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The burrowing sea anemone, Metedwardsia akkeshi (Uchida, 1932), which was originally described from Lake Akkeshi, Hokkaido, and is the only species in the genus Metedwardsia Carlgren, 1947, was again collected from Akkeshi in 2015 and 2017, many decades after it was first described, and was also collected from Lake Furen and Lake Onne-to, both in Hokkaido, in the 2010s. Although the original description of M. akkeshi was comprehensive, it lacked information about the cnidom and detailed figures of each body part. Here, we re-describe M. akkeshi after thorough analyses of the newly collected specimens in detail, and based on these topotypic specimens, we also re-diagnose the genus Metedwardsia by providing more detailed information about characteristic morphological features and the cnidom. In addition, we discuss the possible location of “Akkeshi Cove”, the site where M. akkeshi was originally collected by Tohru Uchida. [ABSTRACT FROM AUTHOR]

Mud banks (Chakara) of Kerala are calm coastal waters that form in several isolated stretches along the coast usually during the southwest monsoon (SWM) period (June-September). They are characterized by the damping of incident waves, generating localized calm sea environment conducive for fishing activities, while the high monsoon waves create hostile environment in the rest of the region. Here, we present the scientific basis of the yellowish-brown discoloration of water column that occurs off Alappuzha, Kerala annually during the peak and late SWM associated with coastal upwelling-mud bank event. The discoloured waters that occur off Alappuzha associated with these events are locally known as 'pola vellam', which is nothing but diatom blooms. In 2014, pola vellam was actually caused by the bloom of Fragilariopsis (= Fragilaria) sp.; hereafter Fragilariopsis, which was widespread in the study region, even beyond the mud bank domain. This bloom feature is attributable to the nutrient enrichment associated with intense coastal upwelling that was dominant over a larger spatial extent in the study domain, including the mud bank. FlowCAM-based plankton data strongly support the above view, as the abundance, biovolume and biomass of Fragilariopsis had similar temporal trend both in the mud bank and non-mud bank regions. The general ecology and importance of Fragilariopsis bloom in the study domain, from the point of view of commercial fisheries, is also elaborated in this communication. [ABSTRACT FROM AUTHOR]

On the Duuri macrotidal flat along the west coast of Korea, mud sheets exceeding 20 cm in thickness form during summer, and are completely eliminated in the course of the following winter. This cyclical seasonal deposition/erosion of mud on the extensive intertidal flat of Korea has to date not been plausibly explained. To elucidate the responsible mechanism, vertical profiles of suspended sediment concentrations (SSCs) were obtained from March to August 2008 using an ASM-IV, which comprises a vertical array of OBS sensors mounted within a 1.44-m-long pole. The measurements reveal that a high-concentration mud layer begins to develop in mid-May, and reaches concentrations over 10 g/l (fluid mud) by August. SSCs are observed to be generally higher at spring tide than at neap tide. The fluid mud (SSCs >10 g/l) clearly responds to wave action: the calm period being characterized by a two-layer profile, whereas a gradational one-layer profile during the rough summer season. The fluid mud sheet blanketing the exposed flat is supposed to be semi-consolidated mainly by organic processes and solar radiation during low-water slack tide. The differential response of the fluid mud to the variable seasonal wave-energy conditions thus plays a key role in the rapid and widespread formation of ephemeral mud flats in the study area during summer. The available evidence, however, suggests that the summer mud sheet has a very low potential for preservation in the rock record. [ABSTRACT FROM AUTHOR]

The boundary between mud flat and coastal wetland ecosystems is highly productive and a haven of considerable biodiversity. It is also embedded in a highly dynamic environment and can be easily destabilised by environmental changes, invasive species, and human activity. Thus, understanding the processes which govern the formation of this ecotone is important both for conservation and economic reasons. In this study we introduce a simple conceptual model for this joint ecosystem, which demonstrates that the interaction between tidal flooding and habitat elevation is able to produce an ecotone with similar characteristics to that observed in empirical studies. In particular, the transition from mud flat to vegetated state is locally abrupt, occurring at a critical threshold elevation, but, on broader spatial scales can occur over a range of elevations determined by the variability in high tide water levels. Additionally, the model shows the potential for regime shifts, resulting from periods of unusual weather or the invasion of a fast growing, or flood resistant, species. [ABSTRACT FROM AUTHOR]

Dairy cattle spend less time lying and show signs of increased stress when housed in rainy and windy conditions, but no work has separated the effects of exposure to inclement weather from muddy conditions underfoot. Our objective was to evaluate the effects of muddy conditions alone on lying behavior, hygiene, and physiological responses. We housed pairs of pregnant, nonlactating dairy cattle (n = 12; 6 primigravid heifers, 6 multiparous cows) in enclosed pens with dirt floors and a concrete feed apron. Cattle were exposed to 3 levels of soil moisture: 90 (dry), 74 (muddy), or 67% (very muddy) dry matter for 5 d each in a replicated 3 × 3 Latin square design. Lying time was measured on all days with data loggers, and lying locations and postures were recorded on the final day of each treatment. Before and after each treatment, blood samples were collected, and the percentage of dirty surface area was measured on the udder, hind leg, and side of each animal. Cattle spent less time lying down in muddier conditions, especially in the first 24 h of exposure, when cows and heifers spent only 3.2 and 5.8 h, respectively, lying down in the muddiest treatment compared with 12.5 and 12.7 h on dry soil. When the soil was dry, cattle never chose to lie down on concrete, but in muddier conditions they spent a greater proportion of their lying time on concrete (mean ± SE: 56 ± 14 and 10 ± 8% in the very muddy and muddy treatments, respectively). The shift in lying location was more marked for heifers, and all 6 spent ≥87% of their lying time on concrete in the muddiest treatment. When cattle chose to lie down on wetter soil, they limited the surface area exposed to their surroundings by tucking their legs beneath their bodies (mean ± SE: 30 ± 11, 15 ± 4, and 5 ± 2% of lying observations in the very muddy, muddy, and dry treatments, respectively). Despite cattle spending less time on wetter soil, all 3 measured body parts became dirtier in muddier conditions (1.4-, 1.6-, and 1.8-fold more on the leg, udder, and side, respectively, in the muddiest compared with the driest treatment). In addition, higher soil moisture levels resulted in greater reductions in white blood cell counts relative to baseline levels (-0.95, -0.43, and 0.34 × 109/L relative to baseline levels in the very muddy, muddy, and dry treatments). Muddy conditions, even in the absence of wind or rain, are aversive for cattle and have negative implications for their welfare. [ABSTRACT FROM AUTHOR]

