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J. Mar. Sci. Eng., Volume 10, Issue 7 (July 2022) – 162 articles

Cover Story (view full-size image): Coasts are highly dynamic and geomorphologically complex systems, exposed to several natural and anthropic factors, and are vulnerable to climate change and coastal erosion. Consequently, it is necessary to quantify the vulnerability of coastal hazards and develop tools to monitor coastal risks and support climate adaptation policies. This study aims to develop and compare two methods to estimate coastal vulnerability to flooding and the erosion of the Ionian Basilicata coast. Our results reveal a spatial variability in the vulnerability, due to the morphology of the beach, and further highlight the need to develop a strategic approach to coastal management as well as define mitigation measures, considering relevant risk aspects, such as vulnerability and exposure degree. View this paper
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13 pages, 1272 KiB  
Article
Craft Product Export Promotion Competitiveness: The Mediating Effect between Niche Differentiation Strategy and Export Performance
J. Mar. Sci. Eng. 2022, 10(7), 999; https://doi.org/10.3390/jmse10070999 - 21 Jul 2022
Cited by 3 | Viewed by 2021
Abstract
Export competitiveness is an important factor for national development and economic growth. The craft product market is one of the commodities with high growing value. Thus, many craft product companies are encouraged to export their products to foreign markets. This study aims to [...] Read more.
Export competitiveness is an important factor for national development and economic growth. The craft product market is one of the commodities with high growing value. Thus, many craft product companies are encouraged to export their products to foreign markets. This study aims to examine the strategies and competitiveness of exporting craft products. The sample of 400 respondents who completed the questionnaires represents people working in craft product export companies using marine transport in Thailand. The data analysis was conducted using structural equation modelling (SEM). The findings show that the niche differentiation strategy of craft products positively relates to export promotion competitiveness. Moreover, a niche differentiation strategy positively affects export performance. The results indicate that export promotion competitiveness partially mediates the relationship between niche differentiation strategy and export performance. This study contributes to the craft product export business using marine transport and helps the companies to improve their competitiveness and export performance. Full article
(This article belongs to the Special Issue Marine Policy)
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4 pages, 1327 KiB  
Correction
Correction: Xing et al. An Investigation of Adaptive Radius for the Covariance Localization in Ensemble Data Assimilation. J. Mar. Sci. Eng. 2021, 9, 1156
J. Mar. Sci. Eng. 2022, 10(7), 998; https://doi.org/10.3390/jmse10070998 - 21 Jul 2022
Viewed by 755
Abstract
The authors wish to make the following corrections to this paper [...] Full article
(This article belongs to the Section Ocean Engineering)
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22 pages, 15864 KiB  
Article
Seasonal Evolution of Chlorophyll-a in the North Indian Ocean Associated with the Indian Ocean Dipole and Two Types of El Niño Events
J. Mar. Sci. Eng. 2022, 10(7), 997; https://doi.org/10.3390/jmse10070997 - 21 Jul 2022
Viewed by 1231
Abstract
To investigate the main modes of interannual variation of chlorophyll-a (Chla) with seasonal evolution and its variation cycle in the North Indian Ocean based on satellite-derived products during 1998–2016, a season-reliant empirical orthogonal function (S-EOF) analysis and power spectrum analysis based on Fourier [...] Read more.
To investigate the main modes of interannual variation of chlorophyll-a (Chla) with seasonal evolution and its variation cycle in the North Indian Ocean based on satellite-derived products during 1998–2016, a season-reliant empirical orthogonal function (S-EOF) analysis and power spectrum analysis based on Fourier transform are applied in the study. The first three dominate modes reveal distinct Chla variability, as the S-EOF1 features by one dipole pattern have a negative anomaly in the central western Indian Ocean and a positive anomaly off the Java–Sumatra coasts, which is mainly synchronously associated with the climate indices of the positive Indian Ocean dipole (IOD) and eastern Pacific El Nino (EP-El Niño). The S-EOF2 indicates a tripolar structure with positive anomalies located in the central Indian Ocean surrounded by two negative anomalies, which is one year behind a positive IOD and EP-El Niño event. The S-EOF3 exhibits a different dipole distribution, with a positive anomaly in the central west and a negative anomaly in the southeast, synchronized or lagging behind the central Pacific El Nino (CP-El Niño). Moreover, regarding the correlation between the main modes of interannual variation and the IOD and El Nino events, the dynamic parameters (such as SST, SLA, rain, and wind) of the tropical Indo-Pacific Ocean are discussed using time-delay correlation and linear regression analysis to explain the key factors and possible influencing mechanism of the joint seasonal and interannual variations of Chla in the northern Indian Ocean. Full article
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16 pages, 8509 KiB  
Article
Netting Damage Detection for Marine Aquaculture Facilities Based on Improved Mask R-CNN
J. Mar. Sci. Eng. 2022, 10(7), 996; https://doi.org/10.3390/jmse10070996 - 21 Jul 2022
Cited by 7 | Viewed by 1920
Abstract
Netting damage limits the safe development of marine aquaculture. In order to identify and locate damaged netting accurately, we propose a detection method using an improved Mask R-CNN. We create an image dataset of different kinds of damage from a mix of conditions [...] Read more.
Netting damage limits the safe development of marine aquaculture. In order to identify and locate damaged netting accurately, we propose a detection method using an improved Mask R-CNN. We create an image dataset of different kinds of damage from a mix of conditions and enhance it by data augmentation. We then introduce the Recursive Feature Pyramid (RFP) and Deformable Convolution Network (DCN) structures into the learning framework to optimize the basic backbone for a marine environment and build a feature map with both high-level semantic and low-level localization information of the network. This modification solves the problem of poor detection performance in damaged nets with small and irregular damage. Experimental results show that these changes improve the average precision of the model significantly, to 94.48%, which is 7.86% higher than the original method. The enhanced model performs rapidly, with a missing rate of about 7.12% and a detection period of 4.74 frames per second. Compared with traditional image processing methods, the proposed netting damage detection model is robust and better balances detection precision and speed. Our method provides an effective solution for detecting netting damage in marine aquaculture environments. Full article
(This article belongs to the Section Marine Aquaculture)
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22 pages, 13134 KiB  
Article
Underwater Electromagnetic Guidance Based on the Magnetic Dipole Model Applied in AUV Terminal Docking
J. Mar. Sci. Eng. 2022, 10(7), 995; https://doi.org/10.3390/jmse10070995 - 21 Jul 2022
Cited by 8 | Viewed by 1634
Abstract
To address the poor effect of optical/visual guidance used in AUV terminal docking with strong background light and turbid water quality, an underwater electromagnetic guidance method based on the magnetic dipole model is proposed in this paper. According to the magnetic dipole model, [...] Read more.
