scholarly journals Improving the quantitative estimation of trawling impacts from sidescan-sonar and underwater-video imagery

2007 ◽  
Vol 64 (9) ◽  
pp. 1692-1701 ◽  
Author(s):  
C. J. Smith ◽  
A. C. Banks ◽  
K-N. Papadopoulou
Keyword(s):  
Quantitative Estimation ◽  
Rapid Assessment ◽  
The Other ◽  
Sidescan Sonar ◽  
Silty Clay ◽  
Underwater Video ◽  
Data Usage ◽  
Video Imagery ◽  
Assessment Techniques ◽  
Clay Sediment

Abstract Smith, C. J., Banks, A. C., and Papadopoulou, K.-N. 2007. Improving the quantitative estimation of trawling impacts from sidescan-sonar and underwater-video imagery. – ICES Journal of Marine Science, 64: 1692–1701. The techniques of sidescan sonar and towed, underwater-video sled were assessed as rapid-assessment methodologies for investigating trawl impacts on the substratum. Sidescan sonar is able to image a swathe of ∼200 m with a resolution of ∼20 cm at a speed of 2–3 knots, and marks of trawl doors could be observed. The towed video system imaged a swathe of 1–2 m with a resolution of 1–2 cm at a speed of ∼1 knot, and trawl-door marks, scrape marks, local bioturbation features, and fauna could be observed. Multiple tows using both methodologies were carried out in two areas in Heraklion Bay, Crete. One area, experimentally trawled, was 80–90 m deep and characterized by mixed, maerly sediments; the other was a commercial trawl lane ∼200 m deep characterized by silty-clay sediment. Descriptions of the types of trawling feature and impacts caused by trawling were made for both areas. Images were analysed from the commercial deeper trawling ground for area assessment. For sidescan-sonar records, direction of trawling and trawl-mark density by category were estimated at periodic intervals along the track. For video, categories for trawl-mark density and level of bioturbation were estimated, along with the density of the crinoid Leptometra phalangium. Using geo-referenced positioning for each data point, area maps were constructed for each of the parameters, and correlations were tested between the different datasets. The use of the assessment techniques (characteristics, data usage, mapping, complementarity) in relation to trawling-impact studies is discussed, as well as possibilities for the use of the resulting data for management.

scholarly journals Recycling and Reuse of Sediments in Agriculture: Where Is the Problem?

2021 ◽  
Vol 13 (4) ◽  
pp. 1648
Author(s):  
Giancarlo Renella
Keyword(s):  
Scientific Evidence ◽  
Significant Proportion ◽  
Silty Clay ◽  
Fine Sediments ◽  
Sediment Fraction ◽  
Biodegradation Process ◽  
Component Material ◽  
Long Time ◽  
Clay Sediment ◽  
International Conventions

Though suggested by international conventions for a long time, there are still several technical and legislative limitations to a complete reuse and recycling of dredged sediments. In particular, reuse of unpolluted sediments can be practiced, whereas sediment recycling is still affected by several downsides, and a significant proportion of the recycled fine sediments has no practical use and must be landfilled. However, the silty clayey fraction of the recycled sediments is rich in organic matter and macro- and micronutrients useful for plant growth. Nevertheless, sediment recycling in agriculture is not possible, even in non-food agricultural sectors, due to the lack of a permissive legislation and of consolidated supply chains. In addition to plant nutrients, the silty-clay sediment fraction may also accumulate organic and inorganic pollutants, and while the organic pollutants can be effectively biodegraded, metals and metalloids may concentrate at concentrations higher than the limits set by the environmental and agricultural legislations. In this paper, I briefly summarize the scientific evidence on the potential reuse and recycling of sediments in agriculture, and I discuss the main reasons for hindrance of sediment recycling in agriculture. I also present evidence from a real industrial biodegradation process that produces bioremediated fine sediment fractions with suitable properties as a mineral ingredient for plant-growing media. I propose that nutrient-rich recycled sediments could be reconsidered as a component material category in the new EU regulation on fertilizers.

scholarly journals Can biosensors and sensors operating in a complex matrix of local and international standards solve environmental quality problems of catchments?