The polarimetric characteristics of a mud flat area in the intertidal zone near Jiangsu, China, are analyzed under different environmental conditions using X-band and C-band spaceborne synthetic aperture radar (SAR) data from the TerraSAR-X (TSX) and Radarsat-2 (R2) satellites. The dominant scattering mechanisms of different objects, including mud flats and aquaculture facilities in the intertidal zone, are studied based on the polarimetric target decomposition of fully polarimetric R2 data. The polarimetric characteristics of different objects in the intertidal zone are quantitatively compared using the depolarization parameters derived from the R2 data, which indicate that tides have different effects on the dominant scattering mechanisms of the mud flats and aquaculture farms. Furthermore, comparisons of the C-band and X-band polarimetric characteristics of the mud flats and aquaculture farms in the intertidal zone are analyzed by combining the TSX and R2 data. The results show that surface scattering is the dominant mechanism of the mud flats, whereas different dominant mechanisms occur in the aquaculture areas present during different tides. Interestingly, strikingly similar polarimetric characteristics of mud flats and aquaculture in X-band and C-band SAR are observed, and these novel results were achieved through a depolarization analysis based on the TSX and R2 data in synergy. [ABSTRACT FROM AUTHOR]

A remarkable Middle Triassic (Pelsonian, Anisian) fossil track site at Bernburg in Central Germany permits reconstruction of a tetrapod fauna at the point of recovery when early poposaur quadruped dinosaurs diversificated globally. The site has yielded numerous tetrapod and thousands of arthropod horseshoecrab tracks from several levels in intertidal biolaminites with intercalated storm and seismic-influenced carbonates. The tetrapod tracks, Procolophonichnium, Rhynchosauroides, Chirotherium, and Isochirotherium, are assigned to smaller Archosauromorpha and large Archosauria. The largest chirotheroid tracks Isochirotherium herculis (Egerton in Proc Geol Soc London 3:14-15, ) reach up to 350-mm-long pes sizes and 120-mm-long manus imprints. Those were most probably made by a 5-m-long poposauroid archosaur like Arizonasaurus, based on matching skeleton anatomy and trackways including a new three-dimensional model of those giants in locomotion. A first German poposauroid bone record is added herein with a scapula from shallow marine carbonates of similar Pelsonian ages. These crurotarsan archosaurs were at the top of their food chains globally, and fed most probably on smaller tetrapods ( Hescheleria, Macrocnemus), the latter also represented well by long behavioural escaping Rhynchosauroides trackways. The smaller reptiles may have fed especially on 'Millions' of horseshoecrab eggs in those arthropod reproduction seasons in the intertidal carbonate mud flats. Such tidal flats and sabkhas extended over hundreds of square kilometres surrounding the Germanic Basin in Central Europe in the Middle Triassic, representing a drastic change in the palaeoenvironment of central Pangaea, and a possible trigger for continuing diversification of archosauromorphs and eventually dinosaurs. The horseshoecrab reproduction seasons seem to have caused a food chain reaction along the southern Pangaean (northern Tethys) coast in carbonate mud flats between Northern America, Africa, Europe and China, with possibly long-distance migrations of poposauroids such as Arizonasaurus, whose bones were found in terrestrial to shallow marine carbonate deposits in terrest to coastal context. [ABSTRACT FROM AUTHOR]

Cerithideopsilla is a genus of potamidid snails found in high abundance on sedimentary intertidal flats and beneath mangrove trees on continental shores in the tropical and subtropical Indo- West Pacific region and Mediterranean Sea. Taxonomic revisions have recognized four species, but recent molecular studies have hinted at a higher diversity. Here, we analyse 377 individuals sampled from across the known range and use a combination of molecular phylogenetic (mitochondrial COI and 16 S r RNA, and nuclear 28S r RNA genes), statistical (generalized mixed Yule-coalescent GMYC method) and morphological (shell form) criteria to delimit 16 species. These form four species groups, corresponding with the traditionally recognized species C. alata, C. 'djadjariensis' (for which the valid name is C. incisa), C. cingulata and C. conica. Distribution maps were compiled using museum specimens identified by diagnostic shell characters. In combination with the molecular phylogenetic trees, these suggest an allopatric speciation mode, with diversification centred on the East Asian coastline and northern Australia, and a pronounced gap in the 'eastern Indonesian corridor', an area of low oceanic productivity. There is, however, frequently geographical overlap between sister species and we suggest from several sources of evidence (e.g. presence of C. conica in isolated saline lakes 900 km from the sea) that post-speciation transport by migratory birds has occurred. Nine of the 16 species occur between the Gulf of Tonkin and Hong Kong, so southern China is significant for both the evolution and conservation of Cerithideopsilla species. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 114, 212-228. [ABSTRACT FROM AUTHOR]

A Thick multiple-bed tsunami deposit consisting of sandstones and conglomerates has been discovered and investigated in the Camarillas Formation (~ 130.6–128.4 Ma, Barremian age) in eastern Spain. The tsunami deposit is interbedded within red mudstones deposited in mud flats of a back-barrier system. It crops out along 7 km in length and at its base a great number of dinosaur tracks assigned to sauropods, ornithopods and theropods have been preserved as natural casts; then constituting an exceptional regional megatracksite associated with tsunami deposits. On the basis of sedimentological features and the lateral and vertical architecture of the involved lithofacies, up to five couplets of inflow-backflow deposits, formed by a tsunami wave train, have been recognized overlying the tracks. Although sedimentation mainly took place during backflow currents, inflows led to the removal of sand from a fronting barrier island and the rip-up of lagoonal carbonate and clay pebbles, depositing them in the protected back-barrier lagoon. Its unusually great thickness is interpreted, among others, as being the result of the filling of the previous low topography of the back-barrier lagoon. [ABSTRACT FROM AUTHOR]

To understand the degradation processes of organic matter related to sulfate reduction by Sulfate Reduction Bacteria (SRB) in the tidal flat sediments of Hwang-do and Sogeun-ri, Tae-an Peninsula in Chungnam-do, biogeochemical characteristics were analyzed and highlighted using specific microbial biomarkers. The organic geochemical parameters (TOC, δ13Corg, C/N ratio, long-chain-n-alkane) indicate that most of the organic matter has been derived from marine phytoplankton and bacteria in the fine-grained sediment of Sogeun-ri, although terrestrial plant components have occasionally been incorporated to a significant degree in the coarse-grained sediment of Hwang-do. The concentration of sulfate in pore water is a constant tendency with regard to depth profile, while methane concentration appears to be slightly different with regard to depth profile at the two sites. Especially, the sum of bacteria fatty acid (a-C15:0 + i-C15:0 + C16:1w5) confirms that the these concentrations in Sogeun-ri are related to the degradation of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) compounds from the crude oil retained in the sediments as a result of the Hebei Spirit oil-spill accident in 2007. The methane-related microbial communities as shown by lipid biomarkers (crocetane, PMI) are larger in some sedimentary sections of Hwang-do than in the Sogeunri tidal flat. These findings suggest that methane production by microbiological processes is clearly governed by SRB activity along the vertical succession in organic-enriched tidal flats. [ABSTRACT FROM AUTHOR]

