Passage Of Vessels Research Articles

Civilian Vessel Passage in the Turkish Straits: The First Comprehensive Regulation (1994)

Civilian Vessel Passage in the Turkish Straits: The First Comprehensive Regulation (1994)

Automated identification system for ships data as a proxy for marine vessel related stressors

An increasing number of marine conservation initiatives rely on data from Automatic Identification System (AIS) to inform marine vessel traffic associated impact assessments and mitigation policy. However, a considerable proportion of vessel traffic is not captured by AIS in many regions of the world. Here we introduce two complementary techniques for collecting traffic data in the Canadian Salish Sea that rely on optical imagery. Vessel data pulled from imagery captured using a shore-based autonomous camera system (“Photobot”) were used for temporal analyses, and data from imagery collected by the National Aerial Surveillance Program (NASP) were used for spatial analyses. The photobot imagery captured vessel passages through Boundary Pass every minute (Jan–Dec 2017), and NASP data collection occurred opportunistically across most of the Canadian Salish Sea (2017–2018). Based on photobot imagery data, we found that up to 72 % of total vessel passages through Boundary Pass were not broadcasting AIS, and in some vessel categories this proportion was much higher (i.e., 96 %). We fit negative binomial General Linearized Models to our photobot data and found a strong seasonal variation in non-AIS, and a weekend/weekday component that also varied by season (interaction term p < 0.0001). Non-AIS traffic was much higher during the summer (Apr–Sep) and during the weekend (Sat-Sun), reflecting patterns in recreational vessel traffic not obligated to broadcast AIS. Negative binomial General Additive Models based on the NASP data revealed strong spatial associations with distance from shore (up to 10 km) and non-AIS vessel traffic for both summer and winter seasons. There were also associations between non-AIS vessels and marina and anchorage densities, particularly during the winter, which again reflect seasonal recreational vessel traffic patterns. Overall, our GAMs explained 20–37 % of all vessel traffic during the summer and winter, and highlighted subregions where vessel traffic is under represented by AIS.

Panimbang Coastal Area Planning based on Disaster Mitigation

As an attempt in the improvement of economic interest and areal quality, Sunda Strait is appointed as a National Strategic Area. The strait is quite a busy passage for commerce vessels and also acts as link between provinces. The 2018 tsunami event that affect this area has reminded us the importance of coastal area planning based on disaster mitigation. Panimbang District is one of the areas heavily affected by the tsunami, where the population reside and having their livelihoods around the coast, hence coastal area planning of Panimbang is very much needed. This research was conducted to see the condition of Panimbang District coastal area after the tsunami and how the existing national planning policies is in sync with planning policies at regional level in terms of disaster mitigation. Results of spatial analysis show that coastal areas have not adapted and mitigated optimally, we can see some settlements and tourist areas around coastal area are not heeding the policy on protecting coastal areas, this could happened due to lack of law enforcement or lack of socialization to the local community. This paper might provide recommendation to the local government in arranging coastal protection to keep the residential areas and essential infrastructure safe by making the structural and non-structural approaches.

Expression and clinical significance of CD31, CD34, and CD105 in pulmonary ground glass nodules with different vascular manifestations on CT.

Blood vessel passage on CT exerts a vital part in early diagnosis as well as treatment of carcinoma of the lungs. Intratumoral microvascular density (iMVD) has gradually become the focus of research on biological behavior, appearance, and evolution of malignant tumors nowadays. The aim of this paper was to verify whether there is a correlation between the iMVD and the vascular morphology of ground glass nodules (GGNs). A total of 109 patients with pulmonary GGN were classified into three groups (I,II, and III) according to the vascular morphology on CT, and their expression of CD31-, CD34-, and CD105-labeled iMVD was detected by the streptoavidin–biotin method, statistically analyzing the iMVD values of each group. The expression of CD31, CD34, and CD105 in different lung tissues was significantly different, with remarkably higher iMVD in lung cancer tissues than in adjacent normal lung tissues. In the imaging sort of types I, II, and III according to the means of vascular passage, the iMVD expression of CD31, CD34, and CD105 was significantly different between groups. These data suggest that the presence and the abnormal morphology of vessels seen within GGNs indicate the occurrence and progression of lung cancer in pathology. It offers a strong theoretical foundation for early diagnosis of carcinoma of the lungs, thus providing a more precise clinical diagnosis and prognosis of early-stage lung cancer.

