scholarly journals Response of stream ecosystem function and structure to sediment metal: Context-dependency and variation among endpoints

Elem Sci Anth ◽  
2014 ◽  
Vol 2 ◽  
Author(s):  
David M. Costello ◽  
G. Allen Burton
Keyword(s):  
Dose Response ◽  
Environmental Context ◽  
Context Dependency ◽  
Acid Volatile Sulfide ◽  
Sediment Type ◽  
Organic Carbon Content ◽  
Ecological Context ◽  
Sediment Types ◽  
Sediment Metals ◽  
Sediment Metal

Abstract Physicochemical and ecological attributes of ecosystems (i.e., environmental context) can modify the exposure and effects of metals, which presents a challenge for ecosystem management. Furthermore, the functional and structural attributes of an ecosystem may not respond equally to metals or be uniformly responsive to environmental context. We explored how physicochemical and ecological context modified sediment metal dose-response for a suite of functional and structural measures. Two sediments with high (HB) and low (LB) acid volatile sulfide and organic carbon content (i.e., physicochemical context) were amended with copper and nickel to establish a gradient of treatments from non-toxic to potentially toxic. Sediments were deployed in each of two streams (i.e., ecological context), incubated for four weeks, and measured for sediment microbe, biofilm, and macroinvertebrate dose-response to metal. The dose-response of microbial function was affected by physicochemical context, with cotton decomposition negatively related to sediment metal only on LB sediments. The abundance of invertebrates from the orders Ephemeroptera, Plecoptera, and Trichoptera (EPT) responded negatively to sediment metal only on LB sediments; however, this dose-response was only observed in one stream, likely because of greater abundance of sensitive EPT taxa (i.e., Baetidae and Ephemerellidae). Biofilm structure was negatively affected by sediment metal in only one stream and there was no difference in dose-response between the two sediment types. Biofilm function was affected by sediment type and stream; production by biofilms exposed to HB sediment was negatively related to sediment metal in only one stream. In all, the majority of our endpoints exhibited responses that were modified by environmental context; however, each component of the ecosystem exhibited unique context dependency. For management of sediment metals, an understanding of context dependency is useful for informed decision-making, but the application of simple contextual filters are unlikely to protect all elements of an ecosystem.

Subdivisions of the Benthic Environment of the Upper Great Lakes, with Emphasis on Lake Michigan

1968 ◽  
Vol 25 (6) ◽  
pp. 1181-1197 ◽  
Author(s):  
Charles F. Powers ◽  
Andrew Robertson
Keyword(s):  
Organic Carbon ◽  
Thin Layer ◽  
Lake Michigan ◽  
Silty Sand ◽  
Sediment Type ◽  
Organic Carbon Content ◽  
Upper Great Lakes ◽  
Sediment Types ◽  
Clayey Silt ◽  
Benthic Environment

An effort has been made to introduce a greater degree of standardization and reliability into descriptions of the benthic environment made by biologically oriented observers. Comparisons of field descriptions and mechanical analyses showed an encouraging ability to distinguish among four major sediment types in Lake Michigan. The bottom of the lake has been described in terms of these types, which usually occur in the following order with respect to depth: sand, silty sand–sandy silt, silt–clayey silt in a thin layer overlying stiff plastic clay, and silt–clayey silt only. Each sediment type tends to exhibit its own range of organic carbon values, with the amount of carbon increasing with depth. Hard or rocky bottom occurs in more restricted areas and is considered a fifth recognizable bottom category. Certain features of the distribution of the sediments may be related to gross water movements and to the locations of the mouths of large tributary rivers. Limited comparative studies in Lakes Huron and Superior showed similar distributions of sediment types and organic carbon content. It is suggested that the observed uniformity of maximum organic carbon values in the sediments of all three lakes may be related to processes of oxidation.

scholarly journals Distribution and density of Lutraria rhynchaena Jonas, 1844 relate to sediment while reproduction shows multiple peaks per year in Cat Ba-Ha Long Bay, Vietnam

2020 ◽  
Vol 15 (1) ◽  
pp. 721-734
Author(s):  
Do Manh Hao ◽  
Do Trung Sy ◽  
Dao Thi Anh Tuyet ◽  
Le Minh Hiep ◽  
Nguyen Tien Dat ◽  
...  
Keyword(s):  
Sustainable Management ◽  
Fishery Management ◽  
Scientific Basis ◽  
Sediment Type ◽  
Medium Sand ◽  
Management Measures ◽  
Sediment Types ◽  
Study Results ◽  
Long Bay ◽  
Benthic Substrate

