Search results for: collecting marine invertebrates
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1506

Search results for: collecting marine invertebrates

1326 Exploring Marine Bacteria in the Arabian Gulf Region for Antimicrobial Metabolites

Authors: Julie Connelly, Tanvi Toprani, Xin Xie, Dhinoth Kumar Bangarusamy, Kris C. Gunsalus

Abstract:

The overuse of antibiotics worldwide has contributed to the development of multi-drug resistant (MDR) pathogenic bacterial strains. There is an increasing urgency to discover antibiotics to combat MDR pathogens. The microbiome of the Arabian Gulf is a largely unexplored and potentially rich source of novel bioactive compounds. Microbes that inhabit the Abu Dhabi coastal regions adapt to extreme environments with high salinity, hot temperatures, large temperature fluctuations, and acute exposure to solar energy. The microbes native to this region may produce unique metabolites with therapeutic potential as antibiotics and antifungals. We have isolated 200 pure bacterial strains from mangrove sediments, cyanobacterial mats, and coral reefs of the Abu Dhabi region. In this project, we aim to screen the marine bacterial strains to identify antibiotics, in particular undocumented compounds that show activity against existing antibiotic-resistant strains. We have acquired the ESKAPE pathogen panel, which consists of six antibiotic-resistant gram-positive and gram-negative bacterial pathogens that collectively cause most clinical infections. Our initial efforts of the primary screen using colony-picking co-culture assay have identified several candidate marine strains producing potential antibiotic compounds. We will next apply different assays, including disk-diffusion and broth turbidity growth assay, to confirm the results. This will be followed by bioactivity-guided purification and characterization of target compounds from the scaled-up volume of candidate strains, including SPE fraction, HPLC fraction, LC-MS, and NMR. For antimicrobial compounds with unknown structures, our final goal is to investigate their mode of action by identifying the molecular target.

Keywords: marine bacteria, natural products, drug discovery, ESKAPE panel

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1325 Independent Village Planning Based Eco Village and Save Energy in Region of Maritime Tourism

Authors: Muhamad Rasyid Angkotasan

Abstract:

Eco-village is an ecosystem where the countryside or urban communities that are inside trying to integrate the social environment with low impact way of life to achieve this, they integrate the various aspects of ecological design, agriculture permanent, ecological building and the alternative energy. Eco-village in question is eco-village conducted on of marine tourism areas, where natural resources are very good, without ignoring the global issue of climate change. Desperately needed a source of energy, which can support the fulfillment of energy needs in a sustainable. Fulfillment of energy sources that offer is the use or application of environmentally friendly technologies of usage is still very low in Indonesia, the technology namely the Ocean Thermal Energy Conversion (OTEC), OTEC is expected to be a source of the alternative energy, which can support the goal of eco-village of the region's of marine tourism.

Keywords: eco village, saving energy, ocean thermal energy conversion, environmental engineering

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1324 Time Fetching Water and Maternal Childcare Practices: Comparative Study of Women with Children Living in Ethiopia and Malawi

Authors: Davod Ahmadigheidari, Isabel Alvarez, Kate Sinclair, Marnie Davidson, Patrick Cortbaoui, Hugo Melgar-Quiñonez

Abstract:

The burden of collecting water tends to disproportionately fall on women and girls in low-income countries. Specifically, women spend between one to eight hours per day fetching water for domestic use in Sub-Saharan Africa. While there has been research done on the global time burden for collecting water, it has been mainly focused on water quality parameters; leaving the relationship between water fetching and health outcomes understudied. There is little available evidence regarding the relationship between water fetching and maternal child care practices. The main objective of this study was to help fill the aforementioned gap in the literature. Data from two surveys in Ethiopia and Malawi conducted by CARE Canada in 2016-2017 were used. Descriptive statistics indicate that women were predominantly responsible for collecting water in both Ethiopia (87%) and Malawi (99%) respectively, with the majority spending more than 30 minutes per day on water collection. With regards to child care practices, in both countries, breastfeeding was relatively high (77% and 82%, respectively); and treatment for malnutrition was low (15% and 8%, respectively). However, the same consistency was not found for weighing; in Ethiopia only 16% took their children for weighting in contrast to 94% in Malawi. These three practices were summed to create one variable for regressions analyses. Unadjusted logistic regression findings showed that only in Ethiopia was time fetching water significantly associated with child care practices. Once adjusted for covariates, this relationship was no longer found to be significant. Adjusted logistic regressions also showed that the factors that did influence child care practices differed slightly between the two countries. In Ethiopia, a lack of access to community water supply (OR= 0.668; P=0.010), poor attitudes towards gender equality (OR= 0.608; P=0.001), no access to land and (OR=0.603; P=0.000), significantly decreased a women’s odd of using positive childcare practices. Notably, being young women between 15-24 years (OR=2.308; P=0.017), and 25-29 (OR=2.065; P=0.028) increased probability of using positive childcare practices. Whereas in Malawi, higher maternal age, low decision-making power, significantly decreased a women’s odd of using positive childcare practices. In conclusion, this study found that even though amount of time spent by women fetching water makes a difference for childcare practices, it is not significantly related to women’s child care practices when controlling the covariates. Importantly, women’s age contributes to child care practices in Ethiopia and Malawi.

Keywords: time fetching water, community water supply, women’s child care practices, Ethiopia, Malawi

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1323 Data about Loggerhead Sea Turtle (Caretta caretta) and Green Turtle (Chelonia mydas) in Vlora Bay, Albania

Authors: Enerit Sacdanaku, Idriz Haxhiu

Abstract:

This study was conducted in the area of Vlora Bay, Albania. Data about Sea Turtles Caretta caretta and Chelonia mydas, belonging to two periods of time (1984–1991; 2008–2014) are given. All data gathered were analyzed using recent methodologies. For all turtles captured (as by catch), the Curve Carapace Length (CCL) and Curved Carapace Width (CCW) were measured. These data were statistically analyzed, where the mean was 67.11 cm for CCL and 57.57 cm for CCW of all individuals studied (n=13). All untagged individuals of marine turtles were tagged using metallic tags (Stockbrand’s titanium tag) with an Albanian address. Sex was determined and resulted that 45.4% of individuals were females, 27.3% males and 27.3% juveniles. All turtles were studied for the presence of the epibionts. The area of Vlora Bay is used from marine turtles (Caretta caretta) as a migratory corridor to pass from the Mediterranean to the northern part of the Adriatic Sea.

