• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.25 no.4
• /
• pp.307-313
• /
• 1992

To study the seasonal variation of heterotrophic bacteria near the surrounding seawater of Porphyra forming area, samples were collected in the intertidal waters of Mokp'o of the Yellow Sea from February to December, 1990. Annual distribution of heterotrophic bacteria ranged from $7.5\times10^2\;to\;1.1\times10^5\;cfu/ml,$ annual distribution of physiological characteristic bacteria ranged from $5.0\times10\;to\;4.34\times10^4\;cfu/ml$ for proteolytic bacteria, from 0 to $1.35\times10^4\;cfu/ml$ for lipolytic bacteria and from 0 to $1.2\times10^4\;cfu/ml$ for amylolytic bacteria. Sixty-five percent of isolates from seawater were rods, and $76.7\%$ of isolates were Gram-negative. Most isolates were mesophiles and showed utilization of various carbon sources such as glucose, maltose, lactose, sucrose and arabinose. Most isolates also showed tolerance to a broad range of salt concentration. Dominant genus in seawater were Flavobacterium spp., in February, Moraxella spp., Acinetobacter spp. in March, Bacillus spp., Chromobacterium spp., Micrococcus spp., Vibrio spp. in July and Chromobacterium spp., Micrococcus spp., Bacillus spp. in November.

• Journal of Aquaculture
• /
• v.8 no.2
• /
• pp.85-98
• /
• 1995

In Kunsan coastal areas, there are some plans to construct industrial zone and, it will affect physical and chemical parameters of marine environment of the area. As one of many environmental surveys on the aquacultural farm in Korean west coast, the survey on the bottom sediment characteristics of intertidal farm was conducted from May 1992 to April 1993. Dominant grain size was fine sand $(69-98\%)$ and the pH of sediment was ranged of $7.2\~9.1$. Especially the pH increased after embank was constructed. The water holding capacity was $11.1-28.1\%$ and showed high value in silt and clay area. The COD was 1.27 mg/g dry mud and increased after embank was constructed. The total organic matter content ranged of $0.84-8.11\%$ and the DO absorption was $0\~6.56 mg/g$ dry mud. The value of DO absorption showed low in winter and spring, but high in summer and fall. The total nitrogen and the sulfide were rang of $0\~402{\mu}g/g$ dry mud and $0\~122{\mu}g/g$ dry mud respectively. These values were high in summer and winter season, and higher in upper layer than that of lower layer in general.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.1
• /
• pp.72-82
• /
• 1986

There were three important species among the marine organisms which were cultured in the inter tidal zone in the old days, and an ark-shell was one of them. Exaiming old books and reports concerning fishery were made in order to reveal the history and industrial trend of ark-shell culture. Ark-shell was called by the different names in the old days "Komak" and "Sohap". The name of Komak was originated in the southern coast area in the 1,700s, and from the begining of 18 century Komak was used only. Ark-shell was produced in all southern and western coast areas, where a little of fresh water flows into the calm inner sea and the intertidal zone is well developed. It was well known that ark-shells shell as well as its flesh took the effect of a medicine. Its culturing method in Korea seems to be derived from China in the beginning of 19 century, it was cultured first at the southern area of Chollanam-do. It was considered as the side business, but after Korean war it is produced on the basis of cooperative work, now its production is quite increased (more than $5,000\fra{M}{T}$) due to the goverments development policy.

• Korean Journal of Environment and Ecology
• /
• v.30 no.2
• /
• pp.155-164
• /
• 2016

In this study we analyzed the spatial and temporal distribution and preferred habitat type of the Kentish plover (Charadrius alexandrinus) based on the 3rd National Ecosystem Survey. Kentish plovers were observed in 97 maps out of a total 842 maps (11.8%) between 2006 and 2012, mainly along the western and southern coasts of Korea. They were also observed in the eastern coast of Korea, inland rivers (Han, Geum, Nakdong, Seomjin, and Yongsan River), the western and eastern coast of Jeju island, and Daecheong Island in the Yellow Sea. The observations were mainly made during the spring breeding season and migration seasons in spring and autumn. The occurrence of kentish plovers was positively influenced by the area of water and wetland according to the middle classification level of land cover type analysis and the area of coastal wetlands in the detailed classification level of land cover types. Most (90%) of the kentish plovers recorded maps had coastal wetlands. Kentish plovers were known to be susceptible to change of habitat. As the occurrence of kentish plovers could be associated with the habitat-change of coastal wetlands and it is possible to estimate the number of individuals, it is recommended that kentish plovers be used as a bioindicator species for the ecological assessment of ecosystem in intertidal zones.

