Clean Ocean Research Articles

Application of Path Planning and Obstacle Avoidance for Riverbank Inspection.

Most coastal trash comes from land. To prevent and control ocean pollution, it should be handled using sources that can maintain a clean ocean and improve the marine ecological environment. The proposed system can be used to inspect riverbanks and identify garbage on riverbanks. This waste can then be cleaned up before flowing into the sea. In this study, we utilized an unmanned aerial vehicle (UAV) to inspect riverbanks and applied path planning and obstacle avoidance to enhance the efficiency of UAV performance and ensure good adaptability in a complicated environment. Since most rivers in the middle and upper sections of the study area are rough and meandering, path planning was first addressed so that the drone could use the shortest path and less energy to perform the inspection task. Branches frequently protrude from the riverbank on both sides. Therefore, an instant obstacle avoidance algorithm was added to avoid various obstacles. Path planning was based on an Improved Particle Swarm Optimization (IPSO). A fuzzy system was added to the IPSO to adjust the parameters that could shorten the planned path. The Artificial Potential Field (APF) was applied for real-time dynamic obstacle avoidance. The proposed UAV system could be used to perform riverbank inspection successfully.

Multilateral Debt Relief for Clean Ocean Energy

As states bring more and more offshore wind online and build renewable energy capacity, the promise of large-scale ocean renewables such as offshore wind is not shared equally across all coastal states. This paper examines the situation of coastal states identified by the World Bank as Heavily Indebted Poor Countries (HIPCs) in the context of the boom in offshore wind investment. Specifically, the paper looks at the limited access to renewable energy production exacerbated by ongoing public debt loads, and the almost complete lack of access to clean ocean energy development for the poorest coastal states. Using statistics from the International Renewable Energy Agency and datasets from the Our World in Data project, this paper highlights that the most indebted coastal states only have access to 0.69% of the available renewable energy even though these states represent 4.6% of the global population. In the context of state responsibility for failing to meet climate obligations under the UNFCCC, this paper argues that a sovereign debt relief package offers an equitable remedy to HIPC coastal states, many of whom owe a substantial portion of their GDP as external public debt. The debt service payments would be invested in the upfront capital costs of ocean-based clean energy. These types of debt relief arrangements address international state responsibility and offer the dual co-benefits of long-term economic development and low-carbon sustainability.

Analysis of affecting factors for laser underwater transmission echo signals based on semi-analytic Monte Carlo

ABSTRACT In order to design an economical and reliable LiDAR, it is necessary to quantify the influence of different factors on the attenuation of laser propagation in water. Although these factors have been widely investigated, a complete understanding is still few. In addition, a comparative analysis between the measured data and the simulation results of LiDAR to build the design of LiDAR is still lacking. For these reasons, a semi-analytical Monte Carlo method was applied to establish a simulation model of the underwater laser echo signal propagation. The control variable method was quantified with the three major types of influencing factors: 1) LiDAR system parameters, 2) water optical characteristics and 3) external conditions. The effects of these different influencing factors on laser underwater echo signal transmission were investigated. With the experimental results, the attenuation rate of laser transmission in turbid harbour was 7.1 and 19.2 times higher than that in coastal water and clean ocean. Compared with other influencing factors, the optical characteristics of water have the most significant influence on underwater laser transmission. The laser echo signals in water with different concentrations of suspended solids were investigated in a laboratory tank using a LiDAR prototype developed by our research group. The results were compared with that from the semi-analytical Monte Carlo simulation to further explore the influence of the inherent optical characteristics of water on laser energy attenuation. The experimental results showed that with increasing water turbidity, the light beam diverged by strong scattering, the size of the light spot increased, the energy of the echo signal decreased as a whole and the backscattering signal of the water changed significantly. The determination coefficients and relative errors of the measured echo signals and the normalized simulation results were 0.99 and 0.01, respectively, which demonstrate the reliability of LiDAR prototype.

COMPOSTOS PERFLUORADOS: UMA AMEAÇA AO OCEANO LIMPO

PERFLUORINATED COMPOUNDS: A THREAT TO THE CLEAN OCEAN. Per- and polyfluorinated compounds (PFAS) have been produced for more than seven decades and widely used in the most diverse areas, from food packaging, textile industry, aqueous film-forming foam to pesticides and surfactants. However, the characteristics that allow the wide range of applications also bring environmental concerns due to their persistence and toxic effects. Although the ocean might be the final destination of PFAS, in Brazil few studies have been carried out about PFAS and there are many gaps regarding their environmental occurrence, sources and distribution. Therefore, this article presents a review of the production, use, behavior in the environment, legislation, the occurrence of classic PFAS in the Brazilian marine environment, as well as perceptions about their fluorinated substitutes.

