scholarly journals Numerical Study of Microplastic Dispersal in Simulated Coastal Waters Using CFD Approach

Water ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 3432
Author(s):  
Mohammadreza Fatahi ◽  
Guven Akdogan ◽  
Christie Dorfling ◽  
Petrie Van Wyk
Keyword(s):  
Spatial Distribution ◽  
Marine Environment ◽  
Numerical Study ◽  
Distribution Patterns ◽  
Horizontal Distribution ◽  
Spherical Particles ◽  
Marine Habitats ◽  
Coastal Marine ◽  
Position Data ◽  
Type Size

Microplastics are accumulated in coastal regions due to human activity. Although limited data from beach surveys show an increase in microplastics in marine habitats, continuous monitoring is required on microplastics loading and distribution in the marine environment. In this study, CFD numerical simulations using VOF and Airy wave models coupled with DPM were carried out to investigate the effects of various variables on microplastics motion and distribution in a simulated coastal marine environment. PET, PU, and PP microplastic particles were released from the oceanside to investigate the effects of microplastic type, size, and shape with two different ocean–water flow velocities and temperature conditions. Particle position data from their tracking were used to determine the effect of each variable on the spatial distribution of particles. The quantitative analysis of vertical and horizontal distribution of microplastics particles revealed that, with low water velocity, most of the large denser spherical PET and PU microplastics would sink towards the bottom and settle at the ocean floor, while most of the small non-spherical particles would float near the surface and travel towards the shoreline. For lighter PP microplastics, larger spherical particles would float more readily than denser spherical ones. Large spherical and smaller non-spherical PP particles travel farthest reporting to the shoreline. Increasing the oceanwater velocity altered the distribution patterns in which lighter PP particles, almost independent of shape and size, travel swiftly to the shoreline together with smaller non-spherical denser microplastics. Lastly, the simulation results revealed that the oceanwater temperature did not play any significant role in the spatial distribution of microplastic particles.

scholarly journals Acoustic surveys for juvenile anchovy in the Bay of Biscay: abundance estimate as an indicator of the next year's recruitment and spatial distribution patterns

2013 ◽  
Vol 70 (7) ◽  
pp. 1354-1368 ◽  
Author(s):  
G. Boyra ◽  
U. Martínez ◽  
U. Cotano ◽  
M. Santos ◽  
X. Irigoien ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Distribution Patterns ◽  
Horizontal Distribution ◽  
Bay Of Biscay ◽  
Spatial Distribution Patterns ◽  
Abundance Estimate ◽  
Juvenile Abundance ◽  
Wide Range ◽  
Acoustic Surveys ◽  
Management Advice

Abstract Boyra, G., Martínez, U., Cotano, U., Santos, M., Irigoien, X., and Uriarte, A. 2013. Acoustic surveys for juvenile anchovy in the Bay of Biscay: abundance estimate as an indicator of the next year's recruitment and spatial distribution patterns. – ICES Journal of Marine Science, 70: . A series of acoustic surveys (JUVENA) began in 2003 targeting juvenile anchovy (Engraulis encrasicolus) in the Bay of Biscay. A specific methodology was designed for mapping and estimating juvenile abundance annually, four months after the spawning season. After eight years of the survey, a consistent picture of the spatial pattern of the juvenile anchovy has emerged. Juveniles show a vertical and horizontal distribution pattern that depends on size. The younger individuals are found isolated from other species in waters closer to the surface, mainly off the shelf within the mid-southern region of the bay. The largest juveniles are usually found deeper and closer to the shore in the company of adult anchovy and other pelagic species. In these eight years, the survey has covered a wide range of juvenile abundances, and the estimates show a significant positive relationship between the juvenile biomasses and the one-year-old recruits of the following year. This demonstrates that the JUVENA index provides an early indication of the strength of next year's recruitment to the fishery and can therefore be used to improve the management advice for the fishery of this short-lived species.

Spatial distribution of fallout 137Cs in the coastal marine environment of India

2012 ◽  
Vol 113 ◽  
pp. 71-76 ◽  
Author(s):  
S.K. Jha ◽  
S.S. Gothankar ◽  
S. Sartandel ◽  
M.B. Pote ◽  
P. Hemalatha ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Marine Environment ◽  
Coastal Marine Environment ◽  
Coastal Marine

The impact of urban effluents on the coastal marine environment of Mediterranean islands

1995 ◽  
Vol 32 (9-10) ◽  
pp. 85-94 ◽  
Author(s):  
Michael O. Angelidis
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Marine Environment ◽  
Suspended Particle ◽  
Pollution Source ◽  
Mediterranean Islands ◽  
Coastal Marine Environment ◽  
Coastal Marine ◽  
The Impact ◽  
The City

The impact of the urban effluents of Mytilene (Lesvos island, Greece) on the receiving coastal marine environment, was evaluated by studying the quality of the city effluents (BOD5, COD, SS, heavy metals) and the marine sediments (grain size, organic matter, heavy metals). It was found that the urban effluents of Mytilene contain high organic matter and suspended particle load because of septage discharge into the sewerage network. Furthermore, although the city does not host important industrial activity, its effluents contain appreciable metal load, which is mainly associated with the particulate phase. The city effluents are discharged into the coastal marine environment and their colloidal and particulate matter after flocculation settles to the bottom, where is incorporated into the sediments. Over the years, the accumulation of organic matter and metals into the harbour mud has created a non-point pollution source in the relatively non-polluted coastal marine environment of the island. Copper and Zn were the metals which presented the higher enrichment in the sediments of the inner harbour of Mytilene.

