Speed dependence, sources, and directivity of small vessel underwater noise.

Small vessels (<10 m) radiate underwater noise in sensitive coastal environments, but there is insufficient knowledge of their noise radiation. Through detailed measurements of seven small boats and a jet ski in a shallow water environment on the Swedish west coast, this study presents results on the speed dependence of small vessel underwater noise, its sources, and its directivity. For vessels with planing hulls, broadband source levels increase with speed until planing is attained. When planing, source level dependence on speed is weak. A detailed noise source analysis of one vessel showed that at low speed, tonals from the engine dominate the noise radiation, whereas at higher speeds, propeller tonals and broadband noise dominate. Noise radiation into different horizontal angles shows little angle dependence, and noise levels relative to the closest point of approach show a similar pattern across all investigated vessels. Received noise levels at approximately 100 m range are not high enough to cause hearing impairment in marine animals, but fast-moving small vessels may cause behavioural reactions or stress responses across several marine animal groups.

Males miss and females forgo: Auditory masking from vessel noise impairs foraging efficiency and success in killer whales.

Understanding how the environment mediates an organism's ability to meet basic survival requirements is a fundamental goal of ecology. Vessel noise is a global threat to marine ecosystems and is increasing in intensity and spatiotemporal extent due to growth in shipping coupled with physical changes to ocean soundscapes from ocean warming and acidification. Odontocetes rely on biosonar to forage, yet determining the consequences of vessel noise on foraging has been limited by the challenges of observing underwater foraging outcomes and measuring noise levels received by individuals. To address these challenges, we leveraged a unique acoustic and movement dataset from 25 animal-borne biologging tags temporarily attached to individuals from two populations of fish-eating killer whales (Orcinus orca) in highly transited coastal waters to (1) test for the effects of vessel noise on foraging behaviors-searching (slow-click echolocation), pursuit (buzzes), and capture and (2) investigate the mechanism of interference. For every 1 dB increase in maximum noise level, there was a 4% increase in the odds of searching for prey by both sexes, a 58% decrease in the odds of pursuit by females and a 12.5% decrease in the odds of prey capture by both sexes. Moreover, all but one deep (≥75 m) foraging attempt with noise ≥110 dB re 1 µPa (15-45 kHz band; n = 6 dives by n = 4 whales) resulted in failed prey capture. These responses are consistent with an auditory masking mechanism. Our findings demonstrate the effects of vessel noise across multiple phases of odontocete foraging, underscoring the importance of managing anthropogenic inputs into soundscapes to achieve conservation objectives for acoustically sensitive species. While the timescales for recovering depleted prey species may span decades, these findings suggest that complementary actions to reduce ocean noise in the short term offer a critical pathway for recovering odontocete foraging opportunities.

Discharge of ballast residual sediments during de-ballasting procedures: A more realistic estimate of propagule pressure.

Ship ballast residual sediments are an important vector of introduction for non-indigenous species. We evaluated the proportion of residual sediments and associated organisms released during de-ballasting operations of a commercial bulk carrier and estimated a total residual sediment accumulation of ∼13 t, with accumulations of up to 20 cm in some tank areas that had accumulated over 11 years. We observed interior hull-fouling (anemones, hydrozoans, and bryozoans) and high abundances of viable invertebrate resting stages and dinoflagellate cysts in sediments. Although we determined that <1 % of residual sediments and associated resting stages were resuspended and released into the environment during individual de-ballasting events, this represents a substantial inoculum of 21 × 107 viable dinoflagellate cysts and 7.5 × 105 invertebrate resting stages with many taxa being nonindigenous, cryptogenic, or toxic/harmful species. The methods used and results will help estimate propagule pressure associated with this pathway and will be relevant for residual sediments and nonindigenous species management.

Contemplating Maritime Autonomous Surface Ships (MASS) under the international law on ship-source pollution.

