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Late Holocene diatoms were identified from four sediment cores from the Gonggeomji Wetland in Korea. In total, 52 diatom species belonging to three classes, 21 families, and 29 genera were investig...

In this study, tidal stream energy resources of the Southwestern Sea of Korea were assessed using a numerical model, Modelo Hidrodinâmico (MOHID). This numerical model is based on the finite volume method, which allows numerical experiments on estuaries, coasts, and oceans. For the numerical experiment, we used grid data of at least 90 m resolution by applying bathymetry data created by the Korea Institute of Ocean Science & Technology (KIOST) and FES2012 data as a tidal boundary condition. Strong tidal currents occur in the Southwestern Sea of Korea due to the characteristics of the tidal systems of the West Sea and the South Sea, and the topographical characteristics of a Ria coast. These characteristics were appropriately reproduced by the numerical experiment. Accordingly, the average and maximum tidal currents calculated by the numerical model were used in the assessment. Two regions, Jangjuk and Maenggol-Geocha, were selected as the candidate areas for tidal stream energy development. In addition, the amounts of tidal stream energy resources were evaluated using geographical information system-based spatial analysis by applying the tidal current, depth data, and area of each region. The resource amounts were estimated to be 4,841 MW, with 5,743 tidal stream energy converters (TECs) for Jangjuk, and 3,497 MW, with 3,676 TECs for Maenggol-Geocha.

The west coast of South Korea is characterized by a wide macrotidal area with a maximum tidal range of ∼10 m. The sea surface elevation varies with the tidal phase, which leads to significant changes in the vertical structure of the physical, chemical, and biological properties of the water column, especially when the interaction by waves and/or the freshwater and sediment input from the river increases. Under such conditions, it is difficult to carry out continuous and consistent measurements of the vertical structures of the water qualities using a conventional observation system that is fixed to the seabed or sea surface because the thickness of the water column constantly changes. Based on the demand for long-term observations of the vertical structures of the water properties in macrotidal environments, the Intelligent Buoy System (INBUS) was developed by the Korea Institute of Ocean Science and Technology (KIOST). INBUS is a buoy equipped with an instrument frame, which is similar to other buoys that are fixed to the sea surface. During every measurement, INBUS detects the water depth and sends the frame down to the seabed to measure the water quality at every vertical level set up in the system. For example, if N levels are set in INBUS, the water depth of each measurement is divided by N layers and the instruments in the lifting frame measure the water properties of each of the N layers while they are descending to the bottom. Based on this procedure, the vertical structure of the water column is consistently measured in N layers regardless of changes of the water depth due to tides and waves. The lifting and measuring process is automatically controlled by INBUS once it is set up in the system. In addition, because INBUS allows bidirectional communication through code division multiple access (CDMA), the system can be controlled by stations on land. If the CDMA communication becomes inoperable owing to extreme wave conditions or the buoy is lost because of incidents such as a collision with a ship, the location of INBUS can be tracked by low-earth-orbit satellites.

Glacier retreat is a major long-standing global issue; however, the ecological impacts of such retreats on marine organisms remain unanswered. Here, we examined changes to the polar benthic community structure of “diatoms” under current global warming in a recently retreated glacial area of Marian Cove, Antarctica. The environments and spatiotemporal assemblages of benthic diatoms surveyed in 2018–2019 significantly varied between the intertidal (tidal height of 2.5 m) and subtidal zone (10 and 30 m). A distinct floral distribution along the cove (~ 4.5 km) was characterized by the adaptive strategy of species present, with chain-forming species predominating near the glacier. The predominant chain-forming diatoms, such as Fragilaria striatula and Paralia sp., are widely distributed in the innermost cove over years, indicating sensitive responses of benthic species to the fast-evolving polar environment. The site-specific and substrate-dependent distributions of certain indicator species (e.g., F. striatula, Navicula glaciei, Cocconeis cf. pinnata) generally reflected such shifts in the benthic community. Our review revealed that the inner glacier region reflected trophic association, featured with higher diversity, abundance, and biomass of benthic diatoms and macrofauna. Overall, the polar benthic community shift observed along the cove generally represented changing environmental conditions, (in)directly linked to ice-melting due to the recent glacier retreat.