Modeling spatial distribution of the unionid mussels and the core-satellite hypothesis

1998 ◽  
Vol 38 (7) ◽  
pp. 73-79 ◽  
Author(s):  
Hooi-Ling Lee ◽  
Donald DeAngelis ◽  
Hock-Lye Koh
Keyword(s):  
Spatial Distribution ◽  
Life Cycle ◽  
Success Rate ◽  
Distribution Patterns ◽  
Fish Host ◽  
Limited Movement ◽  
Unionid Mussels ◽  
Species Characteristics ◽  
Major Factors ◽  
Fish Hosts

This paper discusses the spatial distribution patterns of the various species of the Unionid mussels as functions of their respective life-cycle characteristics. Computer simulations identify two life-cycle characteristics as major factors governing the abundance of a species, namely the movement range of their fish hosts and the success rate of the parasitic larval glochidia in finding fish hosts. Core mussels species have fish hosts with large movement range to disperse the parasitic larval glochidia to achieve high levels of abundance. Species associated with fish host of limited movement range require high success rate of finding fish host to achieve at least an intermediate level of abundance. Species with low success rate of finding fish hosts coupled with fish hosts having limited movement range exhibit satellite species characteristics, namely rare in numbers and sparse in distributions.

scholarly journals Spatio-temporal distribution patterns of Plutella xylostella (Lepidoptera: Plutellidae) in a fine-scale agricultural landscape based on geostatistical analysis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jian-Yu Li ◽  
Yan-Ting Chen ◽  
Meng-Zhu Shi ◽  
Jian-Wei Li ◽  
Rui-Bin Xu ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Plutella Xylostella ◽  
Agricultural Landscape ◽  
Seasonal Pattern ◽  
Distribution Patterns ◽  
Geostatistical Analysis ◽  
Distribution Model ◽  
Detailed Knowledge ◽  
Fine Scale ◽  
Spatio Temporal

AbstractA detailed knowledge on the spatial distribution of pests is crucial for predicting population outbreaks or developing control strategies and sustainable management plans. The diamondback moth, Plutella xylostella, is one of the most destructive pests of cruciferous crops worldwide. Despite the abundant research on the species’s ecology, little is known about the spatio-temporal pattern of P. xylostella in an agricultural landscape. Therefore, in this study, the spatial distribution of P. xylostella was characterized to assess the effect of landscape elements in a fine-scale agricultural landscape by geostatistical analysis. The P. xylostella adults captured by pheromone-baited traps showed a seasonal pattern of population fluctuation from October 2015 to September 2017, with a marked peak in spring, suggesting that mild temperatures, 15–25 °C, are favorable for P. xylostella. Geostatistics (GS) correlograms fitted with spherical and Gaussian models showed an aggregated distribution in 21 of the 47 cases interpolation contour maps. This result highlighted that spatial distribution of P. xylostella was not limited to the Brassica vegetable field, but presence was the highest there. Nevertheless, population aggregations also showed a seasonal variation associated with the growing stage of host plants. GS model analysis showed higher abundances in cruciferous fields than in any other patches of the landscape, indicating a strong host plant dependency. We demonstrate that Brassica vegetables distribution and growth stage, have dominant impacts on the spatial distribution of P. xylostella in a fine-scale landscape. This work clarified the spatio-temporal dynamic and distribution patterns of P. xylostella in an agricultural landscape, and the distribution model developed by geostatistical analysis can provide a scientific basis for precise targeting and localized control of P. xylostella.

scholarly journals Defining and Characterising Clusters in Palaeolithic Sites: a Review of Methods and Constraints

2021 ◽  
Author(s):  
Laura Sánchez-Romero ◽  
Alfonso Benito-Calvo ◽  
Joseba Rios-Garaizar
Keyword(s):  
Distribution Patterns ◽  
Horizontal Distribution ◽  
Spatial Studies ◽  
Innovative Methods ◽  
General Terms ◽  
Fabric Analysis ◽  
Gis Tools ◽  
Definition Of ◽  
Intentional Activities ◽  
Statistical Criteria

AbstractSpatial analysis studies in Palaeolithic archaeology arise as indispensable research tools for understanding archaeopalaeontological sites. In general terms, spatial studies have been specialised in the description of the distribution of materials and in the definition of accumulation areas, with the aim of distinguishing intentional activities or studying postdepositional processes. In recent decades, the development of GIS tools has enabled huge strides forward in the field of spatial archaeology research, such as spatial inferential statistics. These tools are particularly useful in the identification and location of clustering from statistical criteria, facilitating the subsequent analysis of accumulations through other archaeological, taphonomic and spatial techniques, such as fabric analysis or directional distribution. The cluster analysis, and its contextualisation considering all the archaeological and stratigraphical variables, allows the inference of some of the processes and factors that could have taken part in the accumulation of materials, as well as assessing how this affected the composition and preservation of the archaeological assemblage. The present article reviews the more traditional and innovative methods for studying horizontal distribution patterns and the objective definition of clusters, highlighting the parameters, uses and limitations of these techniques. We present an application of these methods to different Palaeolithic sites, going through different scenarios, such as location (open-air vs. cave), context, scale (large vs. small area), excavation methodology and spatial record methods.

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