Understanding the distribution of seagrass meadows is the first critical step toward their effective conservation and management. This study provides the first comprehensive assessment of Zostera species distribution along the southeastern coast of Korea’s South Sea. The survey encompassed coastal areas from Haeundae in Busan to Changwon, Geoje, Tongyeong, Sacheon, Goseong, Namhae, and Hadong in Gyeongsangnam-do, using local fisheries cooperative questionnaires, boat-based snorkeling, and SCUBA diving. Four Zostera species were identified: Zostera marina, Z. caespitosa, Z. caulescens, and Z. japonica. Among the 162 surveyed sites, Z. marina was the most prevalent, occurring at 140 sites (86.4%), followed by Z. japonica (10 sites, 6.2%), Z. caespitosa (9 sites, 5.6%), and Z. caulescens (3 sites, 1.9%). The total seagrass coverage by Zostera species in the region was 1,174.2 hectares, with species-specific coverage as follows: Z. marina (798.7 ha, 68.0%), Z. japonica (339.4 ha, 28.9%), Z. caulescens (29.0 ha, 2.5%), and Z. caespitosa (7.1 ha, 0.6%). The mean occurrence depths were 2.0±0.1 m for Z. marina and 2.7±0.2 m for Z. caespitosa, with the latter found slightly deeper. Z. caulescens occurred at the greatest depths, averaging 6.8±0.5 m (range: 5.0~8.8 m), while Z. japonica was limited to the intertidal zone. Z. marina predominated in all regions except Busan, while the Nakdong River estuary contained the nation’s largest Z. japonica habitat. Z. caespitosa was observed in Geoje, Changwon, and Tongyeong, whereas Z. caulescens was restricted to Geoje. These findings provide essential baseline data for the conservation and management of Zostera species in Korean coastal waters.

This study investigated the characteristics of fish communities and distribution of endangered species in the mid-upper reach of Geumgang River, Korea, from September to October 2021. A total of 17,177 fish of 11 families and 46 species were collected from 13 survey stations during the survey period. The dominant species was Zacco koreanus (relative abundance of 17.45%), and the subdominant species was Z. platypus (16.73%), followed by Acheilognathus koreensis (8.49%), Hypomesus nipponensis (8.27%), Pungtungia herzi (7.28%), Coreoleuciscus splendidus (6.80%), Gobiobotia brevibarba (6.58%), Pseudopungtungia nigra (4.67%), A. yamatsutae (3.77%), G. macrocephala (3.38%), and Rhinogobius brunneus (3.04%). Among the collected fish species, 21 (45.65%) were identified as Korean endemics, and two exotic species, Lepomis macrochirus and Micropterus salmoides, were also observed. There were six species of endangered species that were designated by the Ministry of Environment (Class I: P. nigra and Liobagrus obesus; Class II: G. brevibarba, G. macrocephala, Hemibarbus mylodon, and Coreoperca kawamebari). H. mylodon is also a natural monument designated by the Korea Heritage Service. The cluster analysis showed that the dominance index was low, while the diversity and richness indices were high, indicating a stable and healthy fish community. The mid-upper reach of Geumgang River has a well-conserved and diverse aquatic environment and is inhabited by many endangered species and natural monuments. Therefore, continuous attention and systematic management are required.

In this study, 41 individuals in 7 locations within CP, MG, UC, and DN map sheets were observed. The MG map sheet had the highest number (n=13) of individuals, while the CP-3 site on the CP map sheet had the lowest number (n=1) of individuals. Land use analysis indicated that the MG site with the highest number of individuals had a high percentage (70.56%) of forest land areas with a small percentage (12.63%) of farmland areas. The CP-3 site with the lowest number of individuals had a small percentage (26.47%) of farmland areas. It also had the highest percentage (32.13%) of residential and commercial areas, covering 19,616 m2. Measurement results of the physical habitat environment for B. karubei indicated a mean substrate of -2.1 (Φm), an average water depth of 63.0 cm, and a flow velocity of 0.2 m s-1. The association rule analysis for co-occurring species revealed that Semisulcospira coreana, Ecdyonurus kibunensis, and Goera japonica had the highest associations among lotic species, while Limnodrilus gotoi and Calopteryx japonica demonstrated the highest association among lentic species.

This study was conducted to collect data from various regions of Jejudo Island, Korea to establish a more accurate and complete academic listing of mushrooms on the island by identifying and organizing them using base sequence analysis. The investigation was performed over five years, from 2019 to 2023, and included a total of nine sites in the southern, western, and eastern areas of Jejudo Island. In total, 481 unique mushroom varieties were collected during the study. These mushrooms included 387 specimens that were classified into 6 classes, 18 orders, 55 families, 118 genera, and 201 species, and 94 unclassified specimens for which the precise species was not known. The collected mushrooms classified by ecotype consisted of 148 species of saprophytes, 47 species of symbionts, and 6 species of parasites. Differences in occurrence patterns were also observed depending on topographical characteristics and vegetation. Finally, three climate-sensitive biological indicator species and two candidate species were also collected, as well as the tropical mushroom Macrocybe gigantea. This study identified 91 species of mushrooms that were previously unreportedon the Jejudo Island. According to the current findings and those previously reported, 7 classes, 26 orders, 123 families, 399 genera, and 1,102 species of mushrooms have been compiled on Jejudo Island to date.

This study presents a fine scale distribution of the endangered species, Odontobutis obscura, through field surveys and literature reviews. Using the mark-recapture method, the population size in major habitats was determined. Field surveys conducted on 18 streams in Geoje Island revealed that the O. obscura was only found in the main streams and tributaries of the Sanyang, Gucheon, and Buchun Streams, which are part of the Sanyang Stream watershed. The O. obscura exhibited relative abundances ranging from 0.5% to 35.3% at different locations, with certain spots showing higher relative abundances (18.8% to 35.3%), indicating major habitat areas. A review of six literature studies confirmed the presence of the O. obscura, although there were differences in occurrence status depending on the purpose, scope, and duration of the studies. Combining the results of field and literature surveys, it was found that the O. obscura inhabits the main and tributary streams of the Sanyang, Gucheon, and Buchun Streams, from the upper to lower reaches. Currently, the O. obscura population in the Sanyang Stream watershed maintains a stable habitat, but its limited distribution range suggests potential issues such as genetic diversity deficiency in the long term. The population size of the O. obscura was confirmed at two specific locations, with densities of 0.5 to 1.5 individuals per m2. The average movement distance from the release point was 13.1 m, indicating the limited mobility characteristic of ambush predators. Understanding the distribution and population size of endangered species is the first step towards their conservation and protection. Based on this information, further research could significantly contribute to the conservation of the O. obscura.