West Coast Of South Korea Research Articles

기후 및 해양 요인과 김 생산량과의 관계에 관한 연구

While some steps in laver aquaculture production can be controlled artificially to a certain extent, the culturing process is largely affected by natural factors, such as the characteristics of seawater, climatic and oceanographic conditions, etc. This study aims to find a direct relationship between climatic and oceanographic factors (water temperature, air temperature, salinity, rainfall, sunshine duration and wind speed) and laver aquaculture production in Wando region, the biggest aquaculture production area of laver, located in the southwest coast of Korea using a multiple regression analysis. Despite the small sample size of a dependent variable, the goodness of model fit appeared acceptable. In addition, the R-squared value was 0.951, which means that the variables were very explanatory. Model results indicated that duration of sunshine, temperature, and rainfall during the farming period from the end of September to the end of April would be important factors affecting significantly to the laver aquaculture production.

Asymmetric genetic exchange in the brown seaweed Sargassum fusiforme (Phaeophyceae) driven by oceanic currents

Geological phenomena (e.g. drastic sea level fluctuations during the Quaternary Ice Age in the Northern Hemisphere) have been demonstrated to intensively affect the biogeographic patterns and tempo-spatial compositions of genetic diversity of marine organisms. However, it is poorly understood whether contemporary factors such as oceanic surface currents have also shaped inter-regional population genetics of specific coastal marine flora, with or without limited dispersal capability. In this study, we determined mtDNA Cox1 gene sequences of the brown seaweed Sargassum fusiforme from nine populations along the Chinese coast and one population from the west coast of South Korea, in an effort to understand what factors are contributing to their current genetic structure and geographic distribution patterns. Genetic analyses indicated a deep genetic break between the Yellow-Bohai Sea (YBS) and the other two marginal seas, the East China Sea (ECS) and the South China Sea (SCS). In particular, the amount of genetic exchange from the SCS to each of the ECS and YBS was significantly higher than that from the opposite directions. Our analyses supports the hypothesis that biogeographic patterns of genetic variation in S. fusiforme are probably an interactive consequence of post-glacial colonization from two scattered refugia driven by the offshore Kuroshio Current and asymmetric gene flow among adjacent sea margins.

Propagation of abnormal waves on 25 April 2008 at the West Coast of South Korea

ABSTRACT Kim, M.S. and Woo, S.B., Eom, H.M., 2013. Propagation of abnormal wave on 25 April 2008 at the West Coast of South Korea On 31 March 2007, abnormal waves suddenly hit the West Coast of South Korea, causing heavy casualties and huge economic loss. Since the cause of wave generation is unknown, we aim to study the direction of wave propagation by investigating the abnormal wave signal recorded in the tidal stations. To determine the propagation direction of abnormal waves, we analyzed tidal level observation data at 1-min intervals, provided by the Korea Hydrographic and Oceanographic Administration (KHOA). To remove tidal components, wavelet decomposition, which filters wave periods ranging from 2 to 60 min, was performed. If the daily maximum amplitude exceeding 95% confidence interval of the total daily maximum amplitudes appeared simultaneously at more than three tidal stations, the day was defined as the day when abnormal waves occurred. Because of nonstationarity and localized peak in the tim...

The difference in wave environments between intertidal sand beaches and mud flats

Kim, T.R and Lee, J.H., 2013. The difference in wave environments between intertidal sand beaches and mud flats.The characteristics of wave environments are studied and compared between an intertidal beach and a mud flat. The Mohang Beach is an intertidal sand beach, located on the southwest coast of Korea with tidal range of over 5 meters. Strikingly, it lies just next to the large intertidal mud flat. In order to find the wave energy difference between the intertidal sand beach and mud flat, a numerical wave model is performed with same boundary input conditions, and a wave directional spectrum is calculated at the entrance of each site. Unstructured grids for numerical wave model are used because the details of the shore orientation and topography are important to simulate wave propagation and shallow water effects in nature. It is found that the sand beach is more exposed to the wave forces than the mud flat in all wave directions. The field measurement also shows higher wave heights at the sand beach than the mud flat. The local difference of wave propagation and energy is the main factor maintaining the two adjacent environments with disparate sedimentological characteristics.

