• The Korean Journal of Ecology
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• v.22 no.6
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• pp.317-324
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• 1999

A research on the coastal mantle communities in South Korea and Japan was carried out. This study was accomplished by using syntaxa and hierarchical system of the coastal mantle communities in South Korea and Japan in terms of the Zurich-Montpellier School's method. The coastal mantle communities in South Korea and Japan are included in the Rosetalia rugosae of northern type and the Viticetea rotundifoliae of southern type, which are characterized by Rosa rugosa and Vitex rotundifolia, respectively. The coastal mantle communities in South Korea are subordinated and are considerably corresponded to those which already identified in Japan. Each syntaxon of the coastal mantle communities in South Korea and Japan is briefly characterized floristically and ecologically, and their distribution is shown on maps.

• The Korean Journal of Ecology
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• v.23 no.3
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• pp.193-199
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• 2000

The research about distributional characteristics of coastal mantle communities in South Korea was accomplished. This study was carried out by direct analysis of the latitude and temperatures of each releve site on the basis of syntaxonomy and hierarchical system of coastal mantle communities which was already obtained from Zurich-Montpellier School's method. The distribution of coastal mantle communities in South Korea appeared from North to South in the order of Rosa rugosa community, Vitex rotundifolia community, the Linario-Viticetum rotundifoliae, the Roso-Viticetum rotundifoliae and the Imperato-Viticetum rotundifoliae, and it was recognized that tendencies of continuous and overlapped distribution pattern in adjacent syntaxa. Consequently, It is suggested that the syntaxonomical, geographical and bioclimatic informations of Japan, North Korea and China are essential to determine the distributional patterns of coastal mantle communities in Korean Peninsula.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.49 no.3
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• pp.200-207
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• 2013

This paper presents the mesh selectivity of a net pot for common octopus Octopus minor for the sustainable resources management of common octopus. The filed experiments were carried out the total 10 times in the southern part of coastal sea in Korea from March to May in 2010 using net pots of five different mesh sizes (16, 18, 20, 22 and 26mm). The test of size selectivity, indicated a 50% selection value on the logistic master curve of 3.195, whereby 50% of individuals with a mantle size of approximately 70.3mm selected a mesh size of 22mm. Considering that 50% of common octopus entering sexual maturity have a mantle size of 70.6mm, the optimum mesh size should be equal to, or larger than 22mm.

• The Korean Journal of Ecology
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• v.24 no.5
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• pp.267-271
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• 2001

A phytosociological study on the hierarchical classification system of the Rosetalia rugosae, developed at the coastal dunes in the cool-temperate region of Northeast Asia, was carried out. Currently, the Rosetalia rugosae is subordinated to the Rosetea multiflorae which is the highest rank of the mantle vegetation in Northeast Asia, however its hierarchical system is somewhat ambiguous. This study was accomplished by using the syntaxa and hierarchical system of the Rosetalia rugosae and Rosetea multiflorae, and by also using 197 homogeneous relevns of the Rosetalia rugosae in South Korea and Japan in terms of the Zbrich-Montpellier School. For the hierarchical analysis of the Rosetalia rugosae, the constancy, the frequency and the net contribution degree were evaluated. It is estimated that the Rosetalia rugosae and the Rosetea multiflorae are hardly related to reciprocally. Thus, the subordination of the Rosetalia rugosae to the Rosetea multiflorae is comparatively irrational. Accordingly, the syntaxonomical hierarchy of the Rosetalia rugosae must be reconsidered that is correspond to the Viticetea rotundifoliae of the warm-temperate coastal dune shrub vegetation.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.2
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• pp.113-120
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• 2022

The purpose of this study is to provide information about annual variations in catch size and changes in reproductive biology in the common octopus, Octopus vulgaris, a commercially important species in Jeju Island. Samples were collected from coastal waters of Jeju Island, Korea by coastal trap fishery from January to November 2021. Octopus vulgaris have been decreasing in this region since 1984. The mantle length (ML) ranged from 4.5 to 17.8 cm and body weight (BW) ranged form 88.5 to 2,657.5 g. A χ²-test revealed that the number of males was significantly greater than females (χ² = 32.712, df = 10, P<0.05). Mature females were found from January to July and male occurred January to August. The gonadosomatic index value was higher from July to August than other months. The relationship between mantle length and body weight was BW = 2.4527ML^2.3139 (female) and BW = 2.6785ML^2.3159 (male). At 50% group maturity, female and male average weight was estimated to be 554.7 g and 330.6 g, respectively.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.57 no.3
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• pp.185-193
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• 2021

