Typology And Spatiotemporal Patterns Of Illegal Fishing Activities In The Philippines: Implications For Fisheries Management,
2026
Institute of Marine Affairs and Resource Management, National Taiwan Ocean University, Keelung 20224, Taiwan, R.O.C.
Typology And Spatiotemporal Patterns Of Illegal Fishing Activities In The Philippines: Implications For Fisheries Management, Marlowe O. Acevedo, Tzu-Yun Ching, Chih-Shin Chen
Journal of Marine Science and Technology–Taiwan
Illegal, unreported, and unregulated (IUU) fishing activity is a global threat and continues to undermine the effectiveness of fisheries regulations and management measures. However, the extent of illegal fishing in Philippine waters remains unclear. This study aims to identify the types of illegal fishing in Philippine waters and analyzed their temporal and spatial patterns. Data were obtained from the records of the Philippine Coast Guards (PCG) and Maritime Law Enforcement Agencies from 2015 to 2020. A total of 602 apprehensions were recorded, resulting in 813 violations, of which 630 cases were fishery violations. Most of the watercrafts involved in the …
A Quantitative Analysis Of Burrowing And Subterranean Locomotion In The Sand Lance Using A Transparent Sediment,
2026
Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido, Japan
A Quantitative Analysis Of Burrowing And Subterranean Locomotion In The Sand Lance Using A Transparent Sediment, Issei Fujita, Makoto Tomiyasu, Jun Yamamoto, Yasuzumi Fujimori
Journal of Marine Science and Technology–Taiwan
Sand lances (Ammodytes spp.) rely on rapid burrowing into sediment for predator avoidance. Although their sediment grain-size preferences are well documented, the biomechanics underlying burrowing success remain unclear because natural substrates are opaque. Using a transparent-sediment system, we directly visualized and quantified burrowing kinematics to: (1) test the effect of body size (total length, TL) on burrowing success; (2) examine entry mechanisms (e.g., swimming speed, entry angle); and (3) describe locomotion within sediment. Logistic regression on the full dataset (N = 28 fish) identified TL as the primary determinant of success, with larger individuals exhibiting significantly higher success …
Cruise Network Design Under Sequential Duopolistic Entry,
2026
Department of Logistics Management, National Kaohsiung University of Science and Technology, Kaohsiung, Taiwan
Cruise Network Design Under Sequential Duopolistic Entry, Ta-Hui Yang, Ching-Hui Tang, Wan-Tien O
Journal of Marine Science and Technology–Taiwan
This study addresses the network design for international cruise services in a duopolistic market, where carriers enter and make decisions sequentially. The leader, who makes the first move, makes decisions as there is no competitor in the market. The follower, who makes decisions later, has to design their network considering the existing leader’s network. The leader’s model is a mixed integer linear problem while the follower’s model is a mixed integer nonlinear problem. Therefore, a heuristic is proposed to solve the problem. The commercially available general algebraic modeling system is used in conjunction with its different solvers to solve the …
Effect Of Heat Treatment On The Corrosion And Wear Behavior Of 17-4 Ph Stainless Steel For Marine Applications,
2026
Department of Optoelectronics and Materials Technology，National Taiwan Ocean University，Keelung 202,Taiwan
Effect Of Heat Treatment On The Corrosion And Wear Behavior Of 17-4 Ph Stainless Steel For Marine Applications, Syuan Tai, I-Kon Lee, Ming-Yuan Lin, Kang-Yu Liao, Chin-Chun Chang, Hung-Bin Lee
Journal of Marine Science and Technology–Taiwan
This study explores the tribocorrosion behavior of conventionally cast 17-4 PH stainless steel under real seawater conditions, focusing on the effects of three heat treatments (Solution, H900, H1100). Electrochemical tests, tribocorrosion experiments, SEM, XPS, and quantitative analysis were used to establish a three-stage tribocorrosion mechanism. Results show that H900 exhibits superior corrosion and wear resistance, while H1100 suffers increased material loss and surface cracking at high potentials. Elemental analysis revealed NbC migration forming third-body particles, which, although briefly reducing friction, induced local stress concentration and crack initiation. The findings highlight the critical influence of microstructure, passive film stability, and third-body …