To address the poor effect of optical/visual guidance used in AUV terminal docking with strong background light and turbid water quality, an underwater electromagnetic guidance method based on the magnetic dipole model is proposed in this paper. According to the magnetic dipole model, the electromagnetic field of 1 kHz frequency generated by the coil in the range of terminal docking is the near field, where the position can be figured out through the amplitude and phase information of three orthogonal magnetic field intensity vectors. A triaxial-coil magnetometer with three orthogonal coils and a method for extracting the amplitude and phase information of the induced voltage are presented in this paper. According to Faraday’s law, the amplitude and phase information of the induced voltage of a triaxial-coil magnetometer replace the information of magnetic field intensity in relation to positioning. The underwater positioning results show that the average positioning error within 6 m can reach the centimeter level. Five underwater terminal docking tasks were carried out, and four of them were successfully completed, which verified the feasibility of the proposed method. Full article
(This article belongs to the Section Ocean Engineering)
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2 pages, 178 KiB  
Editorial
Passive Acoustics to Study Marine and Freshwater Ecosystems
J. Mar. Sci. Eng. 2022, 10(7), 994; https://doi.org/10.3390/jmse10070994 - 21 Jul 2022
Cited by 1 | Viewed by 1141
Abstract
Passive acoustic monitoring is becoming an important tool to study the ecosystem thanks to technological improvements, high temporal resolution, relatively low cost and time effort, and the zero impact on environment and animal behavior [...] Full article
(This article belongs to the Special Issue Passive Acoustics to Study Marine and Freshwater Ecosystems)
24 pages, 2470 KiB  
Article
Availability Analysis of an Offshore Wind Turbine Subjected to Age-Based Preventive Maintenance by Petri Nets
J. Mar. Sci. Eng. 2022, 10(7), 1000; https://doi.org/10.3390/jmse10071000 - 21 Jul 2022
Cited by 4 | Viewed by 1630
Abstract
This paper analyses the production availability and the associated maintenance costs of an offshore wind turbine with a horizontal axis configuration using Petri Nets modelling with Monte Carlo Simulation. For this purpose, different features are implemented: the reliability and maintainability characteristics of the [...] Read more.
This paper analyses the production availability and the associated maintenance costs of an offshore wind turbine with a horizontal axis configuration using Petri Nets modelling with Monte Carlo Simulation. For this purpose, different features are implemented: the reliability and maintainability characteristics of the components; the logistics of the production and maintenance operations, including different types of vessels, the mobilization time, costs and weather window. The maintenance strategies consist of corrective maintenance and age-based imperfect preventive maintenance that depends on the components’ age and age reduction ratio. Thereby, to increase the operating income and to reduce the costs associated with the operation and maintenance activities, the optimal parameters of the age-based preventive maintenance are estimated. As a case study, a generic offshore wind turbine that operates at the Viana do Castelo wind farm in Portugal is adopted. The wind farm is located 18 km off the shore. The turbine’s total exploration life is 25 years. Full article
(This article belongs to the Special Issue Offshore Wind Energy)
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31 pages, 11688 KiB  
Article
Numerical Study of Wave Drift Load and Turning Characteristics of KVLCC2 Ship in Regular Waves Based on TEBEM
J. Mar. Sci. Eng. 2022, 10(7), 993; https://doi.org/10.3390/jmse10070993 - 20 Jul 2022
Cited by 2 | Viewed by 1758
Abstract
Maritime traffic has increased considerably in recent years, making energy efficiency and navigation safety of ships more crucial than ever. Hence, a two-time scale model based on the Taylor expansion boundary element method (TEBEM) is proposed to predict ship turning trajectories in regular [...] Read more.
Maritime traffic has increased considerably in recent years, making energy efficiency and navigation safety of ships more crucial than ever. Hence, a two-time scale model based on the Taylor expansion boundary element method (TEBEM) is proposed to predict ship turning trajectories in regular waves. The maneuvering motion is calculated using a three degrees of freedom MMG model that considers the wave drift loads. TEBEM overcomes the shortcomings of the constant panel method in solving tangential induced velocity at a non-smooth boundary and that of the high-order boundary element method in dealing with a high-order derivative of the velocity potential at the corner. This significantly improves the calculation accuracy of the induced velocity and high-order derivative of velocity potential. Firstly, based on the TEBEM, the surge and sway wave drift forces and yaw moment of the KVLCC2 model with drift angle under full wave headings are calculated and compared with computational fluid dynamics results, using which the calculation accuracy of TEBEM is verified. Subsequently, the two-time scale model is used to calculate the turning trajectories of the KVLCC2 model in regular waves with different wave headings, wave frequencies, and wave steepness. The numerical results show that the drift angle has a certain effect on the wave drift loads of the ship, and the proposed model can effectively predict the ship’s turning motion in regular waves. Full article
(This article belongs to the Section Ocean Engineering)
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32 pages, 3504 KiB  
Article
Hydrogen Refueling Stations and Carbon Emission Reduction of Coastal Expressways: A Deployment Model and Multi-Scenario Analysis
J. Mar. Sci. Eng. 2022, 10(7), 992; https://doi.org/10.3390/jmse10070992 - 20 Jul 2022
Cited by 11 | Viewed by 1994
Abstract
Hydrogen is considered to the ultimate solution to achieve carbon emission reduction due to its wide sources and high calorific value, as well as non-polluting, renewable, and storable advantages. This paper starts from the coastal areas, uses offshore wind power hydrogen production as [...] Read more.