IMPACT OF FLOODS IN THE KOLYMA RIVER DELTA ON NAVIGATION CONDITIONS IN THE EAST SIBERIAN SEA

The problem of improving the quality of medium- and long-term forecasting of changes in the ice situation on the Northern Sea Route, and in particular in the East Siberian Sea, where one of the methods for choosing waterways is the passage of vessels in the areas of flaw polynya, is considered. The hypothesis that in the summer months such changes can be significantly affected by the terms of floods onset in the Kolyma River Delta is tested. The data of the GLORYS12v1 global reanalysis supported by the Copernicus Marine Service are used as factual material on the ice cover and levels of the East Siberian Sea in the months from May to October of 1993-2019. The reanalysis is based on mathematical models of the NEMO family, verified using altimetry data from satellite measurements. Using the developed methodology for the selected periods of the year, the dates of sharp changes in the level and ice cover on the pre-estuary seaside of the Kolyma River are estimated. Using statistical methods, the validity of the stated hypothesis for a number of the East Siberian Sea areas, along which the shipping lanes of the Northern Sea Route pass, is confirmed. It has been established that the greatest influence of the floods terms on the ice situation and navigation conditions in such areas takes place in July. It has been shown that early floods in the Kolyma delta generally lead to an improvement in the ice situation, and late floods lead to its complication. The identified relationships are recommended for use in forecasting changes in ice conditions. The assumption that with further climate warming and a shift in the flood terms to earlier dates, it is possible that the ice conditions will become more complicated due to the freezing of the formed polynya, is made.

Optimal Design Method for Vessel-Bridge Collision Based on Life-Cycle Theory

As structures crossing waterways, bridges are obstacles to vessels. Vessel-bridge collisions are inevitable. They not only involve the safety of vessel passage but also seriously affect the safe operation of bridges. Vessel-bridge collisions cause not only huge economic losses and casualties but also severe political and environmental losses. Vessel collision safety of existing and new bridges is one of the key technical problems that engineers and bridge managers must solve. Comprehensive consideration of vessel-bridge collision risk loss and structural performance in the design stage to achieve optimal cost over the life cycle is an important aspect of bridge design. Based on the current life-cycle design theory of engineering structures, this paper proposes a theoretical framework for vessel-bridge collision optimization design based on the life cycle, which includes three parts: vessel-bridge collision probability analysis, vessel-bridge collision vulnerability analysis, and vessel-bridge collision hazard. Taking the minimum cost of the bridge structure in the design service life period as the objective function, the optimization design model and design process of vessel-bridge collision based on whole life are established, and the key problems to be solved in each part are expounded.

Compound Effects of Flood Drivers, Sea Level Rise, and Dredging Protocols on Vessel Navigability and Wetland Inundation Dynamics