Enhancing Underwater Imagery And Organism Detection Using Reinforcement Learning,
2026
College of Engineering Guindy, Anna University, Chennai, Tamil Nadu, India
Enhancing Underwater Imagery And Organism Detection Using Reinforcement Learning, K. Arul Deepa, P. Ramya, Karpaga Vinodha, Dharmaraja C
Journal of Marine Science and Technology–Taiwan
Underwater environments pose significant challenges in assessing image quality and organism detection due to light scattering and absorption, which limits visibility and color fidelity. Existing solutions often fail to effectively address these challenges, resulting in suboptimal image quality and hindering organism identification. This paper examines the problem through a dual-focused approach: enhancing underwater images and detecting organisms using the Underwater Image Enhancement Benchmark (UIEB) dataset. The first step introduces a state-of-the-art method for image enhancement by applying reinforcement learning (RL) principles. By formulating the enhancement process as a Markov Decision Process (MDP)—where states are represented by image features and actions …
Spectral Analysis Of Traffic Accidents In New York's Capital Region,
2026
University at Albany, State University of New York
Spectral Analysis Of Traffic Accidents In New York's Capital Region, Michael Barr
Electronic Theses & Dissertations (2024 - present)
In this paper we estimate the spectral density of traffic accident events in the Capital Distict, NY area using a band-pass filter known as the Kolmogorov-Zurbenko Fourier Transform (KZFT). The source data is provided by Moosavi, et al. (2019) and originally captured from various public entities and sensors in the road network. Spectral density estimation with KZFT suppresses noise to reveal the constituent frequencies embedded in the noisy signal. Signal reconstruction based on KZFT produces an approximate weekly accident arrivals for this noisy signal, or in other words a pattern which is proportionate to the event expectation viewed over a …
Multi-Satellite Image Matching And Deep Learning Segmentation For Detection Of Daytime Sea Fog Using Gk2a Ami And Gk2b Goci-Ii,
2025
Pukyong National University
Multi-Satellite Image Matching And Deep Learning Segmentation For Detection Of Daytime Sea Fog Using Gk2a Ami And Gk2b Goci-Ii, Jonggu Kang, Hiroyuki Miyazaki, Seung Hee Kim, Menas Kafatos, Daesun Kim, Jinsoo Kim, Yangwon Lee
Institute for ECHO Articles and Research
Traditionally, sea fog detection technologies have relied primarily on in situ observations. However, point-based observations suffer from limitations in extensive monitoring in marine environments due to the scarcity of observation stations and the limited nature of measurement data. Satellites effectively address these issues by covering vast areas and operating across multiple spectral channels, enabling precise detection and monitoring of sea fog. Despite the increasing adoption of deep learning in this field, achieving further improvements in accuracy and reliability necessitates the simultaneous use of multiple satellite datasets rather than relying on a single source. Therefore, this study aims to achieve higher …
An Algorithm For Extracting Bathymetry From Icesat-2 Data That Employs Structure And Density Using Concentric Ellipses,
2025
University of New Hampshire, Durham
An Algorithm For Extracting Bathymetry From Icesat-2 Data That Employs Structure And Density Using Concentric Ellipses, Yuri Rzhanov, Kim Lowell
Faculty Publications
The ICESat-2 satellite collects LiDAR data along linear orbital tracks using a photon-counting green wavelength (532.27 nm) instrument. The utility of combining ICESat-2 data with satellite imagery for training and subsequently applying satellite-derived bathymetry models to provide estimates of shallow water depth is well-established. However, automating and improving the accuracy of the identification of ICESat-2 photon events (PEs) representing bathymetry remains a challenge. This article presents an algorithm for automated extraction of PEs reflected from the ocean floor (rather than the ocean surface or noise in the water column). The algorithm is unique in examining both the density of PEs …
