• Korean Journal of Ichthyology
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• v.20 no.3
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• pp.179-189
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• 2008

Standard length (SL) and gonadosomatic index (GSI) of Plecoglossus altivelis were investigated from March to October 2007 in Seomjin River and streams flowing to the East Sea, Korea. Water temperatures were $17{\sim}23^{\circ}C$ during the spawning season, which ran from late September to early November in Seomjin River and early August to mid-October in streams flowing to the East Sea. The GSI and HSI variations of ayu population in Seomjin River increased earlier than in populations in streams flowing to the East Sea with similar variation in water temperature. Histological study of ovaries showed that the start of spawning of P. altivelis in Seomjin River was later than in streams flowing to the East Sea. Overall, fecundity increased with increase in SL and not by site specificity. The SL of P. altivelis increased as the river scale increased. Mean length of specimens from Seomjin River (river length: 223.86 km, river area: $4,911.89km^2$) was $194{\pm}15.3mm$, from Osip Stream (55.76 km, $393.78km^2$) $185{\pm}15.5mm$, from Yangyang Namdae Stream (54 km, $474.08km^2$) $142{\pm}11.8mm$, and from Joosoo Stream (21.1 km, $141.47km^2$) $136{\pm}16.7 mm$.

• Korean Journal of Ichthyology
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• v.19 no.2
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• pp.142-153
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• 2007

Fertilized eggs of Plecoglossus altivelis over than 1,000,000 were introduced into Okjeong, Jeollabuk-do, Korea by K-water, 2001. Since then, this lake and the neighbouring tributaries gave sufficient habitat to maintain their life cycle which are being the land-locked. A land-locked ayu of annual life is ascending and descending from Lake Okjeong to streams for spawning and growth. Among the streams, the Churyeong stream reaching about 32 km in length is a major site for growth and spawning. But the land-locked ayu was no longer seen in the upper regions of the Churyeong stream over than about 12 km distance from Lake Okjeong. Because there were 11 weirs along with the Churyeong stream, it was difficult for them to move freely up to upper regions, and it causes irregular growth condition although they must be actively growing with feeding for spawning. During three survey years (2004 to 2006), in lowest rainfall-recorded 2005, the ayu population was not able to move up actively across the weirs and just stayed around the weirs, and finally it let them grow slowly and unstably. Also although there are 11 weirs, only 3 fish ways existed. Such environmental factors will seriously affect growth, spawning and size of ayu population in this area.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.615-626
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• 2022

This study investigated the habitat characteristics and spawning ecology of Hippocampus haema (Syngnathidae) in Soando Island, Korea, from May 2015 to December 2016. The survey site where seahorses inhabit was mainly formed by seagrass of Zostera marina populations. Total density and biomass (Mean±SE) of Z. marina were the highest at 136±14.4 shoots/m² and 489.8g DW/m², respectively, in spring (May), while the total density was lowest at 93±7.0shoots/m²in autumn (October), and biomass was the lowest and at 122.3g DW/m² in winter (February). During the study period, 293 individuals were identified through a diving and kick net survey, and the total length of H. haema ranged from 10.1 to 87.0mm. Male individuals nurturing fertilized eggs or larvae appeared beginning in May and were collected until October in both 2015 and 2016. Juvenile individuals were captured beginning in July 2015 and June 2016. As a result of a comprehensive analysis of the spawning season characteristics, it was estimated that the spawning season of H. haema was from April to October. The number of fertilized egg or larvae inside the male brood pouch were 38.3±14.8 (20-76), and the number of fecundity identified from female were 47.2±8.6 (31-59). The male-to-female ratio of H. haema was 1:1.7, indicating the dominance of males.

• Journal of Ecology and Environment
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• v.38 no.2
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• pp.241-247
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• 2015

A participatory approach of local stakeholders is important to create a balance between nature protection and the sustainable use of natural resources in a nature reserve and its vicinity area. The zoning and management policy of biosphere reserves (BRs) is a good example of this idea, especially for island reserves. Yakushima was inscribed as a World Natural Heritage (WH) in 1993. Almost all of its residents did not remember that Yakushima was a BR. In addition, Yakushima has some problems in nature reserve management. Overabundance of the deer population is a critical threat to both agriculture and natural vegetation in the world heritage site. There are too many tourists visiting the WH site and Nagata-hama beach. The beach is a Ramsar site and one of the most important spawning grounds of sea turtles in the north Pacific. Now, residents and the municipality have decided to reactivate the Yakushima BR. Although the Ministry of the Environment of Japan has an initiative to manage the WH and the Ramsar site, the BR is managed by the municipality and local stakeholders. Local activities of both nature conservation and the sustainable use of natural resources are encouraged in the BR site. The islanders willingly included all areas of the island into the BR site. Scientists who have participated in the Society of Yakushimaology have played a significant role to build trust between local stakeholders and to seek feasible policies on the nature reserves. The concept of the "Yakushima Environmental Culture Village" is a good model for the extension plan of the Yakushima and Kuchinoerabujima BRs.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.21 no.4
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• pp.11-23
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• 2018

