scholarly journals Sediment Bulk Density Effects on Benthic Macrofauna Burrowing and Bioturbation Behavior

2021 ◽  
Vol 8 ◽  
Author(s):  
Lauren E. Wiesebron ◽  
Natalie Steiner ◽  
Claudia Morys ◽  
Tom Ysebaert ◽  
Tjeerd J. Bouma
Keyword(s):  
Grain Size ◽  
Bulk Density ◽  
Benthic Macrofauna ◽  
Hediste Diversicolor ◽  
Sediment Grain Size ◽  
Sediment Reworking ◽  
Sediment Compaction ◽  
Scrobicularia Plana ◽  
Lower Bulk Density ◽  
And Behavior

Benthic macrofauna are a key component of intertidal ecosystems. Their mobility and behavior determine processes like nutrient cycling and the biogeomorphic development of intertidal flats. Many physical drivers of benthic macrofauna behavior, such as sediment grain size, have been well-studied. However, little is known about how sediment bulk density (a measure of sediment compaction and water content) affects this behavior. We investigated the effect of bulk density on the burrowing rate, burrowing depth, bioturbation activity, and oxygen consumption of bivalves (Limecola balthica, Scrobicularia plana, and Cerastoderma edule) and polychaetes (Hediste diversicolor and Arenicola marina) during a 29-day mesocosm experiment. We compared four sediment treatments consisting of two sediments of differing grain size classes (sandy and muddy) with two bulk densities (compact and soft). Overall, bulk density had a strong effect on benthic macrofauna behavior. Benthic macrofauna burrowed faster and bioturbation more intensely in soft sediments with low bulk density, regardless of grain size. In addition, L. balthica burrowed deeper in low bulk density sediment. Finally, we found that larger bivalves (both C. edule and S. plana) burrowed slower in compact sediment than smaller ones. This study shows that benthic macrofauna change their behavior in subtle but important ways under different sediment bulk densities which could affect animal-sediment interactions and tidal flat biogeomorphology. We conclude that lower bulk density conditions lead to more active macrofaunal movement and sediment reworking.

scholarly journals Bioaccumulation of heavy metals by the flora and benthic macrofauna of the Bouregreg estuary wetland

2018 ◽  
Vol 149 ◽  
pp. 02054
Author(s):  
M. Khamar ◽  
E. Cherkaoui ◽  
A. Nounah
Keyword(s):  
Heavy Metals ◽  
River System ◽  
Benthic Macrofauna ◽  
Organic Chemical ◽  
Benthic Species ◽  
Hediste Diversicolor ◽  
Estuarine Ecosystem ◽  
Water And Sediment ◽  
Dominant Plant Species ◽  
Scrobicularia Plana

Estuarine systems account for a high proportion of wetlands in Morocco due to the development of the river system. These estuarine and coastal Moroccan environments are as rich in fauna and flora as their European equivalents and present much originality. However, these coastal areas are generally highly urbanized and industrialized, and therefore subject to domestic and industrial discharges. The Bouregreg Estuary represents a good example of this situation, in view of this pollution (organic, chemical and biological) and the absence of fresh water supply upstream of the estuary after the dam was built, is increasingly unable of restoring the equilibrium of this ecosystem. This tide can instead ensure the polluting discharge downstream or upstream. Metallic contamination affects the different compartments of the estuarine ecosystem (sediment, water) and benthic species (fauna and flora). The objective of this study is to assess the accumulation and bioaccumulation of five heavy metals (Cu, Fe, Zn, Cr and Pb) at the sediment level of two dominant plant species (Artiplex portulacoides and Sarcocornia fructicosa) and three species of benthic macrofauna (Scrobicularia plana, Venerupis decussata and Hediste diversicolor) from the wetland of this estuary. This work will enable us to clearly understand the nutritional relationships between plant, animal, water and sediment species. The results of the analysis revealed that bioaccumulation varies from one species to another and from one metal to another. Thus, the levels of Lead and Chromium at Sarcocornia fructicosa are higher than those found at Artiplex portulacoides. Nevertheless, the latter accumulates better the other metals: Cu, Zn and Fe. While, the macrofauna shows a fairly large variation depending on the life style and sensitivity of species. Thus, Hediste diversicolor showed high levels of the various metals analyzed compared to Scrobicularia plana and Venerupis decussata.