Stability Analysis Of Thermohaline Convection With A Time-Varying Shear Flow Using The Lyapunov Method,
2025
University of Connecticut - Storrs
Stability Analysis Of Thermohaline Convection With A Time-Varying Shear Flow Using The Lyapunov Method, Kalin Kochnev
Honors Scholar Theses
This work applies the Lyapunov method to identify instabilities and compute the growth rate of a linear time-varying system. The linear system studied describes cold fresh water on top of hot salty water with a periodically time-varying background shear flow. A time-dependent weighting matrix is employed to construct a Lyapunov function candidate. The resulting linear matrix inequalities are discretized in time using the forward Euler method. As the number of temporal discretization points increases, the growth rate predicted by the Lyapunov method or Floquet theory, used for comparison, will converge to the same value obtained from numerical simulations. Furthermore, the …
User Interface And Watchstation Improvements Required For Multi-Vehicle Usv Operations,
2025
University of New Hampshire, Durham
User Interface And Watchstation Improvements Required For Multi-Vehicle Usv Operations, Val Schmidt, Joshua Bergeron
Faculty Publications
In October 2024, the University of New Hampshire and NOAA’s Uncrewed Systems Office embarked on a mapping mission in the Gulf of Maine, simultaneously operating two DriX Un-crewed Surface Vehicles. Goals of the project were focused on testing hypotheses related to concepts of operation, including the safety of operations, cognitive loading of operators, management of vehicle endurance, vehicle logistics, maintenance and field support, refueling and a host of others.
Spatio-Temporal Characterization Of Trace Metals Across The West Florida Shelf And During The Decline Of The North Atlantic Spring Bloom,
2025
University of South Florida
Spatio-Temporal Characterization Of Trace Metals Across The West Florida Shelf And During The Decline Of The North Atlantic Spring Bloom, Delfina Paola Navarro-Estrada
USF Tampa Graduate Theses and Dissertations
Phytoplankton in the marine environment require the trace metals manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), and cadmium (Cd) to catalyze cellular processes driving photosynthesis, including macronutrient (nitrogen, phosphorus, and carbon) acquisition, light harvesting, and protection from oxidative stress. The high biological demand for these elements, coupled with their low concentrations in the ocean, can limit primary production and shape community composition in marine ecosystems, highlighting the need to understand the drivers behind trace metal distributions and their interplay with phytoplankton growth across biogeochemical regimes. This dissertation characterizes the spatial and temporal distributions of dissolved …
Mapping Seagrass Extent Using Sentinel-2 Satellite Imagery: A Case Study In Salt River Bay, United States Virgin Islands,
2025
University of South Florida
Mapping Seagrass Extent Using Sentinel-2 Satellite Imagery: A Case Study In Salt River Bay, United States Virgin Islands, Chelsea O. Bryant
USF Tampa Graduate Theses and Dissertations
Seagrass beds provide important services in many coastal ecosystems. They provide habitat and food for a wide range of marine species, stabilize sediments, and prevent coastal erosion. These services support local fisheries and tourism-driven economies. Yet, seagrass ecosystems are threatened by changes in water quality, sedimentation, and other stressors. This study investigated the interannual variability in seagrass extent in Salt River Bay, United States Virgin Islands (USVI), from 2018 to 2024. The goals were to better understand temporal dynamics in seagrass extent and evaluate the influence of turbidity as a driver of seagrass health and distribution. The overarching research question …
What Controls Ice Shelf Isotopic Variability? Local And Global Processes Preserved Within Ice Cores Across The Larsen C Ice Shelf, Antarctica,
2025
