Oceanography Commons^™

Evalution Of The Ability To Infer Tilt Angle And Size Distributions Of Fish Using A Broadband Scientific Echosounder Based On Simulation, Jing Liu

Journal of Marine Science and Technology–Taiwan

The biological information, such as species, size, and tilt angle, is crucial for converting the echo data into biomass information in acoustic surveys. Typically, the information can be obtained through trawl net sampling or underwater camera observations. However, both methods have some limitations. To overcome these limitations, scientists have utilized inversion methods with multi-frequency and broadband echosounders to derive biological information about fish, plankton, and krill. However, evaluating the reliability and accuracy of these inversion methods has been challenging due to the difficulty in obtaining accurate biological information. In this study, a numerical simulation method was used to generate fish …

Density-Dependence Inside A Marine Protected Area Increases Natural Mortality And Stunts The Growth Of A Spiny Lobster, Emma-Jade Tuffley, Simon De Lestang

Fisheries Research Articles

Sustainable fisheries management often requires the modelling of stocks under unfished conditions, when the influence of population densities on animal growth and mortality can be substantial. This can be especially true for species such as spiny rock lobster, which are very habitat specific. Using western rock lobster (Panulirus cygnus) tag-recapture data from adjacent and similar fished and unfished areas, the key life history parameters of natural mortality and growth were examined and compared under different population density scenarios. In an area representative of virgin biomass levels, lobsters exhibited reduced growth rates and a substantially higher rate of natural mortality …

A Marine Knowledge System For Ocean Affairs: Integrating Data, Evaluating Usage, And Enabling Sustainable Marine Management, Yu-Jen Pan

Journal of Marine Science and Technology–Taiwan

This study presents the evolution and assessment of the Marine Knowledge Education System (MKES), designed to improve user acceptance among students in professional marine science courses in Taiwan. The MKES leverages real-world maritime cases from the General Coast Guard Administration and is built upon existing technologies like cloud services, social networks, and data analysis tools. The technology acceptance model (TAM) provides the theoretical underpinning for the assessment of user confidence. Data was collected from 190 participants through purposive sampling. Path analysis confirmed all hypothesized relationships within the TAM with statistical significance (p < 0.001). Additionally, paired-sample t-tests revealed a significant increase in student acceptance of the MKES after integrating it into the marine science curriculum. These findings underscore the capacity of the MKES as a digital learning tool to enrich course pedagogy and improve student learning outcomes, thereby offering valuable support in advancing the education of professional marine managers.

Corrigendum To “Evaluation Of Operational Performance Of Wusongkou Cruise Port Through Network Data Envelopment Analysis”

Journal of Marine Science and Technology–Taiwan

No abstract provided.

Analysis Of The Potential For Enhancing The Efficiency Of A Floating Photovoltaic (Fpv) System, How-Ping Wu, Ching-Yi Tseng, Chuan-Chung Jen, Yuan-Ching Chiang, Sih-Li Chen

Journal of Marine Science and Technology–Taiwan

This study examined the power generation capabilities of FPV systems and the advantages of employing active cooling on floating solar panels. Floating solar panels exhibit improved efficiency due to operating at lower temperatures facilitated by the cooling effect of water evaporation. Additionally, the high availability of water renders the application of the active cooling technique economically viable. This study developed a comprehensive simulation of a floating solar system, integrating a mathematical model to validate experimental findings and a temperature model derived from an energy equation specific to floating solar panels. This model calculates the heat transfer among the three different …

Heavy Metals Implications To Sediment Microbiome And Coral Response To Arsenic Dosing, Dimitrios G. Giarikos, Amy Hirons, Jose V. Lopez, Abigail Renegar, Jason Gershman

SECLER Data

No abstract provided.