scholarly journals Spatial and seasonal changes in benthic macrofauna from two dissipative sandy beaches in eastern Brazil)

2017 ◽  
Vol 65 (4) ◽  
pp. 666-677 ◽  
Author(s):  
Mariane Silva Coutinho ◽  
Angelo Fraga Bernardino
Keyword(s):  
Grain Size ◽  
Tidal Energy ◽  
Sandy Beaches ◽  
Benthic Macrofauna ◽  
Tropical Region ◽  
Benthic Assemblages ◽  
Sediment Grain Size ◽  
Spatial And Temporal Scales ◽  
Spatial Changes ◽  
Hierarchical Sampling

Abstract Sandy beaches are dynamic ecosystems with strong interaction of sediments, waves and tidal energy, with marked effects on benthic assemblages. Although there are numerous efforts in understanding spatial-temporal variation of benthic macrofauna on sandy beaches along the southern and southeastern Marine Ecoregions in Brazil, there is poor sampling along beaches of the Eastern Marine Ecoregion (EME). Here we examined spatial and temporal scales of variability in benthic macrofauna (> 500 µm) through a hierarchical sampling of two dissipative sandy beaches within the EME between two seasons (winter 2011 and summer 2012). We tested the hypothesis that spatial changes (i.e., meters to hundreds of meters scales) in the structure of benthic assemblages will be more pronounced compared to the weak seasonal fluctuations at this tropical region. We found weak temporal and spatial changes in sediment grain size and beach slope, but differences in macrofaunal assemblages were evident. Contrary to our hypothesis, hierarchical sampling indicated significant changes in macrofaunal composition and density at multiple local scales (meters to hundreds of meters) and on seasonal scales. The macrofauna density and composition was directly related to changes on the sediment organic matter and grain size.

scholarly journals Assessment of Metal Pollution in the Sediments of Ras Al-Ardh and Yacht Club Marinas, Kuwait

2021 ◽  
pp. 1-13
Author(s):  
Amr A. El-Sammak ◽  
Amal F. Alotaibi
Keyword(s):  
Grain Size ◽  
Trace Metals ◽  
Trace Metal ◽  
Sediment Quality ◽  
Contamination Factor ◽  
Distribution Patterns ◽  
Pollution Load Index ◽  
Sediment Grain Size ◽  
Yacht Club ◽  
And Behavior

This study aims to investigate the fate and behavior of five trace metals (Fe, Ni, Pb, Cu and V) in the surface sediments of two selected marinas, namely Ras Al-Ardh and Yacht Club, along the coastal area of Kuwait. Leached and total concentrations of Fe, Ni, Pb, Cu and V were measured along with the total organic carbon (TOC) and sediment grain size. The bioavailability of the trace metals was also determined using simple extraction techniques. The contamination factor (CF), enrichment factor (EF) and pollution load index (PLI) were used for assessing sediment quality at the marinas. The results indicated that TOC was related to the mean grain size, where higher TOC concentrations were associated with finer grain fractions. Trace metal distribution patterns were similar to the TOC in the sediments. The value of PLI showed that the Ras Al-Ardh marina had higher metal enrichment than that of the Yacht Club marina. The results of CF and EF indicated that the sediments within both marinas are "slightly polluted" to "moderately polluted". The sediments were less contaminated with Cu relative to Pb and Ni. The PLI class of metals at the Yacht Club indicated that the marina can be classified as "non-polluted" to "moderately polluted", while the Ras Al-Ardh marina can be classified as "moderately polluted" to "polluted". The study revealed that sediment grain size, TOC, and trace metal concentrations varied spatially within each marina depending on the type of development and the probable source of metals. Sediment quality has changed tremendously due to the expansion of tourism, progress in industrial activities and increase in recreational requirements near the coastal areas.