The purpose of this study is to identify the ecological characteristics and biological interactions between species of the abandoned rice paddy field in mountainous areas and to suggest a management strategy for stable food chain formation and biodiversity enhancement. The study site is located in Uldae wetland of Songchu district Bukhansan National Park, site characteristics and biological habitat characteristics were identified through site survey and literature survey. With regard to physical environment, among geographical features, the Uldae Wetland and the neighborhood inside the basin was a gently sloping area($5{\sim}15^{\circ}$). And 64.0% of basin faced the north. With regard to water environment, the Uldae Wetland was wetland of rainfed paddy field depending on precipitation and the system of stream flowing into the wetland from valley. According to the results of examining flora in plant ecology, in general, they were herbaceous wetland species. 88.6% of existing plants inside the Uldae Wetland basin was a forest in the mountain. And Quercus spp. community and Pinus densiflora community accounted for 64.6% of that, and was dominant. Except for that, Salix koreensis community was distributed. The existing vegetation of Uldae Wetland inhabited wetland species and terrestrialization indicator species, and it was thought that partial terrestrialization inside the Uldae Wetland was in progress after the discontinuation of paddy cultivation, such as the expansion of Salix koreensis distribution area. In the status of appearing faunae in the Uldae Wetland with regard to wildbirds of appearing principal species, The Uldae wetland was based on a abandoned rice paddy field various wildlife, and was a wildlife feeding, spawning, and resting place. The water environment was an important factor in maintaining the wetland living creatures function, habitat of waterbirds and benthic macroinvertebrates, amphibians and odonate are spawning ground and habitat, it was affecting the vegetation ecosystem based on wetlands. In order to maintain the diversity of wildlife, it was important to maintain smooth water supply and water level. A stable food chain will be formed and the Uldae wetland biodiversity will be abundant by establishing the relationship between the species of Uldae wetland, which is abandoned rice paddy field, and the habitat environment favored by species belonging to the ecosystem stepwise linkage. The ecological characteristics of the Uldae wetlands and the relation between the species were analyzed and the environmental conditions were reflected in the planning and management plan of Uldae wetland ecology.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.2
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• pp.23-38
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• 2022

This study investigates the characteristics and physical habitat requirements for each Bufo gargarizans life history through a literature survey. After deriving variables for each component of Bufo gargarizans, in order to reduce regional deviations from eight previously studied literature research areas for deriving the criteria for variables, a total of 12 natural habitats of Bufo gargarizanss are selected as spatial ranges by selecting four additional sites such as Umyeonsan Ecological Park in Seoul, Wonheungibangjuk in Cheongju in the central region, Changnyeong Isan Reservoir in the southern region, and Mangwonji in Daegu. This study presents Bufo gargarizans SI, a species endemic to Korea, whose population is rapidly declining due to large-scale housing site development and road development, and develops a Bufo gargarizans HSI model accordingly to improve the function of the damaged Bufo gargarizans habitat and to present an objective basis for site selection of alternative habitat. At the same time, it provides basic data for adaptive management and follow-up monitoring. The three basic habitat requirements of amphibians, the physical habitat requirements of Bufo gargarizans, synthesized with shelter, food, and water, and the characteristics of each life history, are classified into five components by adding space and threats through literature research and expert advice. Variables are proposed by synthesizing and comparing the general characteristics of amphibians, among the previously studied single species of amphibians, the components of HSI of goldfrogs and Bufo gargarizans, and the ecological and physical environmental characteristics of Bufo gargarizans. Afterwards, through consultation with an amphibian expert, a total of 10 variables are finally presented by adjacent forest area(ha), the distance between spawning area and the nearest forest land(m), the soil, the distance from the wetland(m), the forest layered structure, the low grassland space, the permanent wetland area(ha), shoreline slope(%), PH, presence of predators, distance from road(m), presence or absence of obstacles. n order to derive the final criteria for each of the 10 variables, the criteria(alternative) for each variable are presented through geographic information analysis of the site survey area and field surveys of the previously studied literature research area. After a focus group interview(FGI) of 30 people related to the Bufo gargarizans colony in Cheongju, a questionnaire and in-depth interviews with three amphibians experts are conducted to verify and supplement the criteria for each final variable. Based on the finally developed Bufo gargarizans HSI, the Bufo gargarizans habitat model is presented through the SI graph model and the drawing centering on the Bufo gargarizans spawning area