Keywords: Caretta caretta, Chelonia mydas, CCL, CCW, tagging, Vlora Bay

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1322 The Application of Sequence Stratigraphy to the Sajau (Pliocene) Coal Distribution in Berau Basin, Northeast Kalimantan, Indonesia

Authors: Ahmad Helman Hamdani, Diana Putri Hamdiana

Abstract:

The Sajau coal measures of Berau Basin, northeastern Kalimantan were deposited within a range of facies associations spanning a spectrum of settings from fluvial to marine. The transitional to terrestrial coal measures are dominated by siliciclastics, but they also contain three laterally extensive marine bands (mudstone). These bands act as marker horizons that enable correlation between fully marine and terrestrial facies. Examination of this range of facies and their sedimentology has enabled the development of a high-resolution sequence stratigraphic framework. Set against the established backdrop of third-order Sajau transgression, nine fourth-order sequences are recognized. Results show that, in the composite sequences, peat accumulation predominantly correlates in transitional areas with early transgressive sequence sets (TSS) and highstand sequence set (HSS), while in more landward areas it correlates with the middle TSS to late highstand sequence sets (HSS). Differences in peat accumulation regimes within the sequence stratigraphic framework are attributed to variations in subsidence and background siliciclastic input rates in different depositional settings, with these combining to produce differences in the rate of accommodation change. The preservation of coal resources in the middle to late HSS in this area was most likely related to the rise of the regional base level throughout the Sajau.

Keywords: sequence stratigraphy, coal, Pliocene, Berau basin

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1321 Analysis of the Contribution of Coastal and Marine Physical Factors to Oil Slick Movement: Case Study of Misrata, Libya

Authors: Abduladim Maitieg, Mark Johnson

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Developing a coastal oil spill management plan for the Misratah coast is the motivating factor for building a database for coastal and marine systems and energy resources. Wind direction and speed, currents, bathymetry, coastal topography and offshore dynamics influence oil spill deposition in coastal water. Therefore, oceanographic and climatological data can be used to understand oil slick movement and potential oil deposits on shoreline area and the behaviour of oil spill trajectories on the sea surface. The purpose of this study is to investigate the effects of the coastal and marine physical factors under strong wave conditions and various bathymetric and coastal topography gradients in the western coastal area of Libya on the movement of oil slicks. The movement of oil slicks was computed using a GNOME simulation model based on current and wind speed/direction. The results in this paper show that (1) Oil slick might reach the Misratah shoreline area in two days in the summer and winter. Seasons. (2 ) The North coast of Misratah is the potential oil deposit area on the Misratah coast. (3) Tarball pollution was observed along the North coast of Misratah. (4) Two scenarios for the summer and the winter season were run, along the western coast of Libya . (5) The eastern coast is at a lower potential risk due to the influence of wind and current energy in the Gulf of Sidra. (6) The Misratah coastline is more vulnerable to oil spill movement in the summer than in winter seasons. (7) Oil slick takes from 2 to 5 days to reach the saltmarsh in the eastern Misratah coast. (8) Oil slick moves 300 km in 30 days from the spill resource location near the Libyan western border to the Misratah coast.(9) Bathymetric features have a profound effect on oil spill movement. (9)Oil dispersion simulations using GNOME are carried out taking into account high-resolution wind and current data.

Keywords: oil spill movement, coastal and marine physical factors, coast area, Libyan

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1320 Evaluation and Risk Assessment of Heavy Metals Pollution Using Edible Crabs, Based on Food Intended for Human Consumption

Authors: Nayab Kanwal, Noor Us Saher

Abstract:

The management and utilization of food resources is becoming a big issue due to rapid urbanization, wastage and non-sustainable use of food, especially in developing countries. Therefore, the use of seafood as alternative sources is strongly promoted worldwide. Marine pollution strongly affects marine organisms, which ultimately decreases their export quality. The monitoring of contamination in marine organisms is a good indicator of the environmental quality as well as seafood quality. Monitoring the accumulation of chemical elements within various tissues of organisms has become a useful tool to survey current or chronic levels of heavy metal exposure within an environment. In this perspective, this study was carried out to compare the previous and current levels (Year 2012 and 2014) of heavy metals (Cd, Pb, Cr, Cu and Zn) in crabs marketed in Karachi and to estimate the toxicological risk associated with their intake. The accumulation of metals in marine organisms, both essential (Cu and Zn) and toxic (Pb, Cd and Cr), natural and anthropogenic, is an actual food safety issue. Significant (p>0.05) variations in metal concentrations were found in all crab species between the two years, with most of the metals showing high accumulation in 2012. For toxicological risk assessment, EWI (Estimated weekly intake), Target Hazard quotient (THQ) and cancer risk (CR) were also assessed and high EWI, Non- cancer risk (THQ < 1) showed that there is no serious threat associated with the consumption of shellfish species on Karachi coast. The Cancer risk showed the highest risk from Cd and Pb pollution if consumed in excess. We summarize key environmental health research on health effects associated with exposure to contaminated seafood. It could be concluded that considering the Pakistan coast, these edible species may be sensitive and vulnerable to the adverse effects of environmental contaminants; more attention should be paid to the Pb and Cd metal bioaccumulation and to toxicological risks to seafood and consumers.

Keywords: cancer risk, edible crabs, heavy metals pollution, risk assessment

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1319 Catch Composition and Amount of Illegal and Unreported Fishing in Iranian Coastal Waters - Hormozgan Province

Authors: Yasemi Mehran, Parsa Mehran, Farzingohar Mehrnaz

Abstract:

Illegal, unreported, and unregulated (IUU) fishing has been identified as one of the most serious threats to the sustainability of the world’s fisheries. In the present study, illegal and unreported fishing of different species in waters of Persian Gulf and Oman Sea (Hormozgan province) were evaluated. Among 47 species of 33 families identified in this study, with 39 species belong to teleosts, 4 species belong to elasmobranchs and 4 species belong to invertebrate. The total weight of illegal and unreported catch were 78525.22 tonnes. Maximum and minimum values were found for Dussumiera acuta (20640.74 tonnes) and Tenualosa ilisha (0.733 tonnes), respectively. The most commercial species group was scombridae, carangidae and clupeidae, respectively. Teleosts with 91.15%, elasmobranchs with 4.82 and invertebrates with 4.03% constituted total weight of illegal and unreported fishing. Results of this study provide valuable information in order to access a sustainable management on fish resources.