Hydrogen is considered to the ultimate solution to achieve carbon emission reduction due to its wide sources and high calorific value, as well as non-polluting, renewable, and storable advantages. This paper starts from the coastal areas, uses offshore wind power hydrogen production as the hydrogen source, and focuses on the combination of hydrogen supply chain network design and hydrogen expressway hydrogen refueling station layout optimization. It proposes a comprehensive mathematical model of hydrogen supply chain network based on cost analysis, which determined the optimal size and location of hydrogen refueling stations on hydrogen expressways in coastal areas. Under the multi-scenario and multi-case optimization results, the location of the hydrogen refueling station can effectively cover the road sections of each case, and the unit hydrogen cost of the hydrogen supply chain network is between 11.8 and 15.0 USD/kgH2. Meanwhile, it was found that the transportation distance and the number of hydrogen sources play a decisive role on the cost of hydrogen in the supply chain network, and the location of hydrogen sources have a decisive influence on the location of hydrogen refueling stations. In addition, carbon emission reduction results of hydrogen supply chain network show that the carbon emission reduction per unit hydrogen production is 15.51 kgCO2/kgH2 at the production side. The CO2 emission can be reduced by 68.3 kgCO2/km and 6.35 kgCO2/kgH2 per unit mileage and per unit hydrogen demand at the application side, respectively. The layout planning utilization of hydrogen energy expressway has a positive impact on energy saving and emission reduction. Full article
(This article belongs to the Section Coastal Engineering)
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21 pages, 2499 KiB  
Article
Interval-Valued Fuzzy Multi-Criteria Decision-Making with Dependent Evaluation Criteria for Evaluating Service Performance of International Container Ports
J. Mar. Sci. Eng. 2022, 10(7), 991; https://doi.org/10.3390/jmse10070991 - 20 Jul 2022
Cited by 5 | Viewed by 1217
Abstract
Due to COVID-19 barriers, the needs of international container ports have become more important than in the past. Therefore, it is very critical and essential for the scientific developments of port-logistics. To gain the scientific developments of port logistics, effective and efficient evaluation [...] Read more.
Due to COVID-19 barriers, the needs of international container ports have become more important than in the past. Therefore, it is very critical and essential for the scientific developments of port-logistics. To gain the scientific developments of port logistics, effective and efficient evaluation methods for decision-making are indispensable, especially for assessing service performance of international container ports based on dependent evaluation criteria (DEC). Among numerous decision-making methods, technique for order preference by similarity to ideal solution (TOPSIS) was often expanded under fuzzy environments into fuzzy multi-criteria decision-making (FMCDM) to preserve imprecise messages. The FMCDM was able to be associated with quality function deployment (QFD) into a hybrid method to solve problems with DEC. To gain more messages, QFD and TOPSIS are combined and then expanded under interval-valued fuzzy environment (IVFE) to solve a FMCDM problem with DEC. Practically, evaluating service performance of international container ports in Taiwan and the surrounding sea areas is considered a problem with DEC because the related evaluation criteria are partially connected. By the hybrid method of combining QFD with TOPSIS under IVFE, international container ports with DEC are effectively and efficiently evaluated for service performance, and more insights are gained than the past for establishing essential fundamentals in recent scientific developments of port logistics on account of breaking down COVID-19 barriers. Full article
(This article belongs to the Special Issue Recent Scientific Developments in Port Logistics)
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25 pages, 16857 KiB  
Article
Contourite and Turbidite Features in the Middle Caspian Sea and Their Connection to Geohazards Derived from High-Resolution Seismic Data
J. Mar. Sci. Eng. 2022, 10(7), 990; https://doi.org/10.3390/jmse10070990 - 20 Jul 2022
Cited by 1 | Viewed by 1648
Abstract
High fluvial input combined with specific topographic and oceanographic settings in the Caspian Sea create favorable conditions for contourite deposition. For the first time in its middle portion, contourite deposits have been observed in high-resolution seismic profiles. Various types of contourite drifts and [...] Read more.
High fluvial input combined with specific topographic and oceanographic settings in the Caspian Sea create favorable conditions for contourite deposition. For the first time in its middle portion, contourite deposits have been observed in high-resolution seismic profiles. Various types of contourite drifts and mixed depositional systems have been revealed on the lower slope and in the adjacent basin, some of which are accompanied by sediment wave fields. The deposition of contourites or turbidites and their lateral distribution is controlled by sea-floor topography and oceanographic processes, as well as the modern activity of gravity flows downslope on the western Caucasian slope and in the channel system on the Mangyshlak Sill. The contourite drifts and sediment wave fields form several contourite depositional systems, which seem to merge in the Caspian contourite depositional complex. This occurs near the foot of slopes of the Derbent Basin and is related to the counterclockwise circum-Caspian current in the Middle Caspian Sea. The fact that the Caspian Sea is the largest lake in the world makes this region a significant area for research into the “lake contourites” issue. The Caspian Sea is an important oil-producing area, and sedimentary processes related to the contourite and turbidite can be a source of potential geohazards in the construction and exploitation of underwater engineering structures Full article
(This article belongs to the Special Issue Recent Advances in Geological Oceanography)
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26 pages, 19553 KiB  
Article
Geologic Framework, Anthropogenic Impacts, and Hydrodynamics Contribute to Variable Sediment Availability and Shoreface Morphology at the Rockaway Peninsula, NY
J. Mar. Sci. Eng. 2022, 10(7), 989; https://doi.org/10.3390/jmse10070989 - 20 Jul 2022
Cited by 1 | Viewed by 1431
Abstract
Recent field and modeling studies have shown that barrier island resiliency is sensitive to sediment fluxes from the shoreface, making it important to evaluate how shoreface sediment availability varies in coastal systems. To do this, we assessed shoreface geology and morphology along the [...] Read more.
Recent field and modeling studies have shown that barrier island resiliency is sensitive to sediment fluxes from the shoreface, making it important to evaluate how shoreface sediment availability varies in coastal systems. To do this, we assessed shoreface geology and morphology along the Rockaway Peninsula, NY, USA. We find that spatial variability in shoreface volume is influenced by sediment accommodation above the Holocene-Pleistocene (H-P) contact, historical barrier island evolution, and natural and engineered morphologic features, suggesting that simply identifying the H-P boundary may not be adequate for defining the shoreface reservoir. Further, sediment flux from the lower shoreface to the beach may be reduced by geologically limited cross-shore sediment distribution and shoreface steepening mediated by human modifications to the shoreline. Finally, the geologic limit of the shoreface is often shallower than a wave-based estimate of shoreface extent, implying that the geologic shoreface extent at our study site can be mobilized over short time scales (years-decades) and that the wave-based shoreface extent may be inaccurate when estimating shoreline response to sea-level rise. Our results demonstrate that the combination of hydrodynamics, humans, and geology on shoreface sediment fluxes impact how barrier islands respond to future changes in sediment supply and climate. Full article
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23 pages, 13305 KiB  
Article
Hydraulic Performance of Seawater Intake System Using CFD Modeling
J. Mar. Sci. Eng. 2022, 10(7), 988; https://doi.org/10.3390/jmse10070988 - 19 Jul 2022
Cited by 15 | Viewed by 2512
Abstract
In recent years, tapping the sea for potable water has gained prominence as a potential source of water. Since seawater intake systems are often used in the infrastructure industry, ensuring proper efficiency in different operating conditions is very important. In this paper, CFD [...] Read more.
