Fresh Water Studies Commons^™

Key Steering Characteristics For Training Remote Operators Of Maritime Autonomous Surface Ships In Collision Avoidance, Soyeong Lee, Ik-Hyun Youn

Journal of Marine Science and Technology–Taiwan

Maritime Autonomous Surface Ships (MASS) require remote operators (ROs) who need to be trained in collision avoidance (CA) maneuvers. In order to develop a training system, this study investigated differences in the steering characteristics of expert and novice navigators such as the timing of the initial rudder operation, rudder angle at a relative bearing 0°, heading at the maximum rate of turn to starboard, and, heading at the closest point of approach. The experts exhibited relatively consistent and controlled steering patterns characterized by earlier rudder adjustments and smoother heading transitions while novices demonstrated delayed reactions and greater variability in heading …

Subsurface Origin Of Tex86 Signals Revealed By Cross-Seasonal Gdgt Distributions In Suspended Particulate And Sediment Samples From The Southern East China Sea, Hung-Lin Tsai, Da-Chen Lin

Journal of Marine Science and Technology–Taiwan

The TetraEther indeX of 86 carbon atoms (TEX₈₆) proxy, which is based on isoprenoid glycerol dialkyl glycerol tetraethers (isoGDGTs) produced by Thaumarchaeota in marine environments, is widely used to reconstruct past sea surface temperatures (SSTs). However, evidence suggests that this proxy often instead reflects subsurface conditions, particularly in dynamic marginal seas. Therefore, we conducted a cross-seasonal study of glycerol dialkyl glycerol tetraether (GDGT) distributions in the southern East China Sea (ECS), which is characterized by strong monsoonal and current-driven hydrographic variability. We analyzed surface sediments and the high-resolution vertical profiles of suspended particulate matter (SPM) collected from 2016 …

The Current Status And Challenges Of Efforts To Generate Blue Carbon Credits In Okinawa Prefecture, Takashi Tamura, Wei-Chung Chen, Takafumi Sasaki

Journal of Marine Science and Technology–Taiwan

In Okinawa Prefecture, the Mozuku aquaculture industry is keen on establishing Blue Carbon Credits. This enthusiasm stems from various perspectives, including climate change mitigation, improvement of fishing grounds, industry maintenance, and enhancement of fishing ground surveillance functions. However, the industry faces several challenges. One significant challenge is the lack of a clear remaining coefficient for Mozuku, which complicates the creation of credits. Additionally, there is a shortage of manpower within the fisheries cooperative, further exacerbating the problem. To address these challenges, it is crucial to secure human resources that can promote system understanding and establish a financial base for undertaking …

In-Situ And Laboratory Sound Velocities Of Unconsolidated Sediments In The Western South Korea Plateau Of The East Sea, Kiju Park, Gil Young Kim, Yuri Kim, Bo Yeon Yi, Nyeon Keon Kang, Gwang Soo Lee

Journal of Marine Science and Technology–Taiwan

The in-situ velocity of unconsolidated shelf sediments in the western South Korea Plateau of the East Sea was directly measured using the Korea Institute of Geoscience and Mineral Resources (KIGAM) Seafloor Acoustic Probe. Physical properties, including laboratory velocity, were also measured for core samples collected from the same location. The laboratory measurements were conducted at a temperature of 23℃ and under atmospheric pressure. Owing to the in-situ temperature and pressure (0.5–1.5℃ and 100–180 atm, respectively) at the sampling site, the laboratory velocity was adjusted to the in-situ conditions. In addition, a comparison with a theoretical prediction model (Biot-Stoll model) was …

Diel Variations In Abundance Of Viral, Picoplankton, And Nanoplankton In Coastal Waters Of Taiwan In Spring, Patrichka Wei-Yi Chen, Madeline Olivia, Vladimir Mukhanov, Ufimtseva Margarita, Liashko Tatiana, Sakhon Evgenii, Supriyadi Supriyadi, Intan Dwi Puspitasari, Arpita Ghosh, An-Yi Tsai