AbstractLutraria rhynchaena Jonas, 1844 is of great commercial interest, but its reserves have dramatically declined over recent decades. Therefore, there is an urgent need of scientific basis to propose effective fishery management measures and improve artificial aquaculture of the clam. In this study, we investigated the distribution and density of L. rhynchaena, sediment characteristics, and established the clam’s reproductive cycle through monthly observations from August 2017 to July 2018. The study results showed that distribution and density of clams are related to sediment types, and the sediment type of medium sand is likely the best benthic substrate for the clams. The spawning of clams occurred throughout the year with three spawning peaks in January, April and September. For the sustainable management of the clam resource in Cat Ba-Ha Long Bay, the fishery authorities can issue a ban on harvest of the clam in spawning peak months in January, April and September.

Sedimentary provinces, and associated bedforms and benthos on the Scott Reef-Rowley Shoals platform off north-west Australia

1988 ◽  
Vol 39 (2) ◽  
pp. 133 ◽  
Author(s):  
RJ McLoughlin ◽  
TLO Davis ◽  
TJ Ward
Keyword(s):  
Grain Size ◽  
Carbonate Content ◽  
Sediment Type ◽  
Sediment Grain Size ◽  
North West ◽  
Significant Relationships ◽  
Sediment Types ◽  
Sea Bed ◽  
Mean Grain Size ◽  
High Carbonate

The distribution of sediment types on the Scott Reef-Rowley Shoals platform, a marginal plateau adjoining the continental shelf of north-west Australia, has been investigated. Sediments in this region are predominately muds, with a high carbonate content. Sands, which are scarce, are mainly composed of both benthic and pelagic skeletal remains, with any gravel-sized material consisting of relict molluscan debris and, occasionally, relict coralline material. Correlation of sediment type with sea-bed characteristics as determined from photographs of the bottom at the same site showed significant relationships between mean grain size, and degree of sediment rippling and benthic activity. Similar correlations were found for the skewness measure of the analysis of sediment grain-size frequency. It is concluded that sediment type bears strong relationships with benthic activity and bedform morphology. Correlations between sediment provinces and the distribution of Australian scampi (Metanephrops sp.), a relatively new fishery in the region, are discussed.

Estimating acoustic attenuation from a quantitative seismic profiler

Geophysics ◽  
1981 ◽  
Vol 46 (10) ◽  
pp. 1364-1378 ◽  
Author(s):  
Robert C. Tyce
Keyword(s):  
Sediment Type ◽  
Carbonate Sediments ◽  
Seismic Profiles ◽  
Acoustic Attenuation ◽  
Sea Floor ◽  
Sediment Types ◽  
Physical Laboratory ◽  
High Lateral Resolution ◽  
Wide Range ◽  
Depth Of Burial

Recent work has indicated that acoustic attenuation in marine sediments can be estimated from thin wedges of sediment by means of a quantitative seismic profiler. A capability for near‐bottom seismic profiling at 4 kHz has been developed at the Scripps Institution of Oceanography Marine Physical Laboratory and utilized to determine effective attenuation for several areas of the sea floor. As part of the deep‐tow instrumentation system of the Marine Physical Laboratory, this profiler provides very high lateral resolution. Real time computer displays of equivalent plane‐wave pressure and intensity for seismic profiles have been developed as part of this system. These displays are produced on a standard graphic recorder and can be employed directly to determine effective attenuation by plotting displayed equivalent intensity as a function of depth of burial for a reflector covered by a wedge of sediment. For pelagic sediments, values of about 0.25 dB/m at 4 kHz appear to be common. For the Southern California borderland, a wide range of sediment types is observed, with measured values of effective attenuation ranging from 0.21 to 0.63 dB/m. Highly calcareous (85 percent carbonate) sediments of the Carnegie ridge give quite low values, from 0.1 to 0.2 dB/m, with a suggestion of a rapid decrease in attenuation with depth. For nonbiogenous sediments, values of effective attenuation appear useful for predicting other physical properties such as grain size and porosity, as well as general sediment type, from established interrelations.

scholarly journals Impact of coastal environmental factors on quinolone distribution in intertidal surface sediments of the Bohai Sea and Yellow Sea, China