2019 ◽  
Vol 6 (4) ◽  
pp. 199-208
Author(s):  
Clifford Tafangenyasha
Keyword(s):  
Internet Of Things ◽  
Environmental Quality ◽  
Rapid Assessment ◽  
International Standards ◽  
Assessment Tools ◽  
Complex Matrix ◽  
River Catchment ◽  
Sugarcane Production ◽  
Laboratory Techniques ◽  
Assessment Techniques

This research aims at throwing light on applications of biological rapid assessment tools in the monitoring of environmental quality in Runde River catchment with intensive commercial sugarcane production. Burdened with drudgery in wet laboratory techniques, biological sensors (biosensors) and sensors can integrate catchment data from rapid assessment techniques to networks or Internet of Things (IoT). This research examines the techniques presented by biosensors and sensors and provides the checkboxes for sustained catchment monitoring. With available recent evidence from surveys it turns out the Runde River may not be polluted but this may reflect the time the survey was undertaken and suggestions made for routine checks

The complex of hand-made pottery from the watch-tower Kazan II near Uzunlar earth bank (morphology and technological analysis)

2018 ◽  
Author(s):  
М.Е. Клемешова
Keyword(s):  
The Other ◽  
Raw Material ◽  
Silty Clay ◽  
Cultural Groups ◽  
North West ◽  
South West ◽  
West Central ◽  
Technological Analysis

The paper presents the description of hand-made pottery from the excavation of the watch-tower Kazan II near Uzunlar earth bank in 2017. The tower is dated to the second half of the I c. B.C. Technological analysis of 92 vessel rims of was carried out, using the method developed by A. A. Bobrinsky. The information about the raw material and paste composing was obtained. The analysis results demonstrate two clearly distinguishable pottery-making traditions: one with the paste composed of silty clay and grog and the other, with the paste composed of silty clay and crushed shell. Morphologically, the pottery with grog is similar to the vessels from the late-scyphian sites of North-West, Central and South-West Crimea. Most of the big container vessels and some of the small pots are made according to this pottery making tradition. The pottery with crushed shell is similar to vessels from Polyanka settlement in morphology and paste. Most of the small pots, bowls and cultic and votive ceramic are made according to this pottery making tradition. The author supposes that the tower garrison consisted of members of two cultural groups who made pottery according to the abovementioned traditions. The group producing ceramic with grog might be similar to late scyphian population of Crimea.

An Approach to the Collection, Processing, and Analysis of Towed Camera Video Imagery for Marine Resource Management

2014 ◽  
Vol 48 (4) ◽  
pp. 86-95 ◽  
Author(s):  
Ashley Knight ◽  
James Lindholm ◽  
Andrew DeVogelaere ◽  
Fred Watson
Keyword(s):  
Model Comparison ◽  
Scuba Diving ◽  
Video Data ◽  
Limiting Factors ◽  
Monterey Bay ◽  
Public Outreach ◽  
Underwater Video ◽  
Video Imagery ◽  
Effective Depth ◽  
Organism Identification

AbstractA variety of video and photographic imaging platforms are used to survey seafloor habitats and organisms beyond the effective depth of most SCUBA diving (>30 m). Each platform has benefits and shortcomings, with the most frequently limiting factors being (a) access to the most advanced instruments, (b) response of organisms, and (c) resolution of organism identification. Here, we describe the approaches used to collect, process, and analyze video imagery collected with a simple towed camera sled in the Monterey Bay National Marine Sanctuary as part of a larger, ongoing characterization project that began in 2006. We describe the details of deployment, imagery collection, postprocessing, and analyses gleaned from hundreds of hours of underwater video. Data extracted from camera sled imagery have been analyzed using multivariate model comparison techniques and have been represented in a variety of forms to support management needs and public outreach efforts.

Do All Dynamic Assessment Techniques Assess Learning Potential?

2008 ◽  
Vol 7 (3) ◽  
pp. 411-418 ◽  
Author(s):  
Yuriy Karpov
Keyword(s):  
Problem Solving ◽  
Dynamic Assessment ◽  
The Other ◽  
Learning Potential ◽  
Other Hand ◽  
Qualitative Level ◽  
Assessment Techniques ◽  
The Individual ◽  
Graduated Prompts

It is not only that different dynamic assessment (DA) techniques evaluate different “learning potentials” of the individual; some such techniques do not evaluate any kind of learning potential. In particular, graduated prompts techniques, rather than evaluating learning potential of the individual, evaluate the level of his or her mastery of a certain problemsolving procedure. On the other hand, DA techniques that target the qualitative level at which the individual is able to learn a brand new problem-solving procedure evaluate indeed the individual’s general learning potential.

