• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.8 no.1
• /
• pp.1-13
• /
• 2003

To investigate the community structure and meiofaunal density in seagrass/bare non-seagrass beds, a survey was conducted at three seagrass bed locations in Doomoojin of Baegryongdo, inner harbor of Eocheongdo in May 1999, and Yulim of Dolsando for every month from February to July 1999. Meiobenthic samples were collected from sediments within seagrass beds (SB) and non-seagrass bed (or adjacent to barren sand area, NSB). Nematodes were the most dominant group among representative 13 meiofaunal groups. The sub-dominant groups were benthic for-aminiferans, benthic harpacticoids, and annelids. The highest density of meiofauna was recorded at a seagrass bed of Yulim (7,244 ind/10 $\textrm{cm}^2$ in June), and lowest density was recorded at a non-seauass bed of Baegryoungdo (438 ind/ 10 $\textrm{cm}^2$ in May). For vertical distribution, the highest density of meiofauna was recorded at 0-2 cm depth, and the density abruptly decreased with depth in all stations. The density of meiofauna in size between 0.125 m and 0.25 mm was maximum. Sediment types for the study areas ranged from sandy to sandy mud by the Folk's classification. The density of total meiofauna, the number of taxa, and the density of the dominant groups (nematodes, benthic for-aminiferans, benthic harpacticoids, annelids) between SB and NSB were significantly different. The results clearly showed the importance of seagrass bed as suitable habitat for meiofauna.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.2 no.1
• /
• pp.14-20
• /
• 1997

The southwestern continental shelf of the East Sea, Korea developed mud deposits as a belt in the inner shelf area from Pusan to Pohang. The general surface sediments consist of very poorly to poorly sorted muddy sediment. The differences of physical, geological and geomorphic conditions in the study area may control and produce distinctive foraminiferal populations. To establish a baseline of environment for the muddy sediments in the southwestern continental shelf of the East Sea, 17 stations were sampled and proved to contain 45 species of living benthic foraminifera. Analysis of the foraminiferal populations in cluster analysis recognized to five habitat zones. These habitat zones contain distinctive cooccurrences of the entire occurring species. Foraminiferal community composition appeared to be closely interrelated of water masses, depths, nutrients and sediment characters.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.27 no.4
• /
• pp.492-499
• /
• 2021

In this study, the benthic environmental and microbial community structure were investigated by mixing granulated coal ash(GCA) and contaminated estuary sediments. Estuary sediments and GCA were mixed in a ratio of 8:2 and allowed to interact for 1 month, then sediment environmental factors were investigated. The pH of the experimental sediment was mixed increased to 11. The concentration of DIP(Dissolved inorganic phosphorus) in the experimental case decreased by 30 % compared to the control case, and this should be due to formation of calcium phosphate through the chemical reaction of DIP and calcium which diluted from GCA. The high abundance of Gammaproteobacteria seen in the experimental sediment compare to the control can af ect the DIP reduction. The DIN(Dissolved inorganic nitrogen) concentration increased over two times in the experimental case than the control, and this should be due to the high pH condition and release of NH₄⁺-N from the GCA. Microorganisms related to nitrogen circulation were not identified in both the control and experimental cases. It was confirmed that the GCA were effective in reducing the DIP concentration in contaminated estuary sediment, and that benthic microbial communities were shown to influenced the phosphorus circulation.

• Journal of the Korean earth science society
• /
• v.24 no.7
• /
• pp.635-649
• /
• 2003

Heavy metal concentrations and benthic foraminiferal distributions were investigated in three short sediment cores in order to understand the pollution history in Masan Bay. Sedimentation rates were 0.33 cm/yr, 0.20 cm/yr and 0.33 cm/yr in the inner bay, the out fall of Dugdong sewage disposal plant, and bay mouth, respectively. The rapid increases of copper, zinc and lead concentrations at the core depth of 10 cm the upper part indicated that Masan Bay has been polluted with industrial wastes since the 1940s. Benthic foraminifera in core sediments show that the variations in their distribution were followed by industrial pollution in the bay. The number of individuals and species diversity decreased, whereas agglutinated tests increased upward in the cores with increased heavy metal pollution. These shifts effectd the abundance of few tolerant forms and consequently decreased the species diversity. The opportunistic species Eggerella advena and Trochammina pacifica increased in polluted sediments. These species can be used as an indicator for assessments of environmental quality in Masan Bay.

• Journal of Life Science
• /
• v.22 no.3
• /
• pp.332-339
• /
• 2012

Horizontal distributions and their ecotoxicological implications relating to organochlorine compounds (OCs) were determined in surface sediments sampled from the West Nakdong River. The concentrations of polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), hexachlorocyclohexanes (HCHs), and hexachlorobenzene (HCB) in surface sediments were in the range of 0.57-3.68, 0.41-8.35, 0.63-1.65, and n.d.-0.56 ng/g, respectively. DDTs represent the major OC in the West Nakdong River. Concentrations of PCBs and DDTs correlate with the total organic carbon (PCBs: r=0.874, p<0.001, and DDTs: r=0.762, p<0.05, respectively), indicating that organic content in the sediments is one of the major factors for influencing horizontal distribution of the organochlorine compounds in this river. Examining the potential poisonous character of the surface sediments to benthic organisms according to the sediment quality guideline (SQG), set out by the Canadian Council of Ministers of the Environment (CCME) and the National Oceanic and Atmospheric Administration (NOAA), we found that the concentrations of total PCBs, p,p'-DDD, and ${\gamma}$-HCH were lower than the effects range-low (ER-L) and the probable effects level (PEL). As a result, it is considered that the effect of organochlorines in the region considered on benthic organisms is very low from the perspective of environmental toxicology. However, in terms of the Canadian SQC, p,p'-DDE, p,p'-DDT, and total DDTs, respectively, exceeded the interim sediment quality guidelines (ISQG) and the threshold effect level (TEL) in 30%, 17%, and 19%, respectively, of the sediment samples analyzed.

