. P. rostrata는 밀물때 밤에는 평균해수면 (MSL) 위 100cm까지 나타나지만, 낮에는 MSL 위쪽에 나타나지 않았다 그러나, 썰물때는 낮과 밤 모두 MSL 부근부터 MSL 아래 150cm 사이에 분포했다. S. lenorostralum과 A. angusta는 썰물때만 나타났으며, 분포범위는 전자가 MSL 150cm보다 아래쪽, 후자가 MSL부근부터 MSL 아래 150 cm 사이였다. P. rostrata와 S. lenorostralum과 A. angusta의 최고 밀도는 각각 32, 26, 3마리/$m^2$였다. 그리고, 모래해안에 사는 단각류의 분포양상과 생활양식의 관계를 논의했다. Sledge net samples were taken over the neap and spring tide cycles in January 1993 from the bottom and surface of 1 m depth and at the water's edge in the sandy shore surf zone of Dolsando, southern Korea. Zonation pattern of three dominant gammarid amphipods was compared. The amphipods were more abundant on the bottom and at water's edge than in the surface. Average densities at both sites of Pontogeneia rostrata and Allorchestes angusta were higher during the neap tide than the spring tide, whereas that of Synchelidium lenorostralum was lower during the neap tide. P. rostrata migrated horizontally during the flooding and ebbing tides, but S. lenorostralum and A. angusta did not. Unlike other species, P. rostrata was significantly more abundant at night, suggesting its active nocturnal movement. During flooding tide, P. rostrata was not found on the shore above the mean sea level (MSL) during daytime, but found in 100 cm above MSL at night. Zonal distribution of P. rostrata which was restricted from MSL to 250 cm below MSL, however, did not vary with the day-night cycle during ebbing tide. S. lenorostralum and A. angusta were not found during flooding tide but ebbing tide. The upper distribution limit of the former was 150 cm below MSL, and the distribution of the latter ranged from MSL to 150 cm below MSL. The highest densities of P. rostrata, S. lenorostralum and A. angusta were 32, 26 and 3 ind. $m^{-2}$, respectively. We discussed the relationships between the distribution pattern of three dominant species of gammarid amphipods and their life styles in the sandy shore.

갈조류 감태(Ecklonia cava)의 포자체와 배우체 생장에 영향을 주는 수온과 pCO₂ 농도의 상호작용

오지철,유옥환,최한길,Oh, Ji Chul,Yu, Ok Hwan,Choi, Han Gil 한국해양과학기술원 2015 Ocean and Polar Research Vol.37 No.3

To examine the effects of increased $CO_2$ concentration and seawater temperature on the photosynthesis and growth of forest forming Ecklonia cava (Laminariales, Phaeophyta), sporophytic discs and gametophytes were cultured under three $pCO_2$ concentrations (380, 750, 1000 ppm), four temperatures (5, 10, 15, $20^{\circ}C$ for sporophytes; 10, 15, 20, $25^{\circ}C$ for gametophytes), and two irradiance levels (40, $80{\mu}mol$ photons $m^{-2}s^{-1}$) for 5 days. Photosynthetic parameter values ($ETR_{max}$, $E_k$, and ${\alpha}$) were generally higher as sporophytic discs were grown under low temperature and increased $CO_2$ concentration at 750 ppm. However, photosynthesis of Ecklonia sporophytes was severely inhibited under a combination of high temperature ($20^{\circ}C$) and 1000 ppm $CO_2$ concentration at the two photon irradiance levels. The growth of gametophytes was maximal at the combination of 380 ppm (present seawater $CO_2$ concentration) and $25^{\circ}C$. Minimal growth of gametophytes occurred at enriched $pCO_2$ concentration levels (750, 1000 ppm) and high temperature of $25^{\circ}C$. The present results imply that climate change which is increasing seawater temperature and $pCO_2$ concentration might diminish Ecklonia cava kelp beds because of a reduction in recruitments caused by the growth inhibition of gametophytes at high $pCO_2$ concentration. In addition, the effects of increased temperature and $pCO_2$ concentration were different between generations - revealing an enhancement in the photosynthesis of sporophytes and a reduction in the growth of gametophytes.