Keywords: catch composition, illegal, unreported fishing, Hormozgan province

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1318 Sclerobiont Assemblages on Macro-Invertebrates from the Cenomanian Strata of Djebel Bouarif (Aurès Range, Algeria)

Authors: Salmi-laouar Sihem, Kara Ahmed Imad

Abstract:

The ichnological study of the Djebel BouarifCenomaniandeposits(Northern Aurès Range, Algeria) revealed relatively abundant and diverse sclerobiont communities that are preserved in corals, bivalves, and gastropods ; all are described herein. Fossil traces are dominated by exceptionally preserved Gastrochaenolitesoften with tracemakers (bivalves), which are preserved in situ, Entobia, and Maeandropolydora. Other borings are rare and are represented by a single specimen of Rogerella, Nihilichnus, and Spirolites. Amongsclerozoans, encrustingjuvenile oysters, and non-oyster bivalves (Pseudolimea?granulata) are the mostabundant groups. Otherepibionts, such as gastropods and polychaetes (Glomerulaserpentina), are lesscommon; dwarfgastropods were located on a single oyster Costagyraolisiponensis, whereas Glomerula specimens were clustered on the lower and upper surfaces of coral Aspidiscuscristatus. Gastrochaenoliteswith original tracemakers and all the epibionts studied herein have not been described from the Djebel BouarifCenomaniandeposits to date. The rare occurrences of Spirolites and Nihilichnus are reported from Algeria for the first time.

Keywords: bioerosion, sclerobionts, upper creataceous, southern tethys, atlasic domain

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1317 Predicting of Hydrate Deposition in Loading and Offloading Flowlines of Marine CNG Systems

Authors: Esam I. Jassim

Abstract:

The main aim of this paper is to demonstrate the prediction of the model capability of predicting the nucleation process, the growth rate, and the deposition potential of second phase particles in gas flowlines. The primary objective of the research is to predict the risk hazards involved in the marine transportation of compressed natural gas. However, the proposed model can be equally used for other applications including production and transportation of natural gas in any high-pressure flow-line. The proposed model employs the following three main components to approach the problem: computational fluid dynamics (CFD) technique is used to configure the flow field; the nucleation model is developed and incorporated in the simulation to predict the incipient hydrate particles size and growth rate; and the deposition of the gas/particle flow is proposed using the concept of the particle deposition velocity. These components are integrated in a comprehended model to locate the hydrate deposition in natural gas flowlines. The present research is prepared to foresee the deposition location of solid particles that could occur in a real application in Compressed Natural Gas loading and offloading. A pipeline with 120 m length and different sizes carried a natural gas is taken in the study. The location of particle deposition formed as a result of restriction is determined based on the procedure mentioned earlier and the effect of water content and downstream pressure is studied. The critical flow speed that prevents such particle to accumulate in the certain pipe length is also addressed.

Keywords: hydrate deposition, compressed natural gas, marine transportation, oceanography

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1316 Coastal Water Characteristics along the Saudi Arabian Coastline

Authors: Yasser O. Abualnaja1, Alexandra Pavlidou2, Taha Boksmati3, Ahmad Alharbi3, Hammad Alsulmi3, Saleh Omar Maghrabi3, Hassan Mowalad3, Rayan Mutwalli3, James H. Churchill4, Afroditi Androni2, Dionysios Ballas2, Ioannis Hatzianestis2, Harilaos Kontoyiannis2, Angeliki Konstantinopoulou2, Georgios Krokkos1, 5, Georgios Pappas2, Vassilis P. Papadopoulos2, Konstantinos Parinos2, Elvira Plakidi2, Eleni Rousselaki2, Dimitris Velaoras2, Panagiota Zachioti2, Theodore Zoulias2, Ibrahim Hoteit5.

Abstract:

The coastal areas along the Kingdom of Saudi Arabia on both the Red Sea and Arabian Gulf have been witnessing in the past decades an unprecedented economic growth and a rapid increase in anthropogenic activities. Therefore, the Saudi Arabian government has decided to frame a strategy for sustainable development of the coastal and marine environments, which comes in the context of the Vision 2030, aimed at providing the first comprehensive ‘Status Quo Assessment’ of the Kingdom’s coastal and marine environments. This strategy will serve as a baseline assessment for future monitoring activities; this baseline is relied on scientific evidence of the drivers, pressures, and their impact on the environments of the Red Sea and Arabian Gulf. A key element of the assessment was the cumulative pressures of the hotspots analysis, which was developed following the principles of the Driver-Pressure-State-Impact-Response (DPSIR) framework and using the cumulative pressure and impact assessment methodology. Ten hotspot sites were identified, eight in the Red Sea and two in the Arabian Gulf. Thus, multidisciplinary research cruises were conducted throughout the Red Sea and the Arabian Gulf coastal and marine environments in June/July 2021 and September 2021, respectively, in order to understand the relative impact of hydrography and the various pressures on the quality of seawater and sediments. The main objective was to record the physical and biogeochemical parameters along the coastal waters of the Kingdom, tracing the dispersion of contaminants related to specific pressures. The assessment revealed the effect of hydrography on the trophic status of the southern marine coastal areas of the Red Sea. Jeddah Lagoon system seems to face significant eutrophication and pollution challenges, whereas sediments are enriched in some heavy metals in many areas of the Red Sea and the Arabian Gulf. This multidisciplinary research in the Red Sea and the Arabian Gulf coastal waters will pave the way for future detailed environmental monitoring strategies for the Saudi Arabian marine environment.

Keywords: arabian gulf, contaminants, hotspot, red sea

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1315 Evaluating the Impact of Marine Protected Areas on Human-Shark Interactions at a Global Scale

Authors: Delphine Duval, Morgan Mangeas, Charlie Huveneers, Adam Barnett, Laurent Vigliola

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The global number of shark bites has increased over the past four decades with, however, high regional variability both in space and time. A systematic review, aligned with the 2020 PRISMA guidelines, explored the peer-reviewed literature published between 1960 and 2023 to identify factors potentially explaining trends in human-shark interactions. Results revealed that variations in the frequency of human-shark interactions could be explained by a plethora of factors, including changes in prey availability, environmental conditions, human and shark population density and behavior, as well as habitat destruction. However, to our best knowledge, only five studies have conducted statistical assessments of the relative contribution of these factors. The increased number in human-shark interactions and the frequent clusters of shark bites within short timeframes offer opportunities to test the causative factors that may explain trends in unprovoked shark bites. it study aims to evaluate the impact of marine protected areas (MPAs) on the number of human-shark interactions, using data from the Global Shark Attack File and the World Database on Protected Areas. Results indicate contrasting effects of MPAs at different spatial scales. Enhancing our understanding of the factors contributing to shark bites is essential for improving risk reduction policies for humans and conservation plans for shark populations.