Ko, D.H.; Park, J.-S., and Lee, K.-S., 2018. Assessment of tidal current energy potential at Uldolmok in the southwestern coast of Korea. In: Shim, J.-S.; Chun, I., and Lim, H.S. (eds.), Proceedings from the International Coastal Symposium (ICS) 2018 (Busan, Republic of Korea). Journal of Coastal Research, Special Issue No. 85, pp. 1301–1305. Coconut Creek (Florida), ISSN 0749-0208. Quantitative assessment for the tidal current energy potential and marine conditions should be preceded to construct the optimal tidal energy farm. Assessment of tidal energy resource at Uldolmok which is the optimal candidate sites for tidal energy farm was carried out. In order to collect the field data, static survey using ADCP(Acoustic Doppler Current Profiler) was conducted and harmonic analysis was done to predict the annual tidal current. As a result, the dominant direction of ebb current was southeast and flood current was northwest. The maximum ebb current speed was about 4.09 m/s. While, annual power density...

Blue carbon science requires the estimates of organic carbon stock and sequestration rate; however, holistic data analysis remains limited in South Korea. The present study reports current organic carbon stocks and sequestration rates in the coastal areas of West Sea, South Sea, and East Sea of South Korea, encompassing entire intertidal areas using long-term field survey combined with remote sensing technology. Twenty-one intertidal flats were targeted across seven provinces (Gyeonggi, Chungnam, Jeonbuk, Jeonnam, Gyeongnam, Gyeongbuk, Gangwon). Out of the evaluated environmental parameters, mud content represented a significant factor controlling sedimentary organic carbon stocks across target areas, and was significantly positively correlated to the total organic carbon (p < 0.05). Organic carbon stocks measured in salt marshes (i.e., upper intertidal zone) reflected the high carbon fixation capacity of halophytes through primary production. Sediment textural type was classified using analysis of remotely sensed imagery, and was closely correlated to field-based classification data (p < 0.05). Using field and remote sensing results, we estimated total organic carbon stocks (13,142,149 Mg C) and sequestration rates (71,383 Mg C yr-1) in the tidal flats of South Korea. This study presents the first report on blue carbon potential in the Korean tidal flats, providing baseline information on the carbon dynamics of intertidal sediments in this region and, potentially, elsewhere.

In order to evaluate water quality and biological productivity, observation data sets were collected and analyzed in Yeongsan River Estuary, Korea. We also set up a numerical model to resolve hydrodynamics and fate of water quality variables in the system. Results show that most of nutrients loading are trapped in the lake and higher concentrations of nutrients and organic matters (OM) are present only inside of the artificial sea dike. There exist episodial discharges at the dam, which coincide mostly with rainfall events during summer monsoon periods. During this discharge event, lower salinity and higher suspended solids, nutrients, and OM are observed in surface layer of the estuarine section. Hydrodynamic model results show that circulation in the estuarine section is governed by freshwater discharge from the lake, resulting in an enhanced two-layer estuarine circulation being dominated, during and after the freshwater is discharged. Such two-layer estuarine circulation combined with higher concentration of nutrients in the surface layer results in that outfluxes of nutrients in the surface layer dominate over the influxes in the bottom layer during summer high precipitation periods. Meanwhile, numerical dye experiment results show that the discharged water with elevated nutrients levels have a short residence time (∼5-10 days) in the estuarine section. Due to this fast flushing rate, excessive nutrient loadings are not used to produce biological matters in the estuarine section. This limited biological productivity, characterized by seaward side of the artificial sea dike, makes Yeongsan estuarine system excluded from acting as an active carbon sink.