Abstract: The processes of wetting and drying have many important physical and biological impacts on shallow water systems. Inundation and dewatering effects on coastal mud flats and beaches occur on various time scales ranging from storm surge, periodic rise and fall of the tide, to infragravity wave motions. To correctly simulate these physical processes with a numerical model requires the capability of the computational cells to become inundated and dewatered. In this paper, we describe a method for wetting and drying based on an approach consistent with a cell-face blocking algorithm. The method allows water to always flow into any cell, but prevents outflow from a cell when the total depth in that cell is less than a user defined critical value. We describe the method, the implementation into the three-dimensional Regional Oceanographic Modeling System (ROMS), and exhibit the new capability under three scenarios: an analytical expression for shallow water flows, a dam break test case, and a realistic application to part of a wetland area along the Georgia Coast, USA. [Copyright &y& Elsevier]

The concentrations of Cd, Cu, Pb, Fe, Ni and Zn were determined in the different parts of the soft tissues (foot, cephalic tentacle, mantle, muscle, gill, digestive caecum and remaining soft tissues) and three parts of hard tissues or shells (anterior shell, middle shell and posterior shell) of the mud-flat snail Telescopium telescopium collected from Sepang Besar River. From the cluster analysis, the dendrogram shows that the three parts of the shells are clustered separately from the different parts of the soft tissues, indicating different mechanisms and strategies of metal accumulation and regulation of heavy metals in the shells from the different soft tissues. Among the different soft tissues, the dendrogram also shows that the digestive caecum is clustered differently from other soft tissues, indicating that this organ is distinctly high in metal accumulation and this may probably suggest a different route of metal sequestration from the rest of the soft tissues. The metal distribution found in the different soft tissues of T. telescopium is an important knowledge in establishing this mud-flat gastropod as a promising biomonitor of metal contamination and bioavailability for the intertidal area of Peninsular Malaysia. [ABSTRACT FROM AUTHOR]

Abstract: Mineralogical studies, chemical analyses and K–Ar dating were carried out on clay fractions from tidal mud flats along the Lower Saxony coast and its bays to identify material sources and sedimentary processes at this dynamic interface between air, land and sea. From the coast into the bays, sediments are enriched in fine-grained smectite relative to the coarser grained illite, chlorite and kaolinite, due to the weakening of the tidal current energy in the bays. In addition, the study area can be divided into two provinces on the basis of the illite K/Rb ratios and Mg contents. To the west [Schiermonnikoog, Dollart, Ley Bay up to Norderney island], longshore currents carry suspensions from the Belgian and Dutch coasts; to the east [from Langeoog island, Jade Bay to the Helgoland mud area] suspensions from the Elbe and Weser rivers are mixed with submarine reworked glacial sediments, whereas the portion of longshore current suspensions from the west decreases, becoming negligible in the Helgoland mud area off the Elbe and Weser estuaries. The illite K–Ar data vary considerably and fail as source indicators due to differential settling and mixing of the clay material and probably to Ar loss from illite by biodegradation during digestive processes. Only further offshore, outside the zone of dynamic sediment dispersion, do the K–Ar data fit provenance patterns. [Copyright &y& Elsevier]

Tidal channel networks are important factors influencing the morphodynamics of tidal flats and surface sedimentary facies. Here we investigate the relationship between channel distribution and sedimentary facies in Geunso Bay tidal flat, Korea. The tidal channel networks were extracted from a high spatial resolution aerial photograph, and for each sedimentary facies the pattern of tidal channel distribution was compared in terms of fractal analysis, channel density, and distance from the channel. The tidal channels in each sediment facies had relatively constant meandering patterns, but the density and complexity were distinguishable. The second fractal dimension was 1.87 in the mud flat, 1.41 in the mixed flat, and about 1.30 in the sand flat. The channel density was 0.036-0.06 m/m in the mud flat and 0-0.024 m/m in the mixed and sand flat areas. This implies that the tidal channels in the mud flat area represent a complex and dendritic pattern with high density compared to those in the mixed or sand flat areas. The results were used to test the applicability of adjusting sedimentary facies classification generated from interpolation of survey data. We quantitatively estimated the pattern of tidal channel distribution for each sedimentary facies based on a high spatial resolution aerial photograph. We suggest that tidal channel network features can be useful to surface sedimentary facies classification in tidal flats. [ABSTRACT FROM AUTHOR]

Abstract: Spatial variation in biotic and abiotic conditions, and differences in dispersive behavior of different life history stages can result in the formation of zones with different demography for infaunal and epifaunal species within vast intertidal flats. In this study, we evaluated within-mudflat homogeneity of the infaunal amphipod Corophium volutator found in the mud (residents), colonizing artificially disturbed areas (immigrants), and caught in the water column (swimmers) on a large mudflat in the upper Bay of Fundy, Canada. Densities of residents, immigrants, and swimmers were well structured in space (both along and across shore). Occasionally, significant differences in size structure, sex ratio, and proportion of ovigerous females were found at different intertidal levels, but these were short-lived. Comparisons of size and sex structure of residents, immigrants, and swimmers revealed occasional marked differences, with small juveniles and large adult males moving most. However, this size-bias in movement did not translate into zones with different population dynamics, suggesting that ample dispersal, through swimming and drifting in the water column, homogenized the population and masked potential effects of variation in environmental conditions. We therefore conclude that the mudflat represents one homogeneous population. [Copyright &y& Elsevier]

For maintaining the tidal waterways in the Scheldt basin, including the rivers Rupel and Durme and a large part of the Nete catchment, and for ecological monitoring of the mud flats, salt marshes and riverbank vegetation, the Flemish government needs detailed maps of these rivers and their bank structures. These maps indicate not only vegetation types, plant associations and sediment types but also hard structures, such as quays, locks, sluices and roads. Different remote sensing techniques were used to collect the data necessary to produce the required detailed maps. During the months of July and August 2007 an airborne flight campaign took place to collect hyperspectral and LiDAR data of the Scheldt basin and the Nete catchments. These rivers have a total length of about 240 km. The Airborne Imaging Spectrometer for Applications (AISA) Eagle sensor acquired hyperspectral data in 32 spectral bands covering the visible/near-infrared (VIS/NIR) part of the electromagnetic spectrum with a ground resolution of 1 m. A multiple binary classification algorithm based on Fisher's linear discriminant analysis (LDA) was used to map the salt marshes and riverbank vegetation. Ground truth information, that is vegetation and sediment types, together with their geographical locations collected around the time of the flight campaign, was used to train the classifier in the later classification step. Laser scanning was performed using the Riegl LMS-Q560. The LiDAR dataset obtained had a resolution of at least 1 point per m2 and was used to produce a digital elevation model (DEM) that contains all elements of the terrain. From this DEM a digital terrain model (DTM) was derived by applying appropriate filtering techniques. The elevation models were used primarily to derive information on the height, slope and aspect of the banks and dikes, but they also served as expert knowledge in the classification of the mud flats and bank vegetation. Overall, this work illustrates how airborne hyperspectral and LiDAR data can be used to derive highly detailed maps of the sediments, vegetation and hard structures along tidal rivers in large river basins. It also shows how large datasets can be handled in an expert system, in combination with different classification techniques, to produce the required result and accuracy. [ABSTRACT FROM AUTHOR]