Green maritime practices in an emerging economy towards the achievement of sustainable development: a Ghanaian context

PurposeThe objective to achieve economic growth and sustainable development (SD) within the maritime industry has ever since been the ultimate goal of the International Maritime Organization and its stakeholders. Coupled with this effect, the United Nations organization has also mandated all its bodies to adopt sustainable working policies and practices towards the achievement of SD in its 2030 Agenda. From the standpoint of an emerging economy, this study aims to examine green maritime practices adopted by maritime authorities towards the achievement of SD in the maritime industry of Ghana. The proposed conceptual model of this study supports the natural resource-based view theory advocated by Hart (1995).Design/methodology/approachThe dataset of this study was gathered using semi-structured questionnaires. A total of 635 valid responses were received as feedback which were tested and analyzed using partial least square structural equation modelling. The rationale for the adoption of this analytical tool is its resilient ability to handle a relatively small quantity of datasets. It is also suitable for empirical studies involving model development and at the early stage of theory development.FindingsThe findings of the study are as follows; firstly, quality maritime education and training directly and significantly influence green maritime transport (GMT), clean ocean and maritime resource conservation (COMRC), green port operations and services (GPOS), SD and waste management and treatment systems (WMTS). Secondly, GMT, COMRC, GPOS and WMTS have a direct significant influence on SD. Lastly, GMT, COMRC, GPOS and WMTS partially mediate the relationship between quality maritime education and training and SD.Practical implicationsThis study proposes a conceptual model that attempts to explain to maritime authorities and stakeholders that although the adoption of green maritime practices significantly influences SD, yet, it may be insufficient without quality maritime education and training provided to maritime professionals. Hence, emphasizing that all maritime personnel receive quality maritime education and training to enhance the long-term achievement of SD in the maritime industry. It also attempts to prove and suggest to maritime authorities how they can collectively integrate both onshore and offshore green maritime practices to achieve SD.Originality/valueThe originality of this study shows in testing a conceptual model that affirms that, achieving SD in the maritime industry is dependent on quality maritime education and training received by maritime personnel, hence, demonstrating the significant role of maritime training institutions towards the maritime industry and the achievement of SD.

A Reinforcement-Learning-Based Beam Adaptation for Underwater Optical Wireless Communications

Underwater optical wireless communications (UOWCs) have recently appeared as an attractive solution for many applications, such as remote controlling and sensing due to its advantages, such as high transmission rate, ultrawide bandwidth, and low latency. However, due to the harsh underwater conditions, UOWC faces challenges, such as water absorption, scattering, and pointing-acquisition-and-tracking (PAT) problems. This is mainly due to the dynamicity existing underwater. Consequently, this leads to packet loss and hence deteriorates the reliability and link quality of such networks. Such a problem can affect the degree of connectivity and end-to-end (E2E) performance of the communication system. The existing solutions in the literature are based on predefined models, assuming full knowledge of the environment. However, such models do not optimally treat the dynamicity existing underwater. This article proposes novel beam adaptation methods based on reinforcement learning (RL) for point-to-point UOWC. The first method aims to optimize the light beamwidth; the second method focuses on adapting the beam orientation, whereas the last one optimizes both the light’s beamwidth and beam orientation. Our proposed RL-based solutions yield optimal positioning and beamwidth of the light source and improve the considered communication link’s success rate. They also guarantee better link quality in terms of signal-to-noise ratio (SNR) compared to the uncertainty disk static method for four different underwater environments, including pure seawater, clean ocean, coastal ocean, and turbid harbor.