While there have been many reports of the species ‘Berkeleya scopulorum’ from Northeast Asia mainly as Navicula scopulorum, the observation of the living specimen of the species has revealed that the species should be the member of the genus Climaconeis. Here we describe the species as Climaconeis mabikii sp. nov. based on microscopic observations by means of both light (LM) and scanning electron microscope (SEM). As part of the review, the regional distribution of C. mabikii as well as the worldwide biogeography of the taxa belonging to the genus Climaconeis are discussed. Newly described C. mabikii from the present study is the seventeenth member of the genus. The discovery of the true identity of the diatom identified for a long time as ‘Berkeleya scopulorum’ and its description as a new Climaconeis species contributes to the proper appreciation of the diversity of the Northeast Asian diatom assemblage and fills old gaps in the published records.

Sedimentary organic matters in the typical intertidal areas were investigated to address year-round monthly distributions and site-specific sources. Target areas included four natural tidal flats (Ganghwa, Garolim, Sinan, and Suncheon) and one artificially closed estuary (Nakdong River), South Korea (in 2018). Among the parameters monitored, mud content was a key factor controlling organic matter contents, across varying habitats, with significant positive correlations to total organic carbon (TOC, r = 0.66, p

The species composition of tidal pool fish on the coasts of Jeju Island was preliminarily investigated for the first time, looking at tidal pool fish diversity by sampling relatively large tidal pools (n = 7, 28.3–326.9 m2 in area) in four regions. Fifty species belonging to 23 families (20–37 species per region) were collected, including a single unrecorded species. The most speciose family was Gobiidae (eight species) followed by Pomacentridae (seven species) and Blenniidae (six species). Yerae (southern coast) exhibited the most diverse composition with 37 species, whereas Oedo (northern coast) had the least with 20 species. Ten species were collected across all four regions. In spite of the short study period, the species richness of Jeju Island is high, and thus we can now better understand the biodiversity and ecological importance of the intertidal zone, particularly in tidal pools. However, direct comparisons of fish diversity between similar studies would not be proper considering the differences in environments. Therefore, comprehensive and intensive research is required into the rocky marine biodiversity of this island, including tidal pools, to better understand the fish diversity.

Trophodynamics of intertidal mudflats are significantly driven by microphytobenthos (MPB) production but spatial and temporal dynamics of this production source is poorly known. To understand the temporal dynamics and spatial heterogeneity of intertidal MPB, benthic chlorophyll a, phaeopigments, and sediment properties were determined in Gyehwa (sandy) and Gwanghwal (muddy) tidal flats of Saemangeum area over a year at 97 stations. This study set out to: (i) characterize the spatial-temporal patterns in MPB biomass on a year-round basis, (ii) identify the abiotic and biotic factors associated with MPB distributions, (iii) investigate the use of satellite-derived chlorophyll a data and verify with in field measurements, and (iv) determine minimum required sample size for in situ biomass measurement. Concentrations of benthic chlorophyll a and phaeopigments were greater in winter and spring with a high magnitude of variance than in summer and fall at both areas. Benthic chlorophyll a and phaeopigments tended to decrease approaching lower tidal zone, being associated with the corresponding decrease in shore level and/or exposure duration. Compared to available data on macrozoobenthos distribution, the spatial variation of microalgal biomass seems to be attributed to distribution of deposit-feeders. A significant positive correlation (p < 0.001) between in situ MPB biomass and satellite-derived normalized difference vegetation index (NDVI) values was observed, but was much weaker in the lower tidal zone. Mirroring algal heterogeneity, the minimum required sample size for in situ biomass measurement were greater in blooming season and sandy bottom, suggesting that sampling design for spatio-temporal mapping of MPB should consider the sampling season and/or abiotic and biotic features of study area. Overall, spatio-temporal dynamics of intertidal MPB seem to be influenced by a combination of abiotic and biotic factors.