Background: Wind setdown is the drop in water level caused by wind stress acting on the surface of a body of water for an extended period of time. As the wind blows, water recedes from the upwind shore and exposes terrain that was formerly underwater. Previous researchers have suggested wind setdown as a possible hydrodynamic explanation for Moses crossing the Red Sea, as described in Exodus 14. Methodology/Principal Findings: This study analyzes the hydrodynamic mechanism proposed by earlier studies, focusing on the time needed to reach a steady-state solution. In addition, the authors investigate a site in the eastern Nile delta, where the ancient Pelusiac branch of the Nile once flowed into a coastal lagoon then known as the Lake of Tanis. We conduct a satellite and modeling survey to analyze this location, using geological evidence of the ancient bathymetry and a historical description of a strong wind event in 1882. A suite of model experiments are performed to demonstrate a new hydrodynamic mechanism that can cause an angular body of water to divide under wind stress, and to test the behavior of our study location and reconstructed topography. Conclusions/Significance: Under a uniform 28 m/s easterly wind forcing in the reconstructed model basin, the ocean model produces an area of exposed mud flats where the river mouth opens into the lake. This land bridge is 3-4 km long and 5 km wide, and it remains open for 4 hours. Model results indicate that navigation in shallow-water harbors can be significantly curtailed by wind setdown when strong winds blow offshore. [ABSTRACT FROM AUTHOR]

A series of experiments investigated the potential role of microbial mats in nutrition of the early settlement stages of Penaeus semisulcatus. From 3 days post-metamorphosis, the microbial mat supported high growth and survival rates in postlarvae, equivalent to that supported by a control diet of Artemia nauplii and mussel. Examination of gut contents indicated that benthic postlarvae feed indiscriminately on the microbial mat. However, when postlarvae were fed separated size-fractions of the microbial mat, only the fraction containing a high concentration of infauna (mainly nematodes) was able to support the same growth as intact microbial mat. This appears to be due to the low nitrogen content (0.4–0.9 mmol g−1) of the various size-fractions, compared to that of infauna (4.0 mmol g−1). The stable isotope composition of the dietary size-fractions and postlarval shrimp tissue supports the hypothesis that the shrimp assimilated C and N primarily from the associated infauna. This may be due to selective feeding that is not apparent from stomach contents, due to rapid digestion of fauna soft tissues, or to differential assimilation of infaunal prey relative to other microbial mat components. The results demonstrate that microbial mats may support survival and growth in early-stage penaeid shrimp postlarvae on intertidal mud flats. [ABSTRACT FROM AUTHOR]

The high salinity of coastal saline field is a key factor limiting the reclamation. Halophytes have been utilized in the reclamation of saline land. The study area is in Yancheng, China. An analysis of the concentrations of Rb, Cs, Sr, and Ba, the ratio of Rb/Cs, and Sr/Ba in soils in autumn shows that the soil of this study area has great homogeneity. Artemisia halodendron, Gossypium hirsutum, and Sesbania cannabina were selected as the reclamation plants in the present study. In order to know the spatial-temporal distribution of soil salinity, the influence of plant-specific vegetation, and the difference of desalination among these halophytes in coastal flat, the authors analyze the soil-layers and seasonal variation in salt ions. Sodium chloride was accumulated in 0--5 cm topsoil with no vegetation during the winter and spring. The effect of desalinization of halophytes is significant. Of the three plant species, Sesbania cannabina has the greatest desalinization. The difference of ions composition of soils covered with various plant species is significant. It can be concluded that halophytes have better amelioration of coastal soil salinity. Special attention should be paid to the selection of plant species and measures to plant and cultivate crops in the reclamation of saline land. [ABSTRACT FROM AUTHOR]

The ecological quality status (EcoQ) of intertidal mudflats constrained by Pacific oyster farming was assessed by single (H’, AMBI, BENTIX and BOPA) and multimetric (M-AMBI and average score) index approaches in the Pertuis Charentais (SW France). Fifteen sampling stations were monitored seasonally for sedimentological features and macrozoobenthos in 2004. Sediments affected by oyster biodeposits showed organic matter enrichment, and sediments from off-bottom culture sites had higher organic matter contents and lower redox potentials than sediments from on-bottom culture sites. Biotic indices consistently registered responses of macrozoobenthos to organic enrichment but there was only partial agreement between single index-derived EcoQs. The average score was better than M-AMBI and single indices for determining EcoQs. Accordingly, oyster farming alters intertidal macrozoobenthic assemblages moderately, and off-bottom cultures cause more disturbance than on-bottom cultures. Hydrodynamics and seasons may interact with culture practices in smothering/strengthening biodeposition-mediated effects through dispersal/accumulation of biodeposits. [Copyright &y& Elsevier]

Intertidal mudflats in Bahrain provide essential feeding grounds for a good number of shorebirds. The spatial distribution of soft-sediment macrobenthic invertebrate assemblages inhabiting a mudflat designated as a natural marine protected area was investigated to characterize shorebird food supplies. Molluscs accounted for 88% of the total macroinvertebrates community, reflecting a dominance of gastropod grazers. Six species of wading birds were recorded feeding in the protected area. Bird disturbance associated with human recreational activities that may interfere with the conservational benefits of this protected area was explored. This study highlighted the crucial need for management plans for protected areas and for further research concerning bird disturbance. [ABSTRACT FROM AUTHOR]

We show that, as previously described, there are conflicts between areas used by people and shorebirds. However, we propose that burrowing organisms add complexity to the shorebird-human interaction that should be taken into account for management and conservation. This is because SW Atlantic mudflats are dominated by high densities (up to 60 crabs m-2) of a strong bioturbator, the burrowing crab Neohelice granulata (=Chasmagnathus granulatus). These crabs affect the habitat use and foraging performance of shorebird species. The two-banded plover Charadriusfalkiandicus feed more in burrow areas whereas the yellowlegs Tringa spp. and the white-rumped sandpiper Calidris fuscicollis tend to avoid burrow areas. We evaluated the effect of human recreational activities on shorebirds, taking into account shorebird-crab interaction, during shorebird migratory periods (November to April) of 2001, 2002, and 2003. This study was performed at the Mar Chiquita coastal lagoon (37° 40′ S, Argentina). Results showed that people only rarely used the extensive soft bottom intertidals dominated by burrowing assemblages of N. granulata because the soft sediments make walking difficult. Therefore, human impact is reduced for the two-banded plover. However, for several migratory shorebirds that also avoid burrow areas, these areas act as suboptimal alternative areas when human impact is important in their preferred habitats. When human activity is low, shorebirds remain foraging in the area but they decrease their feeding intakes. The extensions of burrow areas differ among estuaries and are likely to generate between-estuaries differences as stopover sites for shorebirds. Also, other species that form large burrowing assemblages can have a similar impact on shorebird-human interactions. [ABSTRACT FROM AUTHOR]