Changes In Reef Tourism’S Adaptive Capacity After Severe Climate Disturbances, Henry Bartelet, Michele Barnes, Lalu Bakti, Graeme S. Cumming

Quantitative Methods and Information Technology Faculty Publications

Knowledge about adaptive capacity and its determinants has increased significantly over the last decade. However, most research on adaptive capacity has been static, not considering how adaptive capacity might change over time, particularly after severe disturbances. We studied the adaptive capacity dynamics of Asian-Pacific reef tourism operators affected by coral bleaching and tropical cyclones compared with a control group with non-affected operators. We found that impacts from tropical cyclones were associated with frequent changes in adaptive capacity. Notably, we found a reduction in tangible attributes (assets and flexibility) of adaptive capacity, whereas intangible attributes (agency and social organization) increased. Our …

Applied Depositional Geosystems Of The Coos Bay Basin, Oregon: Organic Geochemistry, Maturation, Paleoenvironmental Reconstruction And Biostratigraphy Of The Coaledo Delta During The Middle Eocene Climatic Optimum (Meco), Allison K. Barbato

LSU Doctoral Dissertations

The Coos Bay Basin on the southwestern coast of Oregon is a forearc basin that contains exceptionally preserved Eocene to Miocene, tidal to wave-dominated, shallow deltaic to deep marine sediments of the Coaledo Delta. Coastal depositional environments are known to host source, reservoir, and seal rocks. Climate, topographic relief, and geographical position all play an important role in regional vegetation development and oceanic setting. This study assesses 84 outcrop and 12 core samples from Coos Bay for their organic geochemical characteristics and microfossil assemblage to provide source rock characterization information, organofacies descriptions, environmental reconstructions, and age control.

Results indicate the …

Assessing The Impacts Of Anthropogenic Activities On Coral Reef Health In Ushongo, Tanzania Using Coral Diversity And Parrotfish Abundance As Indicators, Thao Mai

Independent Study Project (ISP) Collection

Coral reefs, covering two-thirds of our oceans, are vital and diverse ecosystems, earning them the nickname of “rainforests of the sea”. Despite occupying only 1% of the ocean’s floor, they support 25% of all marine species, providing shelter, nursery ground and food, all the while also protecting the coast and providing job opportunities for local communities. Considered keystone species, coral reefs are highly sensitive to disturbances caused by pollution, climate change, but also anthropogenic activities such as coastal development, destructive fishing practices and tourism, endangering their existence and the entire marine ecosystem. Parrotfish, a crucial resident of these ecosystems, often …

Early Report Of A Microcosm Of The Fourth Major Global Bleaching Event: A Comprehensive Survey Of Coral Bleaching At Chumbe Island Coral Park, Zanzibar, Christian Boudreaux

Independent Study Project (ISP) Collection

Coral reefs harbor a wealth of the biodiversity present in the ocean. They provide an array of ecological and economic services that make them crucial to the function of a healthy ocean and prosperous coastal communities. Due to an array of anthropogenic stressors, including an increase in ocean temperatures as a result of climate change, reefs have been devastated worldwide. This is, in large part, due to the process of coral bleaching, the expelling of symbiont algae which the coral needs to produce energy, for an extended period until death. This study surveyed bleaching and death at a deeper and …

Assessing The Impact Of Climate Change On Harbor Seals: Haul-Out Patterns In Iceland Using Cmip6 Projections, Colin Lau

Independent Study Project (ISP) Collection

Harbor seals (Phoca vitulina) are known to exhibit a preference for specific environmental and weather conditions when hauling out, particularly during the pupping and molting cycles during summer. Climate change is projected to have a significant impact on the haul-out patterns and site conditions of harbor seals in Iceland, which could further diminish their dwindling population. A comprehensive literature review was conducted to identify and discuss the environmental variables that can affect haul-out probability. Among them, surface wind speed and air temperature are reported to have the biggest influence on harbor seal haul-out numbers between May and August. Climate projections …

Feasibility Study Of Coral Farming In Southwest Madagascar: In-Situ And Ex-Situ Approaches, Raquel Reis

Independent Study Project (ISP) Collection

The southwest coast of Madagascar is home to hundreds of miles of coral reefs that for decades have been susceptible to intense degradation due to anthropogenic influences on marine environments. For reasons involving economic opportunity, conservation strategies, human health safeguarding and advancements to coral research, coral aquaculture in the Toliara region presents an opportunity to restore quality of life and the environment. Other countries in the west Indian ocean have seen great success in coral aquaculture; however, Madagascar, despite having ideal natural circumstances, has not deeply explored coral aquaculture. This review presents an investigation into the feasibility of coral farming, …