• Korean Journal of Remote Sensing
• /
• v.23 no.2
• /
• pp.131-135
• /
• 2007

The tidal channel is influenced by sediment type, grain size, grain composition and tidal currents in tidal flat. The development of tidal channel including density, shape and order can be used to analyze the characteristics of tidal channel. The quantitative investigation to the tidal channel is insufficiency. In this paper, we represented the fractal analysis method according to the quantitatively analysis in tidal channel and compared with the different intertidal channel patterns. The tidal channel was extracted from the IKONOS image of the southern part of the Kanghwa-do. We used the Box-counting method to estimate fractal dimensions for each tidal channel. As a result, the fractal dimension values (D) were 1.31 in the southern Kanghwa-Do. Linear pattern and less dense channel development area had low D values (from 1.0563 to 1.0672). Dendritic pattern and dense channel development area had high D values (from 1.2550 to 1.3016). In other words, fractal dimension values had difference about 0.2 values according to the characteristic of tidal channel development. We concluded that fractal analysis can be able to quantitatively classification in tidal channel.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.10 no.1
• /
• pp.8-18
• /
• 2005

We studied seasonal distribution of the microphytobenthos and their primary production with $C^{14}$ method and carried out pigment analysis with HPLC in an estuarine mudflat of the Ganghwa Island, Korea from May 2002 to April 2004. The abundances of microphytobenthos were higher at the middle than upper part and lower part of intertidal flat. Abundances of microphytobenthos ranged from $2.3{\times}10^5\;cells\;cm^{-2}$ to $140.9{\times}10^5\;cells cm^{-2}$. The bloom of microphytobenthos was observed in the early spring and then it decreased from spring to summer and autumn. The pennate diatom was a predominated group among the microphytobenthos in this area. The dominant species were Paralia sulcata, Cylindrotheca closterium and Nitzschia sp.. Nitzschia sp. and Cylindrotheca closterium were predominant in February. The results of pigment analysis suggest the presence of diatoms, euglenophytes, chlorophytes, cyanobacteria, cryptophytes, chrysophytes, prymnesiophytes, dinoflagellates and prasinophytes. The biomass of microphytobenthos ranged from 1.18 to 34.25 mg chl-a $m^{-2}$, with a mean of 7.60 mg chl-a $m^{-2}$. The mean ratio of Fuco/Chl a was 0.7 which indicates that most of biomasses of microphytobenthos were due to diatoms. The ratios of Chl b/Chl a ranged from 0 to 0.82(with a mean of 0.17), implying that euglenophytes and chlorophytes lived together in special period seasonally. Temporal variation of primary production ranged from 4.2 to 113.0 $mgC{\cdot}m^{-2}{\cdot}hr^{-1}$(mean value was 33.9 $mgC{\cdot}m^{-2}{\cdot}hr^{-1}$ and initial slope$({\alpha})$ was measured from 0.002-0.005$(mgC\;mgchl-a^{-1}\;hr^{-1}){\cdot}({\mu}E\;m^{-2}\;s^{-1})^{-1}$. Assimilation number$(P_m)$ was in the range of 0.50-1.32 $mgC{\cdot}mgChl-a{\cdot}hr^{-1}$ and daily primary production ranged from 20.9 to 678.1 $mgC{\cdot}m^{-2}{\cdot}d^{-1}$(mean value was 206.72 $mgC{\cdot}m^{-2}{\cdot}^{-1}$).

• Korean Journal of Environmental Biology
• /
• v.26 no.3
• /
• pp.159-169
• /
• 2008

This study was aimed to classify the intertidal macrozoobenthic community status after 2 years of Sea Prince oil spill, and oil spill effects along oil spreading track from heavily impacted to unaffected reference site. Field sampling was initiated in late February and continued through November 1998 seasonally, after 2.5 years of oil spill. 7 rocky sampling sites were selected among coastal regions coated and/or affected by the Sea Prince spilled oil. Identified species was 158 species, 65 family, 24 order, 9 class, 5 phylum. Mollusca was the dominant faunal group comprising 100 species (63.3%), and followed by 38 species of Crustacea (24.1%), 12 species of Echinodermata (7.6%), 5 species of Porifera (3.2%), and 3 species of Cnidaria (1.9%). On Dugpo of Sori Island, the fewest species was collected from 28 species to 35 species seasonally among sampling stations. But far away Dugpo toward Gamak Bay, the number of species increased, collecting the maximum on Sohwoenggan Island. At the wreck site of Sori Island, especially the species number of attached animals such as poriferans and anthozoans was very low compared to another site. The density and biomass on the higher tidal zone increased toward the low affected sites, but biomass on middle tidal zone decreased. The invertebrate biomass of study area was dependent on the sessile animals. The major dominant species were small-sized barnacles, Chthmallus challengeri, periwinkles, Littorina brevicula, mussels, Septifer virgatus, and so on. The biomass of C. challengeri and L. brevicula on the higher tidal zone was highest in the wreck site of Sori Island and decreased further and further. However, mussels on the middle tidal zone showed the inverse trends because of the larger individual size of mussel inhabited in Sori Island than those of another sites. As a result of community analysis, the effect of oil spill was not found distinctly. Several ecological indices and cluster analysis did not show the meaningful variation with oil track despite of the conspicuous differences among tidal heights. These indicate that the macrozoobenthic community level of oil spreaded zone recovered in some degree after the Sea Prince oil spill accident, but population or individual levels of dominant sessile animals took more recovery times.