As part of the Humber flood defence upgrade works (Urgent works) undertaken by the Environment Agency, the Paull Holme Strays site was identified as one of twelve potential managed realignment sites within the Humber catchment. The site was breached in September 2003, creating 80 hectares of new intertidal habitat. Initial accretion monitoring commenced in December 2003 with annual surveys of invertebrate colonisation commencing in October 2004. The present study gives details of the physical development of the newly created mudflat within the site, together with invertebrate colonisation and benthic community change over time. Comparisons between the newly created habitat and the existing mudflat outside the old sea wall are made. The macrofaunal communities found within the area as a whole are considered to be characteristic of the area with low species diversity, high abundance and small body size. The community within the managed realignment site is still in an early successional stage with low abundance and diversity in comparison with other sites within this part of the Humber. However the community biomass increased considerably between 2004 and 2005. Colonisation within the managed realignment site is still primarily concentrated in the areas around the two breach sites and is thought to be restricted in other areas due to infrequent tidal inundation. [Copyright &y& Elsevier]

Abstract: Network analysis was used to analyse steady-state models of the food webs of two intertidal mudflat ecosystems: Aiguillon Cove and Brouage Mudflat, on the South-Western Atlantic Coast of France. The aim was to highlight emergent properties of food-web functioning in these two ecosystems and to compare these properties with other coastal ecosystems. Both ecosystems imported detritus in parallel to a high benthic primary production. They were characterised by a high diversity of resources. Both also exported living material, leading to a high quality production, quantified as export of Exergy. This export was mainly composed of cultivated bivalves during the cold season for Brouage Mudflat, and of the migration of grazing fish in Aiguillon Cove during the warm season. Their internal organization was characterised by short pathways, high recycling, high redundancy and low net ecosystem production, compared to the other systems selected. These characteristics, encountered in many estuaries, presented less extreme values. [Copyright &y& Elsevier]

Abstract: This study examined the neuroendocrine status of clams on intertidal mud flats in the St. Lawrence Estuary and Saguenay Fjord areas during late gametogenesis. The impact of pollution was determined by a test battery of early stress markers (metallothioneins, heme levels, glutathione S-transferase activity), tissue damage (lipid peroxidation and DNA damage) and morphologic characteristics (age, soft-tissue weight ratio and growth index). Neuroendocrinal status was examined by tracking serotonin and dopamine metabolism, monoamine adenylate cyclase activity in synaptosomes, monoamine oxidase and arachidonate cyclooxygenase activities in relation to gametogenetic activity: pyrimidine synthesis, (aspartate transcarbamoylase activity or ATC), vitellogenin-like proteins and gonado-somatic index. The results show that clam soft tissue weights were reduced at sites close to harbours and higher at sites near domestic wastewater outfalls. The age-to-length ratio of clams was generally higher at impacted sites, suggesting reduced growth. The biomarkers of stress or damage confirmed that oxidative stress, DNA damage, metallothioneins and glutathione S-transferase activity were significantly increased at varying degrees, at the polluted sites. Vitellogenin-like proteins and gametogenetic activity were significantly increased at sites influenced by domestic wastewaters. Furthermore, the clams were still in active gametogenesis and not ready for spawning, as indicated by the concordance of the serotonin/dopamine ratio with vitellogenin-like proteins and pyrimidine synthesis. However, gonadal cyclooxygenase activity was increased at polluted sites and significantly correlated with most of the stress biomarkers, suggesting that the clams were in a state of inflammation rather than at the spawning stage. Finally, a multivariate analysis revealed that the sites were readily discriminated with high efficiency (>71%) and that both neuroendocrine physiological markers and stress responses were identified as the major components, thus explaining the global physiological response of the clams. We conclude that the effects of pollution compromise the clams’ health status and that the initiation of gametogenesis in environments contaminated by municipal wastewaters or harbours contributes to the toxic effects of pollution. [Copyright &y& Elsevier]

Intertidal mudflats are important nursery grounds for juveniles of many fish species. However, they are being used increasingly to farm bivalve molluscs, which produce large amounts of organic “fluff”, overlying the mud. Fish such as sole, Solea solea, hide in this fluff from potential predators, but the energy consumed by respiring the fluff may be high due to its biorheological properties. We developed an ichthyoviscometer. It incorporates a freshly killed fish as a viscometer, and we developed it to measure the rheological properties of fluids and suspensions, including fluff, at scales encompassing those in gill ventilation. We have shown that the rheological behaviour of fluff is close to that of a gel with a yield stress strongly dependent on particulate organic matter concentration ([POM]). This has allowed us to model fluff flow through the gill channels in living sole as a function of fish size and [POM], showing that in a 26-g sole, fluff would halve flow at a [POM] value of 3.2 g l−1, and stop it at 3.4. [ABSTRACT FROM AUTHOR]

Techniques for measurement, modeling, and management of fluid mud are available, but research is needed to improve them. Fluid mud can be difficult to detect, measure, or sample, which has led to new instruments and new ways of using existing instruments. Multifrequency acoustic fathometers sense neither density nor viscosity and are, therefore, unreliable in measuring fluid mud. Nuclear density probes, towed sleds, seismic, and drop probes equipped with density meters offer the potential for accurate measurements. Numerical modeling of fluid mud requires solving governing equations for flow velocity, density, pressure, salinity, water surface, plus sediment submodels. A number of such models exist in one-, two-, and three-dimensional form, but they rely on empirical relationships that require substantial site-specific validation to observations. Management of fluid mud techniques can be classified as those that accomplish: Source control, formation control, and removal. Nautical depth, a fourth category, defines the channel bottom as a specific fluid mud density or alternative parameter as safe for navigation. Source control includes watershed management measures to keep fine sediment out of waterways and in-water measures such as structures and traps. Formation control methods include streamlined channels and structures plus other measures to reduce flocculation and structures that train currents. Removal methods include the traditional dredging and transport of dredged material plus agitation that contributes to formation control and/or nautical depth. Conditioning of fluid mud by dredging and aerating offers the possibility of improved navigability. Two examples—the Atchafalaya Bar Channel and Savannah Harbor—illustrate the use of measurements and management of fluid mud. [ABSTRACT FROM AUTHOR]