This study was conducted to evaluate the performance of the octopus pot according to mesh sizes. Entering behavior of Octopus minor and bait (Macrophthalmus japonicus) escape rate on the mesh sizes of the pots were investigated for six times in indoor tank. The sea trials for evaluating the performance of Octopus minor pot to different mesh sizes (22, 20 and 18 mm) were conducted for six times from 2017 to 2018 in the coastal sea of Deukyang Bay, the Republic of Korea. Behavior patterns of contact pot to leaved pot were more frequent than contact pot to bait search. When the octopus contacted to the pot, there was no clear search behavior to distinguish the mesh sizes. Total catch of 46% was accounted for 18 mm pots, followed by 34% at 20 mm and 20% at 22 mm (P < 0.05). Catch per unit effort was calculated as 30 g/pot at 22 mm, 44 g/pot at 20 mm and 59 g/pot at 18 mm. As a result of evaluating 50% selection of mantle length and weight on the mesh sizes, mantle length (mm) and weight (g) were 84.6 and 147.8 in 22 mm, followed by 20 and 18 mm.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.407-419
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• 2013

Cyclotella species were collected at 51 sites from July 2010 to June 2013 in Korean coastal waters. A total of five Cyclotella species (C. atomus var. marina, C. baltica, C. litoralis, C. meduanae, and C. meneghiniana) were identified in this study. The diagnostic characteristics for five Cyclotella species are described, focusing on the spacing, position, number of satellite pores of the mantle fultoportula and valve face fultoportula. In addition, we put the salinity ranges of five species of Cyclotella together. Of the five Cyclotella species, C. baltica, C. litoralis and C. meduanae are newly recorded in Korea.

• The Korean Journal of Malacology
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• v.20 no.2
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• pp.155-157
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• 2004

The true cuttlefishes genus Sepia (Doratosepion) Linne, 1758, characterized by shell thick, entirely calcareous, shell almost as long as mantle, was collected from the coastal of Dong-Am, Busan, Korea in April, 2004. The specimen agreed closely with description of Sepia (Doratosepion) kobiensis Hoyle, 1885 and S. tokioensis Ortmann, 1888. We herein described the species, being as the first record of S. kobiensis and tokioensis from the region. New Korean names are also provided.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.1
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• pp.57-66
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• 2020

The purpose of this study was to provide information about annual variations in catch size and changes in reproductive biology in the common octopus Octopus vulgaris, a commercially important species. Samples were collected from coastal waters off Gyeongnam, Korea, by coastal trap and coastal complex fishery from February to December 2018. Octopus vulgaris have been decreasing in this region since 2007 and catch prices have been increasing. The mantle length (ML) of O. vulgaris ranged from 1.2 to 21.2 cm and body weight ranged from 42.6 to 5,537 g. The sex ratio differed significantly from what was expected, at 0.45:0.55 (P<0.05). Mature females were found from February to December, except in October and November, and males occurred from February to December, except in October. The gonadosomatic index value was higher from May to September than in other months. The total number of eggs in fecund individuals ranged from 40,280 in 578.1 g of body weight to 138,994 in 1,666.5 g of body weight. The relationship between body weight and fecundity was F=76.486BW^1.0087 (r²=0.7897). At 50% group maturity, average weight was estimated to be 636.35 g, while it was 969.30 g at 75% maturity and 1736.55 g at 97.5% maturity. This study highlights changes in catch size and reproductive biology between 2007 and 2018. These results provide basic evidence that may be used to establish regulatory policy for O. vulgaris fisheries.

• The Korean Journal of Ecology
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• v.18 no.3
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• pp.307-321
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• 1995

Division of ecoregions having respective functions was attempted through quantitative and qualitative analysis on vegetation diversity, and heterogeneity and on soil environment of the study sites. Field research was carried out in a square of 81 ㎢ around Andongpo (126°38'E, 37°30'N), Kimpo-gun, Kyonggi provice. Conventional methods applied are as follows: classical syntaxonomy by the Zurich-Montpellier School, interpolation method to determine the degree of diversity, heterogeneity and distribution pattern of vegetation, and correlation analysis between soil properties and plant communities. 41 plant communities were identified and composed of 6 forests, 4 mantle and 31 herb communities including 6 saltmarsh plant communities. In a mesh, number of plant communities was highly correlated to the number of species. The highest number of plant community and species was 25 communities·km-2·mesh-1 and 381 species· km-2·mesh-1 ,and the highest value of vegetation heterogeneity was 28.1 species· community-1·mesh-1. Their lowest numbers were 4 communities·km-2·mesh-1. and 28 species·km-2·mesh-1. and 7 species·community-1·mesh-1, respectively. Contour map on vegetation diversity and heterogeneity enabled us to establish two regions; coastal and inland vegetation. Isoline 〔150〕,〔10〕and〔10〕and〔15〕on the species diversity, the community diversity and the vegetation heterogeneity, respectively, were regarded as ecolines in the study area. Cl- content was recognized as the most important factor from correlation analysis between soil properties. Ordination of sites indicated that the study area be divided into two edaphic types: inland and coastal habitats. It was considered that the extent of desalinization in soil played a major role in determining the species composition in the reclamed area. By matching edaphic division of habitats with division of vegetation structures, designation of ecoregion was endorsed. The approach of current study was suggested as an effective tool to implement an assessment of the vegetation dynamics by the disparity of natural environment and anthropogenic interferences.