University of South Florida
What Controls Ice Shelf Isotopic Variability? Local And Global Processes Preserved Within Ice Cores Across The Larsen C Ice Shelf, Antarctica, Orion Laurene Schomber
USF Tampa Graduate Theses and Dissertations
The Antarctic Peninsula (AP) is one of the foremost indicators of anthropogenic global warming as it interacts with both atmospheric and oceanic processes. Although ice shelves across the AP have undergone increased rates of disintegration over the last 30 years, limited in-situ measurements have been investigated. Assessment of three short (~30 m) firn cores (J108, J208, and J409) across the Larsen C ice shelf (LCIS) provide insight into local, regional, and global processes. Average core densities and isotopic variability (δ¹⁸O and δ²H) fall within expected ranges for all cores, indicating signal preservation through firn. However, isotopic maxima in J108 and …
Identifying B-Vitamin Requirements And Phycosphere Interactions For The Hab-Forming Dinoflagellate, Pyrodinium Bahamense Var. Bahamense,
2025
University of South Florida
Identifying B-Vitamin Requirements And Phycosphere Interactions For The Hab-Forming Dinoflagellate, Pyrodinium Bahamense Var. Bahamense, Lydia A. Ruggles
USF Tampa Graduate Theses and Dissertations
Harmful Algal Blooms (HAB) negatively affect economies, ecosystems, and public health through mass proliferation and toxin production. The HAB species, Pyrodinium bahamense var. bahamense, is a saxitoxin-producing dinoflagellate found in tropical and subtropical estuarine waters globally. In two Florida estuaries, Old Tampa Bay and the Indian River Lagoon, P. bahamense is a recurrent HAB species, and the exact timing and intensity of bloom peaks in these estuaries vary interannually. Factors that are suspected to contribute to blooms include temperature, residence times, nutrients, and salinity. However, many HAB dinoflagellates require vitamin B12 for growth and bloom development. Thus, B12 may influence …
Quantifying Single, Compound And Cascading Climate Extremes: Implications For Agricultural Resilience In California,
2025
Chapman University
Quantifying Single, Compound And Cascading Climate Extremes: Implications For Agricultural Resilience In California, Shahryar Fazli, Wenzhao Li, Rejoice Thomas, Surendra Maharjan, Mohammad Sina Jahangiri, Andre Daccache, Hesham Morgan, Mohamed Allali, Hesham El-Askary
Mathematics, Physics, and Computer Science Faculty Articles and Research
As climate change intensifies, extreme weather increasingly threatens California’s Central Valley (CV), a vital agricultural region exposed to rising risks from heatwaves (HW), droughts (DR), and compound extremes. These events disrupt crop productivity and broader processes like water demand, pest dynamics, and soil stability, posing systemic risks. This study examines the spatiotemporal dynamics of HW, coldwaves (CW), DR, excessive rainfall (ER), and their compound (e.g., HWDR) and cascading forms from 1951 to 2025, using NOAA nClimGrid-Daily data. We assessed trends in frequency, intensity, and duration over long-term (1951–2025) and mid-term (1981–2025) periods. Results show increasing HW and DR in the …
Multimodel And Multidiagnostic Ensemble-Based Deep Convective Area Forecast For Aviation Operations Using The Global Unified Model And Korean Integrated Model,
2025
Seoul National University
Multimodel And Multidiagnostic Ensemble-Based Deep Convective Area Forecast For Aviation Operations Using The Global Unified Model And Korean Integrated Model, Yi-June Park, Jung-Hoon Kim, Dan-Bi Lee, Hyun-Joo Choi, Soo-Hyun Kim, Matthias Steiner, Seung Hee Kim
Institute for ECHO Articles and Research
To provide safe and efficient guidance for aircraft operation to avoid deep convective areas (DCAs) in Korea and broader East Asia, we developed a multimodel and multidiagnostic ensemble (MMDE)-based forecast system. This system utilizes two global numerical weather prediction (NWP) models based on the Unified Model (UM) and the Korean Integrated Model (KIM) operated by the Korea Meteorological Administration. To predict hazardous weather conditions, we defined DCAs using ground-based radar mosaic data where the 15-dBZ echo-top height exceeds flight level (FL) 250 (about z = 6.5 km) and FL350 (about z = 9 km). For predictors, we employed a …