The Carillon Formation underlies the Ottawa Embayment, a craton-interior extension of the regional Laurentian paleoshelf, defined today by the Ottawa–Bonnechere Graben. Facies within the embayment during the Middle Ordovician identify a mixed-sediment (carbonate, siliciclastic), tide-influenced, peritidal and schizohaline basin, host to a mosaic of dolomitic tidal mudflats, shallow lagoons or ponds, and channels. Skeletal metazoans were rare, but bioturbation increased with episodic influx of less saline water carrying sand and mud, possibly in response to regional climate change. Stratigraphic analysis reveals that the formation coincides with a third-order eustatic sea level cycle, but higher order stratigraphic patterns show no obvious eustatic link. Instead, a stepwise onlap geometry coincided with local faulting that produced widespread syndepositional sediment deformation. In particular, stages of faulting and post-Carillon erosion are mapped along the present-day trace of a northwest–southeast-oriented lineament, the Gloucester Fault, within the present graben. Other present-day northwest–southeast-oriented faults of the graben may also possess Middle Ordovician histories. Platform-interior tectonism and development of the Carillon Formation coincided with the onset of Taconic deformation along the outer paleoshelf (western Newfoundland). The formation defines the initial stage of foreland basin sedimentation in the embayment. Platform-interior faulting identifies a predisposed structural weakness associated with underlying Neoproterozoic structure, possibly enhanced by a regional structural connection (an ocean-to-onland transform fault system) with the distal (~1200 km), convergent, plate boundary. [ABSTRACT FROM AUTHOR]

Benthic infaunal communities at Mai Po Inner Deep Bay mudflat, Hong Kong were investigated between August 2002 and August 2003. A total of 55 species belonging to 8 Phyla from more than 99,074 specimens were recorded. The species richness varied between 13 at Station B in August 2002 and 28 at Station D in August 2003 with an average of 21 across the mudflat and the species diversity was low [ H′(log2) = 0.7–3.5 with an average H′ = 2.4]. Seasonal variations were also observed through abundance and biomass across the mudflat among the seasons. The abundance density was between 8,977 individuals m−2 at Station D in February 2003 and 77,256 individuals m−2 at Station B in November 2002 and the overall average density was 25,274 individuals m−2 for the four stations. The benthic infauna were dominated by pollution tolerant species at this wetland mudflat. [ABSTRACT FROM AUTHOR]

Nemerteans can experience fluctuating salinity during exposure to low tides in intertidal mudflats. This study attempted to determine if stress proteins (SPs) can be induced in nemerteans exposed to fluctuating salinities under laboratory conditions. Paranemertes peregrina Coe 1901 were collected from intertidal mudflats. The ribbon worms were then acclimated at 34‰ for 3–4 days prior to the salinity stress experiments. For the hyperosmotic experiment, 39 and 44‰ were selected. Salinities of 24 and 29‰ were used for the hyposmotic experiment. Both experiments used 34‰ as the control. Three worms were sampled at 0, 2, 4, 6, 12, 18 and 24 h after incubation at each of the salinities. Weights were recorded before and after the sampling periods to determine water efflux and influx under hyperosmotic and hyposmotic conditions, respectively. SPs detected in the nemertean proteins were separated by SDS–PAGE electrophoresis and identified using Western immunoblots with specific antibodies. SP levels were then quantified by densitometry. Worms from the 39 and 44‰ treatments showed significant weight loss compared with control worms. Worms from the 24 and 29‰ treatments had significant weight gain compared with control worms. SP70 and SP90 were identified. Two‐way analysis of variance showed varying significant effects of salinity, time and the interaction between the two parameters on the induction of SP70 and SP90 in both the hyperosmotic and hyposmotic experiments. Detection of SPs demonstrates their importance in the physiological response of nemerteans to fluctuating salinities. [ABSTRACT FROM AUTHOR]

Abstract: The bivalve Mya arenaria L. is a common inhabitant of intertidal sediments along the southcentral Alaskan coastline. Its current distribution along the Pacific coast of the continental USA, Canada and Alaska has resulted from a series of intentional and unintentional introductions as well as larval transport between points of introduction over the previous century. Despite the apparent success of M. arenaria in intertidal habitats of coastal Alaska, no study has examined its distribution in this environment. We sampled four times over a two-year period (2001–2002) to document the distribution of M. arenaria in intertidal sedimentary habitats of the Copper River Delta and adjacent Orca Inlet (southeastern Prince William Sound), Alaska. Sampling was performed along a gradient of tidal elevations at three sites (Hartney Bay, Eyak and Pete Dahl) chosen to represent the range of physical/chemical settings of protected intertidal sand and mud flats within the study area. Among the three sampling sites, abundance of M. arenaria was lowest at sites near the outflow of the Copper River (Pete Dahl) and highest in areas of higher salinity and water clarity (Hartney Bay and low tidal elevation plots at Eyak). Within each of the two sites located on the Copper River Delta (Eyak and Pete Dahl), abundances of M. arenaria were highest at low tide plots (+1.1 m for Eyak, +1.4 m for Pete Dahl), a pattern consistent with the distribution of M. arenaria within tidal flats in Europe (Wadden and White Seas). For the third site located in Orca Inlet (Hartney Bay), M. arenaria was found at all tidal elevations; however, distinct differences in the distribution of newly recruited M. arenaria (<10 mm shell length [SL]) and older juveniles and adults (>10 mm SL) were evident. Density and growth of M. arenaria in southcentral Alaska were most similar to values reported for the White Sea (Russia); both areas are located at similar latitude and represent the northern extreme of M. arenaria distribution. [Copyright &y& Elsevier]

Cylindrotheca closterium (Ehrenberg) Reiman et Lewin is a raphid diatom widely distributed in mudflat assemblages. Video microscopy showed various movement modalities defined as smooth and corkscrew gliding, pirouette, pivot, rock and roll, rollover, and simultaneous pirouette and gliding. Z-axis projection analysis of images revealed a unique gliding motif with corkscrew motions, which may have important ecological implications for C. closterium movement in muds. The general response to salinity alteration was a decrease in gliding movements with a concomitant increase in other modalities listed above. Short-term responses to salinity change include dramatic alteration in modalities in hypo-saline conditions and cessation of motility in extreme hyper-saline environments. Modality changes were rapid and occurred within 5 s in response to hyper-saline conditions. Hypo- or hyper-saline conditions resulted in decreased gliding speed in standard media. Five- and 15-day acclimation to salinity changes resulted in a progressive reduction in gliding movement, increased non-gliding modalities and increased cell aggregation. Aggregation in hypo-saline conditions was accompanied by a large increase in the polymer extracted by hot bicarbonate- and ethylenediamine tetraaceticacid- fractions of extracellular polymeric substance (EPS), the polymers of which have been implicated in cell attachment/motility phenomena. The monosaccharide profiles of these fractions were altered in response to hypo-saline conditions. In general, monosaccharide profiles showed increased diversity upon cessation of motility and aggregation of cultures. The movement responses of C. closterium in response to environmental changes, accompanied by modifications in EPS, may form part of an adaptive strategy to survive in mudflats and could be useful as bioindicators of environmental changes. [ABSTRACT FROM AUTHOR]

