scholarly journals Mapping and Modeling the Distribution, Abundance, and Habitat Associations of the Endangered Fat Threeridge in the Apalachicola River System

2019 ◽  
Vol 10 (2) ◽  
pp. 653-675
Author(s):  
Adam J. Kaeser ◽  
Reuben Smit ◽  
Michael Gangloff
Keyword(s):  
River Mouth ◽  
River System ◽  
Habitat Associations ◽  
Side Scan Sonar ◽  
Habitat Monitoring ◽  
Fine Sediments ◽  
Smooth Plane ◽  
Apalachicola River ◽  
Future Population ◽  
Mussel Habitat

Abstract Large, Coastal Plain rivers of the southeastern United States contain some of the most diverse freshwater communities in North America; however, surveying the fauna of these large rivers presents numerous logistical and statistical challenges. We assessed the contemporary distribution, abundance, and habitat associations of the endangered fat threeridge mussel Amblema neislerii throughout the Apalachicola River system in northwestern Florida. To achieve this goal, we used side scan sonar to map the distribution of mesohabitats and conducted a system-wide, quantitative survey to define mussel habitat associations. We then used habitat and mussel data to develop predictive models of spatial distribution and to estimate the abundance of fat threeridge across the entire Apalachicola River system. Findings revealed a broadly distributed (i.e., 128 river kilometers occupied), robust population of approximately 9 million individuals (95% CI = 5–12 million), with a center of distribution (i.e., where abundance and occurrence were highest) approximately 45–80 river kilometers upstream of the river mouth. Fat threeridge primarily occupy fine sediment mesohabitats characterized by smooth/plane bedforms that are clearly definable via sonar habitat mapping. We hypothesize that this species may be particularly sensitive to the availability of stable, fine sediments during one or more critical life history phases and that the availability of this habitat may explain its restricted distribution in tributary rivers. Our study provides a quantitative, replicable foundation upon which future population and habitat monitoring can be based.

scholarly journals Experimental assessment of Athabasca River cohesive sediment deposition dynamics

2011 ◽  
Vol 46 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Juan Garcia-Aragon ◽  
Ian G. Droppo ◽  
Bommanna Krishnappan ◽  
Brian Trapp ◽  
Christina Jaskot
Keyword(s):  
Oil Sands ◽  
River Sediments ◽  
Quantitative Measure ◽  
River System ◽  
Athabasca River ◽  
Floc Size ◽  
Fine Sediments ◽  
Annular Flume ◽  
Polycyclic Aromatic ◽  
Settling Characteristics

Polycyclic aromatic hydrocarbons (PAHs) originating from natural sources, and potentially from the Athabasca Oil Sands development, are of concern for the Athabasca River and Lake Athabasca delta ecosystems. In order to model the transport of fine sediments (and associated PAHs), it is important to describe the sediment dynamics within the river system. Flocs possess different settling characteristics compared to individual particles. A key aspect in modelling floc settling behaviour is the mathematical linkage of the floc density to floc size. In this paper, a rotating annular flume is used to determine the settling characteristics of Muskeg River (a tributary of the Athabasca River) sediments under different shear conditions. Simulations of the settling and flocculation behaviour of these sediments were used to calibrate a density vs. floc size model. A relationship of the parameters relating floc size and density with the fractal dimension F shows that as diameter increases flocs become weaker. Recommendations for the practical application of the model are further formulated in this paper. The deposition tests offer a quantitative measure of the relative amount of sediment that is likely to be transported through the river for given flow conditions.

scholarly journals Sustained wood burial in the Bengal Fan over the last 19 My

2019 ◽  
Vol 116 (45) ◽  
pp. 22518-22525 ◽  
Author(s):  
Hyejung Lee ◽  
Valier Galy ◽  
Xiaojuan Feng ◽  
Camilo Ponton ◽  
Albert Galy ◽  
...  
Keyword(s):  
Woody Debris ◽  
Low Frequency ◽  
River System ◽  
Fine Sediments ◽  
Bengal Fan ◽  
Sedimentary Deposit ◽  
Coniferous Wood ◽  
International Ocean Discovery Program ◽  
Sediment Layers ◽  
The Ganges

The Ganges–Brahmaputra (G-B) River system transports over a billion tons of sediment every year from the Himalayan Mountains to the Bay of Bengal and has built the world’s largest active sedimentary deposit, the Bengal Fan. High sedimentation rates drive exceptional organic matter preservation that represents a long-term sink for atmospheric CO2. While much attention has been paid to organic-rich fine sediments, coarse sediments have generally been overlooked as a locus of organic carbon (OC) burial. However, International Ocean Discovery Program Expedition 354 recently discovered abundant woody debris (millimeter- to centimeter-sized fragments) preserved within the coarse sediment layers of turbidite beds recovered from 6 marine drill sites along a transect across the Bengal Fan (∼8°N, ∼3,700-m water depth) with recovery spanning 19 My. Analysis of bulk wood and lignin finds mostly lowland origins of wood delivered episodically. In the last 5 My, export included C4 plants, implying that coarse woody, lowland export continued after C4 grassland expansion, albeit in reduced amounts. Substantial export of coarse woody debris in the last 1 My included one wood-rich deposit (∼0.05 Ma) that encompassed coniferous wood transported from the headwaters. In coarse layers, we found on average 0.16 weight % OC, which is half the typical biospheric OC content of sediments exported by the modern G-B Rivers. Wood burial estimates are hampered by poor drilling recovery of sands. However, high-magnitude, low-frequency wood export events are shown to be a key mechanism for C burial in turbidites.