The Maenggol Channel and Uldolmok Strait, located on the south-west coast of Korea, have notably strong and complex currents due to tidal effects and to local geological factors. In these areas, electric power has been generated using strong tidal currents, the speed of which is more than 3 m/s during spring tides. The region also provides a shortcut for navigation. These tidal conditions are therefore sometimes useful, but may also cause terrible accidents or severe economic damage, in the absence of accurate information regarding ocean conditions. In April 2014, the passenger ferry MV Sewol capsized in the Maenggol Channel, with 295 passengers killed and 9 still missing. While this was unquestionably a man-made disaster, strong currents were one of the contributing causes. It was also difficult to conduct scuba diving rescue operations given strong current speeds, and accurate prediction of the time when the tide would turn was thus critically needed. In this research, we used the high-resolution coastal circulation forecasting system of KOOS (Korea Operational Oceanographic System) for analysis and simulation of strong tidal currents in such areas with many small islands, using measurements and modeling from this research area. For accurate prediction of tidal currents, small grid size-modeling was needed, and in this study, we identified a suitable grid size that offers efficiency as well as accuracy.

The Shihwa Coastal Reservoir (SCR) was created to supply agricultural water during the construction of dikes for land reclamation, with this project representing a striking example of policy failure regarding tidal flat reclamation in Korea. After the completion of dike construction in 1994, the water quality inside the SCR drastically deteriorated. As a result, in 1996, the sluice gates were opened to dilute water pollution levels through the physical mixing of seawater from outside and freshwater from inside. Over the last 20 years, the Korean government has invested more than US $ 1.5 billion to recover SCR water quality by improving public sewage treatment systems, which is 2.7 times the cost of the original dike construction. Yet, within the reservoir, water quality has minimally improved, sediment pollution continues to be detected, and anoxic layers have been observed, due to stratification in summer. Severe sedimentary pollution caused by heavy metals and trace organic pollutants originating from the upstream regions of the watershed was evident during the SCR project; however, pollution levels appeared to decrease after seawater circulation. In parallel, the pelagic and benthic communities have also been affected by the deterioration of multiple water and sediment quality indices. While the recent construction of the tidal power plant has significantly increased the volume of seawater circulation, it has not been enough to improve the water quality of the upstream region of the SCR, where the water remains polluted. The SCR project presents a clear example that how incorrect policy leads to the mishandling of both coastal ecosystems and substantial governmental budgets.

A comprehensive review of benthic macrofaunal studies conducted along the west coasts of Korea over the last 40 years has been made by providing the most updated checklist of the Korean marine benthic invertebrates. Tidal flats were the very habitat of interest with inclusion of subtidal areas. As part of review, a critical re-identification of taxa is provided together with the analysis of faunal assemblages and the regional distribution of the species. A total of 624 species belonging to ten phyla has been compiled from 72 references. The phylum Annelida was found to comprise most taxa (n = 248) followed by Mollusca (n = 196) and Arthropoda (n = 135). While annelids prevailed in the subtidal area compared into intertidal, mollusk and arthropod species prevailed in the intertidal. Among 17 regions across the west coast of Korea, the Incheon exhibited the largest number of macrobenthic animals (n = 272) followed by the Jeonjupo where 173 species have been reported over the past 30 years. More than half of all species compiled are reported from one region only while certain opportunistic polychaetes e.g. Heteromastus filiformis widely distributed across the coast. Overall, we suggest that future macrozoobenthos studies in Korea should focus on long-term changes by broadening target species and regions that fully covered along the entire coast of Korea.

The present article presents a historical overview and key findings in the studies of microphytobenthos (MPBs) in Korea, supporting a biodiversity of the Korean tidal flats. The common internationally recognized topics relating to the tidal flat MPBs were found to be assemblages, dynamics, production, and food web etc. in chronological manner. Accordingly the review on the Korean MPBs studies was provided in the given topics, highlighting pros and cons of individual scientific efforts and data. Especially, the brief summary from the several representative works (selected based on citations) related with the corresponding topics were provided as for comparison, if applicable. The world studies of tidal flat MPBs over the past 100 years generally reflected the subjects being balanced followed by logical development of each topic. Although over 50 years of scientific gap between Korea and the European countries were evidenced historically, a rapid scientific advancement in recent 10 years would be noteworthy. A topic of floral assemblages was found to be steady issue in Korea, with documented MPBs of >400 species (ca. 10 new species) from the Korean tidal flats. As part of review, we reanalyzed our selected data from the previous and current MPBs works encompassing above 4 topics, where our key ecological findings were highlighted. Finally, future research direction was carefully discussed by comparative analysis between worldwide versus Korean studies in various aspects. Overall, the future MPBs studies in Korea would be promising to support unique biogeography in Asian tidal flats, yet with certain limitation in scientific recognition and/or methodological weakness.