BLUE ECONOMY DEVELOPMENT IN INDONESIA

This work is highlighting the possibilities to enhance blue economy development in Indonesia with environmentally friendly and sustainable solutions to assure successful future and growth. Literatures review and Focus Group Discussion were conducted to collect Indonesia profiles and potential factors to be developed in blue economic strategic planning. Blue economy employment opportunities would enhance gender balance also due to specialization job offers where females proved to be potentially more productive than males. Marine Spatial Planning (MSP) originates from nature conservation approach in the Great Barrier Reef. MSP has gain since then a lot of attention due to overused of marine areas. Ecosystem based approach for MSP could result in clean, healthy, safe, productive, and diverse ocean. It could influence where and when the human activities could occur. MSP normally require authority to plan the one and another to implement. Funding normally has government based but could be supported with grants, partnerships, and private sector funding. All activities have to be monitored to assure progress of achievements and environmental effect.
 Keywords: Blue Economy Development, Indonesia, Gresik, Marine Spatial Planning

Multi-dimensional satellite observations of aerosol properties and aerosol types over three major urban clusters in eastern China

Abstract. Using 14 years (2007–2020) of data from passive (MODIS/Aqua) and active (CALIOP/CALIPSO) satellite measurements over China, we investigate (1) the temporal and spatial variation of aerosol properties over the Beijing–Tianjin–Hebei (BTH) region, the Yangtze River Delta (YRD), and the Pearl River Delta (PRD) and (2) the vertical distribution of aerosol types and extinction coefficients for different aerosol optical depth (AOD) and meteorological conditions. The results show the different spatial patterns and seasonal variations of the AOD over the three regions. Annual time series reveal the occurrence of AOD maxima in 2011 over the YRD and in 2012 over the BTH and PRD; thereafter the AOD decreases steadily. Using the CALIOP vertical feature mask, the relative frequency of occurrence (rFO) of each aerosol type in the atmospheric column is analyzed: rFOs of dust and polluted dust decrease from north to south; rFOs of clean ocean, polluted continental, clean continental and elevated smoke aerosol increase from north to south. In the vertical, the peak frequency of occurrence (FO) for each aerosol type depends on region and season and varies with AOD and meteorological conditions. In general, three distinct altitude ranges are observed with the peak FO at the surface (clean continental and clean marine aerosol), at ∼1 km (polluted dust and polluted continental aerosol) and at ∼3 km (elevated smoke aerosol), whereas dust aerosol may occur over the whole altitude range considered in this study (from the surface up to 8 km). The designation of the aerosol type in different height ranges may to some extent reflect the CALIOP aerosol type classification approach. Air mass trajectories indicate the different source regions for the three study areas and for the three different altitude ranges over each area. In this study nighttime CALIOP profiles are used. The comparison with daytime profiles shows substantial differences in the FO profiles with altitude, which suggest effects of boundary layer dynamics and aerosol transport on the vertical distribution of aerosol types, although differences due to day–night CALIOP performance cannot be ruled out.

Offshore Conceptual Plastic Waste Collection and Treatment Towards Clean Ocean

Offshore Conceptual Plastic Waste Collection and Treatment Towards Clean Ocean

Pollutants in the South Atlantic Ocean: Sources, Knowledge Gaps and Perspectives for the Decade of Ocean Science

The current manuscript presents the main issues related to the “Clean Ocean” outcome that arose from the Regional South Atlantic (SA) Planning Workshop for the UN Decade of Ocean Science and five Brazilian Regional Planning Workshops. An interdisciplinary andtrans-sectoral group constituted by the academia, non-governmental agencies, the private sector, decision-makers, the navy, and local communities discussed the main anthropogenic drivers compromising the current environmental status of the SA and its ecological services, and debated the main research gaps, priorities and needs for improving technical and structural capacities in order to roadmap the Brazilian actions for the Decade of Ocean Science. The aim of this review is to contribute to a social solution-driven understanding of the ocean ecosystems, to create conditions to promote sustainable development and to secure a clean, healthy ocean. We are proposing a list of actions to be implemented by the Decade of Ocean Science that will have the pivotal role to promote technical and scientific capacity development, increase research infrastructure and institutional frameworks, develop national public policies aimed at reducing the input of pollutants and management of impacts, and warranting food security and ecosystem health. The earlier the actions in controlling pollutants are implemented, along with the identification of key sources and prevention of crossing of thresholds will help to avert worst-case scenarios, reducing the socio-economic disparities of impacts across nations and social groups and supporting the sustainable development of a pollutant-free ocean.