In recent years, tapping the sea for potable water has gained prominence as a potential source of water. Since seawater intake systems are often used in the infrastructure industry, ensuring proper efficiency in different operating conditions is very important. In this paper, CFD modeling is used to show general hydraulic design (flow patterns, stream flow, vortex severities, and pre-swirl) principles and performance acceptability criteria for pump intakes in different conditions. The authors explore scenarios for avoiding or resolving hydraulic problems that have arisen as a result of hydraulic model studies. The results show that the designer should make every effort to avoid small entrance and filtration areas from the basin to the intake forebay bottom, which could result in jet outlet and/or supercritical flow; too small logs at the basin outflow, which could result in high velocity flow jets; and sudden area contractions at the forebay to pump bay junction. There should be enough submergence at the pumps to reduce harmful vortex severities and pre-swirl. Curtain walls, baffles, fillets, and splitters, as well as flow redistributors, can all aid in improving approach flow patterns. Reduced flow separations and eddies will be greatly assisted by rounding corners and providing guide walls. Using a numerical model to figure out what is wrong and how to fix it will help the facility’s costs and maintenance decrease in the long run. Full article
(This article belongs to the Section Ocean Engineering)
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20 pages, 5330 KiB  
Article
Searching for the Origin and the Differentiation of Haemocytes before and after Larval Settlement of the Colonial Ascidian Botryllus schlosseri: An Ultrastructural Viewpoint
J. Mar. Sci. Eng. 2022, 10(7), 987; https://doi.org/10.3390/jmse10070987 - 19 Jul 2022
Cited by 4 | Viewed by 1500 | Correction
Abstract
The colonial ascidian Botryllus schlosseri possesses an innate immunity, which plays fundamental roles in its survival, adaptability, worldwide spread and ecological success. Three lines of differentiation pathways of circulating haemocytes are known to be present in the haemolymph, starting from undifferentiated haemoblasts: (i) [...] Read more.
The colonial ascidian Botryllus schlosseri possesses an innate immunity, which plays fundamental roles in its survival, adaptability, worldwide spread and ecological success. Three lines of differentiation pathways of circulating haemocytes are known to be present in the haemolymph, starting from undifferentiated haemoblasts: (i) the phagocytic line (hyaline amoebocytes and macrophage-like cells), (ii) the cytotoxic line (granular amoebocytes and morula cells) and (iii) the storage cell line (pigment cells and nephrocytes). Many questions remain about their origin, and thus, observations during various stages of development were undertaken in this study. Haemocytes were detected beginning from the early tailbud embryo stage. Haemoblasts were always present and morula cells were the first differentiated haemocytes detected. In both the next stage, just before hatching, and the swimming tadpole larva stage, hyaline amoebocytes and pigment cells were also recognisable. Some morula cells containing active phenoloxidase migrated from the haemolymph into the tunic after having crossed the epidermis, and this behaviour could be related to the preparation of a defensive function for spatial competition. During larval metamorphosis, macrophage-like cells appeared with their phagosomes positive to acid phosphatase activity and containing apoptotic cells from tail tissue degeneration. After metamorphosis, in the filter-feeding oozoid stage, nephrocytes involved in nitrogen catabolism finally appeared. In both the subendostylar sinus and the peripheral blind-sac vessels (ampullae), clusters of haemoblasts were recognisable, some of which showed incipient specialisations, considering the hypothesis of the presence of putative niches of haemolymph stem cells. Full article
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13 pages, 2252 KiB  
Article
A K-Nearest Neighbors Algorithm in Python for Visualizing the 3D Stratigraphic Architecture of the Llobregat River Delta in NE Spain
J. Mar. Sci. Eng. 2022, 10(7), 986; https://doi.org/10.3390/jmse10070986 - 19 Jul 2022
Cited by 8 | Viewed by 2238
Abstract
The k-nearest neighbors (KNN) algorithm is a non-parametric supervised machine learning classifier; which uses proximity and similarity to make classifications or predictions about the grouping of an individual data point. This ability makes the KNN algorithm ideal for classifying datasets of geological variables [...] Read more.
The k-nearest neighbors (KNN) algorithm is a non-parametric supervised machine learning classifier; which uses proximity and similarity to make classifications or predictions about the grouping of an individual data point. This ability makes the KNN algorithm ideal for classifying datasets of geological variables and parameters prior to 3D visualization. This paper introduces a machine learning KNN algorithm and Python libraries for visualizing the 3D stratigraphic architecture of sedimentary porous media in the Quaternary onshore Llobregat River Delta (LRD) in northeastern Spain. A first HTML model showed a consecutive 5 m-equispaced set of horizontal sections of the granulometry classes created with the KNN algorithm from 0 to 120 m below sea level in the onshore LRD. A second HTML model showed the 3D mapping of the main Quaternary gravel and coarse sand sedimentary bodies (lithosomes) and the basement (Pliocene and older rocks) top surface created with Python libraries. These results reproduce well the complex sedimentary structure of the LRD reported in recent scientific publications and proves the suitability of the KNN algorithm and Python libraries for visualizing the 3D stratigraphic structure of sedimentary porous media, which is a crucial stage in making decisions in different environmental and economic geology disciplines. Full article
(This article belongs to the Special Issue Coastal Systems: Monitoring, Protection and Adaptation Approaches)
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18 pages, 3340 KiB  
Article
Simulation Study on the Performance and Emission Parameters of a Marine Diesel Engine
J. Mar. Sci. Eng. 2022, 10(7), 985; https://doi.org/10.3390/jmse10070985 - 19 Jul 2022
Cited by 1 | Viewed by 1518
Abstract
Development of intelligent ships requires marine diesel engine simulation models of high accuracy and fast response. In addition, with advent of tighter shipping air emissions regulations, such models are required to have emission prediction capabilities. In this article, such a model was developed [...] Read more.