Journal of Marine Science and Technology–Taiwan

The diel variations of viruses (< 0.2 μm), picoplankton (0.2-2 μm; heterotrophic bacteria, Synechococcus spp., and picoeukaryotes), and nanoflagellates (2-20 μm; heterotrophic and pigmented nanoflagellates) were examined for 2 days with approximately 4 h of temporal sampling in the spring of 2024 in coastal surface waters of the subtropical western Pacific. The abundance of bacteria did not follow a consistent diel pattern, and viral abundance was positively correlated with bacterial abundance. Synechococcus spp. was found to grow during the light period and with peak abundance at night, exhibiting a remarkably diel pattern; however, the pattern was opposite in picoeukaryotes. In the size-fractionation experiments, after 32 h of …

New Insights Into Decapod Chemical Communication: A Focus On The Hydrothermal Vent Crab Xenograpsus Testudinatus, Jishnu Panamoly Ayyappan, Mark June S. Consigna, Li-Chun Tseng, Jiang-Shiou Hwang

Journal of Marine Science and Technology–Taiwan

Chemical communication in decapod crustaceans has been extensively studied for over 150 years, with most of the research focusing on sex pheromones. These crustaceans inhabit chemically complex environments and rely on diverse chemical signals for essential behaviors such as mate recognition, predator avoidance, and social interaction. This review synthesizes key findings from studies on shrimp, crayfish, lobsters, and crabs, the most well-documented taxa in crustacean chemical ecology. Various appendages, including the first and second antennae, mouthparts, and walking legs, are involved in chemosensory detection. Special emphasis is placed on chemical communication in extreme environments such as hydrothermal vents (HVs), with …

Apply Cluster Analysis To Improve Interpretation Of Ert Images, Yin-Chun Hung, Yu-Xiang Zhao

Journal of Marine Science and Technology–Taiwan

The completeness and accuracy of collecting and investigating geotechnical and marine engineering geological conditions are key to the success or failure of engineering development. Traditional marine engineering and geotechnical surveys often require the assistance of geophysical methods to fully present the geological conditions. Electrical Resistivity Tomography (ERT) is an advanced geophysical method that produces accurate cross-sections of underground resistivity. Although 2D ERT has been widely used in geotechnical engineering and marine engineering, many uncertainties remain hidden behind the vivid and colorful resistivity profiles. To apply 2D ERT profiles effectively in geotechnical and marine geological surveys and monitoring, it is essential …

Geo-Chemical Fractionations Of Phosphorus In Sediments Of Thuy Trieu Lagoon And Cam Ranh Bay, Vietnam, Phu H. Le, Ngoc H. Pham, Dung T. Le, Tuan Linh T. Vo, Binh V. Tran, The V. Ho

Journal of Marine Science and Technology–Taiwan

The geochemical fractions of phosphorus (P) and its bioavailability in sediments of Thuy Trieu Lagoon and Cam Ranh Bay were investigated. Twenty-four surface sediment samples were collected in the dry season (Jun 2024) and the rainy season (Oct 2024). A sequential extraction procedure was applied to identify the phosphorus (P) fractions in sediments, including Exchangeable P (Ex-P), iron-bound P (Fe-P), aluminum-bound P (Al-P), calcium-bound P (Ca-P), and residual P (Res-P). Total P (TP) ranged from 214.9 to 2365.2 µg.g^-1, and the Ca-P fraction was the dominant chemical form in sediments. Based on the results of Pearson correlation and …

Beyond Basic Needs : Exploring The Antecedents And Outcomes Of Seafarers’ Well-Being, Chian Liou, Cheng Kuo Sung, Kimberly Hsiu-Chin Lee, Jiunn Liang Guo

Journal of Marine Science and Technology–Taiwan

Given the importance of seafarers’ mental health and the limited literature on this topic, this study aims to explore the causes and consequences of seafarers’ well-being. A questionnaire survey was conducted, and the data were analyzed using structural equation modeling and hierarchical regression analysis. Consistent with the predictions of the happy and productive worker thesis, this study found that the more satisfied the seafarers are with the shipping company’s seafarer policy, the higher their well-being tends to be, leading to a more positive work attitude. Interestingly, the study found that a company effect is significantly present in this correlation; that …