Keywords: unprovoked shark interactions, marine protected areas, attack risk, human-wildlife interaction

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1314 Factors Controlling Marine Shale Porosity: A Case Study between Lower Cambrian and Lower Silurian of Upper Yangtze Area, South China

Authors: Xin Li, Zhenxue Jiang, Zhuo Li

Abstract:

Generally, shale gas is trapped within shale systems with low porosity and ultralow permeability as free and adsorbing states. Its production is controlled by properties, in terms of occurrence phases, gas contents, and percolation characteristics. These properties are all influenced by porous features. In this paper, porosity differences of marine shales were explored between Lower Cambrian shale and Lower Silurian shale of Sichuan Basin, South China. Both the two shales were marine shales with abundant oil-prone kerogen and rich siliceous minerals. Whereas Lower Cambrian shale (3.56% Ro) possessed a higher thermal degree than that of Lower Silurian shale (2.31% Ro). Samples were measured by a combination of organic-chemistry geology measurement, organic matter (OM) isolation, X-ray diffraction (XRD), N2 adsorption, and focused ion beam milling and scanning electron microscopy (FIB-SEM). Lower Cambrian shale presented relatively low pore properties, with averaging 0.008ml/g pore volume (PV), averaging 7.99m²/g pore surface area (PSA) and averaging 5.94nm average pore diameter (APD). Lower Silurian shale showed as relatively high pore properties, with averaging 0.015ml/g PV, averaging 10.53m²/g PSA and averaging 18.60nm APD. Additionally, fractal analysis indicated that the two shales presented discrepant pore morphologies, mainly caused by differences in the combination of pore types between the two shales. More specifically, OM-hosted pores with pin-hole shape and dissolved pores with dead-end openings were the main types in Lower Cambrian shale, while OM-hosted pore with a cellular structure was the main type in Lower Silurian shale. Moreover, porous characteristics of isolated OM suggested that OM of Lower Silurian shale was more capable than that of Lower Cambrian shale in the aspect of pore contribution. PV of isolated OM in Lower Silurian shale was almost 6.6 times higher than that in Lower Cambrian shale, and PSA of isolated OM in Lower Silurian shale was almost 4.3 times higher than that in Lower Cambrian shale. However, no apparent differences existed among samples with various matrix compositions. At late diagenetic or metamorphic epoch, extensive diagenesis overprints the effects of minerals on pore properties and OM plays the dominant role in pore developments. Hence, differences of porous features between the two marine shales highlight the effect of diagenetic degree on OM-hosted pore development. Consequently, distinctive pore characteristics may be caused by the different degrees of diagenetic evolution, even with similar matrix basics.

Keywords: marine shale, lower Cambrian, lower Silurian, om isolation, pore properties, om-hosted pore

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1313 Promotion of Renewable Marines Energies in Morocco: Perspectives and Strategies

Authors: Nachtane Mourad, Tarfaoui Mostapha, Saifaoui Dennoun, El Moumen Ahmed

Abstract:

The current energy policy recommends the subject of energy efficiency and to phase out fossil energy as a master question for the prospective years. The kingdom requires restructuring its power equipment by improving the percentage of renewable energy supply and optimizing power systems and storage. Developing energy efficiency, therefore, obliges as a consubstantial objection to reducing energy consumption. The objective of this work is to show the energy transition in Morocco towards renewable energies, in particular, to show the great potential of renewable marine energies in Morocco, This goes back to the advantages of cost and non-pollution in addition to that of the independence of fossil energies. Bearing in mind the necessity of the balance of the Moroccan energy mix, hydraulic and thermal power plants have also been installed which will be added to the power stations already established as a prospect for a balanced network that is flexible to fluctuate demand.

Keywords: renewable marine energy, energy transition, efficiency energy, renewable energy

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1312 Addressing Coastal Community Vulnerabilities with Alternative Marine Energy Projects

Authors: Danielle Preziuso, Kamila Kazimierczuk, Annalise Stein, Bethel Tarekegne

Abstract:

Coastal communities experience a variety of distinct socioeconomic, technical, and environmental vulnerabilities, all of which accrue heightened risk with increasingly frequent and severe climate change impacts. Marine renewable energy (MRE) offers a potential solution for mitigating coastal community vulnerabilities, especially water-energy dependencies while delivering promising co-benefits such as increased resilience and more sustainable energy outcomes. This paper explores coastal community vulnerabilities and service dependencies based on the local drivers that create them, with attention to climate change impacts and how they catalyze water-energy unmet needs in these communities. We examine the vulnerabilities through the lens of coastal Tribal communities (i.e., the Makah Tribe, the Kenaitze Tribe, Quinault Nation), as indigenous communities often face compounded impacts of technical, economic, and environmental vulnerabilities due to their underlying socio-demographic inequalities. We offer an environmental and energy justice indicators framework to understand how these vulnerabilities disproportionately manifest and impact the most vulnerable community members, and we subsequently utilize the framework to inform a weighted decision matrix tool that compares the viability of MRE-based alternative energy futures in addressing these vulnerabilities. The framework and complementary tool highlight opportunities for future MRE research and pilot demonstrations that directly respond to the vulnerabilities of coastal communities.

Keywords: coastal communities, decision matrix, energy equity, energy vulnerability, marine energy, service dependency

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1311 Microplastics in Fish from Grenada, West Indies: Problems and Opportunities

Authors: Michelle E. Taylor, Clare E. Morrall

Abstract:

Microplastics are small particles produced for industrial purposes or formed by breakdown of anthropogenic debris. Caribbean nations import large quantities of plastic products. The Caribbean region is vulnerable to natural disasters and Climate Change is predicted to bring multiple additional challenges to island nations. Microplastics have been found in an array of marine environments and in a diversity of marine species. Occurrence of microplastic in the intestinal tracts of marine fish is a concern to human and ecosystem health as pollutants and pathogens can associate with plastics. Studies have shown that the incidence of microplastics in marine fish varies with species and location. Prevalence of microplastics (≤ 5 mm) in fish species from Grenadian waters (representing pelagic, semi-pelagic and demersal lifestyles) harvested for human consumption have been investigated via gut analysis. Harvested tissue was digested in 10% KOH and particles retained on a 0.177 mm sieve were examined. Microplastics identified have been classified according to type, colour and size. Over 97% of fish examined thus far (n=34) contained microplastics. Current and future work includes examining the invasive Lionfish (Pterois spp.) for microplastics, investigating marine invertebrate species as well as examining environmental sources of microplastics (i.e. rivers, coastal waters and sand). Owing to concerns of pollutant accumulation on microplastics and potential migration into organismal tissues, we plan to analyse fish tissue for mercury and other persistent pollutants. Despite having ~110,000 inhabitants, the island nation of Grenada imported approximately 33 million plastic bottles in 2013, of which it is estimated less than 5% were recycled. Over 30% of the imported bottles were ‘unmanaged’, and as such are potential litter/marine debris. A revised Litter Abatement Act passed into law in Grenada in 2015, but little enforcement of the law is evident to date. A local Non-governmental organization (NGO) ‘The Grenada Green Group’ (G3) is focused on reducing litter in Grenada through lobbying government to implement the revised act and running sessions in schools, community groups and on local media and social media to raise awareness of the problems associated with plastics. A local private company has indicated willingness to support an Anti-Litter Campaign in 2018 and local awareness of the need for a reduction of single use plastic use and litter seems to be high. The Government of Grenada have called for a Sustainable Waste Management Strategy and a ban on both Styrofoam and plastic grocery bags are among recommendations recently submitted. A Styrofoam ban will be in place at the St. George’s University campus from January 1st, 2018 and many local businesses have already voluntarily moved away from Styrofoam. Our findings underscore the importance of continuing investigations into microplastics in marine life; this will contribute to understanding the associated health risks. Furthermore, our findings support action to mitigate the volume of plastics entering the world’s oceans. We hope that Grenada’s future will involve a lot less plastic. This research was supported by the Caribbean Node of the Global Partnership on Marine Litter.

Keywords: Caribbean, microplastics, pollution, small island developing nation

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1310 Climate Change and Its Effects on Terrestrial Insect Diversity in Mukuruthi National Park, Nilgiri Biosphere Reserve, Tamilnadu, India

Authors: M. Elanchezhian, C. Gunasekaran, A. Agnes Deepa, M. Salahudeen

Abstract:

In recent years climate change is one of the most emerging threats facing by biodiversity both the animals and plants species. Elevated carbon dioxide and ozone concentrations, extreme temperature, changes in rainfall patterns, insects-plant interaction are the main criteria that affect biodiversity. In the present study, which emphasis the climate change and its effects on terrestrial insect diversity in Mukuruthi National Park a protected areas of Western Ghats in India. Sampling was done seasonally at the three areas using pitfall traps, over the period of January to December 2013. The statistical findings were done by Shannon wiener diversity index (H). A significant seasonal variation pattern was detected for total insect’s diversity at the different study areas. Totally nine orders of insects were recorded. Diversity and abundance of terrestrial insects shows much difference between the Natural, Shoal forest and the Grasslands.

Keywords: biodiversity, climate change, mukuruthi national park, terrestrial invertebrates

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1309 Network Analysis to Reveal Microbial Community Dynamics in the Coral Reef Ocean

Authors: Keigo Ide, Toru Maruyama, Michihiro Ito, Hiroyuki Fujimura, Yoshikatu Nakano, Shoichiro Suda, Sachiyo Aburatani, Haruko Takeyama

Abstract:

Understanding environmental system is one of the important tasks. In recent years, conservation of coral environments has been focused for biodiversity issues. The damage of coral reef under environmental impacts has been observed worldwide. However, the casual relationship between damage of coral and environmental impacts has not been clearly understood. On the other hand, structure/diversity of marine bacterial community may be relatively robust under the certain strength of environmental impact. To evaluate the coral environment conditions, it is necessary to investigate relationship between marine bacterial composition in coral reef and environmental factors. In this study, the Time Scale Network Analysis was developed and applied to analyze the marine environmental data for investigating the relationship among coral, bacterial community compositions and environmental factors. Seawater samples were collected fifteen times from November 2014 to May 2016 at two locations, Ishikawabaru and South of Sesoko in Sesoko Island, Okinawa. The physicochemical factors such as temperature, photosynthetic active radiation, dissolved oxygen, turbidity, pH, salinity, chlorophyll, dissolved organic matter and depth were measured at the coral reef area. Metagenome and metatranscriptome in seawater of coral reef were analyzed as the biological factors. Metagenome data was used to clarify marine bacterial community composition. In addition, functional gene composition was estimated from metatranscriptome. For speculating the relationships between physicochemical and biological factors, cross-correlation analysis was applied to time scale data. Even though cross-correlation coefficients usually include the time precedence information, it also included indirect interactions between the variables. To elucidate the direct regulations between both factors, partial correlation coefficients were combined with cross correlation. This analysis was performed against all parameters such as the bacterial composition, the functional gene composition and the physicochemical factors. As the results, time scale network analysis revealed the direct regulation of seawater temperature by photosynthetic active radiation. In addition, concentration of dissolved oxygen regulated the value of chlorophyll. Some reasonable regulatory relationships between environmental factors indicate some part of mechanisms in coral reef area.

Keywords: coral environment, marine microbiology, network analysis, omics data analysis

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1308 Examination of the Satisfaction Levels of Pre-Service Teachers Concerning E-Learning Process in Terms of Different Variables

Authors: Agah Tugrul Korucu

Abstract:

Significant changes have taken place for the better in the bulk of information and in the use of technology available in the field of education induced by technological changes in the 21st century. It is mainly the job of the teachers and pre-service teachers to integrate information and communication technologies into education by means of conveying the use of technology to individuals. While the pre-service teachers are conducting lessons by using technology, the methods they have developed are important factors for the requirements of the lesson and for the satisfaction levels of the students. The study of this study is to examine the satisfaction levels of pre-service teachers as regards e-learning in a technological environment in which there are lesson activities conducted through an online learning environment in terms of various variables. The study group of the research is composed of 156 pre-service teachers that were students in the departments of Computer and Teaching Technologies, Art Teaching and Pre-school Teaching in the academic year of 2014 - 2015. The qualitative research method was adopted for this study; the scanning model was employed in collecting the data. “The Satisfaction Scale regarding the E-learning Process”, developed by Gülbahar, and the personal information form, which was developed by the researcher, were used as means of collecting the data. Cronbach α reliability coefficient, which is the internal consistency coefficient of the scale, is 0.91. SPSS computerized statistical package program and the techniques of medium, standard deviation, percentage, correlation, t-test and variance analysis were used in the analysis of the data.