• Economic and Environmental Geology
• /
• v.57 no.2
• /
• pp.243-251
• /
• 2024

In this study, a surface geological survey was first conducted to investigate aggregate resources in the Yeongam area of Jeollanam-do, and a drilling survey was conducted in the lower part of the surface, which was difficult to identify through a surface geological survey, to determine the spatial distribution of aggregates. Drilling sites were selected considering the topographical development and Quaternary alluvium characteristics of the study area, and river aggregate drilling surveys were conducted at a total of 5 points and land aggregate drilling surveys were conducted at a total of 28 points. Borehole core sediments were classified into seven sedimentary units to determine whether they could be used as aggregates, and optically stimulated luminescence dating was performed on representative boreholes to measure the depositional period for each sedimentary unit. As a result of the study, most of the Yeongam area had a very wide river basin, so it was estimated that there would be a large amount of aggregate, but the amount of aggregate was evaluated to be very small compared to other cities and counties. Most of the unconsolidated sedimentary layers in the Yeongam area are composed of blue-grey marine clay with a vertical thickness of more than 10 m. The sand-gravel layer corresponding to the aggregate section is distributed in the lower part of the marine clay, thinly covering the bedrock weathering zone. This is because the amount of aggregates themselves is small and most of the aggregates are distributed at a depth of 10 m below the surface, which is currently difficult to develop, so the possibility of developing aggregates is evaluated to be very low. As a result of dating, it can be seen that the blue-grey marine clay layer is an intertidal sedimentary layer formed as the sea level rose rapidly about 10,000 years ago. The deposition process continued from 10,000 years ago to the present, and as a result, a very thick clay layer was deposited. This clay layer was formed very dominantly for about 6,000 to 8,000 years, and the sand-gravel layer in the section where aggregates deposited in the Pleistocene period can exist was measured to have been deposited at about 13.0 to 19.0 ka, and about 50 ka, showing that it was deposited as paleo-fluvial deposits before the marine transgression process.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.13 no.1
• /
• pp.50-61
• /
• 2010

This study was carried out to find out the way to build a comprehensive wetland ecosystem database using the technique of remote sensing and Geographic Information System. A Landsat TM image (taken in Oct. 30, 2002), Kompsat-2 images (Jan. 17, 2008 & Nov. 20, 2008), LiDAR(Mar. 1, 2009) were used for the primary source for the image analysis. Field surveys were conducted March to August of 2009 to help image analysis and examine the results. An actual wetland vegetation map was created based on the field survey. Satellite images were analyzed by unsupervised and supervised classification methods and finally categorized into such classes as Phragmites australis community, mixed community, sand beach, Scirpus planiculmis community and non-vegetation intertidal area. The map of wetland productivity was developed based on the productivity of Phragmites australis and the relationship to the proximity of adjacent water bodies. The developed 3 dimensional wetland map showed such several potential applications as flood inundation, birds flyway viewsheds and benthos distribution. Considering these results, we concluded that it is possible to use the remote sensing and GIS techniques for producing wetland ecosystem spatial database and these techniques are very effective for the development of the national wetland inventory in Korea.

• Korean Journal of Environmental Biology
• /
• v.37 no.3
• /
• pp.406-425
• /
• 2019

To observe the seasonal fluctuation of the meiobenthic fauna community around the coastal area of Jeju island, 20 stations were selected and seasonal surveys were conducted. Three-replicate meiobenthic samples were collected from each station in April, July, and November 2017; February, May, August, and November 2018; and February in 2019, in a total of eight months from 2017 to 2019. The total density of meiobenthos at each station ranged from 733 to 2,505 ind. 10 cm^-2. The month in which the highest habitat density appeared in most stations was April 2017 and the month in which the lowest habitat density was seen was February 2019. Nematodes were the most dominant faunal group among the representative 13 meiofaunal groups at all stations. The subdominant groups were benthic harpacticoid copepods and nauplius. The nematode/copepod (N/C) ratio, reflecting the health indices within the ecosystem, varied from 0.02 to 87.40 over the entire season and the average station values ranged from 2.00 to 16.80. The lowest N/C ratio value was found in April 2017 (0.02) and the highest N/C ratio was found at Station 11 in February 2019, which was 87.40, indicating the highest level of pollution. Seasonal and regional meiobenthos community structure similarity was divided into three groups through group analysis and multi-dimensional scaling (MDS) analysis, which showed that the meiobenthos community structure was affected by seasonal variations, rather than by regional differences.