Empowering Shipping Management Competence With Artificial Intelligence: A Strategic Approach To External Environmental Volatility, Yu-Kai Huang, Cheng-Hsien Hsieh, Chi-Chang Lin, Yu-Tzu Chang, Yu-Chao Cheng

Journal of Marine Science and Technology–Taiwan

The shipping industry is undergoing significant transformation with advancements in artificial intelligence (AI), yet challenges remain in effectively adopting AI technologies. This study addresses the key concerns influencing AI adoption in shipping management. Using the Analytic Hierarchy Process (AHP) integrated with the PEST model, an evaluation framework was developed to assess AI applications in shipping companies. Based on expert input collected through the Delphi method, four constructs and twelve criteria were identified, with the 'Technological' dimension being the most critical. 'Robustness,' 'Costs,' and 'Data quality' emerged as the top factors affecting AI implementation. The framework offers practical insights for shipping …

Comparative Evaluation Of Deep Learning Models For Predicting Skipjack Tuna (Katsuwonus Pelamis) Catch Based On Climatic Factors, Peng Ding, Hui Xu, Xin Zhuang, Yan-Lun Wu, Fengyuan Shen, Yujie Xiao, Jiensi Zhulidezi, Wei-Yu Lee

Journal of Marine Science and Technology–Taiwan

To investigate the impact of climatic factors on skipjack tuna catch, this study collected and analyzed annual global skipjack tuna catch data spanning from 1960 to 2021, along with corresponding monthly data for the key indicator of El Nino events (Niño1+2, Niño3, Niño4, and Niño3.4), the Southern Oscillation Index (SOI), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO), the North Pacific Index (NPI), and the global sea-air temperature anomaly index (dT). The optimal lag years of climatic factors were identified by selecting the maximum absolute cross- correlation coefficients. Subsequently, the predictive performance of LSTM, BiLSTM, and CNN-BiLSTM models …

Effects Of Train-Ship Direct Transshipment On Container Terminal Operational Efficiency And Energy Consumption: From A Scheduling Perspective, Yiying Du, Yaozong Wang, Zhongzhen Yang

Journal of Marine Science and Technology–Taiwan

On-dock rail integration positions terminals as critical hubs for rail-sea transshipment, which necessitates efficient scheduling for rapid container transfers. Given the strict schedules and batch arrival of railway containers, in this study, we propose a train-ship direct transshipment (TSDT) mode to eliminate nonproductive yard rehandling. To comprehensively evaluate the impact of the proposed mode on terminal handling operations, we developed an operational scheduling model for the entire process of the simultaneous loading of yard containers and railway-handling area (RHA) containers. The model comprises two stages. Stage 1 models the pre-reshuffling operations in the yard before loading, and Stage 2 implements …

Key Success Factors In Using The Lifting Method To Construct A Steel Bridge Pylon, Ming-Chao Su, Hui-Ping Tserng

Journal of Marine Science and Technology–Taiwan

Constructing the inclined steel pylon of cable-stayed bridges is challenging because of the pylon’s height, spatial limitations, and safety concerns. To address these challenges, this study developed a modular lifting method that can enhance the efficiency and precision of pylon construction. The proposed method involves using rotation jigs to temporarily assemble the pylon, horizontal positioning on temporary supports, and synchronized lifting through computer-controlled hydraulic systems. Field implementation on a large-span bridge project revealed that compared with the traditional method, the proposed method resulted in higher welding quality, lower risks associated with great-height operations, and a shorter on-site assembly time. The …

Deep Learning-Based Model For Automated Prediction Of Coastal Changes: A Robust Approach To Environmental Forecasting, Tsair-Fwu Lee, Chu-Ho Chang, Chin-Shiuh Shieh, Chih-Hsien Wu, Jen-Chung Shao, Chien-Liang Chiu