Autonomous ships are seen as the next generation of ships to meet sustainability challenges. While abundant studies have noted the potential of autonomous ships to be emission-free and reduce air pollution, research has paid scant attention to the significant uncertainties of the autonomous shipping that may lead to new environmental risks such as traffic incidents and oil spills. It is therefore necessary to assess the compatibility of the autonomous ships with international environmental laws and regulations. An analytical framework of international law on ship-source pollution has been proposed to contemplate such a legal assessment. Autonomous ships would challenge the relevant treaty provisions on preventing, combating and compensating for ship-source pollution and raise a number of new legal issues, resulting in a current lack of legal predictability and certainty. Only as autonomous ships become more widely tested, recognised and trusted will a robust roadmap for legalising MASS become clearer.

The Determination of On-Water Rowing Stroke Kinematics Using an Undecimated Wavelet Transform of a Rowing Hull-Mounted Accelerometer Signal.

Boat acceleration profiles can provide valuable information for coaches and practitioners to make meaningful technical interventions and monitor the determinants of success in rowing. Previous studies have used simple feature detection methods to identify key phases within individual strokes, such as drive onset, drive time, drive offset and stroke time. However, based on skill level, technique or boat class, the hull acceleration profile can differ, making robust feature detection more challenging. The current study's purpose is to employ the undecimated wavelet transform (UWT) technique to detect individual features in the stroke acceleration profile from a single rowing hull-mounted accelerometer. In this investigation, the temporal and kinematic values obtained using the AdMosTM sensor in conjunction with the UWT processing approach were strongly correlated with the comparative measures of the Peach™ instrumented oarlock system. The measures for stroke time displayed very strong agreeability between the systems for all boat classes, with ICC values of 0.993, 0.963 and 0.954 for the W8+, W4- and W1x boats, respectively. Similarly, the drive time was also very consistent, with strong to very strong agreeability, producing ICC values of 0.937, 0.901 and 0.881 for the W8+, W4- and W1x boat classes. Further, a Bland-Altman analysis displayed little to no bias between the AdMosTM-derived and Peach™ measures, indicating that there were no systematic discrepancies between signals. This single-sensor solution could form the basis for a simple, cost-effective and accessible alternative to multi-sensor instrumented systems for the determination of sub-stroke kinematic phases.

Exploration of port environmental efficiency measurement and influential factors in the Yangtze River Delta Pilot Free Trade Zone.

This study focuses on the environmental efficiency of ports in China's Yangtze River Delta Pilot Free Trade Zone (YRD PFTZ), a critical factor in advancing the high-quality development of ports and facilitating Chinese-style modernization. Current research on port efficiency primarily focuses on the geographical level, with relatively few studies examining the economic regional framework. We selected the YRD PFTZ port for our study to address this gap. Covering 2013 to 2021, we employed the Super-SBM with undesirable outputs and utilized the GML index method. We conducted a spatiotemporal analysis to assess dynamic and static aspects and used the Tobit model to thoroughly investigate the factors influencing the GML Index of these ports. The study showed that: (1) the overall environmental efficiency of these ports was relatively high with a fluctuating trend of initial increase, followed by a decrease, and then an upturn. (2) From a dynamic perspective, the average Green Total Factor Productivity (GTFP) Index is 1.549, denoting an exceptional level primarily driven by technological efficiency. The technical efficiency change index is the main factor improving GTFP in Shanghai, Jiangsu, and Anhui provinces. (3) The port cargo volume and total import and export volume significantly impact the environmental efficiency.

Urbanisation and boating are the main contributors to underwater soundscapes in three temperate estuaries.

Anthropogenic noise has been identified as one of the most harmful forms of global pollutants impacting both terrestrial and aquatic ecosystems. As global populations continue to increase, coastlines are seeing substantial increases in the level of urbanisation. Although measures are in place to minimise stress on fauna, they rarely consider the impact of anthropogenic noise. In Australia, New South Wales (NSW) estuaries have seen extensive increases in urbanisation in recent years. Yet, there remains minimal baseline data on their soundscapes to determine if noise pollution is a threat. This research provides a first assessment of baseline sounds across a temporal and seasonal scale. Recreational boating was the primary soundscape contributor in estuaries, and estuaries with higher urbanisation levels contained higher sound levels. This research provides useful information for managers of NSW estuaries and is of global relevance in an era of increasing generation of anthropogenic noise in estuarine and coastal systems.