First Report of Contamination of the AbaloneHaliotis discus hannaiby Okadaic Acid and Yessotoxin

The presence of the lipophilic toxins okadaic acid (OA), dinophysistoxin-1, pectenotoxin-2, and yesso toxin (YTX) in the abalone Haliotis discus hannai collected between March 2009 and May 2010 was analyzed via liquid chromatographytandem mass spectrometry (LC-MS/MS) and the mouse bioassay. Thirty abalone samples collected from 2 sites, Geumdang and Chungdo on the southwest coast of Korea, were submitted for toxin analysis. Lipophilic toxins OA and YTX were detected in the digestive gland of the abalone by LC-MS/MS, but no toxins were detected in the foot muscle. The highest toxin concentrations in the digestive glands of the abalone were 4.7 ng/g OA and 1.3 ng/g YTX. Okadaic acid and YTX were detected mainly during winter and spring. However, dinophysistoxin-1 and pectenotoxin-2 were not detected in any of the samples by LC-MS/MS. Diarrhetic shellfish poisoning toxins were not detected in the digestive gland or the foot muscle by mouse bioassay. Although low levels of toxins were detected, this is the first report identifying lipophilic toxins in abalone.

탄도만에 서식하는 낙지의 분포 특성

This study is to find out the distribution characteristic of Octopus minor in the Tando Bay on the southwest coast of Korea with conducting surveys from May of 2006 to April of 2007. Surveys were carried out at 20 stations on 2 and 3 tide time in the low speed of high tide at night and conducted during 30minutes (4 times fishing) per station. Catch per unit effort (CPUE) was estimated by total catch per 500hooks at each station. Monthly CPUE showed that they put highest in October, November, April and June at 10.4, 10.5, 9.4 and 7.7 individuals respectively. On the other hand, CPUE put lowest in January, the coldest month, and August, the hottest month, at 0.2 and 0.3 individuals respectively. As for geographical mantle length distribution, average mantle length ranged from 6.2cm to 7.3cm at stations near the tidal channels (St. 1, 4, 5, 6, 8, 9, 10, 13, 14, 15, 18, 19 and 20), and was smaller than 6.0cm at stations located inside of bay (St. 2, 3, 7, 11, 12 and 17). In terms of geographical distribution density, CPUE showed higher than 8.0 at St.4 in Changmaeri, St.8 in Taecheonri, St.13 near Seondo, St.18 in Naeri and St.14 in western part of Tando which are located near the main tidal channels. And distribution density showed low that CPUE was lower than 5.0 individuals at stations located inside of bay (St. 1, 3, 5, 6, 7, 11, 12, 16 and 20). Through the results, the difference of distribution density reflects that distribution of Octopus minor is affected by direction of current and inflow of pollutant from land in direct. Therefore, it is considered that bottom composition of tidal flat and distribution of live food are the crucial cause of identifying the distribution characteristics of Octopus minor. For this reason, it is judged to need additional research on it.

서남해 주요 도서 연안 어장 침적쓰레기의 분포 실태 조사 및 수거 처리 비용 추정

We surveyed and evaluated quantities and distribution characteristics of debris on the sea floor around active fishing grounds around the islands in the southwest coast of Korea in 2007 where the average depth is below 40m. Proper recovery gears mainly to haul the derelict fishing gears are selected considering the sea bed types of the areas. The collected debris amounts were used to estimate the total amount of the surveyed area. The number of hauls per trial times the amount of the debris was extended to whole sampling area and the weighting factor from the opinion was applied to reach the total amount of marine debris on the floor. The amount of the deposited marine debris around Wangdeung-do area is estimated as about 686 , and the cost of the collection and treatment for the deposited marine debris is estimated about 3.9 billion KRW after consideration of the proper size of the working ships, labor, transport and treatment cost.