The present article presents a historical overview of the Saemangeum reclamation projects and key findings from the ecological studies of the Saemangeum tidal flat, highlighting the ecological impact against the grand reclamation project, as a model example, in Korea. First, the scientific efforts given to the area of interest, mainly the inner part of the dikes, during the construction periods of series of four dikes (1991–2006) were summarized in terms of the change of environmental condition followed by the ecological responses over the past 20 years. As part of review, we selected and reanalyzed our series of the Saemangeum data including the current works relating to the microphytobenthos and macrozoobenthos, where the spatio-temporal variations cross the benthos in association with dike effects were carefully discussed in detail. The species composition in the upper intertidal zone, situated relatively far from the dikes, have been lesser changed between the periods of before (1988) and during the dike construction (2003–05). However, the benthic assemblages appeared to be changed in the mid to the lower intertidal zones of several transects and such phenomenon strengthened for the locations near the completed dike, e.g., Sandong transect near the dike of sector IV. Meanwhile, changes of the representative zoning in benthic assemblages during the dike construction were much clearly observed for the faunal species rather than flora. Such long-term ecological impacts including the timely increase of the opportunistic species during the dike construction were further evidenced the compositional change of the dominant benthos spanning two decades or so. In general, a long-term change in benthic community structure clearly reflected the community level impact apparently due to the attenuation of tidal energy by the embankment, varying the degree of impacts depending on the geographical location. Interdisciplinary monitoring and modeling studies are highly recommended to track natural variations in water quality and ecosystem health. Overall a long-term ecological monitoring should be applied to direct sound policy toward conservation of tidal wetlands, by emphasizing the significant biodiversity decline and coastal landscape depreciation.

Kwon, B.-O.; Koh, C.-H.; Khim. J. S.; Park, J.; Kang, S-G., and Hwang, J.H., 2014. The relationship between primary production of microphytobenthos and tidal cycle on the Hwaseong mudflat, west coast of Korea. The present study examined variation in sediment temperature and irradiance with respect to microphytobenthos primary production at the Hwaseong mudflat, west coast of Korea, under different tidal cycles. The study was carried out during March and April 2009, which encompassed two spring tides and one neap tide. It was not possible to continuously measure primary production in situ across the tidal cycles; hence, photosynthesis–irradiance (P-I) curves at different temperatures were obtained experimentally in the laboratory. These readings were then used to calculate primary production, by projecting in situ mooring records of irradiance and temperature onto the P-I curves. The sediment temperature and irradiance were measured continuously, and the averages of 10-minute intervals from the mo...

We report the first record of partial albinism in Dictyosoma rubrimaculatum, collected from Jeju Island, Korea, in July 2015. This specimen has yellowish white coloration of the body, head, and all fins, except for dark stripes on the snout and anterior region of the opercle, dark blotches on the anterior tip of the lower jaw, black eyes, and small melanophores on the posterior region of the body.

We extensively reviewed the macrozoobenthos around Dokdo, Korea, by analyzing metadata collected over the past 50 years. The Dokdo macrozoobenthos was represented by 578 species belonging to 243 families from 12 phyla, where four major phyla (or classes) collectively accounted for 86% to total. Mollusks, arthropods, and cnidarians were semi-equally occurred in intertidal and subtidal areas, while polychetes dominated the subtidal zone. The northern most region of Dokdo had the greatest biodiversity (173 species). The taxonomic distinctness analysis (delta +) indicated a close association between species by region, although the number of species varied greatly. About half of the species did not occur cross the locations (n = 20), indicating strong habitat preferences of Dokdo macrofaunal assemblages. Overall, the diversity of Dokdo was greater than that of Ulleung Island (east coast), but comparable to that of the well-developed tidal flats in the western Korean waters, highlighting its status as a biodiversity hotspot.