Maritime transportation is crucial to national economic development as it offers a low-cost, safe, and efficient alternative for movement of freight compared to its land or air counterparts. River and channel dredging protocols are often adopted in many ports and harbors of the world to meet the increasing demand for freight and ensure safe passage of larger vessels. However, such protocols may have unintended adverse consequences on flood risks and functioning of coastal ecosystems and thereby compromising the valuable services they provide to society and the environment. This study analyzes the compound effects of dredging protocols under a range of terrestrial and coastal flood drivers, including the effects of sea level rise (SLR) on compound flood risk, vessel navigability, and coastal wetland inundation dynamics in Mobile Bay (MB), Alabama. We develop a set of hydrodynamic simulation scenarios for a range of river flow and coastal water level regimes, SLR projections, and dredging protocols designed by the U.S. Army Corps of Engineers. We show that channel dredging helps increase bottom (‘underkeel’) clearances by a factor of 3.33 under current mean sea level and from 4.20 to 4.60 under SLR projections. We find that both low and high water surface elevations (WSEs) could be detrimental, with low WSE (&amp;lt; -1.22 m) hindering safe navigation whereas high WSE (&amp;gt; 0.87 m) triggering minor to major flooding in the surrounding urban and wetland areas. Likewise, we identify complex inundation patterns emerging from nonlinear interactions of SLR, flood drivers, and dredging protocols, and additionally estimate probability density functions (PDFs) of wetland inundation. We show that changes in mean sea level due to SLR diminish any effects of channel dredging on wetland inundation dynamics and shift the PDFs beyond pre-established thresholds for moderate and major flooding. In light of our results, we recommend the need for integrated analyses that account for compound effects on vessel navigation and wetland inundation, and provide insights into environmental-friendly solutions for increasing cargo transportation.

Utilization of Full-Mission Ship-Handling Simulators for Navigational Risk Assessment: A Case Study of Large Vessel Passage through the Istanbul Strait

The MV Ever Given accident, which took place in the Suez Canal in March 2021, showed the financial consequences of marine accidents in narrow channels as vessel sizes increase continuously. Fortunately, this incident did not threaten life nor the environment. Nevertheless, it has shown the need for a thorough investigation of large vessel passages through narrow channels and confined waterways. In this study, the utilization of a bridge simulator for risk assessment and determining safety criteria through the Istanbul Strait, which is one of the most critical and difficult waterways to navigate in the world, is given as a case study. In the literature, there are some studies illustrating the navigational difficulties and proposed countermeasures. However, there has been no study conducted to determine the safe passage conditions of large vessels in the Istanbul Strait. Hence, a Full-Mission Ship-Handling Simulator (FMSHS) was used to simulate the passage of large vessels in the Istanbul Strait. Scenarios were prepared and executed together with Strait Maritime Pilots to ensure the realism. After the scenarios were simulated, the outputs of each scenario were analyzed using the Environmental Stress (ES) model to highlight levels of risk that occur during the passage of large vessels, and finally, the necessary measures are recommended to mitigate the risk.

Хирургическое лечение гигантской плеоморфной аденомы околоушной слюнной железы

A case of surgical treatment of a giant pleomorphic adenoma of the parotid salivary gland is presented. Pleomorphic adenoma of the parotid salivary gland is the predominant form among tumors of the salivary glands. Slow growth, poor symptoms lead to late diagnosis and significant damage to the parotid salivary gland. The complexity of surgical treatment of the tumor is associated with the passage of the main vessels and nerve trunks in the thickness of the gland

Morphometric analysis of mandibular notch in dry human mandibles- A surgeon's guide to the masseteric nerve block

Background: The mandibular notch allows passage of masseteric vessels and nerve to the deep aspect of the masseteric muscle. The existing data gives a fairer idea in locating the masseteric nerve but does not consider much of the various shapes and sizes of the masseteric notch into account. Hence the present study analyses the various size and shapes and depths of the mandibular notch to achieve a more accurate method for masseteric nerve block. Thus, this investigation intends to examine the morphology and morphometry of mandibular notch in the mandibles of the South Indian people. Methods: The morphometric parameters of the mandibular notch were examined in 102 dry mandibles of the peoples of South Indian. The morphometric parameters were estimated by a digital vernier caliper and data was analyzed statistically. Results: The results of this study showed a round-shaped mandibular notch to be the most frequent type on the right side (43.1%) whereas it was 25.5% on the left side. The length and depth from gonion to notch showed a substantial variance between right and left bone (p=0.41), (p= 0.43) respectively, but with respect to width of the notch no significant difference was observed. Conclusion: This study demonstrates that population specific and side-specific variations may be present in the mandibular notch measurements. Knowledge on variations in incisura mandibularis is of significance in maxillofacial surgeries and reconstructive operations. Keywords: Mandibular notch, masseteric vessels, masseteric nerve block, morphometry