Keywords: online learning environment, integration of information technologies, e-learning, e-learning satisfaction, pre-service teachers

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1307 Promoting Social Advocacy through Digital Storytelling: The Case of Ocean Acidification

Authors: Chun Chen Yea, Wen Huei Chou

Abstract:

Many chemical changes in the atmosphere and the ocean are invisible to the naked eye, but they have profound impacts. These changes not only confirm the phenomenon of global carbon pollution, but also forewarn that more changes are coming. The carbon dioxide gases emitted from the burning of fossil fuels dissolve into the ocean and chemically react with seawater to form carbonic acid, which increases the acidity of the originally alkaline seawater. This gradual acidification is occurring at an unprecedented rate and will affect the effective formation of carapace of some marine organisms such as corals and crustaceans, which are almost entirely composed of calcium carbonate. The carapace of these organisms will become more dissoluble. Acidified seawater not only threatens the survival of marine life, but also negatively impacts the global ecosystem via the food chain. Faced with the threat of ocean acidification, all humans are duty-bound. The industrial sector outputs the highest level of carbon dioxide emissions in Taiwan, and the petrochemical industry is the major contributor. Ever since the construction of Formosa Plastics Group's No. 6 Naphtha Cracker Plant in Yunlin County, there have been many environmental concerns such as air pollution and carbon dioxide emission. The marine life along the coast of Yunlin is directly affected by ocean acidification arising from the carbon emissions. Societal change demands our willingness to act, which is what social advocacy promotes. This study uses digital storytelling for social advocacy and ocean acidification as the subject of a visual narrative in visualization to demonstrate the subsequent promotion of social advocacy. Storytelling can transform dull knowledge into an engaging narrative of the crisis faced by marine life. Digital dissemination is an effective social-work practice. The visualization promoting awareness on ocean acidification disseminated via social media platforms, such as Facebook and Instagram. Social media enables users to compose their own messages and share information across different platforms, which helps disseminate the core message of social advocacy.

Keywords: digital storytelling, visualization, ocean acidification, social advocacy

Procedia PDF Downloads 95
1306 Speech Detection Model Based on Deep Neural Networks Classifier for Speech Emotions Recognition

Authors: A. Shoiynbek, K. Kozhakhmet, P. Menezes, D. Kuanyshbay, D. Bayazitov

Abstract:

Speech emotion recognition has received increasing research interest all through current years. There was used emotional speech that was collected under controlled conditions in most research work. Actors imitating and artificially producing emotions in front of a microphone noted those records. There are four issues related to that approach, namely, (1) emotions are not natural, and it means that machines are learning to recognize fake emotions. (2) Emotions are very limited by quantity and poor in their variety of speaking. (3) There is language dependency on SER. (4) Consequently, each time when researchers want to start work with SER, they need to find a good emotional database on their language. In this paper, we propose the approach to create an automatic tool for speech emotion extraction based on facial emotion recognition and describe the sequence of actions of the proposed approach. One of the first objectives of the sequence of actions is a speech detection issue. The paper gives a detailed description of the speech detection model based on a fully connected deep neural network for Kazakh and Russian languages. Despite the high results in speech detection for Kazakh and Russian, the described process is suitable for any language. To illustrate the working capacity of the developed model, we have performed an analysis of speech detection and extraction from real tasks.

Keywords: deep neural networks, speech detection, speech emotion recognition, Mel-frequency cepstrum coefficients, collecting speech emotion corpus, collecting speech emotion dataset, Kazakh speech dataset

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1305 Water Quality and Coastal Management Profile Assessment of Puerto Galera Bay, Philippines

Authors: Ma. Manna Farrel B. Pinto

Abstract:

As global industrialization progresses, the environment remains to be at risk of disturbances brought by developments of cities and communities. Impacts of flourishing industries such as tourism require rapid growth of establishments and may threaten ecosystems and natural resources. Puerto Galera as a biosphere reserve and declared as the Center of the World’s Center of Marine Shorefish Biodiversity is on the brink of ecological deterioration as tourism further develops in its coastal areas. Apparently, attempts were initiated to establish a baseline for designation of protection in the economic and coastal marine zones of Puerto Galera but continuity of its implementation and coordination of concerned units remains deficient. Indications of eutrophication have been observed based on water quality analysis although parameter values still comply with the national standards for coastal waters. Water quality data, biodiversity and hydrodynamic information, gathered from studies, and local government units were analysed to assess the condition of the coast as well as acting policies implemented by the local authorities. Sources of contaminants were also located in its three main communities, and their shores wherein in recommendations for installing wastewater treatment facilities and further improvement of policies of waste discharge must be addressed. With a conceptual framework proposed in the study, a comprehensive data analysis and coordinated management are necessary to form an integrated coastal management for further protection and preservation of the sustainable coastal marine ecosystem of Puerto Galera.

Keywords: coastal management, environmental management, integrated resource management, Puerto Galera

Procedia PDF Downloads 243
1304 Characterization of Nano Coefficient of Friction through Lfm of Superhydrophobic/Oleophobic Coatings Applied on 316l Ss

Authors: Hamza Shams, Sajid Saleem, Bilal A. Siddiqui

Abstract:

This paper investigates the coefficient of friction at nano-levels of commercially available superhydrophobic/oleophobic coatings when applied over 316L SS. 316L Stainless Steel or Marine Stainless Steel has been selected for its widespread uses in structures, marine and biomedical applications. The coatings were investigated in harsh sand-storm and sea water environments. The particle size of the sand during the procedure was carefully selected to simulate sand-storm conditions. Sand speed during the procedure was carefully modulated to simulate actual wind speed during a sand-storm. Sample preparation was carried out using prescribed methodology by the coating manufacturer. The coating’s adhesion and thickness was verified before and after the experiment with the use of Scanning Electron Microscopy (SEM). The value for nano-level coefficient of friction has been determined using Lateral Force Microscopy (LFM). The analysis has been used to formulate a value of friction coefficient which in turn is associative of the amount of wear the coating can bear before the exposure of the base substrate to the harsh environment. The analysis aims to validate the coefficient of friction value as marketed by the coating manufacturers and more importantly test the coating in real-life applications to justify its use. It is expected that the coating would resist exposure to the harsh environment for a considerable amount of time. Further, it would prevent the sample from getting corroded in the process.