Population declines and heavy metal exposure of Swinhoe’s Storm Petrels (Oceanodroma monorhis) breeding on the southwest coast of Korea

We investigated the population dynamics of globally near-threatened Swinhoe’s Storm Petrels on Kugul and Chilbal islets where >90% of the world breeding population have resided for >25years. We also determined the levels of six heavy metals in the seabird species as a possible factor affecting reproduction. Of the 892 and 307 marked burrows since 1986, the breeding density of Swinhoe’s Storm Petrels has changed significantly, based on a 55% decline at Kugul islet, and a 39% decline at Chilbal islet, suggesting that this species has suffered an extensive population decline. Of the individuals studied, five Swinhoe’s Storm Petrels and two Streaked Shearwaters had >8.0μg/g Pb in tissues, which is a potentially lethal level in avian species. Given that substantial changes in their breeding populations may occur in a limited breeding colony, ecological threats including environmental pollutants warrant attention for global conservation of these birds.

New species of free-living marine Sabatieriinae (Nematoda: Monhysterida: Comesomatidae) from

Four new species from the subfamily Sabatieriinae Filipjev, 1934 are described from the south and west coast of South Korea: three new species of Laimella Cobb, 1920 and one new species of Cervonema Wieser, 1954. Two further species of Cervonema are informally described owing to the absence of male specimens. In addition, Laimella filicaudata Ward, 1974 is formally reinstated as an extant species. Sabatieriinae are relatively character poor, defined by a striate cuticle, closely spaced cephalic setae, small buccal cavity, simple arcuate spicules and precloacal supplements minute or absent. However, we have found that the de Man's ratios a, b and c, the comparable lengths of the anterior and posterior cephalic setae, the position of the amphid, shape and length of the oesophageal bulb, and the proportion of the cylindrical tail part are all species informative. Laimella ferreroi sp. nov. is most distinctive species described here, having the largest de Man's ratios a and b, the longest gubernaculum (as abd) and the longest, truly filiform, tail so far recorded in the genus. Laimella socotris sp. nov. has a distinct rounded posterior oesophageal bulb similar only to L. longicauda Cobb, 1920 and L. filicaudata Ward, 1974; in combination with the tail length and the relative length of the anterior and cephalic setae this defines the species. Laimella tongyeongensis sp. nov. is defined by a combination of characters, principally the de Man's ratios a, b, c and c', the oesophageal bulb length and with regards to the length ratio between the anterior and posterior cephalic setae. Cervonema pseudodeltensis sp. nov. is the only species of the genus so far described which appears to have the anterior cephalic setae marginally longer than the posterior cephalic setae. It is also defined by the amphid position and the relative size of the oesophageal bulb. Cervonema sp. A , described only as females, is defined by the total body length and the relative length of the oesophagus and tail (de Man’s b and c). Cervonema sp. B, on the other hand, is distinct with respect to the de Man's ratios a and b, the R2:R3 sensilla length ratio, and the amphid directly behind the cephalic setae. It also has not been fully described here owing to the lack of male specimens.

Complete Genome Sequence of Vibrio vulnificus Bacteriophage SSP002

Vibrio vulnificus phages are abundant in coastal marine environments, shellfish, clams, and oysters. SSP002, a V. vulnificus-specific bacteriophage, was isolated from oysters from the west coast of South Korea. In this study, the complete genome of SSP002 was sequenced and analyzed for the first time among the V. vulnificus-specific bacteriophages.

태안 안면도 조간대에 서식하는 바지락 (Ruditapes philippinarum) 의 조위별 성장양상

Growth patterns of the Manila clam, Ruditapes philippinarum in each tidal level were studied in the intertidal zone in Tae-an on the west coast of South Korea from April to August 2009. Environmental factors and the specimens of R. philippinarum were monthly collected at three intertidal locations: low intertidal zone, low-middle intertidal zone and middle intertidal zone. Temperature of sediment in low intertidal zone were lower than those in other intertidal locations. Concentrations of Chl-<TEX>${\alpha}$</TEX> were not significantly different between in each tidal level. Exposure hours in low intertidal zone were shorter than those in other intertidal locations. Density of each year class in low intertidal zone were higher than those in low-middle intertidal zone and middle intertidal zone. Growth factors of R. philippinarum in low intertidal zone were better than those in other intertidal locations. The growth rate of under one year class individuals of low intertidal zone were higher than those in low-middle intertidal zone and middle intertidal zone, before the main recruitment period of R. pilippinarum. Although the growth patterns of R. philippinarum may be affected by various environmental factors, we suggests that the exposure duration is the main affect in the growth patterns of R. philippinarum in intertidal zone.