The influence of fibres on the structure of thermally dried sludge product

1996 ◽  
Vol 34 (3-4) ◽  
pp. 469-473
Author(s):  
Paul Lowe ◽  
Michael Brown ◽  
Kathleen Hudson
Keyword(s):  
Bulk Density ◽  
Fibre Content ◽  
High Concentration ◽  
Secondary Sludge ◽  
Limited Experience ◽  
Apparent Reason ◽  
Drying Technology ◽  
Dried Sludge ◽  
Lower Bulk Density ◽  
The Relationship

There appears to be a limited experience world-wide in the application of thermal drying technology to processing raw undigested sludge. This limited experience has shown that the products from raw sludge processing have a much lower bulk density than those from digested sludge. The apparent reason for this phenomenon demonstrated by this work, is the high concentration of fibres in the raw undigested sludge. Different sludges show varying degrees of fibre concentration with a decrease in fibre content as the proportion of secondary sludge increases. The relationship between the bulk density of the product and the fibre content are given and this shows that as the fibre content increases the bulk density of the product will fall. It is recommended that a compaction/pelletisation stage is included in the process stream for high fibre sludges.

scholarly journals Centennial Impacts of the East Asian Summer Monsoon on Holocene Deltaic Evolution of the Huanghe River, China

2021 ◽  
Vol 11 (6) ◽  
pp. 2799
Author(s):  
Yanping Chen ◽  
Wenzhe Lyu ◽  
Tengfei Fu ◽  
Yan Li ◽  
Liang Yi
Keyword(s):  
Grain Size ◽  
Yellow River ◽  
Asian Summer Monsoon ◽  
River Delta ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Sediment Grain Size ◽  
Huanghe River ◽  
Huanghe River Delta ◽  
The Huanghe River

The Huanghe River (Yellow River) is the most sediment laden river system in the world, and many efforts have been conducted to understand modern deltaic evolution in response to anthropological impacts. However, the natural background and its linkage to climatic changes are less documented in previous studies. In this work, we studied the sediments of core YDZ–3 and marine surface samples by grain-size analysis to retrieve Holocene dynamics of the Huanghe River delta in detail. The main findings are as follows: The mean value of sediment grain size of the studied core is 5.5 ± 0.9 Φ, and silt and sand contents are 5.2 ± 2.3% and 8.2 ± 5.3%, respectively, while the variance of clay particles is relatively large with an average value of 86.4 ± 8.5%. All grain-size data can be mathematically partitioned by a Weibull-based function formula, and three subgroups were identified with modal sizes of 61.1 ± 28.9 μm, 30.0 ± 23.9 μm, and 2.8 ± 1.6 μm, respectively. There are eight intervals with abrupt changes in modal size of core YDZ–3, which can be correlated to paleo-superlobe migration of the Huanghe River in the Holocene. Based on these observations, the presence of seven superlobes in the history are confirmed for the first time and their ages are well constrained in this study, including Paleo-Superlobes Lijin (6400–5280 yr BP), Huanghua (4480–4190 yr BP), Jugezhuang (3880–3660 yr BP), Shajinzi (3070–2870 yr BP), Nigu (2780–2360 yr BP), Qikou (2140–2000 yr BP), and Kenli (1940–1780 and 1700–1650 yr BP). By tuning geomorphological events to a sedimentary proxy derived from core YDZ–3 and comparing to various paleoenvironmental changes, we proposed that winter climate dominated Holocene shifts of the Huanghe River delta on millennial timescales, while summer monsoons controlled deltaic evolution on centennial timescales.

