• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.21 no.1
• /
• pp.11-23
• /
• 2016

An ecological study on subtidal macrobenthic fauna was conducted off the Namhaedo Island, south coast of Korea from July 2012 to April 2013. A total of 247 species of macrobenthos occurred with a mean density of $1,027ind./m^2$ and a mean biomass of $148.7g/m^2$. Polychaetes was the richest and most abundant faunal group that comprised 37% in both total species number and density whereas echinoderms were biomass-dominant faunal group that accounted for 44% of the mean biomass. There was a seasonal variation in the species richness and abundance of macrobenthos with more species in winter and higher density in spring. Mean faunal density was relatively high at the stations near Namhaedo Island, but gradually decreased toward offshore stations. The most dominant species in terms of density was an amphipod species, Eriopisella sechellensis which occurred as a top ranker during three seasons except spring recorded the fourth rank. E. sechellensis showed its high density at the near shore stations of Namhaedo Island, but this species did not occur around the entrance of Gwangyang and Saryang Bays where Theora fragilis and Lumbrineris longifolia showed high densities. In particular, Tharyx sp., recorded high density between Gwangyang Bay entrance and offshore after Sea Prince oil spill, did not occur in the same area during this study period. The bottom temperature and sorting value of the surface sediments were highly correlated to the spatial distribution of macrobenthic fauna from the Bio-Env analysis. From the cluster analysis, the study area has five station groups with more similar faunal affinities from inner area toward offshore area. Based on the SIMPER analysis T. fragilis, Magelona japonica, E. sechellensis, L. longifolia and Paraprionospio cordifolia were mainly contributed to the classification of station groups. From the BPI, benthic communities in the entrance of Gwangyang Bay and Saryang Bay were considered to be in a slightly polluted condition in contrast to the normal healthy community at the offshore of Namhaedo Island. These results suggested that the benthic community of this area should be regularly monitored to assess the health status of this benthic ecosystem.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.6
• /
• pp.853-865
• /
• 2022

In this study, from August to October 2019, we conducted a survey of the spatial distribution and dominant species of macrobenthos on the rocky intertidal zones of 38 specified islands distributed along the southern coast of Korea. On the basis of observation made using 50 × 50 cm quadrats, we identified a total of 80 species, among which, Mollusca were the most abundant fauna, with 54 species that accounted for 67.4% of the total, followed by Crustacea with 15 species (18.7%). The recorded numbers of Cnidaria, Porifera, and Echinodermata species ranged from 1 to 6. In terms of the regional patterns of species richness, specified islands in Yeosu were found to be the most species rich, supporting 61 species, whereas islands in Hadong, Namhae, and Chujado were found to have a similar level of species richness, ranging from 42 to 46 species. Islands in Boseong and Goheung were home to the fewest species, with only 29 species being recorded. At the sampling station scale, we noted a considerable difference in faunal richness, ranging from 6 (St. 6) to 33 (St. 20) species. Among the recorded species, Echinolittorina radiata was identified as the dominant species on 15 specified islands, with the next most abundant species being Tetraclita japonica, considered an indicator species of climate change, which was recorded on 11 islands. In terms of frequency, E. radiata, found on 36 islands, was identified as the most frequently occurring species, followed by Reishia clavigera (30 islands), Mytilisepta virgata (29), Nerita japonica (28), Ligia. exotica (27), and Littorina brevicula (26). Of the 80 species identified, 9, 4, and 2 species of Mollusca, Crustacea, and Cnidaria, respectively, are classified as Marine fauna of accepted foreign export, whereas 50 are Red List species, 44 are species of Least Concern, 3 are Data Deficient species, and 1 species was not evaluated. However, during the survey, we found no Near Threatened or Not Applicable species. On the basis of the findings of this survey, it would appear that the abundance and richness of macrobenthic fauna inhabiting the rocky intertidal zones of specified islands along the southern coast of Korea differ according to different habitat conditions, particularly with respect to the duration of exposure and the extent and properties of the substrata. The findings of this study will provide baseline data for future monitoring and management of specified islands in Korea.

• The Korean Journal of Malacology
• /
• v.23 no.2
• /
• pp.235-243
• /
• 2007

Macrobenthos were collected in each season by SCUBA diving to investigate the benthic faunal assemblages in the coastal water of Chagwido from September 2004 to August 2005. A total of 201 macrobenthos identified, 74 species (37.2%) of Mollusca were found; 43 species of Arthropoda (19.2%); 34 species of Cnidaria (16.7%) and others including 18 species of Porifera (9.8%). Mean density and biomass were estimated to be 455 individual/$m^2$ and 15,565.0 $g/m^2$, respectively. Whereas annelids was predominant in biomass (1,558.8 g), gastropods were the most dominant faunal group in terms of abundance (5,391 individuals) and the number of species. The dominant species were Trochus sacellus, Batillus cornutus, Pagurus gracilipes, and Cantharus cecillei. The seasonal variation of the number of species and individual Mollusca and Arthropoda was observed. There was a slow increase in spring, the peak in summer, and a slow decrease in autumn and winter. The dominance index was the highest in Gosan and lowest in Yongdang. The biodiversity indice (H') were 1.760-3.497 in each station. Mean biodiversity index was 2.858 (H'). The diversity index, the eveness index (E'), and the dominance index (R) were 3.218-3.743, 0.648-0.720, 17.690-22.826, respectively, in each station.