Abstract P080: Dietary Protein, Especially Meat Protein, is Positively Associated with Bone Stiffness Index in Population Consuming Relatively Low Amounts of Protein

Introduction: Dietary protein has a mixed effect on bone health, and it may differ by amount or source. The majority of epidemiological and clinical studies have demonstrated that dietary protein has a positive association with bone health. However, most studies, so far, have been performed in women and in people with moderate- to high-protein diet. Little is known about relationship between dietary protein and bone health in men and in people who consume relatively low amounts of protein. Hypothesis: Since Korean traditional meals depend heavily on carbohydrate, Korean rural residents consume protein, especially animal protein, at relatively low levels compared with that in the Western diets. Therefore, we assessed whether protein intake is beneficial for the people who consume relatively low amounts of protein. Methods: Participants were recruited for a baseline examination of a community-based cohort study in Kangwha, which consist of ten islands with rural villages and a small town on the west coast of South Korea. Among 3,330 participants recruited for a baseline examination between 2008 and 2010,1,182 men and 1,393 postmenopausal women were eligible for the present analyses. Diet was assessed over a 1-year period using a 103-item semi-quantitative food-frequency questionnaire developed for Korean adults. Bone density, measured at the os calcis with a quantitative ultrasound device, was expressed as the stiffness index (SI). A series of analysis of covariance was performed to calculate the adjusted mean SI across sex-specific tertiles of protein intake and their linear trends using a generalized linear model procedure. Total energy intake, age, weight, current smoking status (men only), current hormone therapy (women only), and moderate to high intensity of exercise were potential confounders. Results: In the present study population, the median daily protein intake was 50.5 g in men and 44.0 g in women. In men, the multivariate-adjusted mean SI showed an increasing trend with a higher total protein intake ( P for trend = 0.041). Among various sources of protein, only meat protein was positively associated with the SI ( P for trend = 0.009). Meanwhile, in postmenopausal women, neither total protein nor any protein subtype showed a significant association with the SI. Conclusions: Our findings suggest that total protein, especially meat protein, contributes bone health in men who consume relatively low amounts of protein. Further research is needed to evaluate long-term effects of protein on bone health in this population.

Discovery of Halicyclops continentalis (Cyclopidae, Halicyclopinae) from Estuaries and Salt Marshes on the West Coast of South Korea

A cyclopoid species from several salt marshes and estuaries on the west coast of South Korea were identified as Halicyclops continentalis Ueda and Nagai, 2009, recently described from Ariake Bay at northwestern Kyushu, Japan. Detailed examination on the Korean specimens justifies Ueda and Nagai's proposition that the H. sinensis sensu Tai and Chen, 1979 formerly known from the Chinese coast of the Yellow Sea should be identical to H. continentalis. Furthermore, this report reinforces their assumption on the geographical distribution of H. continentalis, that is, the Ariake Bay population is a continental relict of the East Asia continent. Herein, a redescription of the species is provided on the basis of the Korean specimens, with a comment on the morphological comparison among three populations around the Yellow Sea.