A quantitative assessment of continuous versus structured methods for the detection of marine mammals and seabirds via opportunistic shipboard surveys.

Marine monitoring efforts are increasingly supported by opportunistic shipboard surveys. However, opportunistic survey methods often require adaptation to suit the vessel and the operations being conducted onboard. Whilst best-practice techniques for surveying marine wildlife on vessels of opportunity are yet to be established, testing and development of alternative methods can provide means for capturing ecological information in otherwise under-surveyed areas. Explicitly, survey methods can be improved while baseline ecological data for new regions are gathered simultaneously. Herein, we tested different survey approaches on a vessel of opportunity in a remote offshore area where little is known about the community composition of top-order marine vertebrate predators: western and south-western Tasmania, Australia. We found that continuous surveys provide greater species counts than structured "snapshot" surveys over the course of a voyage, but that structured surveys can be more practical when managing factors such as observer fatigue. Moreover, we provide a baseline dataset on the marine vertebrate community encountered in western and south-western Tasmania. This information will be critically important for industry and conservation management objectives, and is key to our understanding of the offshore ecosystem around Tasmania.

Ballast water transport of alien phytoplankton species to the brazilian amazon coast.

The aim of this study was to investigate the presence of alien phytoplankton species transported through ballast water of ships that docked on the Amazon coast. Phytoplankton samples were collected from 25 ships between 2012 and 2014, revealing 215 identified species, mostly comprising oceanic planktonic marine species. However, several coastal and freshwater species not yet documented on the Maranhão coast were also observed. The identification of several coastal and freshwater species not yet recorded for Amazonian environments in the ballast water of the Ponta da Madeira Maritime Terminal (TMPM), as well as toxic microalgae genera such as the dinoflagellates Alexandrium and Gymnodinium and of some diatom species from the genus Pseudo-nitzchia, raises concerns regarding the possibility of introducing species. This indicates that ballast water can be responsible for the introduction of alien species in Amazonian aquatic environments, thereby highlighting the TMPM as a critical hotspot in the Amazonian region.

A latent profile analysis of shift work tolerance among Chinese male sailors during a prolonged non-24-h rotating shift schedule at sea.

Shift work tolerance (SWT) refers to the ability to adapt to shift work without significant adverse consequences. The present study aimed to examine the individual differences in SWT and their predictors and outcomes. Latent profile analyses were conducted using cross-sectional data collected form 448 Chinese male sailors who experienced a prolonged (>30 d) non-24-h rotating shift schedule at sea. Depression, anxiety, sleep disturbance, fatigue, domestic disruption, job satisfaction, work engagement, digestive and cardiovascular symptoms were included as indicators of SWT. The results showed that there existed 2 latent profiles of SWT named as High SWT group and Low SWT group. High SWT group was characterized by low levels on all negative bio-psycho-social outcomes but high levels of work engagement and job satisfaction, while Low SWT group exhibited completely opposite characteristics compared to High SWT group. The level of hardiness could predict profile membership that those with higher level of hardiness were more likely to belong to High SWT group. However, there were no significant differences observed in job performance between two groups. In conclusion, hardiness can serve as a predictor of personnel selection for shift work and hardiness-based intervention programs should be encouraged among the shift workers.

Polycyclic aromatic hydrocarbons in ship breaking area and associated ecological risk assessment: evidence from the Sitakund ship-breaking area in Bangladesh.