Abstract: From January 1993 to September 1995, Cyathura carinata was a target species of a monitoring programme carried in the Mondego Estuary (Portugal). Being one of the key species of the intertidal mud flats, this isopod was found to be most abundant in a eutrophic area, where seasonal macroalgal blooms usually occur. Its density decreased towards downstream areas, where some Zostera noltii beds exist. At the Mondego Estuary, the present work stated that C. carinata: (a) had a 2-year life span, even though, 80–90% of the individuals died when 1 year old, revealing a strong post-reproduction mortality; (b) produced a single cohort per year; (c) showed continuous growth (with lower rates during winter); (d) evidenced protogynous hermaphroditism and (e) presented a high growth production and a low turnover ratio. A latitudinal gradient reflected in the life features of C. carinata was described. Except for the life span and the frequency of reproduction, which are generally valid for all populations, C. carinata from the Mondego Estuary fitted the characteristics of other populations from the south of Europe. The effects of macroalgal blooms were assessed. Cyathura carinata seemed to temporarily benefit from the presence of macroalgae, due to higher energy resources and more efficient protection against predators. In a long term, algal blooms had negative consequences. It was particularly evident on the recruitment success, which had repercussions in population abundance, and on the secondary production. Therefore, repeated events of algal blooms embracing the distribution areas of C. carinata represent a threat to this species in eutrophic estuaries. [Copyright &y& Elsevier]

Experimental hauls of a small seine for juvenile yellowfin goby, Acanthogobius flavimanus, were carried out on a tidal mudflat in the Shinhama Lagoon, central Japan, between April and June 2001. Immediately before each haul, visual censuses were conducted to evaluate whether juvenile densities estimated from the catches accurately reflected real densities in the area. The densities estimated from the net samples were significantly lower than those determined by visual censuses throughout the study period. The catch efficiency of the small seine for juveniles of ca. 17–40?mm in standard length was estimated as 23–71%, a negative relationship between efficiency and fish length being found. [ABSTRACT FROM AUTHOR]

Venice Lagoon is suffering from a deficit in sediment supply, which results in the progressive destruction of salt marshes and tidal flats [Consorzio Venezia Nuova, 1996]. Nevertheless, some of the intertidal areas are accreting showing morphological changes, which are in contrast with the general trend within the Lagoon. The morphological evolution of Palude della Centrega, a well-preserved and vegetated intertidal area located in the northern part of the Lagoon, was investigated over a period of 3 years. The short-term accretion rate was measured to be 1.52 cm/year and was used to calibrate a three-element box model, Simulation of LIttoral Morphodynamics (SLIM) constructed to predict which of the accounted factors are more relevant to the evolution of the accreting intertidal mudflat.Sensitivity analyses using SLIM on Palude della Centrega suggest that the evolution of the flats is controlled by the balance between wave erosion during Bora events and tidal sedimentation during fine weather. This balance is strongly affected by (1) turbidity of the waters flooding the tidal flats, (2) sea grass density that suppresses wave action and tidal flow and (3) biostabilisation due to microphytobenthos, which enhances stability. [Copyright &y& Elsevier]

Habitat structure is often assumed to be a predictor of habitat function. However, habitat structure may be insufficient to predict the functional significance of a habitat if the level of resources in the habitat is a consequence of the interaction between the habitat structure and physical or biological factors. In this study, we investigated whether depressions in tidal flat sediments generated by stout razor clams, Tagelus plebeius, affect the spatial patterns of pit digging by deposit-feeding burrowing crabs, Chasmagnathus granulata. The pits dug by crabs while feeding overlapped with clam siphon holes at a frequency higher than expected at random, and measurements of pit-digging by crabs integrated over several days indicated a higher frequency of feeding in the sediment of depressions. The daily frequency of pit-digging by crabs in depressions was positively related to the organic matter content of their sediments, but was significantly higher than the frequency of pit-digging away from clam siphon holes only after events of high bedload sediment transport, when the organic matter in the sediments of these depressions peaked. This example demonstrates the conditional nature of the relationship between habitat structure and function by illustrating how a physical process—bedload sediment transport—may introduce variation in the function that depressions play as feeding sites for burrowing crabs. Published information suggests that such conditional responses of organisms to habitat structure: (1) occur in a variety of habitats; (2) involve a variety of structures either of biotic or abiotic origin; and (3) are the consequence of either physical or biological controls that vary in importance according to the general mechanism through which habitat structure affect resources. This broad experimental evidence suggests that the accuracy of predictive models linking habitat structure and function can be improved by incorporating a mechanistic perspective that allows recognition of the potential for conditional responses of organisms to habitat structure. [ABSTRACT FROM AUTHOR]

The usefulness of field-based digital Colour-InfraRed (CIR) photography to quantify concentrations of chlorophyll on the surface of exposed mudflats is investigated. Multiple images, each 626 mm by 467 mm, were acquired during Austral summertime using a Duncantech three-band CIR camera from two areas of mudflat in the upper reaches of Sydney Harbour. Sediment samples were obtained from within the field of view of the camera and their chlorophyll concentration was estimated spectrophotometrically. After the camera images were normalised to compensate for the effects of variations in the intensity of downwelling solar radiation, chlorophyll was estimated for each 0.9 mm square pixel using a suite of five different vegetation indices. Regression analysis was used to determine the strength of the relationship between the index values and the estimates of chlorophyll from the in situ samples. Indices constructed from near-infrared and red bands were found to have the strongest relationships with in situ chlorophyll estimates (R2 ranging from 0.28 to 0.79) and indices derived from near-infrared and green bands the weakest (R2 ranging from 0.16 to 0.22). The vegetation indices highlighted complex small-scale variability in chlorophyll distribution that was not evident in the original camera images. These findings indicate that field-based CIR photography will provide a useful tool for the non-destructive determination of benthic chlorophyll. [Copyright &y& Elsevier]

The intertidal cockle Austrovenus stutchburyi exists in a symbiotic relationship with the mud flat anemone Anthopleura aureoradiata, the latter using the shell of buried cockles as the only available hard substrate for attachment. The cockles are also host to a detrimental larval trematode Curtuteria australis that invades the bivalves through the filtration current, and here we demonstrate that the anemones significantly depress the rate by which cockles accumulate parasites in the field. Along the tidal gradient, the relative parasite load of cockles was lowest where anemones were most abundant, and the area occupied by anemones per square meter sediment surface explained 30% of the spatial variation in infection intensity. At a smaller spatial scale, parasite loads were significantly lower (34%) in cockles from patches with than without anemones at the same tidal height. A field experiment manipulating the density of anemones showed that the rate of parasite accumulation in cockles decreased with increasing anemone density, and that the generally positive relationship between infection intensity and cockle size tended to disappear in the presence of anemones. The results suggest that the anemone-cockle symbiosis is a non-obligate mutualistic relationship in which the former is provided with a suitable substrate for attachment whereas the latter obtains protection against parasitic infections. [ABSTRACT FROM AUTHOR]