Development of intelligent ships requires marine diesel engine simulation models of high accuracy and fast response. In addition, with advent of tighter shipping air emissions regulations, such models are required to have emission prediction capabilities. In this article, such a model was developed and validated for a 30,000-ton bulk carrier main engine using MATLAB/Simulink. The simulation is based on mean value model, which predicts both the steady-state and dynamic performance of the engine. The results show that the steady-state performance parameters of the main engine are predicted within 2.2% error, and the exhaust emissions parameters are predicted within 7% error as compared to the bench test data from the engine manufacturer. The Maximum Continuous Rating (MCR) points at 100%, 75%, 50% and 25% of the E3 duty cycle were investigated with emphasis according to the diesel propulsion characteristics. In dynamic simulation, it is found that the compressor pressure fluctuation is greater than that of the exhaust pressure with the load variation. Furthermore, the compressor and the exhaust pipe have a similar temperature drop value (about 60 K) when the engine load changes from 100% to 50% MCR, and the exhaust pipe temperature fluctuation is more significant when the load varies from 50% to 25% MCR. The above results show the model’s good transient capability in simulating the dynamic characteristics of the engine. This model can be used especially for the development and control of marine diesel engines in intelligent ships as well as training-oriented marine engine and ship simulators. Full article
(This article belongs to the Section Ocean Engineering)
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17 pages, 2955 KiB  
Review
Development History of the Numerical Simulation of Tides in the East Asian Marginal Seas: An Overview
J. Mar. Sci. Eng. 2022, 10(7), 984; https://doi.org/10.3390/jmse10070984 - 19 Jul 2022
Cited by 12 | Viewed by 2803
Abstract
As a ubiquitous movement in the ocean, tides are vital for marine life and numerous marine activities such as fishing and ocean engineering. Tidal dynamics are complicated in the East Asian marginal seas (EAMS) due to changing complex topography and coastlines related to [...] Read more.
As a ubiquitous movement in the ocean, tides are vital for marine life and numerous marine activities such as fishing and ocean engineering. Tidal dynamics are complicated in the East Asian marginal seas (EAMS) due to changing complex topography and coastlines related to human activities (e.g., land reclamation and channel deepening) and natural variability (e.g., seasonal variations of ocean stratification and river flow). As an important tool, numerical models are widely used because they can provide basin-scale patterns of tidal dynamics compared to point-based tide gauges. This paper aims to overview the development history of the numerical simulation of tides in the EAMS, including the Bohai Sea, the Yellow Sea, the East China Sea, the East/Japan Sea, and the South China Sea, provide comprehensive understanding of tidal dynamics, and address contemporary research challenges. The basic features of major tidal constituents obtained by tidal models are reviewed, and the progress in the inversion of spatially and temporally changing model parameters via the adjoint method are presented. We review numerical research on how a changing ocean environment induces tidal evolution and how tides and tidal mixing influence ocean environment in turn. The generation, propagation, and dissipation of internal tides in the EAMS are also reviewed. Although remarkable progresses in tidal dynamics have been made, nonstationary tidal variations are not fully explained yet, and further efforts are needed. In addition, tidal influences on ocean environment still receive limited attention, which deserves special attention. Full article
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17 pages, 2775 KiB  
Article
Variable Natural Frequency Damper for Minimizing Response of Offshore Wind Turbine: Principle Verification through Analysis of Controllable Natural Frequencies
J. Mar. Sci. Eng. 2022, 10(7), 983; https://doi.org/10.3390/jmse10070983 - 18 Jul 2022
Cited by 3 | Viewed by 1856
Abstract
Resonance causes extreme stress, acceleration of fatigue, and reduction in lifespan of offshore wind structures. The main factors that cause resonance are environmental loads such as wind and waves, and dynamic loads caused by rotor movement. Estimation of the natural frequency at the [...] Read more.
Resonance causes extreme stress, acceleration of fatigue, and reduction in lifespan of offshore wind structures. The main factors that cause resonance are environmental loads such as wind and waves, and dynamic loads caused by rotor movement. Estimation of the natural frequency at the design stage is highly uncertain, and natural frequency changes occur due to various factors during long-term operation. Therefore, it is important to ensure structural safety from resonance through a vibration-monitoring system or an additional damper. In this study, the effect of seawater existing inside the substructure on the natural frequency of the structure was dealt with. The natural frequency estimation equation for a fixed offshore wind structure was derived with the “inner fluid simplification assumption”. The finite element modal analysis was performed to verify the principle of Variable Natural Frequency Damper (VNFD), a system that controls the natural frequency of offshore wind structures through a pump, and to find the range of natural frequency control. As a result, interior fluid affects the natural frequency of the wind turbine support structure. Specifically, the variable natural frequency range was very low, at about 0.027% for the monopile model at a depth of 10 m, but increased rapidly to about 3.66% at a depth of 70 m. Furthermore, when estimating the natural frequency of a fixed offshore wind turbine in deep water without consideration of interior fluid, the estimates can be higher than with consideration of it. Full article
(This article belongs to the Topic Sustainable Energy Technology)
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19 pages, 7644 KiB  
Article
A Wet/Dry Point Treatment Method of FVCOM, Part II: Application to the Okatee/Colleton River in South Carolina
J. Mar. Sci. Eng. 2022, 10(7), 982; https://doi.org/10.3390/jmse10070982 - 18 Jul 2022
Cited by 4 | Viewed by 1533
Abstract
The wet/dry point treatment method of FVCOM was applied to simulate the tide-induced flooding/drying process in the estuarine–tidal-creek–saltmarsh complex of the Okatee/Colleton River Estuary, South Carolina. The simulation results were compared with observed currents at three mooring sites and flooded areas observed from [...] Read more.
The wet/dry point treatment method of FVCOM was applied to simulate the tide-induced flooding/drying process in the estuarine–tidal-creek–saltmarsh complex of the Okatee/Colleton River Estuary, South Carolina. The simulation results were compared with observed currents at three mooring sites and flooded areas observed from remote-sensing hypsometric measurements, demonstrating that FVCOM can robustly reproduce tidal and residual currents in the river and the flooding process onto the intertidal saltmarsh. The simulated flow field reveals that the Okatee/Colleton River Estuary is characterized by multiple residual eddies. Driven by the periodic tidal forcing, this estuarine system features a chaotic water transport process. Numerous residual eddies around the barrier complex in the Colleton River likely enhance the water exchange between the Okatee/Colleton River Estuary and the outer Broad River. A sensitivity study of flooding speed to the slope of the inter-tidal zone suggests that the saltmarsh bathymetry considerably influences the water elevation near low slack water but not on the maximum water coverage area at high slack water. Full article
(This article belongs to the Special Issue Ocean Dynamics: Numerical Models and Applications)
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18 pages, 4251 KiB  
Article
Effects of Bionic Bone Flexibility on the Hydrodynamics of Pectoral Fins
J. Mar. Sci. Eng. 2022, 10(7), 981; https://doi.org/10.3390/jmse10070981 - 18 Jul 2022
Viewed by 1460
Abstract
Compared with traditional underwater equipment powered by propeller, the manta-ray-inspired vehicle with MPF mode (Median fin/paired fin) has the advantages of stable swimming attitude, high maneuverability, and low noise, etc. As one of the sources of advancing power when the manta-ray-inspired vehicle swims, [...] Read more.