Assessing Meteorological Impacts On Hydrological Switches In The Conus,
2025
Chapman University
Assessing Meteorological Impacts On Hydrological Switches In The Conus, Surendra Maharjan, Wenzhao Li, Sujan Shrestha, Hesham El-Askary
Mathematics, Physics, and Computer Science Faculty Articles and Research
Hydrological switches, defined as rapid transitions between extreme meteorological events such as droughts and floods, are becoming increasingly frequent across the contiguous United States (CONUS) due to climate variability. This study analyzes the spatial and temporal patterns of these hydrological switches and their correlation with large-scale meteorological indices, such as the Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI). Streamflow data from the US Geological Survey (USGS) is analyzed to investigate the impact of meteorological drivers on hydrological variability. Results indicate that regions dependent on snowmelt exhibit delayed hydrological responses to climatic conditions, while areas in the Eastern …
Investigating The Relationships Among Suspended Sediment Concentration, And Marsh Edge Erosion In Barataria Bay, La,
2025
Louisiana State University and Agricultural and Mechanical College
Investigating The Relationships Among Suspended Sediment Concentration, And Marsh Edge Erosion In Barataria Bay, La, Lily Vowels
LSU Master's Theses
Barataria Bay, Louisiana, USA exhibits a unique microtidal, wind-driven hydrodynamic climate where extensive levee infrastructure throughout Louisiana has starved Barataria Bay and similar interdistributary bays of the historic levels of terrigenous sediment import. This has contributed to extreme coastal wetland loss in Louisiana. This project seeks to understand how hydrodynamic and meteorological conditions are linked to sediments’ fate after erosion from the marsh edge. Specifically, this project seeks to differentiate the roles of wave resuspension and marsh edge erosion (MEE) in sediment dynamics in Barataria Bay. An acoustic wave and current profiler (AWAC) was used to capture hydrodynamic conditions, and …
Concentration And Composition Of Organic Contaminants In Blackfin Tuna, Yellowfin Tuna, And The Common Clubhook Squid In The Western Gulf Of Mexico,
2025
University of South Florida
Concentration And Composition Of Organic Contaminants In Blackfin Tuna, Yellowfin Tuna, And The Common Clubhook Squid In The Western Gulf Of Mexico, Lisa Rose-Mann
USF Tampa Graduate Theses and Dissertations
Cephalopods are an important component of pelagic food webs. They play ecological roles not only as predators but also as prey. However, their role as prey in the trophic transfer of organic contaminants to apex predators such as tunas in the Gulf of Mexico (GoM) is not well known. To investigate the importance of cephalopods in tuna diets, stomach samples were collected in February 2020 from tunas caught by rod and reel aboard the F/V Gulf Eagle near two large offshore floating oil/gas platforms in the northwestern GoM. Cephalopod samples were obtained from gut content analysis of 41 tunas caught …
Atmospheric Teleconnection Patterns And Hydrological Whiplashes In The Western U.S.,
2025
Chapman University
Atmospheric Teleconnection Patterns And Hydrological Whiplashes In The Western U.S., Wenzhao Li, Surendra Maharjan, Hesham El-Askary
Mathematics, Physics, and Computer Science Faculty Articles and Research
The Western U.S. is undergoing notable transformations in its hydrological patterns, distinguished by rising variability and recurrent “whiplash” shifts between extreme wet and dry phases. Our comprehensive analysis of 469 streamflow stations from 1981 to 2023 reveals a substantial increase in hydrological whiplash events, with a peak of 206 stations experiencing dry-to-wet whiplash in the early 1990s. We establish strong links between these streamflow extremes and sub-seasonal to seasonal teleconnection factors, particularly the Western Pacific Oscillation (WP) and Eastern Pacific/North Pacific Oscillation (EPO). Additionally, we demonstrate the combined impacts of the El Niño-Southern Oscillation (ENSO) and the Madden-Julian Oscillation (MJO), …
