Ecological Health Assessments on Stream Order in Southern Han River Watershed and Physical Habitat Assessments

2013 ◽  
Vol 31 (4) ◽  
pp. 440-447 ◽  
Author(s):  
Ji-Woong Choi ◽  
◽  
Kwang-Guk An
Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 956
Author(s):  
Jong-Kwon Im ◽  
Yong-Chul Cho ◽  
Hye-Ran Noh ◽  
Soon-Ju Yu

Volatile organic compounds (VOCs), with negative impacts on the aquatic ecosystem, are increasingly released into the environment by anthropogenic activities. Water samples were collected from five areas of the Han River Watershed (HRW) tributaries, South Korea, to detect 11 VOCs, which were classified as halogenated aliphatic hydrocarbons (HAHs) and aromatic hydrocarbons (AHs). Among the 11 VOCs, 1,1-dichloroethylene, 1,1,1-trichloroethane, and vinyl chloride were undetected. The highest concentration compounds were chloroform (0.0596 ± 0.1312 µg/L), trichloroethylene (0.0253 ± 0.0781 µg/L), and toluene (0.0054 ± 0.0139 µg/L). The mean concentration (0.0234 µg/L) and detection frequency (37.0%) of HAHs were higher than those of AHs (0.0036 µg/L, 21.0%, respectively). The Imjin Hantan River area exhibited the highest mean concentration (0.2432 µg/L) and detection frequency (22.9%), because it is located near industrial complexes, thus, highlighting their role as important VOC sources. However, the detected VOCs had lower concentrations than those permitted by the EU, WHO, USA, and South Korea drinking water guidelines. Ecological risks associated with the VOCs were estimated by risk quotient (RQ); consequently, the predicted no-effect concentration was 0.0029 mg/L, and the toluene and styrene RQ values were >1 and >0.5, respectively. The findings may facilitate policymakers in designing pollution control strategies.


<em>Abstract</em>.—Rivers and streams of the southern United States contain more than 1,800 aquatic species, 500 of which are regionally endemic. At present, 34% of the fish species and 90% of the mussel species in peril nationwide are found in these systems. Declines in these imperiled species are due to many factors, including hydrologic alteration, degraded water quality, loss of instream and watershed connectivity, physical habitat degradation, and the negative effects of nonindigenous species (e.g., predation on, competition with, and hybridization with native forms). In addition, this situation is exacerbated through human population growth, competing water demands, land-use changes, and other interrelated issues. If unchecked, these issues will likely continue to contribute to the imperilment and loss of native species in the region. Of the nine described species and subspecies of black bass, six are endemic to the southern United States: Guadalupe Bass <em>Micropterus treculii</em>, Shoal Bass <em>M. cataractae</em>, Redeye Bass <em>M. coosae</em>, Florida Bass <em>M. floridanus</em>, Alabama Bass <em>M. henshalli</em>, and Suwannee Bass <em>M. notius</em>. In addition, undescribed species and subspecies also exist and all are in need of conservation measures to prevent them from becoming imperiled. In an effort to focus and coordinate actions to support the long-term persistence of endemic black bass populations, local, state, and federal agencies, universities, nongovernmental organizations, and corporations from across the region joined with the National Fish and Wildlife Foundation to form the Native Black Bass Initiative (NBBI). The NBBI provides regional conservation strategies, objectives, and targets to restore and preserve functional processes in those watersheds that support natural habitat conditions and sustainable populations of endemic black bass and other native fishes of the region. Initial actions implemented through the NBBI focus on addressing the conservation needs of Guadalupe Bass in streams of the Edwards Plateau ecoregion of Texas, Redeye Bass in the Savannah River watershed of Georgia and South Carolina, and Shoal Bass populations in the Apalachicola River watershed of Alabama, Florida, and Georgia.


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