Flooding sedimentation at the Yellow River mouth, China

2020 ◽  
Author(s):  
Yu Yonggui ◽  
Shi Xuefa ◽  
Wu Bin ◽  
Qiao Shuqing
Keyword(s):  
Yellow River ◽  
River Mouth ◽  
Extreme Case ◽  
River System ◽  
Large River ◽  
Huanghe River ◽  
Bathymetric Data ◽  
Flooding Event ◽  
Yellow River Mouth ◽  
The Huanghe River

<p>Chinese Huanghe (Yellow River) provides an extreme case of human controlled large river system. Since 2002, a unique Water-Sediment Regulation （WSR） regime was implemented annually through Xiaolangdi Dam to buffer pool infilling and scour the hanging riverbed. This involves transfers of large-volume of water and sediment between reservoirs, becoming a human-made flooding event. 37 surface sediments 8 box cores sampled during the 2018 WSR were analyzed for grain-size, C/N, <sup>13</sup>C, radionuclides, etc. Satellite images together with high-resolution bathymetric data were incorporated to depict the flooding sedimentation at the river mouth. The results show that <sup>7</sup>Be and <sup>210</sup>Pb activity is pretty low, implying its incapability of tracing flood sediments at the Huanghe River mouth. The results also uncover that a majority of the sediment was deposited in the vicinity of the river mouth where the water depth is less than 15 m. Two depocenters with a maximum thickness of 9 m were formed expanding within a very restricted area, which was largely controlled by tidal currents.</p>

Contaminated Sediment as a Source of PCBs in a River System

1990 ◽  
Vol 47 (4) ◽  
pp. 746-754 ◽  
Author(s):  
Per Larsson ◽  
Lennart Okla ◽  
Sven-Olof Ryding ◽  
Bengt Westöö
Keyword(s):  
River Mouth ◽  
River System ◽  
Contaminated Sediment ◽  
Atmospheric Fallout ◽  
Southern Sweden ◽  
Lake Surface ◽  
The Baltic Sea ◽  
Air Interface ◽  
Aroclor 1242 ◽  
The Baltic

The transport of PCBs (Aroclor 1242) in a river system in southern Sweden was governed by outflow from sediment in a 26-ha contaminated lake. Experiments in the lake revealed that 14 g PCBs/d escaped from the sediment, while sedimentation was 3 g PCB/d. Volatilization of PCBs from the lake surface was 0.02 g/d, which was considerably higher than the atmospheric fallout [Formula: see text]. The majority of the sediment-desorbed compounds (80%) remained at the river mouth, 60 km downstream, and entered the Baltic Sea. Desorption increased the ratio of tetrachlorobiphenyls to pentachlorobiphenyls in the water. Transport across the water/air interface was higher for trichlorobiphenyls, while atmospheric deposition was dominated by penta- and hexachlorobiphenyls. Therefore, the sediment of the lake acted as a source of PCBs entering the river system as well as the atmosphere.

scholarly journals GEOACOUSTIC PATTERNS OF THE GUAÍBA RIVER BOTTOM AND SUBBOTTOM AND THEIR RELATIONSHIP WITH SEDIMENTARY AND HYDRODYNAMIC PROCESSES

2019 ◽  
Vol 37 (1) ◽  
pp. 105 ◽  
Author(s):  
Fernando Comerlato Scottá ◽  
Mauro Michelena Andrade ◽  
Vicente Oliveira Silva Junior ◽  
Natacha Oliveira ◽  
Jair Weschenfelder ◽  
...  
Keyword(s):  
Spatial Arrangement ◽  
Human Action ◽  
Side Scan Sonar ◽  
Fine Sediments ◽  
Navigation Channel ◽  
Subaqueous Dunes ◽  
Hydrodynamic Processes ◽  
Surrounding Areas ◽  
Sandy Sediments ◽  
River Bottom