Compared with traditional underwater equipment powered by propeller, the manta-ray-inspired vehicle with MPF mode (Median fin/paired fin) has the advantages of stable swimming attitude, high maneuverability, and low noise, etc. As one of the sources of advancing power when the manta-ray-inspired vehicle swims, the flexible deformation of the pectoral fin is an important factor affecting the hydrodynamic performance. In this paper, a mechanical analysis of the two-dimensional flexible pectoral fin using thin wing theory shows that the main factor affecting the hydrodynamic force of the two-dimensional flexible pectoral fin is the level of curvature of the pectoral fin chordal section. By designing a two-stage bionic skeleton at the leading and rear edges of the manta-ray-inspired vehicle, the root–tip section width of the bionic skeleton is used to characterize the level of the bionic pectoral fin’s flexibility, and a tensiometer is used to quantitatively measure the level of flexibility. The root-to-tip ratio of the cross-section was varied to obtain different levels of pectoral fin flexibility, and the hydrodynamic properties of the pectoral fins during flapping were measured using a force sensor and normalized for analysis. The experimental results show that the reduction of the flexibility of the leading edge and the increase of the flexibility of the rear edge are beneficial to the improvement of the thrust performance, and the experimental results are the same as the distribution of the skeletal flexibility in real organisms. Fitting curves of the pectoral fins’ relative flexibility and the normalized thrust/lift show that the flexibility of the pectoral fins has a significant effect on its hydrodynamic force, and a stiffer leading edge and a softer rear edge can improve the hydrodynamic characteristics of the manta-ray-inspired vehicle. Phase differences interacting with flexibility can also enhance bionic pectoral fins’ dynamic properties within 10~30 degree. Full article
(This article belongs to the Section Ocean Engineering)
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13 pages, 3005 KiB  
Article
Effect of Ultrasound Irradiation on the Properties and Sulfur Contents of Blended Very Low-Sulfur Fuel Oil (VLSFO)
J. Mar. Sci. Eng. 2022, 10(7), 980; https://doi.org/10.3390/jmse10070980 - 17 Jul 2022
Cited by 4 | Viewed by 1532
Abstract
Quality issues concerning very low-sulfur fuel oil (VLSFO) have increased significantly since the IMO sulfur-limit regulation became mandatory in 2020, as most VLSFO is produced by blending high-sulfur fuel oil (HSFO) with VLSFO. For instance, the conversion of VLSFO paraffins (C19 or [...] Read more.
Quality issues concerning very low-sulfur fuel oil (VLSFO) have increased significantly since the IMO sulfur-limit regulation became mandatory in 2020, as most VLSFO is produced by blending high-sulfur fuel oil (HSFO) with VLSFO. For instance, the conversion of VLSFO paraffins (C19 or higher alkanes) into waxes at low temperatures adversely affects cold flow properties. This study investigates the effects of ultrasonication on the chemical composition, dispersion stability, and sulfur content of samples prepared by blending ISO-F-DMA-grade marine gas oil (i.e., VLSFO) and ISO-F-RMG-grade marine heavy oil (i.e., HSFO) in volumetric ratios of 25:75 (BFO1), 50:50 (BFO2), and 75:25 (BFO3). The paraffin content decreased by 19.2% after 120 min of ultrasonic irradiation for BFO1 by 16.8% after 30 min for BFO3. The decrease in the content of high-molecular-weight compounds was faster at higher HSFO content; however, ultrasonication for longer-than-optimal times induced reaggregation, and thus, increased the content of high-molecular-weight compounds and decreased dispersion stability. In addition, ultrasonication did not significantly affect the sulfur content of BFO1 but decreased those of BFO2 (by 19% after 60 min) and BFO3 (by 25% after 30 min). Desulfurization efficiency increased with the increasing content of HSFO, as water present therein acted as an oxidant for oxidative desulfurization. Full article
(This article belongs to the Special Issue Marine Fuels and Green Energy)
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17 pages, 3975 KiB  
Article
Effectiveness of the Speed Reduction Strategy on Exhaust Emissions and Fuel Oil Consumption of a Marine Generator Engine for DC Grid Ships
J. Mar. Sci. Eng. 2022, 10(7), 979; https://doi.org/10.3390/jmse10070979 - 17 Jul 2022
Cited by 6 | Viewed by 1727
Abstract
Recent developments in power electronics, energy storage systems, and renewable energy; increased market demands for more efficient and cleaner electric power to meet stricter environmental regulations; and development in gigawatt (GW)-class DC (direct current) transmission systems for transmission of greater power over longer [...] Read more.
Recent developments in power electronics, energy storage systems, and renewable energy; increased market demands for more efficient and cleaner electric power to meet stricter environmental regulations; and development in gigawatt (GW)-class DC (direct current) transmission systems for transmission of greater power over longer distances than similar alternative current (AC) systems, have supported the development of the DC grid, making it a promising solution for both the onshore and offshore industries. This paper presents an experimental study on the effectiveness of an engine speed reduction strategy on exhaust gas emission and fuel consumption when applied to a 4-stroke generator engine equipped with a cam-driven plunger diesel injection system. The experiments were performed on an 8-cylinder V-type 4-stroke generator engine installed in the MASTC laboratory, which is the only demonstration testbed for the ship’s electric propulsion system in Korea. Experimental results showed that fuel consumption decreased, but emission mass fraction in exhaust gas increased when maintaining engine power while reducing engine speed. This study has shown economic benefits in reducing fuel consumption, but incurred penalties for the emission performance of 4-stroke generator engines equipped with cam-driven plunger diesel injection systems when applying the engine speed reduction strategy. Full article
(This article belongs to the Special Issue Marine Alternative Fuels and Environmental Protection II)
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20 pages, 6758 KiB  
Article
Research on Multi-Ship Target Detection and Tracking Method Based on Camera in Complex Scenes
J. Mar. Sci. Eng. 2022, 10(7), 978; https://doi.org/10.3390/jmse10070978 - 17 Jul 2022
Cited by 6 | Viewed by 1481
Abstract
Aiming at the problem that multi-ship target detection and tracking based on cameras is difficult to meet the accuracy and speed requirements at the same time in some complex scenes, an improved YOLOv4 algorithm is proposed, which simplified the network of the feature [...] Read more.