East Asian winter monsoon variation during the last 3000 years as recorded in a subtropical mountain lake, northeastern Taiwan

The Holocene ◽  
2021 ◽  
pp. 095968362110190
Author(s):  
Tsai-Wen Lin ◽  
Stefanie Kaboth-Bahr ◽  
Kweku Afrifa Yamoah ◽  
André Bahr ◽  
George Burr ◽  
...  
Keyword(s):  
Grain Size ◽  
East Asian Winter Monsoon ◽  
East Asian ◽  
Winter Monsoon ◽  
Mountain Lake ◽  
Sediment Grain Size ◽  
Global Monsoon ◽  
Asian Winter Monsoon ◽  
The Past ◽  
Monsoon System

The East Asian Winter Monsoon (EAWM) is a fundamental part of the global monsoon system that affects nearly one-quarter of the world’s population. Robust paleoclimate reconstructions in East Asia are complicated by multiple sources of precipitation. These sources, such as the EAWM and typhoons, need to be disentangled in order to understand the dominant source of precipitation influencing the past and current climate. Taiwan, situated within the subtropical East Asian monsoon system, provides a unique opportunity to study monsoon and typhoon variability through time. Here we combine sediment trap data with down-core records from Cueifong Lake in northeastern Taiwan to reconstruct monsoonal rainfall fluctuations over the past 3000 years. The monthly collected grain-size data indicate that a decrease in sediment grain size reflects the strength of the EAWM. End member modelling analysis (EMMA) on sediment core and trap data reveals two dominant grain-size end-members (EMs), with the coarse EM 2 representing a robust indicator of EAWM strength. The downcore variations of EM 2 show a gradual decrease over the past 3000 years indicating a gradual strengthening of the EAWM, in agreement with other published EAWM records. This enhanced late-Holocene EAWM can be linked to the expansion of sea-ice cover in the western Arctic Ocean caused by decreased summer insolation.

Relationships between multibeam backscatter, sediment grain size and Posidonia oceanica seagrass distribution

2010 ◽  
Vol 30 (18) ◽  
pp. 1941-1950 ◽  
Author(s):  
Giovanni De Falco ◽  
Renato Tonielli ◽  
Gabriella Di Martino ◽  
Sara Innangi ◽  
Simone Simeone ◽  
...  
Keyword(s):  
Grain Size ◽  
Posidonia Oceanica ◽  
Sediment Grain Size

scholarly journals Remote sensing of underwater vegetation using single-beam acoustics

2009 ◽  
Vol 67 (3) ◽  
pp. 594-605 ◽  
Author(s):  
Victor Quintino ◽  
Rosa Freitas ◽  
Renato Mamede ◽  
Fernando Ricardo ◽  
Ana Maria Rodrigues ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Grain Size ◽  
Algal Biomass ◽  
Sediment Grain Size ◽  
Coastal System ◽  
Single Beam ◽  
Acoustic Data ◽  
Sediment Types ◽  
Caulerpa Prolifera ◽  
Sandy Sediments

Abstract Quintino, V., Freitas, R., Mamede, R., Ricardo, F., Rodrigues, A. M., Mota, J., Pérez-Ruzafa, Á., and Marcos, C. 2010. Remote sensing of underwater vegetation using single-beam acoustics. – ICES Journal of Marine Science, 67: 594–605. A single-beam, acoustic, ground-discrimination system (QTC VIEW, Series V) was used to study the distribution of underwater macrophytes in a shallow-water coastal system, employing frequencies of 50 and 200 kHz. The study was conducted in Mar Menor, SE Spain, where the expansion of Caulerpa prolifera has contributed to the silting up of the superficial sediments. A direct relationship was identified between algal biomass and sediment-fines content. Acoustic information on sediment grain size and data on algal biomass were obtained in muddy and sandy sediments, including vegetated and non-vegetated seabed. Non-vegetated muddy areas were created by diving and handpicking the algae. The multivariate acoustic data were analysed under the null hypotheses that there were no acoustic differences between bare seabeds with contrasting superficial sediment types or among low, medium, and high algal-biomass areas, having in mind that grain size can act as a confounding factor. Both null hypotheses were rejected, and the results showed that 200 kHz was better than 50 kHz in distinguishing cover levels of algal biomass. The relationship between the 200-kHz acoustic data and algal biomass suggests utility in modelling the latter using the former.

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