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161.
162.
A comparison of growth patterns between non‐indigenous Halophila nipponica and the native sympatric Zostera marina on the southern coast of the Korean peninsula 下载免费PDF全文
The growth dynamics of two co‐occurring seagrass species, Zostera marina and Halophila nipponica, were examined on the southern coast of the Korean peninsula. Zostera marina is a native dominant seagrass species in Korean coastal waters, whereas H. nipponica is a non‐native tropical and subtropical species that has extended its distributional range to the temperate coastal areas of Korea. To examine the differences in the growth dynamics of H. nipponica and Z. marina, their morphology, density, productivity and biomass, as well as local environmental conditions, were monitored monthly from January 2008 to July 2009. Underwater irradiance at the study site was the highest in April 2009 and the lowest in January 2008. Water temperature ranged from 10.4°C in January 2009 to 24.8°C in September 2008. Significant differences in growth dynamics were observed between the species, due to the effect of water temperature at the study site. Density and areal productivity were the highest in April 2008 and June 2008, respectively, for Z. marina but the highest in July 2008 for H. nipponica. Leaf size, shoot height and shoot weight were the highest in July 2008 for Z. marina but the highest in August 2008 or September 2008 for H. nipponica. The productivity of both species was strongly correlated with water temperature at the study site. However, the productivity of these species was not strongly correlated with underwater irradiance or the nutrient availability of either the water column or sediment pore water. Zostera marina exhibited the ecological characteristics of a temperate seagrass, whereas H. nipponica retained the features of a subtropical/tropical seagrass, even after adapting to the temperate coastal waters of Korea. 相似文献
163.
Hyun Suk Park Choong-Gon Kim Sung Kim Yong-Joo Park Hee-Jung Choi Zhizhong Xiao Jun Li Yongshuang Xiao Youn-Ho Lee 《Ocean Science Journal》2018,53(2):261-274
The rock bream, Oplegnathus fasciatus, is a common rocky reef game fish in East Asia and recently has become an aquaculture species. Despite its commercial importance, the population genetic structure of this fish species remains poorly understood. In this study, 163 specimens were collected from 6 localities along the coastal waters of Korea and China and their genetic variation was analyzed with mtDNA COI sequences. A total of 34 polymorphic sites were detected which determined 30 haplotypes. The genetic pattern reveals a low level of nucleotide diversity (0.04 ± 0.003) but a high level of haplotype diversity (0.83 ± 0.02). The 30 haplotypes are divided into two major genealogical clades: one that consists of only Zhoushan (ZS, East China Sea) specific haplotypes from the southern East China Sea and the other that consists of the remaining haplotypes from the northern East China Sea, Yellow Sea, Korea Strait, and East Sea/Sea of Japan. The two clades are separated by approximately 330~435 kyBP. Analyses of AMOVA and Fst show a significant population differentiation between the ZS sample and the other ones, corroborating separation of the two genealogical clades. Larval dispersal and the fresh Yangtze River plume are invoked as the main determining factors for this population genetic structure of O. fasciatus. Neutrality tests and mismatch distribution analyses indicate late Pleistocene population expansion along the coastal waters of Korea and China approximately 133–183 kyBP during which there were periodic cycles of glaciations and deglaciations. Such population information needs to be taken into account when stock enhancement and conservation measures are implemented for this fisheries species. 相似文献
164.
165.
Eung-Oh Kim Seong-Jong Yoon Kyoung-Hyun Park Dae-Hyun Kim Jeung-Wan Do Eun-Seob Cho 《Ocean Science Journal》2009,44(4):215-220
Fish have developed color vision that is closely adapted to their photic environments, where both spectral sensitivity and the number of visual opsins are influenced. The mackerel used in this study is one of the most important fishery stocks in Korea. The opsin gene of the mackerel juveniles after 20 days in hatching was isolated and characterized based on the molecular study of visual photoreceptor. The full-length mackerel opsin gene was obtained by PCR amplification of genomic DNA, as well as cDNA synthesis. Sequence analysis of the opsin gene showed that it contained a 1,080 bp open reading frame encoding 360 amino acids. Based on Schiff’s base formation (S114, K119), glycosylation (E3, F37) and palmitoylation (S281, 282), the deduced amino acid sequence had a typical rod opsin. The mackerel and Gempylus serpens showed 73.7% DNA homology on opsin gene, which was higher than any other of investigated species. In the analysis of phylogenetic relationship, the genetic placement of the mackerel is closer to that of Scombroidei than Labroidei, with supporting somewhat strong bootstrap value. In the analysis of Northern and RT-PCR, the probed products were observed only in rapidly growing juveniles. These findings indicate that in mackerel opsin mRNA expression can be detected in day-20 hatching larvae. It may play an important role in stimulating growth hormone. 相似文献
166.