Interval Data Envelopment Analysis for Inter-Group Data Usage

2020 ◽  
Vol 24 (1) ◽  
pp. 113-122
Author(s):  
Tomoe Entani ◽  
Keyword(s):  
Data Envelopment Analysis ◽  
Efficient Frontier ◽  
Original Data ◽  
Weight Vector ◽  
The Other ◽  
Data Envelopment ◽  
Broad Perspective ◽  
Data Usage ◽  
Group Data ◽  
Multiple Groups

Organizations are interested in exploiting the data from the other organizations for better analyses. Therefore, the data related policies of organizations should be sensitive to the data privacy issue, which has been widely discussed recently. The present study is focused on inter-group data usage for a relative evaluation. This research is based on the data envelopment analysis (DEA), which is used to measure the efficiency of a decision making unit (DMU) relatively employed within a group. In DEA, establishing an efficient frontier consisting of efficient DMUs is essential. We can obtain the efficiency values of a DMU by projecting it to the efficient frontier, and including in the efficiency interval via the interval DEA. When the original data of multiple groups are not open to each other, the alternative is to exchange the information corresponding to the efficient frontiers to estimate the efficiency intervals of a DMU in such a manner that the alternative is in the other groups. Therefore, in this paper, we propose a method to replace the efficient frontier with a weight vector set, from which it is not possible to reconstruct the original data. Considering the weight vector sets of multiple groups, a DMU has three types of efficiency intervals: in its own group, in each of the other groups, and in the integrated group. They provide rich insights on the DMU from a broad perspective, and this encourages inter-group data usage. In this process, we focus on two types of information reduction: one is from the efficient frontier to the weight vector set, and the other is from a union of the groups to the integrated group.

Shark fauna and depositional environment of the earliest Cretaceous Vitabäck Clays at Eriksdal, southern Sweden

2002 ◽  
Vol 93 (1) ◽  
pp. 59-71 ◽  
Author(s):  
Jan Rees
Keyword(s):  
Depositional Environment ◽  
The Other ◽  
Silty Clay ◽  
Southern Sweden ◽  
Lower Salinity ◽  
Shark Teeth ◽  
Large Bulk ◽  
Single Tooth ◽  
Main Portion ◽  
Fin Spines

ABSTRACTA section of the Vitabäck Clays at Eriksdal in southern Sweden was sampled for vertebrate fossils. Large bulk samples were collected from three horizons, including two coquina beds, VC3 and VC11, and a silty clay bed, VC7. Shark teeth are very common and constitute the main portion of the vertebrate material discussed herein. The selachian tooth faunas are almost exclusively represented by hybodonts, although a single tooth from a neoselachian shark, Squatinidae indet., was recorded from one horizon (VC3). Hybodont species identified from the Vitabäck Clay samples include Egertonodus basanus, Hybodus parvidens and Parvodus rugianus. Hybodont remains, other than teeth, include five morphotypes of placoid scales, incomplete cephalic spines and fragmentary fin spines.Other fossil groups represented in the sieved residues from the bulk samples include bivalves, gastropods and bony fish. Together with the selachians, they indicate fluctuating palaeosalinities in the area. The lower coquina bed, VC3, includes taxa indicating mesohaline conditions while the composition of the fauna in the other coquina bed, VC11, suggests oligohaline settings. In bed VC7, the presence of amphibian remains and the rarity of selachian fossils indicate an even lower salinity. Palynomorphs from the basal part of the section, immediately below bed VC3, indicate an earliest Cretaceous (Berriasian) age.

SPRI participation in the Winter Weddell Gyre Study 1989

Polar Record ◽  
1991 ◽  
Vol 27 (160) ◽  
pp. 29-38 ◽  
Author(s):  
P. Wadhams ◽  
D. R. Crane
Keyword(s):  
Sea Ice ◽  
Aerial Photography ◽  
Ambient Noise ◽  
The Other ◽  
Sidescan Sonar ◽  
Ice Thickness ◽  
Research Groups ◽  
Weddell Gyre ◽  
International Group ◽  
Polar Research Institute

AbstractThe Winter Weddell Gyre Study was conducted by an international group of scientists, including members of the Scott Polar Research Institute, from FS Polarstern (FRG) in September and October 1989, in collaboration with RV Akademk Federov (USSR). This was a multi-disciplinary experiment involving biologists, chemists, oceanographers and meteorologists. The SPRI involvement centred on sea-ice research, involving both our own experiments and a programme carried out in collaboration with the other research groups on board. The SPRI programme involved measuring ice thickness; studying the under-ice topography with an upward looking sidescan sonar; investigating the acceleration, tilt and strain of the ice; deploying Argos buoys; aerial photography; iceberg tracking; and two acoustic experiments, one to record ambient noise and the other to acoustically measure the ice thickness.

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