Değişik Ortam Ve Sistem Parametreleri İçin Sualtı Kablosuz Optik Haberleşme Monte Carlo Kanal Kapasitesinin İncelenmesi

Increasing interest in oceans increases the scientific, commercial and military studies in this field, in which underwater wireless communication systems are frequently used. In literature, underwater wireless, synchronous, high speed data transfer can only be done with optical systems. The distorting effects of underwater environment (UE) on optical waves significantly affect the communication distance and speed of underwater wireless optical communication (UWOC) systems. Therefore, in order to design reliable UWOC systems, it is important to examine effects of various UEs on UWOC systems on a realistic channel model. In this study, instead of the approximate channel models, Monte Carlo approach UWOC channel model, which is accepted in literature with its high accuracy and sensitivity, was used, and effects of the transmitter's beam divergence angle and aperture diameter of receiver parameters, which are important design parameters for UWOC systems, on a typical UWOC system were investigated. In this study, three various UEs, namely clean ocean, coastal ocean and harbor waters, which are frequently used as benchmarks in the literature, were taken into consideration, and channel impulse responses, signal to noise ratios and channel capacity distributions were presented and interpreted for each UE. With the results obtained, the communication speed and distance limits of a typical UWOC system were determined, and a prediction was provided for UWOC systems that can be used in various UEs and parameter values.

The Ocean Decade: A True Ecosystem Modeling Challenge

The UN declared the 2021–2030 as the Decade of Ocean Science for Sustainable Development (Ocean Decade). The Ocean Decade's vision is to develop scientific knowledge, build infrastructure and foster relationships for a sustainable and healthy ocean. The Ocean Decade aims to achieve six societal outcomes: (1) A clean ocean, through identifying and removing sources of pollution; (2) A healthy and resilient ocean, with mapped and protected marine ecosystems; (3) A predicted ocean, enabling society to understand current and future ocean conditions; (4) A safe ocean, protecting people from ocean hazards; (5) A sustainably harvested ocean, providing food and resources for the blue economy; and (6) A transparent ocean, giving citizens equitable access to data, information and technologies. It also aims to provide concrete scientific support to coastal management, adaptation and restoration, marine spatial planning, marine protected areas, fisheries management, sustainable expansion of the blue economy, nationally determined contributions to the United Nations Framework Convention on Climate Change (UNFCCC), national ocean policies, development of national Research and Development (R&D), capacity development, and early warning systems.

Simulation Data of Regional Economic Analysis of OTEC for Applicable Area

To mitigate the power shortage problem in the South Pacific island nations and the equatorial area, we studied the development characteristics of ocean thermal energy conversion (OTEC) using abundant clean ocean energy. Through the simulation of open- and closed-cycle OTEC, the generation amount and its economic efficiency were compared, and the application characteristics of the power generation cycle according to the seawater temperature distribution were compared by applying various seawater temperature conditions. According to the characteristics of seawater heat sources in the region, the power generation output was about 883.2 kW in Samoa, and the average power generation by region was about 650.5 kW for the open-cycle OTEC model. Regional revenue up to approximately $8,487,000 was generated in Kiribati, driven by the higher electricity tariff of $0.327/kWh and high water costs of $5.86/ton. With the spread of 50 MW commercial plants, Kiribati had a high net present value of $1,930,402,000, and its internal rate of return was more than 37.0%. This paper is presents a method of securing economic feasibility of OTEC according to various heat source conditions and economic conditions in the region, while it also analyzes the capacity and type of the power plant.

Aerosol Effects on Lightning Characteristics: A Comparison of Polluted and Clean Regimes

AbstractOceanic lightning can be a sensitive indicator of aerosol effects on lightning characteristics as thermodynamic contrast is indistinct over adjacent oceanic regions. The study presents discernable aerosol impacts on lightning characteristics by analyzing 2 years (2017–2018) of intracloud (IC) and cloud‐to‐ground (CG) lightning data from Earth Networks Total Lightning Network over two key regions in southern South China Sea. Mean stroke density, IC/CG ratio, +IC fraction, and +CG fraction in polluted conditions are respectively 3.7, 2, 1.2, and 5.8‐fold larger than unpolluted counterparts. Total stroke contrast is further confirmed with the GLD360 network. Thermodynamic parameters conversely support slightly stronger convection over clean ocean. Clear evidence shows cloud droplet size diminishes with added aerosol. Aerosol invigorates more frequent and robust mixed‐phase development, endowing maritime convection with continental characteristics. Modifications in the charge reversal temperature and lower and upper positive charge regions are speculated on as means for stimulating more positive ICs and CGs.