A Study Of Anthropogenic Impacts On Echinoderms In The Jambiani Intertidal Area, Zanzibar, Amaury O. Halley

Independent Study Project (ISP) Collection

The coastal region of Jambiani, Unguja, hosts a rich diversity of marine life within its extensive intertidal zones. Despite its ecological significance, this area is increasingly exposed to anthropogenic disturbances due to increased human activities. This study examines the impacts of these disturbances on the biodiversity, zonation, and species abundance of echinoderms in the intertidal habitats of Jambiani. Through a comprehensive field study involving fifteen transects and detailed substrate analysis, the project evaluated the distribution and abundance of echinoderm species and assessed the influence of human activities such as seaweed farming, anchor damage, and beach trampling on these communities. The …

Community Knowledge Of Shark Ecology, Abundance, And Species Composition In Wichubwala, Nalunega, And Porvenir Communities In The Guna Yala Comarca, Panamá, Kayley Jane Porter

Independent Study Project (ISP) Collection

Sharks play a critical role in marine ecosystems as apex predators that exert top-down control of lower trophic levels. In recent decades, global shark populations have declined to unprecedented levels, triggering a cascade effect that threatens ecosystem functioning and, therefore, coastal community livelihoods that rely on marine resources for food and income. It is known that shark populations are vulnerable and on the decline due to anthropogenic stressors such as fishing and coastal development, but shark species composition and abundance are difficult to monitor due to the evasive nature of sharks, the often remote and inaccessible location of certain shark …

A Computational Profile Of Invasive Lionfish In Belize: A New Insight On A Destructive Species, Joshua E. Balan

The Journal of Purdue Undergraduate Research

Since their discovery in the region in 2009, invasive Indonesian-native lionfish have been taking over the Belize Barrier Reef. As a result, populations of local species have dwindled as they are either eaten or outcompeted by the invaders. This has led to devastating losses ecologically and economically; massive industries in the local nations, such as fisheries and tourism, have suffered greatly. Attempting to combat this, local organizations, from nonprofits to ecotourism companies, have been manually spear-hunting them on scuba dives to cull the population. One such company, Reef Conservation Institute (ReefCI), operating out of Tom Owens Caye outside of Placencia, …

Multimodel Approach To A Support Stock Assessment Of Standardized Catch And Effort Data: A Case Study Of Blue Shark (Prionace Glauca) In The Indian Ocean By The Taiwanese Large-Scale Longline Fishery, Chun-Yi Hung, Hoang Huy Huynh, Xing-Han Wu, Wen-Pei Tsai

Journal of Marine Science and Technology–Taiwan

In the context of stock assessment and fishery conservation, determining catch per unit effort (CPUE) accurately and reliably is essential. This study estimated trends in the relative abundance of blue sharks (Prionace glauca) in the Indian Ocean from 2005 to 2022. Blue sharks constitute a resilient bycatch species in pelagic tuna and swordfish longline fisheries. We employed a multimodel approach that included delta-lognormal, zero-inflated negative binomial, and vector autoregressive spatiotemporal (VAST) models to standardize catch rates recorded by observers in the Taiwanese large-scale longline fishery. Our analysis concentrated on the CPUE of blue sharks, including standardizing the number of fish …

Region-Specific Drivers Cause Low Organic Carbon Stocks And Sequestration Rates In The Saltmarsh Soils Of Southern Scandinavia, Carmen Leiva-Dueñas, Anna E. L. Graversen, Gary T. Banta, Jeppe N. Hansen, Marie L. K. Schrøter, Pere Masqué, Marianne Holmer, Dorte Krause-Jensen