H.S. Yoon O.A. El-Samni A.T. Huynh H.H. Chun H.J. Kim A.H. Pham I.R. Park 《Ocean Engineering》2009,36(9-10):697-707
The present study numerically investigates the characteristics of three-dimensional turbulent flow in a wavy channel. For the purpose of a careful observation of the effect of the wave amplitude on the turbulent flow, numerical simulations are performed at a various range of the wave amplitude to wavelength ratio (0.01?α/λ?0.05), where the wavelength is fixed with the same value of the mean channel height (H). The immersed boundary method is used to handle the wavy surface in a rectangular grid system, using the finite volume method. The Reynolds number (Re=UbH/ν) based on the bulk velocity (Ub) is fixed at 6760. The present computational results for a wavy surface are well compared with those of references. When α/λ=0.02, the small recirculating flow occurs near the trough at the instant, but the mean reverse flow is not observed. In the mean flow field, the reverse flow appears from α/λ=0.03 among the wave amplitude considered in this study. The domain of the mean reverse flow defined by the locations of separation and reattachment depends strongly on the wave amplitude. The pressure drag coefficient augments with increasing the wave amplitude. The friction drag coefficient shows the increase and decrease behavior according to the wave amplitude. The quantitative information about the flow variables such as the distribution of pressure and shear stress on the wavy surface is highlighted. 相似文献
167.
The purpose of this study was to examine the structural changes that macrozoobenthic communities underwent as a result of the annual summer hypoxia at the northern part of Gamak Bay, Korea. During this study period, summer hypoxia occurred at the northern part of Gamak Bay in July. Under hypoxic conditions, both the number of species and population density decreased rapidly. Species diversity also manifested lower values during this hypoxic period. Faunal composition changed seasonally with Capitella capitata dominant at the hypoxic sites in spring but disappearing in summer. The health condition of the benthic faunal community assessed by the composition of functional groups within community also changed due to the summer hypoxia from a slightly polluted condition to a highly polluted condition. From these results it has been shown that the recent macrozoobenthic community structure in Gamak Bay has returned to a state similar to what it was before dredging works commenced. 相似文献
168.
Ocean Science Journal - Diel and gastrointestinal changes in relation to the feeding intensity and prey composition of Apogon lineatus were investigated through the analysis of the diet contents of... 相似文献
169.
Sumi Kanij Rukshana Kim Soo Cheol Howlader Jewel Sharker Md Rajib Choi Kap Seong Choi Sang Ki Park Jong-In Nou Ill-Sup Kho Kang Hee 《Ocean Science Journal》2019,54(3):363-374
Ocean Science Journal - A carbonic anhydrase VII gene, encoding 277 amino acids, was identified in the intestinal tissue of pufferfish (Takifugu rubripes). The translated protein with an 833-bp... 相似文献
170.
Bhavya P. S. Min Jun-Oh Kim Min-Seob Jang Hyo Keun Kim Kwanwoo Kang Jae Joong Lee Jae Hyung Lee Dabin Jo Naeun Kim Myung Joon Kim Yejin Lee Junbeom Lee Chang Hwa Bae Hyeonji Yoo Hyeju Park Sanghoon Yun Mi Sun Lee Sang Heon 《Ocean Science Journal》2019,54(4):515-528
Ocean Science Journal - Investigations on marine N2 fixation have gained momentum since 1960s with eventual establishments of relevant methodologies to identify species involved and quantify the... 相似文献