Abstract The Gironde mud fields are thin blankets (< 4 m) that extend from the inner to mid-shelf over a restricted area (600 km2 ) and overlie palimpsest sands and gravels seaward of the modern Gironde estuary, south-western France. The bulk of the mud has accumulated over the last two millennia and reflects the complex interactions of: (1) an increasing estuarine supply of suspended particulate matter; (2) resuspension of substrate material by storm events; and (3) biological mixing. The combination of these processes has produced various features within the deposits, related to: (1) the water depth and distance from source of the fine-grained material, which are manifested as a proximal–distal cross-shelf trend, from an area of alternating mud sedimentation (temporary after large river flows) with resuspension by storm events to an area of mud accumulation in deeper water where bioturbation predominates; (2) expansions of the mud depocentres over time, such that they become more remote from sources of coarser shelf sediment, resulting in an upward-fining trend. The lithofacies of the Gironde shelf mud fields exhibit a number of similarities to those of larger scale modern muddy shelves and ancient shallow-water mudrocks; this work provides a detailed description of a facies model for fine-grained shelf sediments deposited under relatively constant sea level. [ABSTRACT FROM AUTHOR]

The Copper River Delta, Alaska is the largest contiguous coastal wetland system along the West Coast of North America. Vast expanses of tidal mud flats formed by sediments carried by the suspended load of the Copper River serve as a connection between the Gulf of Alaska and the extensive network of wetlands, rivers and sloughs of the delta system. In addition to providing habitat for resident fish, shrimp and crabs, these tidal flats serve as critical feeding grounds for up to 5 million migratory shorebirds as well as an entry and exit corridor for three species of commercially fished salmonids. Here we report the first description of the benthic community of these intertidal flats. Between April and September 2000, we conducted three samplings on the Copper River Delta in which we quantified benthic macro-invertebrates inhabiting silt-clay sediments, the dominant substrate in the system, over a range of tidal inundation. Specifically, sampling was performed in two areas on the delta: near the outflows of the Eyak River and Pete Dahl Slough. Pore-water salinity of surficial sediment ranged from 4 psu during peak summer flow of the Copper River to 14 psu in April prior to increased riverine input. Sediment temperatures corresponded to ambient air temperatures with lowest temperatures during the April–September observation period recorded in April (4°C) and warmest in August (16°C). The benthic community of the delta''s tidal flats was characterised by low species diversity and was dominated by the tellinid bivalve Macoma balthica, which reached densities greater than 4000 m−2. Age–length relationship of M. balthica indicated slow growth and longevity of up to 8 years. Polychaete densities, primarily the phyllodocid Eteone longa, were low throughout the study period, reaching a maximum of only 700 m−2 in August. Amphipod densities, primarily the corophid amphipod Corophium salmonis, were high (up to 7000 m−2) only during the August sampling. Spatial patterns of benthic invertebrate abundance were best explained by differences in tidal inundation with longer inundation corresponding to greater invertebrate densities. Temporal changes in abundance of polychaetes, amphipods, and M. balthica recruits corresponded to increases in sediment temperatures. Natural or human-induced changes to M. balthica populations could impact the food web of the delta, which could cascade to larger geographic impacts because of the importance of the delta to migratory species. [Copyright &y& Elsevier]

Presents a method for deriving mean inundation times for a large expanse of intertidal mudflats in Australia. Use of image processing techniques to extract waterlines from two Landsat Thematic Mapper scenes at high and low tides; Use of tidal interpolation equations to generate an inundation time in hours for each cell on the extrapolated Digital Elevation Model.

Thirteen new species and one new genus of poecilostomatoid copepods are described from intertidal mud flats in the central west coast of the Korean Peninsula facing the Yellow Sea. Nine species are found in association with invertebrates: Hemicyclops ventriplanus n. sp. from the decapod crustacean Upogebia major (De Haan); Clausia lobata n. sp. from the polychaete Marphysa sanguinea (Montagu); Presynaptiphilus minutus n. sp. from the ophiuroid Amphiura sinicola (Matsumoto); Synaptiphilus longicaudus n. sp. and Enterophilus cercomegalus n. gen. et n. sp. from the holothurian Protankyra bidentata (Woodward and Barrett); Goidelia pelliviva n. sp. from an echiuroid Thalassema sp.; Lichomolgus bullatus n. sp. from the bivalve Striarca (Didimacar) tenebrica (Reeve); Critomolgus nudus n. sp. from the pennatulacean Virgularia gustaviana (Herklots); and Notoxynus tertius n. sp. from the sea anemone Cerianthus filiformis Carlgren. The other four species are found in stagnant water on the mud flat: Kelleria vaga n. sp., Macrochiron anormalum n. sp., Pseudomacrochiron urostenum n. sp. and Pseudanthessius dentatus n. sp. [ABSTRACT FROM AUTHOR]

Provides information on a study which describes the use of a polyphasic approach to investigate the functional role of sulfur-oxidizing Thiomicrospira species in coastal mud flat of the German Wadden Sea. Materials and methods used on the study; Results and discussion.

The article focuses on the pattern of invasion and the quantitative estimate of change of Spartina townsendii from the mudflats of Poole Harbour in England. The interest in the type of grass is discussed, including its origin, unusual habitat, and possible uses in reclamation and protection of coastal mudflats in the country. The early collections of Spartina species were composed entirely of a plant with sterile stamens. Moreover, a cytological investigation gives corrected chromosome numbers for the different types of grasses.

Spartina anglica (C. E. Hubbard) is a relatively new invasive perennial grass species in Ireland. It is well adapted to the intertidal mudflat environment and forms mono-specific swards. There have been concerns about its potential to impact negatively the ecosystems of mud flats and salt marshes. This ongoing project investigates the ecological effects of S. anglica, and its control, on the mudflats and saltmarsh at Bull Island, and the implications for management of S. anglica. The diversity and density of the macro-invertebrate infauna and some physical factors of the sediment were compared in: a) clumps of S. anglica, b) areas vegetated by Salicornia spp., c) an adjacent area of bare mud, and d) an unvegetated area. Presence of S. anglica had a significant effect on the density and diversity of macro-invertebrate infauna species. The results suggest that clumps of S. anglica can provide a habitat that supports a macro-invertebrate infauna as abundant and species rich as areas vegetated by Salicornia spp. [ABSTRACT FROM AUTHOR]