2018 ◽  
Vol 19 (2) ◽  
pp. 482-491
Author(s):  
Hang Lang ◽  
Liang Chen ◽  
Guohua Hou ◽  
Wenjuan Wang ◽  
Shengzhang Zou ◽  
...  
Keyword(s):  
Environmental Factors ◽  
Yellow Sea ◽  
Surface Sediments ◽  
Oxolinic Acid ◽  
Intertidal Sediment ◽  
Organic Carbon Content ◽  
Intertidal Sediments ◽  
Intertidal Zones ◽  
Sediment Types ◽  
Intertidal Surface

Abstract Freshwater contaminants tend to precipitate into intertidal surface sediments, particularly in the estuary and intertidal zones during freshwater–seawater mixing. Quinolone-type antibiotics are such contaminants, and their concentrations in the intertidal sediments are important indicators for the whole spectrum of antibiotics used in the estuary and adjacent areas. The impacts of sediment types and environmental factors on the distribution of 16 quinolones were probed based on nine Bohai and 42 Yellow Sea intertidal sediment samples. The samples were collected from locations along the coastal areas in China. Quinolones were detected in all samples, while moxifloxacin, ciprofloxacin, and ofloxacin were detected at a frequency >50%. Sediment types, pH, organic carbon content, K, Na and Fe concentrations had little correlation with quinolone distributions in intertidal sediments. However, combined concentrations of Ca + Mg (46.7 g/kg in Bohai and 13.7 g/kg in Yellow Sea samples) appeared to correlate with oxolinic acid detecting frequencies (88.9% and 4.8%, respectively) and concentrations (2.0–10.1 μg/g and up to 3.09 μg/g, respectively). Different detection frequencies of the quinolones could be attributed to the formation of cation bridges between oxolinic acid and Ca + Mg, which results in dominant sorption of oxolinic acid at different locations and sediment matrices.

scholarly journals Application of Neural Computing Methods for Interpreting Phospholipid Fatty Acid Profiles of Natural Microbial Communities

2000 ◽  
Vol 66 (2) ◽  
pp. 694-699 ◽  
Author(s):  
Peter A. Noble ◽  
Jonas S. Almeida ◽  
Charles R. Lovell
Keyword(s):  
Sensitivity Analysis ◽  
Fatty Acid ◽  
Cross Validation ◽  
Phospholipid Fatty Acid ◽  
Computing Methods ◽  
Sediment Type ◽  
Data Set ◽  
Linear Discriminant ◽  
Sediment Types ◽  
Hidden Neurons

ABSTRACT The microbial community compositions of surface and subsurface marine sediments and sediments lining burrows of marine polychaetes and hemichordates from the North Inlet estuary (near Georgetown, S.C.) were analyzed by comparing ester-linked phospholipid fatty acid (PLFA) profiles with a back-propagating neural network (NN). The NNs were trained to relate PLFA inputs to sediment type outputs (e.g., surface, subsurface, and burrow lining) and worm species (e.g., Notomastus lobatus, Balanoglossus aurantiacus, andBranchyoasychus americana). Sensitivity analysis was used to determine which of the 60 PLFAs significantly contributed to training the NN. The NN architecture was optimized by changing the number of hidden neurons and calculating the cross-validation error between predicted and actual outputs of training and test data. The optimal NN architecture was found to be four hidden neurons with 60-input neurons representing the 60 PLFAs, and four output neurons coding for both sediment types and worm species. Comparison of cross-validation results using NNs and linear discriminant analysis (LDA) revealed that NNs had significantly fewer incorrect classifications (2.7%) than LDA (8.4%). For the NN cross-validation, both sediment type and worm species had 3 incorrect classifications out of 112. For the LDA cross-validation, sediment type and worm species had 7 and 12 incorrect classifications out of 112, respectively. Sensitivity analysis of the trained NNs revealed that 17 fatty acids explained 50% of variability in the data set. These PLFAs were highly different among sediments and burrow types, indicating significant differences in the microbiota.

scholarly journals Diversity and ecology of Pilargidae (Annelida: Polychaeta) from the Gulf of Carpentaria and Arafura Sea, northern Australia

Zoosymposia ◽  
2009 ◽  
Vol 2 (1) ◽  
pp. 537-550
Author(s):  
SHONA A. HOCKNULL ◽  
CHRISTOPHER J. GLASBY
Keyword(s):  
Species Composition ◽  
Distribution Patterns ◽  
Sediment Type ◽  
Geological History ◽  
Northern Australia ◽  
Sediment Types ◽  
Arafura Sea ◽  
History Of ◽  
Unit Depth ◽  
Sand And Gravel