동해 발전소 주변의 저서다모류 군집에 영향을 미치는 환경 요인

권순현,이재학,유옥환,KWON, SOON HYUN,LEE, JAE HAC,YU, OK HWAN 한국해양학회 2017 바다 Vol.22 No.1

저서퇴적상은 다모류 군집에 가장 많은 영향을 주고 있지만, 다양한 퇴적상을 가지는 온배수 지역에서 저서다모류 서식에 영향을 주는 환경 요인 연구는 거의 없다. 본 연구는 동해 연안 저서다모류의 종 조성 및 군집 분포에 따른 공간적 분포 양상을 파악하였고, 이에 영향을 미친 환경요인들을 측정하였으며, 발전소에서 배출되는 온배수와 퇴적상의 차이가 저서다모류에 미치는 영향을 조사하였다. 저서다모류 군집의 특성을 조사하기 위하여 2006년 8월에서 2013년 2월까지 온배수 영향이 있는 울진, 고리 지역과 비교대상 지역인 후포 지역을 포함한 세 지역에서 생물을 채집하였다. 조사결과 총 283종, 평균 4,912개체/$m^2$의 저서다모류가 출현하였다. 주요 우점종으로는 Spiophanes bombyx, Magelona japonica, Lumbrineris longifolia, Sternaspis scutata 등 이었으며, 울진과 후포지역은 S. bombyx, 고리 지역은 M. japonica가 최우점 출현하여 지역별로 차이가 있었다. Lumbrineris longifolia와 M. japonica는 일반적인 동해 연안에 많은 수로 우점 서식하지만 조사지역의 발전소 취 배수구 지역에 거의 출현하지 않아 발전소 취 배수구 지역의 인위적인 환경교란이 저서다모류 종 조성에 영향을 주는 것으로 나타났다. 세 지역을 종합하여 다모류 군집 분석을 실시 한 결과 퇴적물 내의 총 유기탄소량과 퇴적물의 입도, 퇴적상에 따른 군집으로 나뉘는 양상을 보였다. 그러므로 본 연구에서 다모류의 군집구조는 발전소 온배수 및 취 배수구의 인위적인 환경 교란에 의한 영향은 발전소 취 배수구 주변에 국한되며 그 이외의 지역에서는 퇴적물 내의 총 유기탄소량과 퇴적물의 입도 등 지역 간 퇴적상 조성에 보다 큰 영향을 받는 것으로 여겨진다. The East Sea is almost entirely composed of sandy facies, and the facies type is the major factor influencing benthic polychaete communities. There have been few studies of the effects of environmental factors on benthic polychaetes in thermal discharge areas consisting of different sediment types. This study identified the spatial distribution patterns based on the species composition and distribution of benthic polychaete communities, and the environmental factors influencing benthic polychaetes near power plants were investigated. The polychaete communities in the Uljin, Hupo, and Gori coastal areas near the power plants in the East Sea were seasonally investigated from August 2006 to February 2013. As a result, 283 species were collected. The dominant species were Spiophanes bombyx, Magelona japonica, Lumbrineris longifolia, and Sternaspis scutata. Spiophanes bombyx was the dominant species at Uljin and Hupo, but M. japonica was the dominant species at Gori. Two dominant species from the coastal waters of the East Sea, Lumbrineris longifolia and M. japonica, were rare in the power plant water intake or drainage areas. Cluster analysis was performed to divide the study area into groups by the total organic carbon content, sediment grain size and facies patterns. This study suggests that the community structures of polychaetes are more affected by the total organic carbon, grain size of sediment and facies than by disturbance from thermal discharge, which only affected the polychaete community near power plant drainage areas.