ABSTRACT. This work aimed at studying the bottom and sub-bottom geoacoustics of the Guaíba River, whose echo patterns are related to hydrodynamic patterns and sedimentary processes. A total of 324 km of seismic transects were surveyed using the Stratabox high-frequency (10 kHz) profiler with concomitant imaging using a side-scan sonar in the northern and central areas of the Guaíba system. The records were interpreted with the aid of complementary data (bathymetry and bottom samples), and maps containing the spatial arrangement of echo-characters were developed. The echo-characters were classified into seven different types according to the presence of sediments controlled by the hydrodynamics of the system or modified by human action. In general, the echoes related to the deposition of fine sediments occurred in deeper areas, the navigation channel or surrounding areas. The echoes in the shallower areas presented strong acoustic reflectivity at sites with lower deposition of fine sediments and predominance of sandy sediments. The occurrence and morphology of asymmetric subaqueous dunes indicated a predominant north-to-south flow and a river behavior.Keywords: shallow geophysics, sedimentology, hydrodynamics, geoprocessing.RESUMO. Este trabalho tem por objetivo o estudo geoacústico de fundo e subfundo do rio Guaíba, cujos padrões de ecos são relacionados aos padrões hidrodinâmicos e aos processos sedimentares atuantes. Foram levantados 324 km de perfis sísmicos em extensão, com o perfilador de alta frequência (10 kHz) Stratabox e concomitante imageamento com Sonar de Varredura Lateral nas áreas Norte e Central do Guaíba. Os registros foram interpretados com o auxílio de dados complementares (batimetria e amostras de fundo) e foram confeccionados mapas com a disposição espacial dos eco-caráteres. Os eco-caráteres foram classificados em sete diferentes tipos, de acordo com a presença de sedimentos controlados pela hidrodinâmica do sistema ou modificados pela ação humana. De uma forma geral, os ecos relacionados à deposição de sedimentos finos ocorrem nas áreas mais profundas, no canal de navegação ou adjacências. Os ecos nas áreas mais rasas apresentam forte refletividade acústica, em locais com menor deposição de sedimentos finos e predomínio de sedimentos arenosos. A ocorrência e morfologia de dunas subaquosas assimétricas indicam um fluxo preponderante no sentido Norte – Sul e um comportamento fluvial do sistema aquático.Palavras-chave: geofísica rasa, sedimentologia, hidrodinâmica, geoprocessamento.

scholarly journals Trace-elements Behavior in the Sedimentary Transport Regime of the Blue Amazon, Brazil

2018 ◽  
pp. 53-63
Author(s):  
Gilmar W. Siqueira ◽  
Fabio Aprile ◽  
Assad Darwich ◽  
Georg Irion
Keyword(s):  
Trace Elements ◽  
Sediment Accumulation ◽  
Chemical Properties ◽  
River Mouth ◽  
Coastal Current ◽  
Shelf Area ◽  
Sediment Distribution ◽  
Fine Sediments ◽  
Physical Chemical ◽  
Marine Currents

Trace elements or trace metals are of great interest in environmental studies due to their toxic and cumulative properties in the biological and sedimentary compartments. The discharge area of the Amazon River mouth receives an immense volume of suspended material with adsorbed trace elements, which mostly ends up depositing in the shelf area influenced by the fluvial-marine currents and physical-chemical properties of the water and sediment. This research aims to quantify and to discuss the routes of trace elements (Cr, Pb, Ni, Zn and Hg), associated with sedimentary transport and deposition in the Amazon Continental Shelf (ACS). The results showed a sediment distribution by zone, with a non-continuous range of erosive processes and areas of deposition for mud and sand sediments. The trace elements contents in the sediments are strongly influenced by the pH, salinity, organic compounds, clay minerals and CaCO3content. Fluvial-marine currents were important drive forces for deposition and accumulation of fine sediments in the shelf, especially the North Brazilian Coastal Current (NBCC). Statistical analysis and hypothesis testing confirmed the trend of sediment accumulation by zone, influenced by the physical-chemical parameters.

scholarly journals Spatial modeling of tidal and land use impacts on Escherichia coli contamination and fluctuation in Asia's urban river environmental gradient

2021 ◽  
Author(s):  
Andri A Wibowo
Keyword(s):  
Escherichia Coli ◽  
Land Use ◽  
Spatial Modeling ◽  
Environmental Gradients ◽  
High Tide ◽  
River Mouth ◽  
River System ◽  
Urban River ◽  
Land Use Impacts ◽  
E Coli

In the river, pathogens are the leading cause for rivers to exceed water and health quality standards. The GIS based spatial modeling and analysis were conducted to estimate Escherichia coli (E. coli) contaminated river bodies based on environmental and spatial gradients such as dissolved oxygen, pH, tidal, temperature and current in Asia urban river located in Kapuas river of Kalimantan. The E. coli was sampled from the river mouth up to the upstream land uses dominated by residential. The E. coli contamination was higher in the river mouth and in residential area as well. Likewise, E. coli contamination was higher during the low tide than high tide. During the high tide, the E. coli contamination were significantly affected by temperature and current (r2>0.5). Meanwhile, during the low tide, there were no dominant environmental factors that affect E. coli contamination. Hence, by knowing the spatial model of E. coli contamination driven by tidal, land use and environmental gradients, this paper has contributed to the advance management of water and river system.

Sign in / Sign up

Export Citation Format

Share Document