Journal of Marine Science and Technology–Taiwan

The coastline stands as a critical domain encompassing industry and the environment. The escalating global warming, leading to elevated sea levels and intensified wave-current interactions, has given rise to substantial coastal erosion. This predicament, in conjunction with excessive human development and Taiwan's coastal areas' extreme climatic impact, accentuates the perceptibility of coastal beach alterations. As a result, coastal erosion has emerged as a pressing issue necessitating resolution. Traditional methodologies for assessing coastline changes have conventionally relied on manual measurements. However, owing to the fluctuating distance of coastlines, influenced by tidal patterns, extended measurement processes over several months are susceptible to …

Hydrographic Influences On Seasonal Variations In Zooplankton Communities Of Taiwan Bank (Southern Taiwan Strait), Bor-Shyr Chen, Frank Paolo Jay B. Albarico, Mark Ariel D. Malto, Aiza D. Gabriel, Chiu-Wen Chen, Cheng-Di Dong

Journal of Marine Science and Technology–Taiwan

Understanding the factors that control ocean productivity is crucial in fisheries management. Taiwan Bank, located between the Taiwan Strait and the South China Sea, is a highly productive ecosystem due to upwelling events. The total zooplankton community (holozooplankton and merozooplankton), diversity, seasonal changes, and environmental drivers remain unexplored despite its productivity. This study evaluates the seasonal and vertical environmental dynamics in the Taiwan Bank and their impacts on the zooplankton community structure. We collected zooplankton and basic water parameters in March, July, and September 2017 at 5, 25, and 50 meters. We recorded significant seasonal changes in zooplankton composition and …

Model Performance For Predicting Trends And Analyzing The Impacts Of Sea Surface Temperature Changes In The Gulf Of Thailand, Tanatpong Udomchaipitak, Nathaphon Boonnam

Journal of Marine Science and Technology–Taiwan

This study focuses on assessing and improving the predictive performance of sea surface temperature (SST) in the Gulf of Thailand under unique environmental challenges. Data from the Hybrid Coordinate Ocean Model (HYCOM) were utilized, covering the period from July 1994 to June 2024 at depths ranging from 0 to 30 meters. After cleaning the data using the Interquartile Range (IQR) method, the processed dataset was tested using four models: Recurrent Neural Network (RNN) architectures, including Long Short-Term Memory (LSTM) and Gated Recurrent Unit (GRU), as well as Convolutional Neural Networks (CNNs). Model performance was enhanced by tuning the parameters over …

Dam It All: A Multi-Scalar Investigation Into The Ecological Role And Function Of Beaver Dams, Kenneth Larsen

Dissertations, Master's Theses and Master's Reports

The central theme of this dissertation is ecological scaling, which examines how small, localized features, such as beaver ponds, contribute to large-scale watershed processes and how different modeling approaches at various scales reveal distinct insights. Through a combination of probabilistic modeling and high-resolution empirical research, this work demonstrates that small ponded systems, particularly those created by beavers (Castor canadensis), serve as critical biogeochemical control points, whose contributions to sediment and nutrient dynamics have been historically underestimated.

In Chapter 1, I contextualize this research within the broader fields of freshwater ecology, watershed modeling, and ecological restoration. I introduce the …

Evaluation Of The Maneuverability Of An 85m Fishing Trawler (Focusing On Dynamic Stability), Chun-Ki Lee, Su-Hyung Kim

Journal of Marine Science and Technology–Taiwan

Most fishing vessels are less than 100 meters in length, so IMO maneuverability standards do not apply. As a result, studies on the maneuverability of fishing vessels are considerably fewer compared to those on merchant ships. However, with technological advancements, the size of fishing vessels continues to grow, and as more fishermen are on board, accidents could lead to fatal casualties. In response, the authors determined that research on the maneuverability of fishing vessels is urgently needed. Thus, the authors conducted a maneuverability evaluation on a fisheries training vessel with the hull shape of a fishing trawler, 85 meters in …

A Hybrid Image Filtering Approach For Improving Edge Detection Of Riverbed Particles With Complex Textures, Po-Wei Lin, Hsun-Chuan Chan

