• Korean Journal of Ichthyology
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• v.32 no.1
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• pp.1-7
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• 2020

Investigations of distribution status and extinction threat evaluation of the Korean endemic species, Iksookimia yongdokensis were undertaken from 2017 to 2018. Among the 22 streams and 97 sampling sites investigated during the study period, samples of I. yongdokensis were collected from 9 streams at 37 sites (from Daejongcheon Stream of Gyeongju-si to Songcheon Stream of Yeongdeok-gun). The appearance of I. yongdokensis was relatively common in streams such as Hyeongsangang River (15 stations), Yeongdeok Oshipcheon Stream (4 stations), Gokgangcheon Stream (4 stations), Chuksancheon Stream (3 stations) and Daejongcheon Stream (3 stations). The main habitat of I. yongdokensis was in pools on flat-land in streams of clean water with slow velocity, and with pebble, gravel and sand bottoms. Previous records of the appearance of I. yongdokensis, indicate they were first seen at seven stations including Jangsacheon Stream, but they were not present in Songcheon Stream. Compared to our results there is evidence as noted for a 38.9% reduction in occupancy within 3 generations (10.5 years), and a decline inhabitat quality. Therefore, I. yongdokensis is now considered vulnerable (VU A2ace) based on the IUCN Red List categories and criteria. The main reasons for the decline were assumed to be dry weathering in the river, the introduction and diffusion of exotic fish species Micropterus salmoides, and river refurbishment project.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.5
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• pp.436-448
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• 1984

The taxonomy of gudgeons of the subfamily Gobioninae in Korea is reviewed and keys to supraspecific taxa (subfamilies and genera) of the subfamily Gobioninae are provided, as well as the synonyms and distribution of the species or subspecies. Abbottina springeri, poorly known in Korea is redescribed with the extention of its known morphological characters and geographical distribution. Squalidus sp. occurring rivers of the Yongdokoship, the Hyongsan, and the Hoeya in the Gyongsangbugdo and in the Gyongsangnamdo differs from three previously described species from Korea in the numbers and structure of lateral line scales, color patterns on the body sides, and eye diameter etc. The genus name of Gonoprcktopterus mylodon should be transferred from Gonoproktopterus to Hemibarbus, because the species is more similar to Hemibarbus longirostris or Belligobio eristrigma than to Gonoproktopterus, an Indian genus of Barbinae. The korean gudgeons of the subfamily Gobioninae are grouped five possible phyletic series, as follow ; Hemibarbus, Pseudorasbora, Sarcocheilichthys, Gnathopogon, and Pseudogobio group. The genus Gobiobotia is not placed in the subfamily Gobioninae but in the subfamily Gobiobotinae in relation to 3 pairs of mental barbels and some osteological characters.

• The Journal of Engineering Geology
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• v.24 no.1
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• pp.91-98
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• 2014

This paper aims to calculate the increase in groundwater quantity following groundwater dam construction, and to assess its impact on surface water. In the study area of Osib-cheon, Yeongdeok, we estimated groundwater quantity, groundwater level, and effective porosity, and examined surface water fluctuations with respect to the increased groundwater quantity based on the flow duration. The results reveal that the increased groundwater quantity was at most $91,746m^3$ in the total drainage basin of the groundwater dam, and the reduced groundwater quantity was at most $11,259m^3$ in the lower zone of the groundwater dam. Therefore, the total groundwater resources secured was $80,487m^3$ and the decrease in groundwater quantity was just 12.27% of the amount of increase. There were changes in discharge rate by up to $3.00{\times}10^{-2}m^3/s$, as deduced from an analysis offlow duration as a result of groundwater dam construction. The overall difference between before and after construction of the dam was almost insignificant compared with the previous dam. The present results indicate that dammed groundwater can serve as an alternative water resource with sufficient quantity.