A ROBUST TECHNIQUES OF ENHANCEMENT AND SEGMENTATION BLOOD VESSELS IN RETINAL IMAGE USING DEEP LEARNING

The retina is the most important part of the eye. Early detection of retinal disease can be done through the passage of the blood vessels of the retina. Enhancement of the quality of retinal images that have both noise and noise is the first step in image processing to help improve the accuracy of the results for image segmentation and extraction. Images store a lot of information, but often there is a decrease in quality or image defects. So that images that have experienced interference or noise are easily interpreted, then the image can be manipulated into other images of better quality using image processing techniques or methods. The neural network-based method that is currently popular is deep learning. The segmentation process is currently a widely used method of deep learning that has grown rapidly used in various studies. One of the popular methods is Convolutional Neural Network (CNN). CNN can handle large-dimensional data such as images because the input to CNN is in the form of a matrix. Since the findings of retinal blood vessel segmentation are often inaccurate and there is always noise, this study will look at how to segment retinal images in blood vessels using CNN U-Net and LadderNet methods. Proper segmentation of retinal blood vessels can be the first step to detecting a disease. Segmentation and analysis of retinal blood vessels can assist medical personnel in detecting the severity of a disease. The stages of image enhancement used are Histogram Equalization and Clahe. Segmentation of blood vessels is done using CNN U-Net and LadderNet Methods. The results of the application of the enhancement and segmentation using the U-Net and LadderNet methods on training and on testing data were tested on the DRIVE dataset. The results of measurement of accuracy, specificity, sensitivity and F1 Score of blood vessel segmentation using the U-Net CNN method were 95.46%, 98.56%, 74.20%, and 80.63%, respectively. While the results of the CNN LadderNet method were 95.47%, 98.42%, 75.19%, and 80.86%, respectively. Based on the results of blood vessel segmentation from two proposed methods, the result of the CNN LaddetNet method is greater than the CNN U-Net method in accuracy, sensitivity, and F1 Score. The proposed approach will be further developed in the future, with the aim of increasing the value of the blood vessel segmentation process evaluation outcomes.

Vessel passage scheduling through cascaded bridges using mixed-integer programming

This paper addresses the problem of guaranteeing efficient inland waterway transport in the presence of sequential movable bridges, which must be operated to grant vessel passage. The main contribution is the formulation of the vessel passage scheduling problem as a mixed-integer programming problem. The scheduling algorithm receives vessel widths and voyage plans, and determines feasible vessel passage through bridges that best matches vessel plans. Process optimization is carried out using a rolling horizon implementation to keep the problem computationally tractable in real-time applications. Finally, a realistic case study based on the Rhine-Alpine corridor is used to test the approach and demonstrate its effectiveness.

Improvement of the procedure for issuing a permit for sailing vessels under a foreign flag by inland waterways of the Russian Federation

The article deals with the organization of navigation of vessels under the flags of foreign countries on the inland waterways of the Russian Federation. The article considers the relevance and problems of international shipping on inland waterways of the Russian Federation. Eurasian economic integration, international cargo flow "North-South". The most important inland waterways of international importance (IWWP), E-50 main waterways. It is proposed to improve the procedure for obtaining permission for navigation of vessels under the flags of foreign countries on inland waterways of the Russian Federation. A set of measures for the development of this type of activity is recommended. The analysis of receiving revenues from passage of vessels under flags of foreign states on inland waterways of the Russian Federation is carried out.