Keywords: 316L SS, scanning electron microscopy, lateral force microscopy, marine stainless steel, oleophobic coating, superhydrophobic coating

Procedia PDF Downloads 462
1303 Amphiphilic Compounds as Potential Non-Toxic Antifouling Agents: A Study of Biofilm Formation Assessed by Micro-titer Assays with Marine Bacteria and Eco-toxicological Effect on Marine Algae

Authors: D. Malouch, M. Berchel, C. Dreanno, S. Stachowski-Haberkorn, P-A. Jaffres

Abstract:

Biofilm is a predominant lifestyle chosen by bacteria. Whether it is developed on an immerged surface or a mobile biofilm known as flocs, the bacteria within this form of life show properties different from its planktonic ones. Within the biofilm, the self-formed matrix of Extracellular Polymeric Substances (EPS) offers hydration, resources capture, enhanced resistance to antimicrobial agents, and allows cell-communication. Biofouling is a complex natural phenomenon that involves biological, physical and chemical properties related to the environment, the submerged surface and the living organisms involved. Bio-colonization of artificial structures can cause various economic and environmental impacts. The increase in costs associated with the over-consumption of fuel from biocolonized vessels has been widely studied. Measurement drifts from submerged sensors, as well as obstructions in heat exchangers, and deterioration of offshore structures are major difficulties that industries are dealing with. Therefore, surfaces that inhibit biocolonization are required in different areas (water treatment, marine paints, etc.) and many efforts have been devoted to produce efficient and eco-compatible antifouling agents. The different steps of surface fouling are widely described in literature. Studying the biofilm and its stages provides a better understanding of how to elaborate more efficient antifouling strategies. Several approaches are currently applied, such as the use of biocide anti-fouling paint6 (mainly with copper derivatives) and super-hydrophobic coatings. While these two processes are proving to be the most effective, they are not entirely satisfactory, especially in a context of a changing legislation. Nowadays, the challenge is to prevent biofouling with non-biocide compounds, offering a cost effective solution, but with no toxic effects on marine organisms. Since the micro-fouling phase plays an important role in the regulation of the following steps of biofilm formation7, it is desired to reduce or delate biofouling of a given surface by inhibiting the micro fouling at its early stages. In our recent works, we reported that some amphiphilic compounds exhibited bacteriostatic or bactericidal properties at a concentration that did not affect eukaryotic cells. These remarkable properties invited us to assess this type of bio-inspired phospholipids9 to prevent the colonization of surfaces by marine bacteria. Of note, other studies reported that amphiphilic compounds interacted with bacteria leading to a reduction of their development. An amphiphilic compound is a molecule consisting of a hydrophobic domain and a polar head (ionic or non-ionic). These compounds appear to have interesting antifouling properties: some ionic compounds have shown antimicrobial activity, and zwitterions can reduce nonspecific adsorption of proteins. Herein, we investigate the potential of amphiphilic compounds as inhibitors of bacterial growth and marine biofilm formation. The aim of this study is to compare the efficacy of four synthetic phospholipids that features a cationic charge (BSV36, KLN47) or a zwitterionic polar-head group (SL386, MB2871) to prevent microfouling with marine bacteria. We also study the toxicity of these compounds in order to identify the most promising compound that must feature high anti-adhesive properties and a low cytotoxicity on two links representative of coastal marine food webs: phytoplankton and oyster larvae.

Keywords: amphiphilic phospholipids, bacterial biofilm, marine microfouling, non-toxic antifouling

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1302 The Development of Micro Patterns Using Benchtop Lithography for Marine Antifouling Applications

Authors: Felicia Wong Yen Myan, James Walker

Abstract:

Development of micro topographies usually begins with the fabrication of a master stamp. Fabrication of such small structures can be technically challenging and expensive. These techniques are often used for applications where patterns only cover a small surface area (e.g. semiconductors, microfluidic channels). This research investigated the use of benchtop lithography to fabricate patterns with average widths of 50 and 100 microns on silicon wafer substrates. Further development of this method will attempt to layer patterns to create hierarchical structures. Photomasks consisted of patterns printed onto transparency films with a high resolution printer and a fully patterned 10cm by 10cm area has been successfully developed. UV exposure was carried out with a self-made array of ultraviolet LEDs that was positioned a distance above a glass diffuser. Observations under a light microscope and SEM showed that developed patterns exhibit an adequate degree of fidelity with patterns from the master stamp.

Keywords: lithography, antifouling, marine, microtopography

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1301 Sustainable Marine Tourism: Opinion and Segmentation of Italian Generation Z

Authors: M. Bredice, M. B. Forleo, L. Quici

Abstract:

Coastal tourism is currently facing huge challenges on how to balance environmental problems and tourist activities. Recent literature shows a growing interest in the issue of sustainable tourism from a so-called civilized tourists’ perspective by investigating opinions, perceptions, and behaviors. This study investigates the opinions of youth on what makes them responsible tourists and the ability of coastal marine areas to support tourism in future scenarios. A sample of 778 Italians attending the last year of high school was interviewed. Descriptive statistics, tests, and cluster analyses are applied to highlight the distribution of opinions among youth, detect significant differences based on demographic characteristics, and make segmentation of the different profiles based on students’ opinions and behaviors. Preliminary results show that students are largely convinced (62%) that by 2050 the quality of coastal environments could limit seaside tourism, while 10% of them believe that the problem can be solved simply by changing the tourist destination. Besides the cost of the holiday, the most relevant aspect respondents consider when choosing a marine destination is the presence of tourist attractions followed by the quality of the marine-coastal environment, the specificity of the local gastronomy and cultural traditions, and finally, the activities offered to guests such as sports and events. The reduction of waste and lower air emissions are considered the most important environmental areas in which marine-coastal tourism activities can contribute to preserving the quality of seas and coasts. Areas in which, as a tourist, they believe possible to give a personal contribution were (responses “very much” and “somewhat”); do not throw litter in the sea and on the beach (84%), do not buy single-use plastic products (66%), do not use soap or shampoo when showering in beaches (53%), do not have bonfires (47%), do not damage dunes (46%), and do not remove natural materials (e.g., sand, shells) from the beach (46%). About 6% of the sample stated that they were not interested in contributing to the aforementioned activities, while another 7% replied that they could not contribute at all. Finally, 80% of the sample has never participated in voluntary environmental initiatives or citizen science projects; moreover, about 64% of the students have never participated in events organized by environmental associations in marine or coastal areas. Regarding the test analysis -based on Kruskal-Wallis and Mann and Whitney tests - gender, region, and studying area of students reveals significance in terms of variables expressing knowledge and interest in sustainability topics and sustainable tourism behaviors. The classification of the education field is significant for a great number of variables, among which those related to several sustainable behaviors that respondents declare to be able to contribute as tourists. The ongoing cluster analysis will reveal different profiles in the sample and relevant variables. Based on preliminary results, implications are envisaged in the fields of education, policy, and business strategies for sustainable scenarios. Under these perspectives, the study has the potential to contribute to the conference debate about marine and coastal sustainable development and management.