사육수 비교환방식을 이용한 포장 사육지에서의 흰다리새우, Litopenaeus vannamei (Boone, 1931)의 초고밀도양식

Shrimp farming is the most important mariculture industry on the west coast of South Korea. However, it has suffered from mass mortality due to viral disease outbreaks and coastal pollution due to water discharge. This study developed an intensive shrimp culture method for outdoor ponds, without water exchange, which minimizes the chance of viral transmission from the environment, reduces coastal pollution by water discharge and enhances shrimp production. A culture trial was conducted in two high-density polyethylene (HDPE)-lined ponds with a <TEX>$550\;m^2$</TEX> surface area. The ponds were stocked with postlarvae of Litopenaeus vannamei, the major farmed shrimp species in Korea, on July 10, 2007, and cultured for 90 days with no water exchange. The stocking density of the postlarvae (B.W. 0.0015 g) was <TEX>$272\;ind./m^2$</TEX>, which is eight times higher than in traditional pond culture in Korea. At harvest, the total production of ponds 1 and 2 was 1,362kg (<TEX>$2.48\;kg/m^2$</TEX>) and 1,282 kg (<TEX>$2.33\;kg/m^2$</TEX>), respectively. This is 20~22 times higher than the mean farmed shrimp production (<TEX>$0.112\;kg/m^2$</TEX>) in Korea and about eight times higher than in traditional ponds with a good harvest. Although there was no water exchange throughout the culture period, the mean concentrations of unionized ammonia and nitrite-nitrogen were as low as 0.038 and 6.0 mg/L, respectively. The feed conversion rate (FCR) was 1.38, which is 20~45% lower than that of traditional pond cultures. The high efficiency of the diet in this study is thought to be due to a well-managed feeding strategy and well-developed bioflocs used as diet additions for the shrimp. The final body weight of the shrimp at harvest was low (12.2~12.5 g), compared with that of traditional pond culture. This may have resulted from the combination of a short culture period, high density of shrimp, and low temperature. This study suggests that a super-intensive shrimp pond culture method using biofloc technology with no water exchange can minimize viral transmission via water exchange, reduce coastal pollution, and enhance shrimp production.

Effect of salinity on growth and nutrient uptake of Ulva pertusa (Chlorophyta) from an eelgrass bed

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates (μ) of U. pertusa ranged from 0.019 to 0.032 d. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-a content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

Effect of tidal flat on seawater temperature variation in the southwest coast of Korea

The seawater temperature observed near macrotidal flats demonstrates distinguished semidiurnal variations. The range of seawater temperature variations was approximately 2–4°C during a clear day in spring. The seawater temperature increased during flood tides but decreased during ebb tides in spring and summer, while the opposite occurred in autumn and winter. A model was developed to evaluate the effect of the tidal flat on changes in the seawater temperature. The seawater temperature, calculated using this model, was verified with observed seawater temperatures. The heat of seawater in shallow zones changed more than 581 J m−3 s−1 (0.5°C h−1) because of heat content exchange with the tidal flat, regardless of season. The maximum heat gain (835 W m−2) of seawater from the tidal flat and heat loss (588W m−2) of seawater from the tidal flat occurred in June 2004, whereas the minimum heat gain (554 W m−2) from the tidal flat occurred in March 2004 and heat loss (316W m−2) to the tidal flat occurred in February 2004.

Real-time PCR Quantification of White Spot Syndrome Virus (WSSV) and Hepatopancreatic Parvovirus (HPV) Loads in Shrimp and Seawaters of Shrimp Ponds on the West Coast of South Korea

Viral diseases are major emerging problems of shrimp that have affected the production, and even complete losses for shrimp farms. In this study, we developed a sensitive TaqMan real-time PCR method to quantify white spot syndrome virus (WSSV) and hepatopancreatic parvovirus (HPV) in the shrimp and pond water in which fleshy shrimp, Fenneropenaeus chinensis, and Pacific white shrimp, Litopenaeus vannamei, are reared. WSSV and HPV in pond seawaters ranged from <TEX>$1.65{\times}10^3$</TEX> to <TEX>$2.43{\times}10^9$</TEX> and from 0 to <TEX>$4.43{\times}10^5$</TEX> copies/L of seawater, respectively. Of 20 ponds analyzed, all pond water and shrimp were positive for WSSv. L. vannamei showed higher susceptibility to WSSV than F chinensis. HPV was detected only in the pond water for F chinensis. In shrimp tissue, however, HPV was found in both species, with 23-times higher infection rate in F chinensis than L. vannamei. The total bacterial counts in the pond water ranged from <TEX>$2.23{\times}l0^3$</TEX> to <TEX>$1.98{\times}l0^5\;CFU/mL$</TEX>. The variations in total bacterial count for each pond appeared to correlate to the variations of the WSSV load. Statistical analysis indicated that there was no significant difference (P>0.05) between the WSSV load in pond water and shrimp, and there was no relationship between total bacterial load and viral load in the pond water. However, a significant difference (P<0.01) was found between HPV load and L. vannamei and F chinensis pond water.