Ship-breaking yards are recognized for releasing hazardous polycyclic aromatic hydrocarbons (PAHs), leading to severe environmental pollution in the sediment of ship-breaking areas. This study assessed the concentrations of 16 priority PAHs in surface sediments collected from the intertidal zone adjacent to the Sitakund ship-breaking yards. The samples underwent Soxhlet extraction and detection using PerkinElmer GC-Clarus 690 and MS-Clarus SQ8C with an Elite-5MS capillary column (30 m × 0.25 mm ID × 0.25 µm). The study utilized PAH concentrations to reveal spatial distribution patterns, identify point sources, and assess potential toxicity. The total PAH concentration ranged from 1899.2 to 156,800.08 ng g-1 dw, while the concentration of 7 carcinogenic PAHs ranged from 822.03 to 1899.15 ng g-1 dw. High molecular weight PAHs dominated among the 16 PAHs, whereas low molecular weight PAHs, such as 2-ring PAHs, were negligible. Source characterization based on different molecular ratios suggested that PAHs in the area originated from pyrolytic processes related to ship dismantling, fishing activities, and water transportation for people. The observed PAH concentrations exceeded both national and international standards for sedimentary PAH levels, indicating significant ecological risks. The total TEQcarc values of sediment samples varied from 564.41 to 10,695.12 ng g-1, with a mean value of 3091.25 ng g-1. The study's findings underscore the immediate biological damage that PAH contamination in the Sitakund ship-breaking area could cause, emphasizing the need for effective control measures to ensure ecological and human safety.

[Cross sectional study of odontological incidences on board the spanish Navy flagship Juan Carlos I during its first international peacekeeping mission]. / Estudio observacional descriptivo de la incidencia odontológica a bordo del buque insignia de la Armada española Juan Carlos I en su primera misión internacional de mantenimiento de la paz.

OBJECTIVE: Oral health is an essential component of the general well-being and quality of life of the population. In Spain, access to dental services and emergency dental care for civilians is relatively straightforward. However, this is not the case for military personnel, especially those deployed on Navy ships that lack dental capabilities and in isolated areas where access to specialized healthcare services is complex and risky. The aim of this study was to evaluate the incidence and management of dental pathology among Spanish military personnel aboard the LHD 61 Juan Carlos I during its first International Peacekeeping Operation. METHODS: A descriptive observational study was conducted on the accumulated incidences of dental pathology and treatments performed between May 1 and June 26, 2018. The population sample consisted of 448 Spanish military personnel aboard the ship. The data were obtained from the databases of the dental activity logbook and the military statistical and health data management systems, which serve to assess the actual health status of the force. RESULTS: A total of 70 patients were treated for dental problems, with gingivitis and caries being the most prevalent conditions, accounting for 23.07% and 18.68% of cases, respectively. The most common treatments performed were dental reconstructions/fillings, making up 40% of the total, and tartar removal, accounting for 21%. CONCLUSIONS: Understanding the incidence of dental pathologies on Spanish Navy ships allows us to establish the training needs of the onboard medical personnel, as well as determine the material resources that should be provided to naval units. Prevention plans and pre-deployment dental check-ups should be conducted well in advance to address any dental issues on land before personnel are deployed.

OBJETIVO: La salud bucodental es un componente esencial para el bienestar general y la calidad de vida de la población. En España el acceso a los servicios odontológicos y a la atención de la urgencia bucodental del personal civil es relativamente sencilla, pero no ocurre lo mismo para el personal militar, especialmente para el que se encuentra desplegado en buques de la Armada que no cuentan con capacidad odontológica y en zonas de aislamiento donde el acceso a los servicios sanitarios especializados es complejo y arriesgado. El objetivo de este estudio fue evaluar la incidencia y manejo de la patología odontológica ocurrida en los militares españoles a bordo del buque LHD 61 Juan Carlos I durante su primera Operación Internacional de Mantenimiento de la Paz. METODOS: Se realizó un estudio observacional descriptivo de incidencias acumuladas de la patología y los tratamientos odontológicos realizados entre el 1 de mayo y el 26 de junio de 2018. La muestra poblacional fue de 448 militares españoles a bordo del buque. Los datos se obtuvieron de las bases de datos del libro de registro de actividad odontológica y de los sistemas militares de estadística y gestión de datos sanitarios que sirven para conocer el estado real de salud de la fuerza. RESULTADOS: Se atendieron un total de 70 pacientes por problemas bucodentales, donde la gingivitis y la caries fueron las enfermedades que más incidencia presentaron, con un 23,07% y un 18,68%, respectivamente. Los tratamientos más realizados fueron las reconstrucciones/obturaciones dentales con un 40% y las tartrectomías con un 21% del total. CONCLUSIONES: El conocimiento de la incidencia de las patologías odontológicas en buques de la Armada Española nos permite establecer las necesidades formativas del personal de sanidad embarcado, así como determinar con qué recursos materiales se debe de dotar a las unidades navales. Los planes de prevención y los reconocimientos odontológicos previos al despliegue deben realizarse con antelación suficiente para poder sanar en tierra las patologías del personal que va a ser desplegado.