Journal of Marine Science and Technology–Taiwan

The distribution of particle size in gravel-bed rivers affects the flow condition, sediment transport, and river morphology. However, conventional particle size analysis is laborious and time-consuming. To enhance the efficiency of particle size analysis, image-based methods have been widely explored, but complex particle textures increase the difficulty in identifying particle edges during image analysis. This study develops a filtering approach based on the rolling guidance filter and leverages the differences in grayscale gradients between particle edges and textures to design a guidance image tailored for the rolling guidance filter. This design enables the filter to preserve particle edges while smoothing …

Comparison Of Canopy Materials To Improve The Performance Of Sea Anchors Used For Fishing Operations, Namgu Kim, Su-Hyung Kim, Yoo-Won Lee, Kyung-Jin Ryu

Journal of Marine Science and Technology–Taiwan

Sea anchors used for fishing operations help improve catch rates by stabilizing vessel drift speeds to match tidal or ocean currents. The underwater resistance experienced by a sea anchor's canopy significantly impacts its performance, yet there has been limited research on canopy materials. This study investigates how different canopy materials can enhance sea anchor performance. Specifically, we tested sea anchors made from three fabrics: the currently used polyamide (PA) material, PA material with increased yarn density in the weft direction, and polyester (PES). Using Korean national standards, we compared the yarn density, weight, water absorption capacity, drying rate, air permeability, …

Research On Ship Track Prediction Based On Ipso-Cnn, Xiangen Bai, Nuo Chen, Xiaofeng Xu

Journal of Marine Science and Technology–Taiwan

With the rapid development of the global economy, international imports and exports have become increasingly important. Timely and effective tracking and prediction of ship trajectories are important in the face of complex maritime traffic. Based on AIS data, this study establishes a ship trajectory prediction model combining improved particle swarm optimization (IPSO) and a convolutional neural network (CNN) that uses the ship's historical navigation trajectory data to predict the future navigation trajectory. The historical ship trajectory data of the Port of Ningbo-Zhoushan were selected for the experiment, and the IPSO-CNN model experiment results were compared with those of other models. …

Impact Of Irrigation Systems On Water Use And Water Productivity: A Case Study Using Aquacrop In Khartoum, Sudan, Abdalhakam Almagzoop

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

Water scarcity significantly challenges agricultural productivity in arid regions like Khartoum, Sudan. This study evaluates the impact of three irrigation systems—furrow, sprinkler, and surface drip—on the water use and productivity of sorghum (Sorghum bicolor L.) under different climatic conditions using the AquaCrop model. Simulations were conducted for three representative years: a wet year (2022), a normal year (2015), and a dry year (2018). The results demonstrate that irrigation substantially improved water use efficiency and crop yield compared to non-irrigated (rainfed) conditions. Rainfed crops resulted in lower biomass, harvest index, and yield, particularly in the dry year, highlighting the importance …

Enhancing Water Sustainability In North Africa: Literature Review And Synthesis Of Current Knowledge Gaps In Sudan, Osman M. A. Adam

Department of Agricultural and Biological Systems Engineering: Masters Project Reports

This study delves into the critical role of groundwater in addressing global water challenges, with a focus on the Nubian Sandstone Aquifer System (NSAS) in north Africa. Groundwater constitutes a source of potable water, irrigation, and industrial use, especially in arid regions where surface water is limited. We analyzed the status of water quantity, withdrawals, recharge, and geological characteristics in the NSAS, specifically in Sudan, Egypt, and Libya. Though the NSAS is largely an untapped resource, water withdrawals from the NSAS in Egypt, Sudan, and Libya are projected to increase substantially from 2000 to 2100 due to population growth, with …

Quantitative Evaluation Of Baseflow Separation Methods Using An Integrated Hydrologic Model: A Case Study In A Snow-Dominated Watershed, Jihad Othman