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 2003.05a
• /
• pp.144-145
• /
• 2003

퇴적물 오염 평가는 크게 화학적 평가, 독성학적 평가 그리고 생태학적인 평가로 나눌 수 있다 (Long et al. 1995) 최근 국내에서도 오염된 연안의 저서환경에 대한 과학적이고 체계적인 평가 방법에 대한 관심이 크게 증대하고 있다. 그러나 아직까지 퇴적물을 비롯한 환경시료에 대한 독성학적인 오염 평가에 대해서는 많은 연구가 이루어지지 못한 실정이다. (중략)

• Proceedings of the Korean Society of Fisheries Technology Conference
• /
• 1996.06a
• /
• pp.284-289
• /
• 1996

• Journal of Wetlands Research
• /
• v.9 no.3
• /
• pp.13-24
• /
• 2007

This study was conducted to confirm if spatial distribution of macrobenthic fauna were related with sedimentary characteristics. Sedimentary characteristics were compared in each community after carrying of community analysis based upon species composition. Macrobenthic animals were distinguished with 4 communities based on the tidal level, of which 3 communities were divided into two groups on the sediment composition. Common species which were presented in all communities, Nephtys californiensis Hartman 1938, Haploscoloplos elongatus Johnson 1901, Glycera sp., Heteromastus sp. Notomastus sp. Timarete amtarctica Mono 1930, Glysinde sp., Lumbrineris japonica Marenzeller 1879 were having different appearance densities at each community area caused by different sedimentary characteristics. But only two species among the common species have a correlation significantly. Temporal variation of common species could not be recognised because of 4 times of seasonal investigation was not enough know their life cycles. So, in the future more frequently sampling method should be required.

• Korean Journal of Environmental Biology
• /
• v.19 no.2
• /
• pp.159-171
• /
• 2001

Community structure, horizontal distribution, density, and ratio between nematodes and benthic harpacticoid copepods of the meiobenthos within the sediments of inner Sihwa Lake were investigated in May 1999 and May 2000. A total of 11 and 8 classes of meiobenthic animals were identified in 1999 and 2000, respectively, which were much lower than other coastal areas. The dominant animals during both sampling periods was the nematodes, followed by sarco-mastigophorans, nauplius of crustaceans, benthic harpacticoid copepods and polychaetes. These five classes of animals comprised more than 90% of total abundance of neiobenthos presented in the samples. In 2000, a lot of polychaete larvae were identified. The most abundant animal were the size that fits in 0.063 mm sieve size. Lower density was observed upper inner part of the Sihwa Lake during both sampling periods, and higher density was observed around the Sihwa floodgates. The average density between those two numbers were observed in the samples collected in the middle of the lake. Lower nematodes to betnhic harpacticoides (N/C) ratio, a relative indicator of environmental pollution, was observed to be lower around the floodgate but higher ratios were observed in the upper inner Sihwa Lake. The present study indicated that inner upper part of the lake becomes unsuitable for the meiobenthos, and the most inner upper lake was considered to be polluted.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.2
• /
• pp.212-223
• /
• 2022

For the remediation and restoration of contaminated sediment at the West Sea-Byeong dumping site, dredged materials was dumped in 2013, 2014, 2016, and 2017. The physicochemical properties and benthic fauna in surface sediments of the capping area (5 stations) and natural recovery area (2 stations) were analyzed annually from 2014 to 2020 to evaluate the capping effect of the dredged materials. The natural recovery area had a finer sediment with a mean particle size of 5.91-7.64 Φ, while the sediment in the capping area consisted of coarse-grained particles with a mean particle size of 1.47-3.01 Φ owing to the capping effect of dredged materials. Considering that the contents of organic matters (COD, TOC, and TN) and heavy metals in the capping area are approximately 50 % lower (p<0.05) than that in the natural recovery area, it is judged that there is a capping effect of dredged materials. As a result of analyzing macrobenthic assemblages, the number of species and ecological indices of the capping area were significantly lower than that of the natural recovery area (p<0.05). The number of species and ecological indices at the capping area were increased for the first four years after the capping in 2013 and 2014 and then tended to decrease thereafter. It is presumed that opportunistic species, which have rapid growth and short lifetime, appeared dominantly during the initial phase of capping, and the additory capping in 2016 and 2017 caused re-disturbance in the habitat environment. In the natural recovery and capping areas, Azti's Marine Biotic Index (AMBI) was evaluated as a fine healthy status because it maintained the level of 2^nd grades (Good), whereas Benthic Pollution Index (BPI) remained at the 1^st and 2^nd grade. Therefore, capping of dredged materials for remediation of contaminated sediment in the dumping site has the effect of reducing the pollution level. However, in terms of the benthic ecosystem, it is recommended that the recovery trend should be monitored long-term. Additionally, it is necessary to introduce an adaptive management strategy when expanding the project to remediate the contaminated sediment at the dumping area in the future.