Uldolmok waterway, located between an island off the southwestern tip of Korean peninsula and mainland, is famous for its strong tidal current that has a maximum current of about 6.0m/s. A series of field observations along with numerical modeling have been carried out in order to understand the tidal dynamics in terms of the force balance along the whole waterway and the energy balance in the narrowest part of the waterway. First, analysis of the ADCP current and the tide level variation data reveals that the tidal dynamics along the total waterway (channel) is balanced dominantly between the pressure gradient and linear bottom frictional forces, with the phase lag of sea level difference for the semi-diurnal constituents leading the current phase about by 10°. Secondly, the result of the numerical modeling reveals that the tidal energy flux vector flows toward the narrowest section, indicating that there should be related nonlinear processes. Through the numerical model experiment with multi-components, the convergence of (M2 + S2) tidal energy flux of 6.68 × 107 Joule/s in the narrow area of the Uldolmok waterway is explained mainly by the energy consumption of 73% through the nonlinear generation of shallow water components and by the bottom frictional energy dissipation of 27%. This reveals that the remarkably strong nonlinear process dominates in the narrowest section of the Uldolmok waterway, compared with other areas, such as Yellow and East China Seas where the total M2 energy flux through the open boundary is balanced in terms of the bottom dissipation (Kang et al. 2003; Choi 1980).

The short-term variability in microphytobenthos (MPB) production, measured by the oxygen microprofiling method, found under different experimental conditions indicated an endogenous production response reflecting in situ diel and tidal conditions. MPB production was measured for submerged core samples (collected from Daebu mudflat, Korea) at a fixed irradiance and temperature in the laboratory under the conditions of (1) constant light (data-I), (2) light–dark incubation (data-II), and (3) in situ reflected (data-III). The experimental design aimed to characterize within-day, across-day, and long term changes in MPB production. Our results showed that, under constant light conditions for 72 h, temporal fluctuations in MPB production (day:night = 2.4:1) were clearly present for three consecutive days (data-I), indicating a diel rhythm in production. Production increased at the beginning of light exposure, and dramatically decreased at the time of submersion, indicating tide-dependent rhythm in production. Furthermore, over a 10 d period under the same light and temperature conditions, a weakening (declining) trend in production was observed, which was logarithmic with diel fluctuation ( r 2 = 0.995, p 14 h /D 10 h ) incubation period across an additional 18 d of measurement (data-II). The decline in production was slower, and more linear ( r 2 = 0.930, p 10 h ) seemed to allow the community to recover to a certain level of production. Finally, the effects of tidal condition (spring tide vs. neap tide) and biomass (dense vs. lesser dense) on the short-term (

A study was performed to better understand the taxonomy and diversity of the diatom genus Amphora (Bacillariophyceae) from Korean coastal environments. Samples were taken from six locations at Saemangeum tidal flats on the west coast of Korea. Light microscopic (LM) and scanning electron microscopic (SEM) observations revealed a total of 23 Amphora species. Thirteen were identified to the species level, and ten to the genus level. Three Amphora species viz. A. arenicola, A. beaufortiana and A. maletractata var. constricta were recorded for the first time in Korea. All the Amphora species were listed and presented with morphological descriptions, dimensional information and photographic information.

Perfluorinated compounds (PFCs) in water, sediment, soil, and biota collected from estuarine and coastal areas of the north Bohai Sea, China, were determined by use of HPLC-MS/MS. Significant concentrations of PFCs were found in water (mean: 18.4 ng/l) and biologic samples (fish: 265 ng/g dw), while concentrations of PFCs in soils and sediments were less. The predominately detected compound was perfluorooctanesulfonate (PFOS), with a maximum concentration of 30.9 ng/l in water and 791 ng/g dw in fish. Concentrations of PFCs were significantly greater in the Liaohe River system than other locations, which suggests point sources in this urbanized and industrialized region. PFOS concentrations in water and biota were both less than the reported threshold concentrations. Detection of PFCs at relatively great concentrations in various environmental matrices from this region suggested that further studies characterizing concentrations of PFCs, their sources and potential risk to both humans and wildlife are needed.