Aiming at the problem that multi-ship target detection and tracking based on cameras is difficult to meet the accuracy and speed requirements at the same time in some complex scenes, an improved YOLOv4 algorithm is proposed, which simplified the network of the feature extraction layer to obtain more shallow feature information and avoid the disappearance of small ship target features, and uses the residual network to replace the continuous convolution operation to solve the problems of network degradation and gradient disappearance. In addition, a nonlinear target tracking model based on the UKF method is constructed to solve the problem of low real-time performance and low precision in multi-ship target tracking. Multi-ship target detection and tracking experiments were carried out in many scenes with large differences in ship sizes, strong background interference, tilted images, backlight, insufficient illumination, and rain. Experimental results show that the average precision of the detection algorithm of this paper is 0.945, and the processing speed is about 34.5 frame per second, where the real-time performance is much better than other algorithms while maintaining high precision. Furthermore, the multiple object tracking accuracy (MOTA) and the multiple object tracking precision (MOTP) of this paper algorithm are 76.4 and 80.6, respectively, which are both better than other algorithms. The method proposed in this paper can realize the ship target detection and tracking well, with less missing detection and false detection, and also has good accuracy and real-time performance. The experimental results provide a valuable theoretical reference for the further practical application of the method. Full article
(This article belongs to the Section Ocean Engineering)
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16 pages, 4271 KiB  
Article
Time-Optimal Path Planning of a Hybrid Autonomous Underwater Vehicle Based on Ocean Current Neural Point Grid
J. Mar. Sci. Eng. 2022, 10(7), 977; https://doi.org/10.3390/jmse10070977 - 17 Jul 2022
Viewed by 1113
Abstract
Path planning is the precondition for Hybrid Autonomous Underwater Vehicles (HAUV) to enter the submerged area to undertake a mission. The influence of ocean currents on HAUV should be further investigated to obtain a time-optimal path. The improved A* algorithm and the neural [...] Read more.
Path planning is the precondition for Hybrid Autonomous Underwater Vehicles (HAUV) to enter the submerged area to undertake a mission. The influence of ocean currents on HAUV should be further investigated to obtain a time-optimal path. The improved A* algorithm and the neural network model are employed in this paper to plan a time-optimal path for the vehicle. The HAUV in glider mode is capable of traveling forward mainly through the zigzag motion in vertical plane. Since the vehicle can only receive the command orders when it surfaces from the water, the path is expected to include a series of discrete waypoints in the water surface. At the same time, the presence of submerged riverbeds is also taken into account to avoid hazards for HAUVs when it navigates in the water. It can be demonstrated that ocean currents can be used to decrease the operating time. The comparison results of the two methods verify that the size of the map affects the calculation time. In addition, the neural node represented method surpasses the modified A* method, especially when the map is too large. Full article
(This article belongs to the Section Ocean Engineering)
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16 pages, 8697 KiB  
Article
Long-Term Monitoring and Change Analysis of Pine Island Ice Shelf Based on Multi-Source Satellite Observations during 1973–2020
J. Mar. Sci. Eng. 2022, 10(7), 976; https://doi.org/10.3390/jmse10070976 - 16 Jul 2022
Cited by 2 | Viewed by 1613
Abstract
Pine Island Glacier (PIG) is one of the largest contributors to sea level rise in Antarctica. Continuous thinning and frequent calving imply significant destabilization of Pine Island Glacier Ice Shelf (PIGIS). To understand the mechanism of its accelerated disintegration and its future development, [...] Read more.
Pine Island Glacier (PIG) is one of the largest contributors to sea level rise in Antarctica. Continuous thinning and frequent calving imply significant destabilization of Pine Island Glacier Ice Shelf (PIGIS). To understand the mechanism of its accelerated disintegration and its future development, we conducted a long-term monitoring and comprehensive analysis of PIGIS, including ice flow velocity, ice shelf fronts, ocean water temperature, rifts, and surface strain rates, based on multi-source satellite observations during 1973–2020. The results reveal that: (1) ice flow velocities of PIGIS increased from 2.3 km/yr in 1973 to 4.5 km/yr in 2020, with two rapid acceleration periods of 1995–2009 and 2017–2020, and its change was highly correlated to the ocean water temperature variation. (2) At least 13 calving events occurred during 1973–2020, with four unprecedented successive retreats in 2015, 2017, 2018, and 2020. (3) The acceleration of ice shelf rifting and calving may correlate to the destruction of shear margins, while this damage was likely a response to the warming of bottom seawater. The weakening southern shear margin may continue to recede, indicating that the instability of PIGIS will continue. Full article
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18 pages, 7627 KiB  
Article
Multiscale Energy Transfers and Conversions of Kuroshio in Luzon Strait and Its Adjacent Regions
J. Mar. Sci. Eng. 2022, 10(7), 975; https://doi.org/10.3390/jmse10070975 - 16 Jul 2022
Cited by 1 | Viewed by 1322
Abstract
Using the local multiscale energy and vorticity analysis (MS-EVA) and based on the global high-resolution ocean reanalysis product GLORYS12V1 for 20 years, this study investigates the energy transfers and conversions of Kuroshio in the Luzon Strait and its adjacent regions through three scales, [...] Read more.