• Journal of Korea Water Resources Association
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• v.52 no.spc2
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• pp.811-822
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• 2019

Environmental flows in the downstream sections of Yongdam Dam, Wonju Stream Dam, and Hongcheon River were estimated with selected target fish species such as Nigra for the site of Yongdam Dam, Splendidus for the site of Wonju Stream Dam, and Signifer for the site of Hongcheon River by considering endangered and domestic species. Physical habitat analysis was performed to estimate environmental flows for the study sites by applying the Physical Habitat Simulation (PHABSIM) and RIVER2D which combined hydraulic and habitat models. Based on the monitored data for ecological environment, the Habitat Suitability Index (HSI) for the target species was estimated by applying the Instream Flow and Aquatic Systems Group (IFASG). In particular, based on the result of fish monitoring, the HSI for each stage of the growth for target species was analyzed. As a result, the Weighted Usable Area (WUA) was maximized at $4.9m^3/s$ of flow discharge during spawning, $5.8m^3/s$ during the period of juvenile, and $8.9m^3/s$ during the adult fish season at the downstream section of Yongdam Dam. The result of the Wonju Stream Dam showed an optimal environmental flow of $0.4m^3/s$, $1.0m^3/s$, and $1.5m^3/s$ during the period of spawning, juvenile, and adult. The habitat analysis for the site of Hongcheon River, which is a non-regulated stream, produced an optimum environmental flow of $5m^3/s$ in the spawning period, $4m^3/s$ in the juvenile stage and $6m^3/s$ in the adult stage.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.3
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• pp.109-118
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• 2015

This study was performed to propose the site selection plan for the restoration of the target Reeve's turtle (Maunemys reevesii) habitat and has developed the AHP model to select the optimal site for Reeve's turtle habitat restoration on the basis of the Reeve's turtle Habitat Suitability Index (HSI) items (factors and variables). The assessment areas were established by the Reeve's turtle HSI factors such as breeding space, feed, cover, water, threatening factors and others and the sub-assessment items by each assessment area were established based on the Reeve's turtle HSI variables. The weighting values of the assessment areas and items were calculated by the developed AHP method. The weighting values of the 5 assessment areas were arranged in order as breeding space(0.293), food(0.273), water(0.217), cover(0.113), and threatening factor(0.104). The final weighting values of the 17 assessment items were arranged in order of height as all kind of food(0.222), water depth(0.096), altitude of spawning ground(0.093). The scoring criteria according to the assessment items and factors were marked and applied by equal intervals considering the criteria by HSI items of the Reeve's turtle and finally the scoring criteria diagram as been proposed for the optimal site selection of the Reeve's turtle habitat restoration.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.51 no.4
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• pp.624-629
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• 2015

To estimate the movement of Pacific cod Gadus macrocephalus in the Korean Southeast Sea, three type tags were used. A total of 97 Pacific cod were tagged and released with either archival tags or conventional tags. Of these releases, commercial fishermen recovered thirteen conventional tags, and five of seven pop-up tags transmitted data to Argos satellites. Pacific cod began to move towards East Sea after release, and they spent most of their time at depths of 100 to 300m, water temperatures of 0.8 to $14.0^{\circ}C$. However, geographical ranges of their movement limited to area around the southern East Sea. Pacific cod attached conventional tag were recaptured near the release site(Jinhae Bay: main spawning ground) about one or two year after release. Data obtained from tagging investigations suggest that they migrated annually from spawning ground to habtat of the Korean Southeast Sea.

• Journal of KIISE:Software and Applications
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• v.26 no.2
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• pp.325-325
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• 1999

This paper presents a locally deterministic abstract machine for a new process model LocPi which is based on a subset of asynchronous polyadic π-calculus and enriched with locations and process mobility. Our calculus has a primitive for migrating and spawning a process to a location(remote site), but does not explicitly represent the place which a process are running at. Running processes may have names attached with their locations and the communication reductions can occur only on located names. So we present how to assign locations to unlocated names. Without a global channel environment, these located names enable us to locate the place which input actions occur at and output messages should be sent to.