Estuarine tidal flats are both ecologically and economically important, hence developing methods to reliably measure ecosystem health is essential. Because benthic fauna play a central role in the food web of tidal flats, in this study we set out to quantitatively describe the intertidal zonation of macro-invertebrates and their associations with specific environmental parameters along three transects in the Saemangeum tidal flat, Korea. The abundance and biomass of intertidal fauna with respect to five environmental parameters (i.e., shore level, mud content, coarse sand content, water content, and organic content) were measured, to identify environmental factors that influence macrofaunal distribution in intertidal soft bottom habitats. A total of 75 species were identified, with dominant species showing distinct zones of distribution along all transects. The number of species recorded in each transect was found to be dependent on sediment characteristics and salinity. Cluster analysis classified the entire study area into three faunal assemblages (i.e., location groups), which were delineated by characteristic species, including (A) ‘Periserrula–Macrophthalmus’, (B) ‘Umbonium–Meretrix’, and (C) ‘Prionospio–Potamocorbula’. Four environmental variables (i.e., shore level, water content, mud content, and organic content) appeared to determine factors that distinguished the three faunal assemblages, based on the discriminant analysis. The faunal assemblage types of the sampled locations were accurately predicted from environmental variables in two discriminant functions, with a prediction accuracy of 98%. It should be noted that the zonation of benthos in the lower section (C) of Sandong had been affected by the construction of a nearby dike, while this parameter had remained essentially unchanged at the other two location groups (A–B). Overall, the zonation of benthos from the Saemangeum tidal flat was explained adequately by the measured environmental variables, implying that faunal assemblages are closely associated with certain combinations of abiotic factors. The identification of such reliable associations may facilitate the development of statistical models to predict faunal distributions based on environmental variables at both local and regional scales. The entire study area was embanked in 2006 (one year after this study), and an integrated plan was set into force to develop claimed land into industrial, residential and agricultural districts, which also included a partial restoration program of the tidal flats located near to the study area.

This study aims to contribute to the development of heuristic statistical models, which are able to predict benthic macrofaunal responses to environmental gradients in coastal areas, such as tidal flats. Ecological response surfaces were derived for 15 intertidal macrobenthic species, using logistic regression based on three separate environmental parameters (shore level, mud content, and organic content) measured on the tidal flats of the Saemangeum estuary, Korea. The presence/absence of the 15 intertidal macrofauna was accurately predicted from each separate environmental factor in the environmental models, with a prediction accuracy of ~65–92%. Subsequently, geographical comparison was made between the mapped probability surfaces and maps of observed species occurrence. The results indicated that the models developed for different species exhibited a wide variety of functional forms, highlighting potential variability in species response to changes in habitat conditions, even for closely associated species with a similar trophic type. Our modeling approach was capable of predicting macrobenthic species distributions with a relatively high degree of accuracy, although the ecological processes controlling intertidal macrobenthic distribution could not be fully determined. Overall, good agreement between modeling results and field observations, with relatively high concordance regardless of target species, emphasized that such an approach would be of practical use in terms of ecosystem approach to tidal flat management.

School of Earth and Environmental Science (Oceanography), Seoul National University, Seoul 151-742, Korea; (present address: University of Rostock, Institute of Biological Sciences, 18051 Rostock, Germany); jinsoonpark@snu.ac.kr Lake Biwa Museum, Oroshimo 1091, Kusatsu, Shiga 525-0001, Japan. ohtsuka@lbm.go.jp School of Earth and Environmental Science (Oceanography), Seoul National University, Seoul 151-742, Korea. kohch@snu.ac.kr