Using the local multiscale energy and vorticity analysis (MS-EVA) and based on the global high-resolution ocean reanalysis product GLORYS12V1 for 20 years, this study investigates the energy transfers and conversions of Kuroshio in the Luzon Strait and its adjacent regions through three scales, namely, the climatological scale, the seasonal scale, and the eddy scale. The results show that the inverse cascades of kinetic energy dominate the energy transfer east of Luzon (at both the eddy and seasonal scales). Kuroshio transfers the climatological kinetic energy to the eddy scale through a forward energy cascade in Luzon Strait and east of Taiwan. Because the topography of Luzon Strait and Kuroshio jointly block and limit the westward propagation of non-local eddies, the eddy energy in the South China Sea west of Luzon Strait tends to depend on local forward potential energy cascades. In these subregions, potential energy drives the accumulation of kinetic energy under the action of buoyancy conversion: interannual (seasonal) potential energy as the source of multiscale energy in the Luzon Strait (the east of Taiwan). Full article
(This article belongs to the Section Physical Oceanography)
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23 pages, 28765 KiB  
Article
On the Adaptation of an AUV into a Dedicated Platform for Close Range Imaging Survey Missions
J. Mar. Sci. Eng. 2022, 10(7), 974; https://doi.org/10.3390/jmse10070974 - 15 Jul 2022
Cited by 10 | Viewed by 2977
Abstract
This study presents the redesign of an existing autonomous underwater vehicle (AUV) with limited maneuverability, transforming it into a platform optimized for autonomous, near-seabed visual imaging missions. This work describes the enhancement of the AUV’s maneuverability through the addition of thrusters, the leveraging [...] Read more.
This study presents the redesign of an existing autonomous underwater vehicle (AUV) with limited maneuverability, transforming it into a platform optimized for autonomous, near-seabed visual imaging missions. This work describes the enhancement of the AUV’s maneuverability through the addition of thrusters, the leveraging of a state-of-the-art thrust allocation algorithm, and the development of both a path-following controller and a dedicated imaging system. The performance of the optimized platform is demonstrated in a simulation and in actual real sea visual survey missions. Full article
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41 pages, 13720 KiB  
Review
Review on Fixed and Floating Offshore Structures. Part II: Sustainable Design Approaches and Project Management
J. Mar. Sci. Eng. 2022, 10(7), 973; https://doi.org/10.3390/jmse10070973 - 15 Jul 2022
Cited by 11 | Viewed by 9324
Abstract
Offshore structures exist in a variety of forms, and they are used for a variety of functions in varied sea depths. These structures are tailored for certain environments and sea depths. Different actions for suitable equipment selection, platform type design, and drilling/production processes [...] Read more.
Offshore structures exist in a variety of forms, and they are used for a variety of functions in varied sea depths. These structures are tailored for certain environments and sea depths. Different actions for suitable equipment selection, platform type design, and drilling/production processes are required for the applications of these offshore structures, as given in Part I. This paper is the second part, which outlines various processes, loads, design approaches and project management of offshore platforms. To achieve these, proper planning must be conducted for lifting, transportation, installation, design, fabrication, and commissioning of these offshore platforms. Some historical developments of some offshore structures are presented, and some project planning routines are undertaken in this research. The ultimate goal is to provide a general overview of the many processes of offshore platform design, construction, loadout, transportation, and installation. Some discussions on the design parameters such as water depth and environmental conditions were presented. It also lists various software programs used in engineering designs covering software programs for structural analysis, 3D rendering, computer-aided design (CAD), hydrodynamic design, oceanic flow analysis, offshore structures analysis, mathematical modelling, coding/algorithm development software, and programming software to aid analytical calculations. The review also includes information on cutting-edge offshore platforms and industry advancements. Ultimately, for long-term operations, various types of offshore platforms for specific seawater depths are available. Full article
(This article belongs to the Special Issue Breakwater Behaviour)
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9 pages, 2532 KiB  
Article
Strategies to Develop the Use of 4R Intermodality as a Combination of Rail Motorways and Motorways of the Sea
J. Mar. Sci. Eng. 2022, 10(7), 972; https://doi.org/10.3390/jmse10070972 - 15 Jul 2022
Cited by 3 | Viewed by 1212
Abstract
This paper introduces the concept of R4 (road-rail-ro-ro), a concept increasingly used in transport and logistics research circles that defines the modern concept of the transport chain as it passes through the intermodal use of rail, road, and ship via ro-ro. The integration [...] Read more.
This paper introduces the concept of R4 (road-rail-ro-ro), a concept increasingly used in transport and logistics research circles that defines the modern concept of the transport chain as it passes through the intermodal use of rail, road, and ship via ro-ro. The integration of the new rail-road freight services into the reference supply model allows us to define the supply model for the design scenario on which the evaluation is now focused in terms of service-mode demand shares and in terms of design network flows and performance indicators carried out by demand-supply interaction models applied to all available service-modes. The use of strength-weaknesses-opportunities-threats analysis (SWOT) allows for the identification of some strategies to enhance and improve the current rail and maritime corridors in order to attract more customers using the different services, ultimately triggering the involvement of more actors in generating bigger and better integrated logistic chains using intermodality. The SWOT analysis allows the identification of a series of measures in order to adapt, maintain, enhance or exploit the aspects arising from the expert analysis. Full article
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14 pages, 5298 KiB  
Article
A New Method of Determining Glass Sponge Reef Adaptive Management Zones for the Hecate Strait and Queen Charlotte Sound Marine Protected Area
J. Mar. Sci. Eng. 2022, 10(7), 971; https://doi.org/10.3390/jmse10070971 - 15 Jul 2022
Viewed by 1310
Abstract
The world’s largest living glass sponge reefs, located in the Hecate Strait and Queen Charlotte Sound off British Columbia, are impacted by bottom contact fishing gear. The existing Adaptive Management Zones (AMZs) for the protection of these reefs were determined by considering the [...] Read more.
The world’s largest living glass sponge reefs, located in the Hecate Strait and Queen Charlotte Sound off British Columbia, are impacted by bottom contact fishing gear. The existing Adaptive Management Zones (AMZs) for the protection of these reefs were determined by considering the potential exposure of glass sponges to suspended sediment due to mobile bottom-contact fishing, but without considering their pumping arrest threshold concentrations. Here, we develop a new method that uses a sediment transport model under horizontally variable near-bottom currents and newly available sponge reef pumping arrest thresholds to determine the size and shape of AMZ for the northern reefs in the Hecate Strait and Queen Charlotte Sound Marine Protected Area. The resulting AMZ is larger than the existing AMZ due to the observation that the largest currents are not always in the direction of the dominant tidal flows, the introduction of the new pumping arrest threshold, and the inclusion of a background sediment concentration. The new AMZ boundary could provide more adequate protection for the glass sponge reefs from the effects of sedimentation induced by mobile, bottom-contact fishing activity. The new method is applicable to other glass sponge reefs in British Columbia waters. Full article
(This article belongs to the Special Issue Numerical Modelling of Atmospheres and Oceans)
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