Research outputs 2022 to 2026

Saltmarshes are known for their ability to act as effective sinks of organic carbon (OC) and their protection and restoration could potentially slow down the pace of global warming. However, regional estimates of saltmarsh OC storage are often missing, including for the Nordic region. To address this knowledge gap, we assessed OC storage and accumulation rates in 17 saltmarshes distributed along the Danish coasts and investigated the main drivers of soil OC storage. Danish saltmarshes store a median of 10 kg OC m−2 (interquartile range, IQR: 13.5–7.6) in the top meter and sequester 31.5 g OC m−2 yr−1 (IQR: 41.6–15.7). …

A Comparison Of Adenosine Triphosphate With Other Metrics Of Microbial Biomass In A Gradient From The North Atlantic To The Chesapeake Bay, Alexander B. Bochdansky, Amber A. Beecher, Joshua R. Calderon, Alison N. Stouffer, Nyjaee N. Washington

OES Faculty Publications

A new, simplified protocol for determining particulate adenosine triphosphate (ATP) levels allows for the assessment of microbial biomass distribution in aquatic systems at a high temporal and spatial resolution. A comparison of ATP data with related variables, such as particulate carbon, nitrogen, chlorophyll, and turbidity in pelagic samples, yielded significant and strong correlations in a gradient from the tributaries of the Chesapeake Bay (sigma-t = 8) to the open North Atlantic (sigma-t = 29). Correlations varied between ATP and biomass depending on the microscopic method employed. Despite the much greater effort involved, biomass determined by microscopy correlated poorly with other …

Nitrogen Uptake Rates And Phytoplankton Composition Across Contrasting North Atlantic Ocean Coastal Regimes North And South Of Cape Hatteras, Yifan Zhu, Margaret R. Mulholland, Peter W. Bernhardt, Aimee Renee Neeley, Brittany Widner, Alfonso Macías Tapia, Michael E. Echevarria

OES Faculty Publications

Understanding nitrogen (N) uptake rates respect to nutrient availability and the biogeography of phytoplankton communities is crucial for untangling the complexities of marine ecosystems and the physical, biological, and chemical forces shaping them. In the summer of 2016, we conducted measurements of bulk microbial uptake rates for six ¹⁵N-labeled substrates: nitrate, nitrite, ammonium, urea, cyanate, and dissolve free amino acids across distinct marine provinces, including the continental shelf of the Mid-and South Atlantic Bights (MAB and SAB), the Slope Sea, and the Gulf Stream, marking the first instance of simultaneously measuring six different N uptake rates in this dynamic region. …

Diel Vertical Migration Rates Of The Dinoflagellate Species Margalefidinium Polykrikoides In A Lower Chesapeake Bay Tributary, S. Clayton, Jacqueline B. Chrabot, Michael Echevarria, Leah Gibala-Smith, Kathryn Mogatas, Peter Bernhardt, Margaret R. Mulholland

OES Faculty Publications

Margalefidinium polykrikoides is a mixotrophic dinoflagellate harmful algal bloom (HAB) species that blooms annually in the lower Chesapeake Bay. M. polykrikoides undertakes a diel vertical migration (DVM) which may give it a competitive advantage over purely phototrophic organisms who cannot access deeper nutrient pools and allow it to form large toxic blooms. Laboratory-based estimates of M. polykrikoides’ DVM rates suggest that it is one of the fastest known dinoflagellate swimmers and understanding this behavior is likely important for modeling and predicting M. polykrikoides blooms. However, to date, no field-derived estimates of M. polykrikoides’ DVM rates have been made in the …

Submarine Groundwater Discharge At A Mega-Tidal Beach, Raymond D. Craddock, Aaron A. Mohammed, Joseph J. Tamborski, Barret L. Kurylyk

OES Faculty Publications

Tidally influenced groundwater systems in coastal environments represent important mixing zones of fresh groundwater and circulating seawater, manifesting as submarine groundwater discharge (SGD). Water circulation induced by tidal pumping enhances the exchange of chemicals between aquifers and coastal waters and thereby influences the biogeochemistry of coastal zones. Here, we report the results of an SGD field study conducted at a steep, mega-tidal sand and gravel beach along the Canadian coast of the Bay of Fundy, a region with the world's highest tides (semi-diurnal tidal ranges exceeding 10 m). Several physical and geochemical measurement techniques were employed to document the spatiotemporal …