• Journal of Wetlands Research
• /
• v.6 no.1
• /
• pp.57-72
• /
• 2004

Macrobenthic fauna were studied on a tidal flat in Garolim Bay in July 2002, in order to understand their spatial distribution with the surface sediment types. Forty-nine stations were set on the tidal flat. A total of 147 species was sampled with the mean density of $1,140ind./m^2$ and the mean biomass of $157.2g/m^2$. The polychaetes were speices- and density-dominant faunal group with 64 species and the mean density of $791ind./m^2$. Mollusks were biomass-dominant faunal group with $132.0g/m^2$. Major dominant species were two polychaetes, Mediomastus californiensis with the mean density of $374ind./m^2$ and Heteromastus filiformis with $224ind./m^2$. Also mollusks such as Umbonium thomasi, Batillaria cumingi and Ruditapes philippinarum was relatively high in the mean density, showing the density of 45, 42, $32ind./m^2$ respectively. Especially, U. thomas was distributed in the mouth of the bay, where sediment grain size is rather coarse, and R. philippinarum at near tidal channel. Based on the cluster analysis, the macrobenthic community on the tidal flat was classified into seven station groups depending on the benthic environmental parameters(sediment types). Compared with other Korean tidal flats, species richness of Garolim tidal flats is more and less low.

• Journal of Wetlands Research
• /
• v.18 no.1
• /
• pp.58-67
• /
• 2016

This study was performed to investigate the long-term changes in water quality and benthic ecology around the Nakdong River Estuary. The effect of the estuarine barrage on the ecosystem was also evaluated. The water quality was interpreted using the field survey (2013 and 2014) and monitoring data (MOE, 1989~2013) and the macrobenthic-fauna was investigated through analysis of the field survey data (2014) and literatures review (1985~2013). The long-term variation of water quality of Nakdong River generally showed increased nutrient concentration with decreased discharge, while abrupt influence of the barrage construction was not observed. However, the nutrient and organic matter concentration inside the barrage distinctly was higher than the concentration outside the barrage because the mixing of fresh and seawater was limited by the barrage. Especially, in the period of low discharge during winter, the Chlorophyll-a concentration clearly increased more in the downstream inside the barrage, showing the barrage effect. In other words, stagnant effect caused by barrage construction had an effect on the water quality degradation in dry seasons. As for the benthic ecology inside barrage after barrage construction, molluscans and brackish-water crustaceans disappeared. Outside the barrage, benthic ecosystem has deteriorated and the small-sized organic indicative species like Prionospio membranacea, Pseudopolydora kempi, Sinocorophium sinensis became dominant due to several construction such as Myeong-Gi Bridge, Airport construction, industrial complex after the Nakdong barrage construction.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.10 no.1
• /
• pp.38-46
• /
• 2005

This study was carried out to quantify the rates of anaerobic mineralization and sulfate reduction, and to discuss the potential effects of benthic fauna on sulfate reduction in total anaerobic carbon respiration in Ganghwa intertidal flat in Korea. Anaerobic carbon mineralization rates ranged from 26 to 85 mmol $C\;m^{-2}\;d^{-1}$, which accounted for approximately 46 tons of daily organic matter mineralization in the intertidal flat of southern part of the Ganghwa Island (approximately $90\;km^2$). Sulfate reduction ranged from 22.6 to 533.4 nmol $cm^{-3}\;d^{-1}$, and were responsible for $31{\sim}129%$ of total anaerobic carbon oxidation, which indicated that sulfate reduction was a dominant pathway for anaerobic carbon oxidation in the study area. On the other hand, the partitioning of sulfate reduction in anaerobic carbon mineralization in October decreased, whereas concentrations of Fe(II) in the pore water increased. The results implied that the re-oxidation of Fe(II) in the sediments is stimulated by macrobenthic activity, leading to an increased supply of reactive Fe(II), and thereby increasing Fe(III) reduction to depress sulfate reduction during carbon oxidation.