All Graduate Reports and Creative Projects, Fall 2023 to Present

Baseflow, commonly referred to as the groundwater contribution to streamflow, constitutes approximately 50% of streamflow in mountainous regions of the Western United States. Accurately quantifying the amount of baseflow is critical for water management and decision-making, as it significantly impacts stream water quality, low flow availability, and ecosystem health. Traditionally, baseflow has been estimated using conceptual and automated baseflow separation methods, which are known to be both arbitrary and ambiguous, posing a challenge to validate them. In this study, we developed an integrated hydrologic model that seamlessly integrated the exchange between surface and subsurface flows to physically quantify the baseflow …

Evaporation Basins For Salinity Management, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

An evaporation basin is an engineered earth structure designed to safely store and evaporate saline water discharged from drainage or pumping, while protecting high-value agricultural land, natural assets or built infrastructure.

DPIRD recommends that evaporation basins should form part of an integrated water and salinity management program. Information on this page is a guide only.

It is recommended that landholders seek expert advice plus engineering design and related support from qualified contractors.

Measuring Soil Salinity, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

To make sound decisions on managing saline sites, you need to know the source of salt, how salinisation is occurring, the landscape context, and most importantly, the actual salt concentration of the soil.

The most common 'measures' of salt concentration are actually estimates based on electrical conductivity of a soil and water solution. Soil salt content can be measured in a laboratory by measuring the total dissolved solids in a sample. In the field, salt concentration can also be estimated using electromagnetic induction-based soil sensors.

Managing Subsurface Water In Wa, Department Of Primary Industries And Regional Development, Western Australia

Natural resources factsheets

The Department of Primary Industries and Regional Development (DPIRD) recommends that subsurface water management is part of an integrated water and salinity program. An integrated program can help to lower water tables and alleviate problems with waterlogging, rising salinity, and infrastructure damage.

Basic Psychological Needs Satisfaction And Well-Being Among Seafarers: An Investigation Of Interaction Effects Through The Lens Of Self-Determination Theory, Nong Vuong Phi, Kung Don Ye, Feng Ming Tsai, Hsiao Chao Hsieh, Shiou-Yu Chen

Journal of Marine Science and Technology–Taiwan

Enhancing employee well-being is a primary goal for enterprise sustainable development. Although seafarers represent a major human resource in the maritime industry, the distinctive demands of their profession often compel them to compromise on certain elements in fulfilling their basic psychological needs, thereby contributing to mental health challenges. Recently, COVID-19 and its associated border control measures have prolonged the voyages of seafarers, drawing public attention to the topic of seafarer well-being. In this study, self-determination theory was used to explore the effects of autonomy, competence, and relatedness as fundamental psychological needs on seafarer well-being. After the independent effects of these …

An Optimal Schedule Recovery Model For Transportation Carriers Under Uncertain Typhoon Disruption Periods, Yi-Chun Chen, Shangyao Yan

Journal of Marine Science and Technology–Taiwan

Due to the unsettled weather conditions caused by typhoons, it is not possible to forecast the time when a typhoon will arrive or depart accurately. The uncertainty regarding the duration of typhoon disruptions makes it challenging for transportation carriers to efficiently adjust their schedules. In this study, to deal with the problem of airline fleet rerouting, flight rescheduling, and passenger reassignment for uncertain disruption periods caused by a typhoon, we utilize network flow techniques with the concept of probability to construct a stochastic model for minimizing the total operating costs. A heuristic algorithm based on the divide-and-conquer technique is adopted …

Prediction Of Mooring System Characteristics Of The Floating Barge Using Deep Neural Networks, Janghoon Seo, Dong-Woo Park

Journal of Marine Science and Technology–Taiwan

The present study establishes deep learning models to predict the tensions and inclinations of mooring lines of a floating barge and verifies applicability of these models. Hydrodynamic and mooring analyses are conducted on the dataset used for the deep learning models. Three types of neural network models include a deep neural network (DNN) with input data representing the six degrees of freedom motions of a floating barge, convolutional neural network (CNN) with input images of the floating barge and mooring lines on a horizontal plane, and hybrid neural network (HNN) that consolidates the characteristics of DNN and CNN models. The …