Keywords: cluster analysis, education, knowledge, young people

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1300 Maintenance Dredging at Port of Townsville

Authors: Mohamed Jaditager, Julie Lovisa, Nagaratnam Sivakugan

Abstract:

The Port of Townsville conducts regular annual maintenance dredging to maintain depths of its harbor basin and approach channels for the navigational safety of the vessels against the natural accumulation of marine sediments. In addition to the regular maintenance dredging, the port undertakes emergency dredging in cases where large quantities of sediments are mobilized and deposited in port waters by cyclone or major flood events. The maintenance dredging material derived from the port may be disposed at sea or on land in accordance with relevant state and commonwealth regulations. For the land disposal, the dredged mud slurry is hydraulically placed into containment ponds and left to undergo sedimentation and self-weight consolidation to form fill material for land reclamation. This paper provides an overview of the maintenance dredging at the Port of Townsville and emphasis on maintenance dredging requirements, sediment quality, bathymetry, dredging methods used, and dredged material disposal options.

Keywords: consolidation, dredged material, maintenance dredging, marine sediments, sedimentation

Procedia PDF Downloads 417
1299 Mitigation of Offshore Piling Noise Effects on Marine Mammals

Authors: Waled A. Dawoud, Abdelazim M. Negm, Nasser M. Saleh

Abstract:

Offshore piling generates underwater sound at level high enough to cause physical damage or hearing impairment to the marine mammals. Several methods can be used to mitigate the effect of underwater noise from offshore pile driving on marine mammals which can be divided into three main approaches. The first approach is to keep the mammal out of the high-risk area by using aversive sound waves produced by acoustic mitigation devices such as playing-back of mammal's natural predator vocalization, alarm or distress sounds, and anthropogenic sound. The second approach is to reduce the amount of underwater noise from pile driving using noise mitigation techniques such as bubble curtains, isolation casing, and hydro-sound dampers. The third approach is to eliminate the overlap of underwater waves by using prolonged construction process. To investigate the effectiveness of different noise mitigation methods; a pile driven with 235 kJ rated energy diesel hammer near Jeddah Coast, Kingdom of Saudi Arabia was used. Using empirical sound exposure model based on Red Sea characteristics and limits of National Oceanic and Atmospheric Administration; it was found that the aversive sound waves should extend to 1.8 km around the pile location. Bubble curtains can reduce the behavioral disturbance area up to 28%; temporary threshold shift up to 36%; permanent threshold shift up to 50%; and physical injury up to 70%. Isolation casing can reduce the behavioral disturbance range up to 12%; temporary threshold shift up to 21%; permanent threshold shift up to 29%; and physical injury up to 46%. Hydro-sound dampers efficiency depends mainly on the used technology and it can reduce the behavioral disturbance range from 10% to 33%; temporary threshold shift from 18% to 25%; permanent threshold shift from 32% to 50%; and physical injury from 46% to 60%. To prolong the construction process, it was found that the single pile construction, use of soft start, and keep time between two successive hammer strikes more than 3 seconds are the most effective techniques.

Keywords: offshore pile driving, sound propagation models, noise effects on marine mammals, Underwater noise mitigation

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1298 The Effect of Oil Pollution on Marine Microbial Populations in Israeli Coastal Waters

Authors: Yael Shai, Dror L. Angel, Dror Zurel, Peleg Astrahan, Maxim Rubin-Blum, Eyal Rahav

Abstract:

The high demand for oil and its by-products is symptomatic of the 21st century and occasionally leads to oil spills and pollution of coastal waters. Marine oil pollution may originate from a variety of sources -urban runoff, tanker cleaning, drilling activities, and oil spills. These events may release large amounts of highly toxic polycyclic aromatic hydrocarbons (PAHs) and other pollutants to coastal water, thereby threatening local marine life. Here, we investigated the effects of crude oil on the temporal dynamics of phytoplankton and heterotrophic bacteria in Israeli coastal waters. To this end, we added crude oil (500 µm thick layer, with and without additional nutrients; NO₃ and PO₄) to mesocosms (1m³ bags) containing oligotrophic surface coastal water collected near Haifa during summer and winter. Changes in phytoplankton biomass, activity and diversity were monitored daily for 5-6 days. Our results demonstrate that crude oil addition resulted in a pronounced decrease in phytoplankton biomass and production rates, while heterotrophic bacterial production increased significantly. Importantly, a few days post addition we found that the oil-degrading bacteria, Oleibacter sp. and Oleispira sp. appeared in the mesocosms and that the addition of nutrients (along with the crude oil) further increased this trend. This suggests that oil-degrading bacteria may be NO₃ and PO₄ limited in Israeli coastal waters. The results of this study should enable us to establish improved science-based environmental policy with respect to handling crude oil pollution in this region.

Keywords: heterotrophic bacteria, nutrients, mesocosm, oil pollution, oligotrophic, phytoplankton

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1297 Research of Acoustic Propagation within Marine Riser in Deepwater Drilling

Authors: Xiaohui Wang, Zhichuan Guan, Roman Shor, Chuanbin Xu

Abstract:

Early monitoring and real-time quantitative description of gas intrusion under the premise of ensuring the integrity of the drilling fluid circulation system will greatly improve the accuracy and effectiveness of deepwater gas-kick monitoring. Therefore, in order to study the propagation characteristics of ultrasonic waves in the gas-liquid two-phase flow within the marine riser, in this paper, a numerical simulation method of ultrasonic propagation in the annulus of the riser was established, and the credibility of the numerical analysis was verified by the experimental results of the established gas intrusion monitoring simulation experimental device. The numerical simulation can solve the sound field in the gas-liquid two-phase flow according to different physical models, and it is easier to realize the single factor control. The influence of each parameter on the received signal can be quantitatively investigated, and the law with practical guiding significance can be obtained.

Keywords: gas-kick detection, ultrasonic, void fraction, coda wave velocity

Procedia PDF Downloads 126