폐쇄형 해수온도차발전의 실증 적용을 위한 지역 경제성 분석 시뮬레이션

As a means to solve the power shortage problem in the South Pacific island nations and the equator, we studied the development characteristics of ocean thermal energy conversion (OTEC) using near-infinity clean ocean energy. Through the simulation of the closed OTEC plant under development, the generation amount and its economic efficiency were compared and the application characteristics of the power generation cycle according to the seawater temperature distribution were compared by applying various seawater temperature conditions. According to the characteristics of seawater heat sources in the region, the power generation output was about 759.9 kW in Kiribati, and the average power generation by region was about 590.9 kW. Regional electricity sales generated about 8,487 thousand dollars in Kiribati, which had a high power cost of 0.327 $/kWh, and 1,278 thousand dollars in Australia, generating 0.29 $/kWh. With the spread of 50 MW commercial plants, Australia and Kiribati have high net present values (NPV) of 108,000 and 580,000 thousand dollars, respectively, and their internal rate of return (IRR) are more than 8.5% and 19.6%, respectively. In the future, various benefits will be applied to secure economic feasibility and accelerate the spread of closed OTEC plant.

Proposed Advanced Training & Educational Methodologies, for Tanker & Gas Industry

Oil and gas are considered to be among the world's most prized resources. Hence, no doubtfully, The oil and gas industry plays a significant role in the global economy. Petroleum itself is used for numerous products, in addition to serving as the world's primary fuel source. Furthermore, The processes and Technologies concerned in producing and distributing oil and gas are highly complex, capital-intensive and necessitate state-of-the-art technology , nonetheless , rather more importantly human resources operating these technologies in a safe efficient mode. Here arises main concern ! What will be ideal global unified education and training methodologies to be provided by Maritime education & Training Institutes " MET for these labour in such critical rather indispensable industry? To ensure " Safer Seas & Cleaner oceans" (IMO/ IMCO 1994). This paper will illustrate ideal training & education methodologies to be delivered to these crews, in campus or rather on-board. Highlighting current conventions for promoting skills and inducing quality for such dedicated rather crucial industry.

Adequacy of national laws for Malaysian ocean governance for the next decade†

AbstractCurrent sectoral practices in ocean governance are insufficient to meet the needs of the next decade where the safety and security of navigation in clean and healthy oceans is a priority without compromising the political independence, integrity and security of the nation. The Ocean Law, Policy and Strategic Framework in Malaysia can be said to be a journey of a 1000 miles of which we have currently embarked on a few steps. There are many factors that play an important role in ocean governance such as government commitment, and institutional and human resource capacity. This paper identifies the lacunae in current legal framework and concludes with some pointers for ocean governance purposes to avoid irreversible trends. For the next decade, one way forward to sustainably develop the living resources of the oceans lies in the adoption of an eco-system based approach to oceans management and for the rest of the challenges a cross-sectoral approach may prove effective.

A Comparative Review between the English Language Programs of Maritime Institutes in Korea and Europe

This paper compares the English language programs of two maritime institutes in very different parts of the world, South Korea and Belgium. It will show that although both institutes comply with the minimum standard set by the STCW Code issued by the IMO, course contents and requirements can vary greatly. Method of class delivery, choice of learning tools and testing will be examined to illustrate some of these differences. This paper will show that in order to train new seafarers in the best possible way that will fulfill the IMO mandate of Safer Shipping and Cleaner Oceans, continual review and development of course curriculum should be an ongoing process that focusing on encouraging cadets to communicate in a targeted, efficient and professional way within a nautical context. This paper will show by comparison the huge potential that the Korean Maritime English program has for positive change and growth.

Toward cleaner oceans

National and international efforts to prevent and reduce marine debris have proven ineffective, according to a new NRC report.

An essential vision transferred from a ”clean ocean” to a ”bountiful ocean” - What was revealed from ”tidal flats - central bay area coupling” and ”benthic-pelagic ecosystem coupling” (the Ecological Connectivity Hypoxia Model J ECOHYM) -

An essential vision transferred from a ”clean ocean” to a ”bountiful ocean” - What was revealed from ”tidal flats - central bay area coupling” and ”benthic-pelagic ecosystem coupling” (the Ecological Connectivity Hypoxia Model J ECOHYM) -