Potential of CO2 sequestration by olivine addition in offshore waters: A ship-based deck incubation experiment.

Ocean alkalinity enhancement is considered as an effective atmospheric CO2 removal approach, but currently, little is known about the carbon sequestration potential of implementing olivine addition in offshore waters. We investigated the effect of olivine addition on the seawater carbonate system by carrying out a deck incubation experiment in the Northern Yellow Sea; the dissolution rate of olivine was calculated based on the increase in seawater alkalinity (TA), and the CO2 sequestration potential was evaluated. The results showed that the dissolution of olivine increased seawater TA and decreased partial pressure of CO2, resulting in oceanic CO2 uptake from the atmosphere through sea-air exchange; it also increased seawater pH and mitigated ocean acidification to a certain extent. The addition of 1 ‰ olivine had a more significant effect on the seawater carbonate system than 0.5 ‰ olivine addition. The average dissolution rate constant of olivine was 1.44 ± 0.15 µmol m-2 d-1. Assuming that olivine settles completely on the seabed due to gravity, the theoretically maximum amount of CO2 removed by applying 1 tonne of olivine per square meter area in the Northern Yellow Sea is only 2.0 × 10-4 t/m2. Therefore, when olivine addition is implemented in the offshore waters, it is necessary to consider reducing the olivine size, prolonging the settling time of olivine in the water column; and spreading olivine in well-mixed waters to prolong the residence time through repeated resuspension, thus increasing its potential in carbon sequestration.

Causal diagnostic model and governance strategies to reduce pollution from ship accidents in Chinese waters.

Ship transportation is a primary mode for global trade and cargo transport, yet even minor discrepancies can lead to ship accidents, causing severe secondary environmental pollution. Maritime accidents involve complex and numerous factors. Formal Concept Analysis (FCA) can identify the key contributing factors and their impact levels by eliminating homogenization factors in maritime accidents. This study constructs an innovative FCA model of ship accidents in Chinese waters, utilizing 172 ship accident reports released by the China Maritime Safety Administration. The analysis reveals seven reduced sets and 23 diagnostic rules of ship accidents. Results show that failed ship registration/security inspection, deficient nautical data and instruments, and management issues are the most critical factors. Three accident chains are identified and corresponding mitigation strategies are proposed to reduce potential pollution from ship accidents. These strategies offer significant reference value for preventing ship accidents and reducing their environmental impact in China and globally.

Abundance, characteristics and ecological risk assessment of microplastics in ship ballast water in ports around Liaodong Peninsula, China.

The development of the shipping industry has led to a large volume of ballast water discharge annually. This accelerates pollutants' transfer and dispersion, such as microplastics. Currently, empirical data on microplastics in ballast water are rarely available. This study innovatively investigated the abundance, morphological characteristics (particle size, shape, and color), and polymer composition of microplastics in ballast water from ports surrounding the Liaodong Peninsula. The results revealed that the average abundance of microplastics in 13 ships' ballast water was 6071.30 ± 1313.85 items/m3. Notably, the small microplastics (0.06-2.50 mm) were most abundant, accounting for 94.52 % of the total microplastics. Transparent, fiber, and polyethylene glycol terephthalate were the most prevalent color, shape, and polymer composition of microplastics detected in the ballast water. The risk assessment indicated that these microplastics present ecological risks to organisms. These findings suggest that ship ballast water is the potential "hotspot" for marine microplastics transport.

Strategic location model for oil spill response vessels (OSRVs) considering oil transportation and weather uncertainties.