A Study on Under Keel Clearance of Gadeok Channel for the Safety Passage of Mega Container Ship

The worldwide sizes of container ships are rapidly increasing. The container ship size in 2005, which was about 9,200 TEU has increased to 24,000 TEU in recent times. In addition to the increase in the sizes of the container ships, the arrivals/departures of large container vessels to/from Korea have also increased. Hence, the necessity for reviewing safe passage of such vessels is emphasized. In the present study, a 24,000 TEU container vessel was used as a model ship to calculate the under-keel clearance (UKC) at Gadeok Channel through which vessels must pass to arrive at Busan New Port, in accordance with the Korean Port and Fishing Port Design Standards and Commentary. In addition, the maximum allowable speed that meets UKC standards was calculated using various squat formulas, whose results were then compared with the current speed limit standards. The analysis results show that Busan New Port requires 10% marginal water depth, and the squat that meets this requirement is 0.95 m. Gadeok Channel requires 15% marginal water depth, and the squat that meets this requirement is 1.78 m; in this case, the maximum allowable speed is calculated as 15 kts. Busan New Port has set the speed limit as 12 kts, which is higher than the calculated 11 kts. Thus, speed limit reconsideration is required in terms of safety. However, the set speed limit for Gadeok Channel is 12 kts, which is lower than the calculated 15 kts. Thus, additional considerations may be provided to increase the speed limits for smooth navigational passage of vessels. The present study, however, is constrained by the fact that it reflects only a limited number of elements in the UKC and allowable speed calculations; therefore, more accurate UKC and safe speed values can be suggested based on extended studies to this research.

Monitoring spatial and temporal soundscape features within ecologically significant U.S. National Marine Sanctuaries.

The U.S. National Oceanic and Atmospheric Administration's Office of National Marine Sanctuaries manages a system of marine protected areas encompassing more than 2,000,000 km2 . U.S. National Marine Sanctuaries (NMS) have been designated to provide protection for their conservation, recreational, ecological, historical, scientific, cultural, archaeological, educational, or aesthetic qualities. Due to the large variability of attributes among NMS, designing coordinated system-wide monitoring to support diverse resource protection goals can be challenging. Underwater sound monitoring is seeing increasing application to marine protected area management because it is able to support this wide variety of information needs. Passive acoustics are providing invaluable autonomous information regarding habitat associations, identifying species spatial and temporal use, and highlighting patterns in conditions that are otherwise difficult to survey. Using standardized equipment and analysis methods this study collected ambient underwater sound data and derived measurements to investigate temporal changes in sound pressure levels and power spectral density, identify presence of select species of importance and support within and among site comparison of ambient underwater sound among eight sites within four U.S. NMS. Broadband sound pressure levels of ambient sound (10-24,000 Hz) varied as much as 24 dB re 1 µPa (max difference 100-124 dB re 1 µPa) among the recording sites, sanctuaries, and seasons. Biotic signals, such as snapping shrimp snaps and vocalizations of fishes, exhibited distinct diel and seasonal patterns and showed variation among sites. Presence of anthropogenic signals, such as vessel passage, also varied substantially among sites, ranging from on average 1.6-21.8 h/d. The study identified measurements that effectively summarized baseline soundscape attributes and prioritized future opportunities for integrating non-acoustic and acoustic variables in order to inform area-specific management questions within four ecologically varying U.S. National Marine Sanctuaries.