• 한국해양학회지
• /
• v.29 no.3
• /
• pp.304-318
• /
• 1994

Macrobenthic fauna in three Keum-Mankyung-Dongjin Estuaries and their nieghbouring coastal region in the west coast of Korea were sampled as 39 stations with van Veen grab to describe the distribution patterns of macrobenthos. Total 61 taxa from 10 faunal taxonomic groups and 5,636 individuals were collected. Abundance, species number, and faunal composition varied among three estuaries and coastal region. Dominant species from estuaries were similar to each other, but different from those of coastal region. Dominant species in estuarine regions were Prionospio cirrifera, potamocorbula amurensis. Nephtys californiensis, Glycera chiron and Glycinde sp, those from coastal area were Mactra chinensis. Magelona japonica, Owenia fusiformis. Anaitides Korean and Nephtys polybranchia. Two most dominant species in estuaries, Potamocorbula amanuensis and Prionospio cirrifer were not found elsewhere in Korean waters. The patchy distribution of dominant species and low species richness were reflected in the low species diversity Filter feeders were a major component in estuaries. High proportion of carnivores and low percentage of subsurface deposit feeders seemed to be a typical trophic composition in the study area. the distribution pattern of macrobenthos was related with the salinity and sediment types.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.2 no.2
• /
• pp.101-109
• /
• 1997

The present study was carried out to investigate the temporal and spatial changes in species composition and abundance of polychaetes in Lake Shihwa. Macrobenthic fauna were collected from eight sampling surveys performed in March, June, September and December of 1994, March and October of 1995, February and August of 1996, using a modified van Veen grab with 0.1 $m^2$ coverage area. Polychaete worms, the most abundant macrofaunal group, comprised of 1~22 species at each investigation; number of species continuously decreased during the survey period. The mean density of polychaete was $794{\pm}1,275\;indiv.{\cdot}m^{-2}$ and showed a large fluctuation over time. The variation in abundance was mainly coupled with the domination of Polydora ligni occupying 83% in total density. The next dominant species were Pseudopolydora kempi (mean density of 31 $indiv.{\cdot}m^{-2}$) and Capitella capitata (mean density of 23 $indiv.{\cdot}m^{-2}$). Abundant polychaetes in Lake Shihwa are known to be tolerant to sediment pollution. Ecological indices such as diversity (H') and dominance (D) also indicated that the number of species significantly decreased and a few species predominated in Lake Shihwa after the dike construction. The azoic zone were extended from the upper reach of Lake Shihwa to the vicinity of the dike over time. The reduced number of species, predominance of pollution indicator species and development of an azoic zone reflect severe deterioration of benthic environments in Lake Shihwa.

• Korean Journal of Environmental Biology
• /
• v.23 no.3 s.59
• /
• pp.238-249
• /
• 2005

The present study was carried out to apprehend that the pollutants originating from Jinhae Industrial Complex affect benthic polychaetous community in the northern Jinhae bay. An investigation on the macrobenthic community in Jinhae bay was conducted in September, December of 2002 and March of 2003. The benthic fauna showed mean density of 2,151 ind. $m^{-2}$ in September of 2002, 2,427 ind. $m^{-2}$ in December of 2002 and 2,394 ind. $m^{-2}$ in March of 2003. Major faunal groups are polychaetes, crustaceans and mollusks, corresponding to $73.7\%,\;12.0\%\;and\;11.7\%,$ in total mean density during all of the sampling season, respectively. The most abundant species was Lumbrineris longifolia $(24.85\%),$ followed by Tharyx sp. $(21.70\%),$ Mesochaetopterus sp. $(6.20\%),$ Heteromastus filiformis $(5.39\%),$ Prionospio sp. $(5.18\%),$ Clycinde sp. $(4.29\%),$ etc. Tharyx sp. was the highest abundant species in September of 2002, and Lumbrineris longifolia was the dominant species in another sampling seasons. The density and the species number of polychaetes were high around Chori Is. and poor near Jinhae Industrial Complex area. Cluster analysis based on the species composition showed that Jinhae bay could be divided into three regions except in March of 2003. In December of 2002, there are very distinct regions by the cluster analysis. The density of benthic polychaetes in Jinhae bay was higher than that in the other coastal area of Korea, due to the predominance by some of opportunistic species, such as Lumbrineris longifolia, Tharyx sp. and Heteromastus filiformis, etc. It means that the study area were in the process of organic enrichment.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.27 no.5
• /
• pp.549-559
• /
• 1994

Razor clam, Solen (Solen) strictus, was collected between May 1989 and July 1990 on a macrotidal flat, Inchon, Korea. The population sampled at just above mean sea level had a mean density of 126 individuals/$m^2$. Age was determined for 872 specimens by counting annuli, a series of closely-spaced concentric growth lines. According to the fatness index spawning seemed to have occurred once per year in June, and the first recruits for the 1989 year cohort population were found in July. Solen (Solen) strictus on the Chokchon tidal flat reached a shell length of 6.2 cm in four years. Mean growth in shell length can be described by the von Bertalanffy function, which yielded estimates of growth parameters equivalent to $L_{\infty}=81.865\;mm$ shell length and K=0.320 per year: $$L_{t}=81.865(1-e^{-0.320(t+0.487)})$$$$W_{t}=7.173(1-e^{-0.320(t+0.487)})^3$$