This study identifies to species or species units 572 lots (>1000 specimens) of pilargids from six localities in the Arafura Sea and Gulf of Carpentaria (including the ports at Gove and McArthur River). We analyze the taxonomic data against geomorphic unit, depth, and sediment type. Preliminary results show that pilargid fauna of northern Australia comprises 13 species in seven genera (Ancistrosyllis, Cabira, Litocorsa, Loandalia, Pilargis, Sigambra, and Synelmis). Although all four localities have a similar diversity of species (six or seven species each), the species composition differs between each region: Litocorsa annamita and Synelmis rigida were found in all sediment types in the Arafura Sea and Gulf of Carpentaria; Ancistrosyllis cf. hartmanae (mud and sand dominated sediments only) and Sigambra pettiboneae (all sediment types) were restricted to the inshore localities of Gove and McArthur River; Loandalia gladstonensis and Sigambra sp. 2 were found on the shelf and in the inshore habitats of the Gulf of Carpentaria only; Litocorsa sp. ‘arafura’, Sigambra sp. ‘arafura’ and Synelmis gibbsi were found only in the Arafura Sea, with sediments dominated by sand and gravel; and Cabira sp. 1 and Sigambra cf. tentaculata were found at all locations, in all sediment types. Based on these distribution patterns and the Recent Quaternary geological history of the area, hypotheses of post-glacial colonization of the Gulf of Carpentaria are presented. The pilargid species composition in northern Australia is also compared to neighboring Indo-west Pacific regions.

scholarly journals Spatial distribution of mangrove species and their association with the substrate sediment types, estuarine sector Térraba-Sierpe National Wetlands, Costa Rica

2016 ◽  
pp. 47-60
Author(s):  
Raquel Marcela Barrantes Leiva ◽  
Alexis Cerdas Salas
Keyword(s):  
Spatial Distribution ◽  
Continuous Distribution ◽  
Floristic Composition ◽  
Sediment Type ◽  
Mangrove Species ◽  
Important Species ◽  
Sediment Types ◽  
Area 7 ◽  
Pelliciera Rhizophorae ◽  
Composition Structure

This research describes the floristic composition and spatial distribution of the main mangroves species and other associated flora present in the estuarine sector of Térraba-Sierpe National Wetland, Costa Rican Pacific. Field survey consists of 1 127 points and 77 sampling points of 60x10m. Results of composition, structure and distribution of mangrove in HNTS exhibits a pattern or species zonation. We found variation from the coast to mainland and from the fringe or estuaries to the interior tidal flats. The species Rhizophora racemosa and Pelliciera rhizophorae showed greater spatial and continuous distribution, with the highest values of abundance (45.44% and 39.92% respectively), frequency (88.31% and 74.03%) and mangrove area (7 670.73ha and 5 824.94ha). The mangrove fern, Acrostichum aureum, was the third most important species, meanwhile, Avicennia spp., Rhizophora mangle y Laguncularia racemosa showed a segregated distribution or a tendency to local conglomeration, Talipariti tiliaceum var. pernambucense, Mora oleifera y Conocarpus erectus were found in very localized areas and other species were considered companions with low contribution to the total coverage. The dependence was confirmed between the presence of mangrove species and sediment type substrate. The species Avicennia spp. and L. racemosa tend to be distributed in sandy substrates more easily than the other species whose distribution is more homogeneous on muddy substrates 

scholarly journals THE CORRELATION BETWEEN BENTHIC FORAMINIFERA AND SEDIMENT TYPES OF SOUTH MAKASSAR STRAIT

2016 ◽  
Vol 29 (2) ◽  
pp. 53
Author(s):  
Sheilla Zallesa ◽  
Kresna Tri Dewi ◽  
Noor C.D. Aryanto
Keyword(s):  
Community Structure ◽  
Benthic Foraminifera ◽  
Diversity Index ◽  
Silty Sand ◽  
Sediment Type ◽  
Sediment Characteristics ◽  
Core Sediment ◽  
Sandy Silt ◽  
Sediment Types ◽  
The Pacific