ICE REGIME IMPACT ON THE COASTAL ZONE OF THE AZOV SEA

Azov is freezing sea it means that forecast of the time of the beginning and the end of ice fields formation needs. The ice condition limited of maritime safety. Modern condition of ice regime in the Azov Sea has been considered. The navigation of the Ukrainian ports Berdjansk and Mariupol depends on ice regime, duration and ice cover thickness. For the passage of vessels along the sea approach channels and recommended courses in the winter, the use of icebreakers is required. The demolition of confining buoys by ice fields and their restoration is reflected in the economic opportunities of the ports. Purpose of the article is to establish the characteristic winter periods of the last decade, taking into account the climatic changes for the rational using of the results of the impact on the economic activity of the marine infrastructure and hydrographic services. The specific purpose of this publication is to evaluate the displacement of the means of navigation equipment – buoys in the winter, taking into account meteorological factors. The authors set the following tasks: 1) to identify periods and vectors of buoys; 2) to define wind and ice characteristics in separate periods; 3) to reveal the basic meteorological cause of the movement of the buoys. It is important to note that there are no similar publications concerning this region. It became very actual after the climate change period was marked. The reserach is based on the data of direct and remote observations, the dates of ice formation in the area of seaports of Ukraine (Berdyansk and Mariupol) the characteristics of ice, the end of freezing, the opening and clearing of ice from the water areas of ports and bays and using the information from NAVTEX warning system, the archival materials of the weather site meteo.ua. The features of the physicochemical properties of sea water during ice formation and the general circulation of the waters of the Azov Sea are examined, which is linked with the influence of fresh runoff of Don and Kuban rivers. In the period 2013–2021 the observations were made on the displacement of navigation aids (buoys) during the winter periods from the approach channels of the port of Mariupol and Berdjansk as well as noticed buoys from the Azov-Don Marine Channel (Russian Federation). The characteristic of winter periods and conditions during the last decade are considered taking into account the influence of climatic changes. It is noted that the ice regime of the Sea of Azov is closely related with the sum of average daily air tem peratures over the sea for the season and wind power. According to this criterion, winters are usually divided into three types: severe, moderate and mild. Over the past 30 years, there were only two severe winters in the Azov Sea in 2005–2006 and 2011–2012. During these winters, the Azov Sea was completely ice covered. The influence of the ice regime to the coastal zone was examined, because it is very important for the industrial and economic needs of state building. To maintain the safety of navigation and reduce economic losses, it is necessary to consider the possibility of removing buoys, which are most often displaced by ice drift. Long-term average observations indicate the beginning of ice formation in Mariupol on December 14, and in Berdyansk on December 20. The Taganrog Bay and the ice accumulation areas are cleared of ice most recently – March 20–28. Under modern climatic changes (increasing the frequency of mild winters, actual costs for the operation of ships, hydrographic, icebreakers, etc.) are expected to be an order of magnitude lower than standard indicators.

IS FEATURES OF THE LEGAL REGIME OF WATER FACILITIES USED FOR THE NEEDS OF HYDRO POWER

The article examines the features of the legal regime of water bodies used for hydropower. The water potential of the state is the natural basis of its economic development, social and environmental well-being. One of the main consumers of water resources is hydropower, which is one of the most promising areas of alternative energy. It was found that the category of legal regime occupies a special place in the system of legal regulation of public relations. It lays the foundations for the use and protection of water resources in general and water bodies used for hydropower in particular, taking into account the general and specific features inherent in legal regimes. It is established that Art. 66 of the Water Code of Ukraine is devoted to the peculiarities of special water use and use of water bodies for hydropower needs, but the provisions of this article do not disclose all features of the legal regime of water use for such purposes, and its practical significance is limited due to its reference to other water, land, tax legislation, technical regulations, etc. The legal regime of water bodies used for hydropower needs is characterized by such elements as ownership, management in the field of use and protection of water bodies, their legal protection, legal regulation of the use of such objects, legal liability for violations of the law in in this area, etc. The special features are that the use of water bodies for the needs of hydropower is carried out for a fee without a permit, without the removal of water resources from the water body, is indefinite. Water users are obliged to: adhere to the established rules of operation of reservoirs, conditions of special water use, modes of accumulation and operation of water reserves, environmental requirements; take measures to reduce water consumption (especially drinking); to ensure the regimes of fluctuations of water levels in the upper and lower reaches and the passage of water through hydroelectric power stations, uninterrupted passage of vessels and fish to spawning grounds in accordance with the projects of fish pass structures, etc.