Age and Growth of the Elongate Ilisha Ilisha elongata

We present age and growth data for Ilisha elongata, based on 363 specimens caught in 1999 and 2000 around Jeju Island and the southwest coast of Korea. Scale and ring radii of each ring group showed a direct one-to-one relationship, with ring radius increasing as scale radius increased. The relationship between fork length and scale radius was FL=39.553SR+60.935 for females, FL=39.474SR+54.026 for males, and FL=39.608SR+57.547 for both sexes. Monthly changes in the marginal index indicated that a new ring appears once each year (in July). Maximum age, mean age and mean fork length of fish were 10 years, 5.0 years, and 349mm, respectively. Von Bertalanffy's growth equations were <TEX>$FL_t=495.4{\times}[1-\exp(-0.2586(t+0.6487))]$</TEX> for fork length (mm) and <TEX>$W_t=1,112.5{\times}[1-\exp(-0.2586(t+0.6487))]^{2.874}$</TEX> for body weight (g) for both sexes. Monthly changes in the gonadosomatic index (GSI) indicated that the spawning period was in June and July, which corresponded closely with ring formation time. Differences in monthly GSI changes in 1999 and 2000 may be related to water temperature variation. Fecundity ranged from 5,664 to 176,290 eggs per individual (n=43, fork length 264-470mm). The relationship between fecundity(F) and fork length was <TEX>$F=7.7{\times}10^{-7}{\times}FL^{4.9269}$</TEX>.

Perfluorinated compounds in streams of the Shihwa industrial zone and Lake Shihwa, South Korea

Concentrations of perfluorinated alkyl compounds (PFAs), including perfluorooctane sulfonate (PFOS), perfluorohexanesulfonate, perfluorobutanesulfonate, perfluorooctanesulfonamide, perfluorodecanoate, perfluorononanoic acid, perfluorooctanoate (PFOA), perfluoroheptanoate, and perfluorohexanoate, were measured in the streams of the Shihwa and Banweol industrial areas on the west coast of South Korea as well as the adjacent Lake Shihwa (an artificial lake) and Gyeonggi Bay. Perfluorinated alkyl compounds were concentrated from water using solid-phase extraction and were identified and quantified by liquid chromatography/ triple-quadrapole tandem mass spectrometry. Of the PFAs measured, PFOS and PFOA occurred at the greatest concentrations. Concentrations of PFOS ranged from 2.24 to 651 ng/L, and concentrations of PFOA ranged from 0.9 to 62 ng/L. The concentrations of PFOS observed in Lake Shihwa were among the greatest ever measured in the environment. These results suggest local industrial sources of PFOS and PFOA as well as other PFAs. Because of dilution, the greatest concentrations occur in a rather restricted area, near the points of discharge of the streams that empty into the lake. The greatest measured concentration of PFOS exceeded the threshold for effects predicted for predatory birds consuming aquatic organisms continuously exposed to this level.

한국 남서해안 자연채묘 양식 김의 DNA 염기서열과 종 동정

Nuclear SSU and ITS1 rDNA and plastid rbcL sequences were determined to identify the seven samples of Porphyra cultivated by means of natural seeding on the southwest coast of Korea and analyzed to access the phylogenetic relationships of them with the natural populations of P. tenera and P. yezoensis from Korea and Japan. SSU, rbcL and ITS1 data from 18, 21 and 31 samples, respectively, including previously published sequences were investigated in the study. Results from our individual and combined data indicated that the seven samples were all P. yezoensis and the entities except one from Muan 2 aquafarm strongly grouped together with the natural populations of P. yezoensis from the south and the west coast of Korea. The sample from Muan 2 seems to be derived from a strain of P. yezoensis introduced from Japan by Porphyra farmers, based on DNA sequence data.