In the event of oil spills in offshore oil and gas projects, containment and dispersion equipment must be sent to the affected areas within a critical time by vessels known as oil spill response vessels (OSRVs). Here, we developed an optimization tool, integrated with an oil spill trajectory simulation model, both in deterministic and stochastic alternatives, to support decision-making during the strategic planning of OSRV operations. The tool was constructed in Python using GNOME for oil spill simulations and the GUROBI to solve the optimization model. The tool was applied to a case study in Brazil and afforded relevant recommendations. In terms of research contributions, we proved the viability of the integration between oil spill simulation and mathematical modeling for OSRV strategic operation planning, we explored the stochasticity of the problem with an innovative strategy and we demonstrated flexibility and easy applicability of the framework on real operations.

Readiness and challenges of carbon capture technologies based on the shipping industry.

In the context of carbon emission reduction in the shipping industry, CCUS technology can modify ships to reduce carbon emissions, providing a new direction for the green development of the shipping industry. Based on this, this paper investigates the technology related to carbon capture on ships, firstly puts forward the applicable requirements of carbon capture technology; and analyses the adaptability of the existing carbon capture solutions to the shipping industry; and discusses the development prospect of carbon capture on ships through the three challenges of space utilisation, safety, and economy; and finally analyses the related policies. After analysis and discussion, this paper concludes that the alcohol-amine method is the most suitable carbon capture solution for ships, but there are challenges in economics and space utilisation. The future research direction lies in optimising the performance of the absorber, improving the energy efficiency of the system and solving the CO2 storage problem.

Improved Z-number and fault tree analysis to predict the risk of air pollution due to ship boiler operation.

Ships present a significant source of air pollution, contributing to environmental degradation and posing health risks. Boilers are a significant part of the vessels in which the water is heated to evaporate and generate steam. The boilers emit pollutants such as hazardous air pollutants (HAPs), particle pollution, and volatile organic compounds (VOC). This paper conducts an extended risk analysis for air pollution due to boiler operation on ships. An improved Z-numbers theory and Fault Tree Analysis (FTA) are adopted to predict risk. Whilst improved Z-number theory is capable of handling uncertainties inherent in risk assessment, the FTA presents systematically the causal relationships among various factors contributing to the risk of air pollution on ships. The findings show that the failure probability of air pollution during ship boiler operation is 2.08E-05 and BE-12 is the most significant event. Results provide valuable data to maritime stakeholders in fostering environmentally sustainable practices.

A method for evaluating safety reliability of descend/ascend drop-weight system and mission abort decision for deep-ocean scientific human submersibles.

Descend and ascend of deep-water human-occupied submersibles based on buoyancy changes are enabled using a denomination of dispensable drop-weights, and loss of buoyancy are managed using emergency drop-weights and jettisoning identified systems. Failing to release the drop weights or jettison results in submersible stranding on the sea floor, leads to emergency recovery, and hence the drop-weight configuration has to be highly reliable. The paper, for the first time, based on hydrostatic stability, descend/ascend velocity needs, ocean salinity profile and loss-of-buoyancy situations, proposes a novel on-demand reliability based methodology for determining the safe drop-weight configuration and degradation-based mission abort strategy for deep-ocean human submersibles. Probabilistic on-demand reliability analysis based on IEC61508 standards for safety-critical systems using component field-failure data is carried out and the drop-weight configuration essential to meet the human-rated safety integrity level 3 during all stages of the subsea mission is identified for the deep-ocean human scientific submersible Matsya6000, based on which a mission abort protocol is evolved.

Sensor-Based Fuzzy Inference of COVID-19 Transmission Risk in Cruise Ships.

Cruise ships are densely populated ecosystems where infectious diseases can spread rapidly. Hence, early detection of infected individuals and risk assessment (RA) of the disease transmissibility are critical. Recent studies have investigated the long-term assessment of transmission risk on cruise ships; however, short-term approaches are limited by data unavailability. To this end, this work proposes a novel short-term knowledge-based method for RA of disease transmission based on fuzzy rules. These rules are constructed using knowledge elicited from domain experts. In contrast to previous approaches, the proposed method considers data captured by several sensors and the ship information system, according to a recently proposed smart ship design. Evaluation with agent-based simulations confirms the effectiveness of the proposed method across various cases.