Contrasting Nitrogen Dynamics Across The Mid-Atlantic Bight Shelfbreak Front: Insights From Nitrate Dual Isotopes And Nitrifier Gene Abundance, Yifan Zhu, Margaret R. Mulholland, Corday R. Selden, Dennis J. Mcgillicuddy Jr., Josie Mottram, P. Dreux Chappell, Weifang Gordon Zhang, Julie Granger, Katherine E. Crider, Meredith G. Meyer, Peter W. Bernhardt, Hilde Oliver, Sophie Clayton

OES Faculty Publications

Observations and model studies suggest that front dynamics can enhance phytoplankton productivity. This study tested whether frontal systems also increase the abundance of nitrifying microbes and nitrogen recycling during repeat sampling transects across the Mid‐Atlantic Bight shelfbreak in July 2019. We measured ammonium concentrations, nitrate dual isotopes (δ¹⁵N, δ¹⁸O), and ammonia monooxygenase subunit A (amoA) genes of ammonia‐oxidizing archaea (AOA) and bacteria (AOB). In subsurface shelf waters, ammonium concentrations exceeded 2 μmol L⁻¹, due to a temporary imbalance in regeneration from sinking particles and subsequent nitrification. The inverse correlation between nitrate δ^{15 …}

Submarine Groundwater Discharge As A Major Nutrient Source In River-Fed Vs. Tidally Dominated Estuaries, Stephanie J. Wilson, Joseph J. Tamborski, Bongkeun Song, Peter Bernhardt, Margaret R. Mulholland

OES Faculty Publications

The tidal tributaries of the lower Chesapeake Bay experience seasonally recurring harmful algal blooms and the significance of submarine groundwater discharge (SGD) as a nutrient vector is largely unknown. Here, we determined seasonal SGD nutrient loads in two tributaries with contrasting hydrodynamic conditions, river-fed (York River) vs. tidally dominated (Lafayette River). Radon surveys were performed in each river to quantify SGD at the embayment-scale during spring and fall 2021. Total SGD was determined from a ²²²Rn mass balance and Monte Carlo simulations. Submarine groundwater discharge rates differed by a factor of two during spring (Lafayette = 11 ± 17 cm …

Building A Coordinated Framework For Research And Monitoring In Large-Scale International Marine Protected Areas: The Ross Sea Region As A Model System, Cassandra Brooks, Sharon Stammerjohn, Grant Ballard, Alice K. Duvivier, Eileen Hofmann, Michelle Larue, Cara Nissen, Alexander J. Orona, B. Jack Pan, Annie E. Schmidt, Nathan Walker, George M. Watters, John Weller

CCPO Publications

To fulfill their conservation potential and provide safeguards for biodiversity, marine protected areas (MPAs) need coordinated research and monitoring for informed management through effective evaluation of ecosystem dynamics. However, coordination is challenging, often due to knowledge gaps caused by inadequate access to data and resources, compounded by insufficient communication between scientists and managers. We propose to use the world's largest MPA in the Ross Sea, Antarctica as a model system to create a comprehensive framework for an interdisciplinary network supporting research and monitoring that could be implemented in other remote large-scale international MPAs. Our proposed framework has three key components: …

A Strategic Framework For Estimating International Container Flows: An Empirical Study, Dung-Ying Lin, Hsin-Chun Huang, Steven Travis Waller, Xiang Zhang

Journal of Marine Science and Technology–Taiwan

Maritime transportation is a highly complex transportation system that plays a pivotal role in international trade. Its low-cost and high-volume advantages have enabled it to cover most of the world’s cargo transportation. However, with the trend of global trade volume increasing almost every year and the recent congestion of ports due to the COVID-19 pandemic, the chaos in global supply chains not only increases operating costs for shippers but also makes it difficult for countries that rely heavily on port trade to plan for their ports’ future. To develop a strategic analytic tool to estimate container flow in liner shipping, …

Exploring Market Segmentation For Autonomous Ferries, Ashari Fitra Rachmannullah, Taih Cherng Lirn, Kuo Chung Shang