АЛГОРИТМ МАНЕВРИРОВАНИЯ АВТОНОМНОГО НЕОБИТАЕМОГО ПОДВОДНОГО АППАРАТА ПРИ ПРОВОДКЕ СУДНА ЧЕРЕЗ ЗАМИНИРОВАННЫЙ РАЙОН

One of the tasks assigned to the autonomous underwater vehicles (AUV) is the fightagainst mine danger, which includes: 1) search for and destroy mines in the mined area;2) ensure their own safety when passing through the mined area or when working in this area;3) ensure the navigation of ships (including submarines) through the mined area. AUV can beconsidered as a further development of mine-fighting equipment, since they have a number ofadvantages over mine-fighting ships: 1) exclude the loss of life in the event of a mine explosion;2) have a lower level of physical fields to which the fuses of sea mines react; 3) are able to maneuverat the optimal depth for searching and classifying mines. In view of this, the creation ofspecialized AUV to combat the mine danger is very important. The search for mines with thehelp of AUV can be carried out either in the interests of their destruction (clearing the area) orfor the purpose of guiding ships through the mined area. This article deals with the secondproblem. The description of the maneuvering algorithm of the AUV when ensuring the passageof a vessel through a mined area is given. The task is solved by detecting different types ofmines using hydroacoustic and magnetometric means of searching and classifying underwaterobjects and bypassing of the mines at a safe distance. To reduce the time required to solve thetask, the detected underwater objects are classified into the "mine-like object" and "other objects"classes. The use of the "mine-like object" class, which includes both the actual mines andobjects that are indistinguishable from mines at the distances of their detection by means ofmine search, allows you to avoid approaching detected underwater objects at a distance of theirconfident classification using high-frequency sonar and television equipment, and thereby increasethe safety of the AUV and reduce the time of passage through the mined area. The algorithmtakes into account the fact that the minimum safe distance between vessel and mine greatlyexceeds the range of detection of mines of different types that does not allow AUV to find asafe vessel passage through the mined area by a single crossing and requires complex maneuveringof the AUV. Algorithm is intended for implementation in the AUV control system.

Exploring how vessel activity influences the soundscape at a navigation lock on the Mississippi River

Vessel sound is now globally recognized as a significant and pervasive pollutant to aquatic life. However, compared to marine environments, there is a paucity of data on sound emitted by vessel activity in freshwater habitats. The Upper Mississippi River (UMR) is home to a diverse array of aquatic life as well as being a key route for barge transportation with 29 locks and dams. In this study, passive acoustic monitoring was conducted at Lock and Dam 19 near Keokuk, Iowa, on the UMR between 20 June – August 28, 2019 to coincide with peak navigation use. There was a significant increase in median sound pressure level (SPL; 50–12,000 Hz) recorded during vessel passages (123 dB re. 1μPa for recreational vessels and 137 dB re. 1μPa for commercial vessels) compared to median background levels (111 dB re. 1μPa). Results provide information on the ambient soundscape at a navigation lock, providing a baseline essential for future studies gauging the effect of anthropogenic sound on aquatic life. Lock 19 has also been identified as a potential site for acoustic deterrent deployment to prevent invasive fish movements. The results of this study can help determine the sound level or frequency deterrents would need to emit, to avoid those currently produced during vessel passage.

A stochastic assessment for oil contamination probability: A case study of the Bosphorus

The Bosphorus is one of the busiest shipping lanes globally as it is the only maritime route for Black Sea countries. Every year about 50,000 ships sail through this lane. Hence, it is necessary to develop emergency response planning strategies due to its high vessel passage rate, distinguished geometry, and delicate hydrodynamics that exhibit two layer stratified flow and exchange water mass between the adjacent seas. In this study, a 3D hydrodynamic model of the Bosphorus is established to simulate oil spill scenarios for improving preparedness for an oil spill event. A stochastic approach is followed to identify oil contamination probability maps for four different ensembles considering two different oil types and two meteo-oceanographic conditions. The results highlight the importance of using different meteo-oceanographic conditions, as probability maps regarding different meteo-oceanographic conditions show large variability. The suggested response strategies can be used to manage oil spill emergencies in the Bosporus more efficiently.