South Makassar Strait is located between Kalimantan and Sulawesi Islands that is an important oceanographic pathway connecting between the Pacific and Indian oceans. This area is a part of sedimentary basin that has specific seabed morphology and sediment characteristics, including foraminifera as a component of sediments. The purpose of this study is to determine community structure of benthic foraminifera related to sediment characteristics. This study used 20 top core sediment samples from water depth between 200 and 1500 m. There are identified 38 species of benthic foraminifera and some of them are characterized the study area: Anomalinoides colligerus, Lenticulina suborbicularis, Planulina wuellerstorfi, , and Pseudonodosaria discrete. The diversity index is categorized as moderate values (1.0=H'= 3) and the average of evenness values is about 0.79. The dominance values are less than 0.5 indicate that there is no dominant species in the study area. In relation to sediment characteristics, it shows that the high abundance of benthic foraminifera occurs in sediment type of silty sand and sandy silt. Moderate abundance appears in sand following by low abundance in silt and sandy silt sediment types. Keywords: benthic foraminifera, community structure, sediment types and Makassar Strait Makassar bagian selatan terletak diantara Pulau Kalimantan dan Sulawesi yang merupakan jalur oseanografik yang penting menghubungkan Samudera Pasifik dan. Wilayah ini merupakan bagian dari cekungan sedimen yang mempunyai morfologi dasar laut dan karakteristik sedimen tertentu termasuk foraminifera sebagai komponen sedimen. Tujuan dari penelitian ini adalah untuk mengetahui struktur komunitas foraminifera bentik dalam kaitannya dengan tipe sedimen dasar laut. Penelitian ini menggunakan 20 sampel sedimen bagian atas dari pemercontoh inti pada kedalaman antara 200 dan 1500 m. Ada 38 spesies foraminifera bentik dan beberapa diantaranya mencirikan daerah penelitian: Anomalinoides colligerus, Lenticulina suborbicularis, Planulina wuellerstorfi, dan Pseudonodosaria discrete. Indeks keanekaragaman termasuk dalam kategori sedang (1,0=H’=3) dan nilai rata-rata keseragaman sekitar 0,79. Nilai dominasi lebih kecil dari 0,5 itu menandakan tidak ada spesies yang dominan pada lokasi penelitian. Terkait dengan karakteristik sedimen menunjukkan bahwa kelimpahan foraminifera bentik tinggi terdapat pada jenis sedimen pasir lanauan dan lanau pasiran. Kelimpahan sedang ditemukan pada jenis sedimen pasir diikuti kelimpahan rendah yang dijumpai pada sedimen lanau dan lanau pasiran. Kata kunci: foraminifera bentik, struktur komunitas, jenis sedimen, Selat Makassar.

scholarly journals ASSESSMENT OF MULTIBEAM BACKSCATTER TEXTURE ANALYSIS FOR SEAFLOOR SEDIMENT CLASSIFICATION

2017 ◽  
Vol XLII-4/W5 ◽  
pp. 177-183 ◽  
Author(s):  
S. A. Samsudin ◽  
R. C. Hasan
Keyword(s):  
Spatial Resolution ◽  
Clustering Algorithm ◽  
High Spatial Resolution ◽  
Texture Classification ◽  
Classification Method ◽  
Sediment Type ◽  
Range Analysis ◽  
Sediment Classification ◽  
Sediment Types ◽  
Seafloor Sediment

Recently, there have been many debates to analyse backscatter data from multibeam echosounder system (MBES) for seafloor classifications. Among them, two common methods have been used lately for seafloor classification; (1) signal-based classification method which using Angular Range Analysis (ARA) and Image-based texture classification method which based on derived Grey Level Co-occurrence Matrices (GLCMs). Although ARA method could predict sediment types, its low spatial resolution limits its use with high spatial resolution dataset. Texture layers from GLCM on the other hand does not predict sediment types, but its high spatial resolution can be useful for image analysis. The objectives of this study are; (1) to investigate the correlation between MBES derived backscatter mosaic textures with seafloor sediment type derived from ARA method, and (2) to identify which GLCM texture layers have high similarities with sediment classification map derived from signal-based classification method. The study area was located at Tawau, covers an area of 4.7&amp;thinsp;km<sup>2</sup>, situated off the channel in the Celebes Sea between Nunukan Island and Sebatik Island, East Malaysia. First, GLCM layers were derived from backscatter mosaic while sediment types (i.e. sediment map with classes) was also constructed using ARA method. Secondly, Principal Component Analysis (PCA) was used determine which GLCM layers contribute most to the variance (i.e. important layers). Finally, K-Means clustering algorithm was applied to the important GLCM layers and the results were compared with classes from ARA. From the results, PCA has identified that GLCM layers of Correlation, Entropy, Contrast and Mean contributed to the 98.77&amp;thinsp;% of total variance. Among these layers, GLCM Mean showed a good agreement with sediment classes from ARA sediment map. This study has demonstrated different texture layers have different characterisation factors for sediment classification and proper analysis is needed before using these layers with any classification technique.

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