Journal of Marine Science and Technology–Taiwan

This study aims to investigate the determinants that underlie psychographic segmentation in the domain of autonomous ferries (AFs) by using the theory of planned behaviour (TPB) as a guiding theoretical construct. The paper focuses on Indonesian individuals who had previously utilised conventional ferry services. TPB was applied as a catalyst to identify possible market segmentation among potential AF passengers. In this study, cluster analysis is used to differentiate passengers by their perception of using AFs. The results identified three market segments through cluster analysis based on passengers’ perceptions of using AFs: Resource-Limited, Resource-Capable, and Value-Optimistic. Among these segments, the Resource-Capable …

Adaptive Prediction Horizon Energy-Saving Collision-Free Mpc Of Ships Based On Ship-Shore Cooperation, Han Xue, Enjie Yang

Journal of Marine Science and Technology–Taiwan

ABSTRACT:In order to perform the close association between ship maneuvering control and energy consumption through the control strategy, this paper designs an adaptive prediction horizon based energy-saving robust nonlinear model predictive control (APHERNMPC) for underactuated ships to deal with the actual control and state constraints during berthing based on ship-shore cooperation. An improved Emperor Penguin Optimizer (EPO) method is proposed for collision avoidance decision. To solve the problems of falling into local optimum and reducing the convergence speed, the traditional EPO is improved based on Sobol sequence in order to enhance the diversity and ergodicity of the population. The multi-ship …

Research And Design A Lifeboat Virtual Reality Simulation System For Maritime Safety Training In Vietnam, Nguyen Dinh Thach, Nguyen Van Hung

Journal of Marine Science and Technology–Taiwan

Ensuring maritime safety and security is crucial for all nations. Training trainees and operational officers in this field aims to enhance their professional skills and ability to manage and resolve incidents at sea. This article outlines the development of a lifeboat simulation system that integrates Virtual Reality (VR) technology in accordance with international maritime regulations. It describes the creation of an algorithm designed to optimize data transmission between simulation systems using the ant colony optimization technique in conjunction with intelligent control algorithms on Unity 3D software for human interaction. In particular, the system combines training with a maritime simulation framework …

Dust-Driven Mechanism For Marine Particle Aggregation: Interactions Between Clay Minerals, Heterotrophic Bacteria And Organic Matter Influences Aggregation In Marine Systems, Vignesh Gokuladas Menon

Dartmouth College Master’s Theses

Atmospheric dust deposition plays a crucial role in marine biogeochemical cycles, yet mechanisms underlying its impact on particle dynamics remain unclear. This study investigates the synergistic interactions between marine heterotrophic bacteria and clay minerals in seawater, focusing on their effect on Transparent Exopolymer Particles (TEP) production and organoclay aggregation. Field experiments in the Gulf of Maine and laboratory roller tank studies were conducted using natural microbial communities and model heterotrophic bacterial strains (Alteromonas sp. EZ55, Marinobacter adhaerens HP15, and Sulfitobacter sp. NAS-14.1). Results demonstrate that clay exposure significantly enhances TEP production by bloom-associated heterotrophic bacteria, with increases up to …

Fretting Corrosion Wear Of Titanium-Based Alloy (Ti-6al-4v) In 0.9 Wt.% Nacl Solution, Chen-En Lu, Wen-Ken Li, Hung-Hua Sheu, Jeou-Long Lee, Hung-Bin Lee

Journal of Marine Science and Technology–Taiwan

In this study, a high precision fretting tribo-corrosion tester used to analyze the wear and corrosion behavior of Ti alloys in a fretting motion condition. The tester, operated in a ball-on-plate mode, was employed in the fretting corrosion study of metallic bio-materials (Ti and Ti-6Al-4V) under different loads (0 and 10 N), electrolytes (0.9 wt% NaCl and SBF) and fixed displacement frequency (1 Hz). Using profilometer, optical microscope in the experimental analysis and three-body mechanism in the theoretical analysis, the fretting corrosion performances of these bio-medical metals, such as velocity accommodation characteristics, friction, wear, and scratch profile were examined in …