Oceanography Commons^™

Dioxins Contamination In Sediment And Their Effect On Accumulation In The Portuguese Oyster (Crassostrea Angulata) And White Shrimp (Litopenaeus Vannamei), Yin-Yu Chen, Yu-Sheng Wu, Hsiang-Yin Chen, Zhen-Hao Liau, Fan-Hua Nan

Journal of Marine Science and Technology–Taiwan

This research aims to realize whether the dioxin accumulation in the oyster and white shrimp which were cultured in the dioxin pollutant sediment. This presented evidence indicated that dioxin was detected in all experimental groups with high concentration accumulated in experiment animals. Observation of the concentration, the PCDD/F, 2,3,7,8-T4CDD was with high concentration in the sediment and declined with the time elapsed. Detection of the dioxin accumulated in the animal, the accumulative maximum amounts was in the oyster as 3746.16 (pg-TEQ/g d.w.) and in the shrimp as 705.44 (pg-TEQ/g d.w.). The detected amount of dioxin in the supernatant was quite …

A Meshless Method With Radial Basis Function For Solving Unsaturated Flow In Heterogeneous Porous Media, Cheng-Yu Ku, Chih-Yu Liu, Wei-Po Huang, Jing-En Xiao

Journal of Marine Science and Technology–Taiwan

This paper presents a study for solving unsaturated flow in heterogeneous porous media using the meshless method with the radial basis function (RBF). For modeling the nonlinear hydrological process in unsaturated zone, an exponential model is introduced in the Richards equation such that we may obtain the linearized Richards equation. We adopt the multiquadric function as the RBF in the meshless method for solving the linearized Richards equation. For simulating the unsaturated flow problems in layered heterogeneous soils, the flux and the head must satisfy the continuity condition at the interface. Several examples are carried out for modeling the hydrological …

Catch Rates And Distribution Pattern Of The Silky Shark, Carcharhinus Falciformis, Caught By The Taiwanese Large-Scale Longline Fishery In The Indian Ocean, Chia Yun Li, Xing-Han Wu, Shang Yin Vanson Liu, Sheng-Ping Wang, Wen-Pei Tsai

Journal of Marine Science and Technology–Taiwan

The silky shark, Carcharhinus falciformis, is widely distributed in tropical and temperate waters, and it is a common bycatch species for tuna longline fisheries. This study examined the distribution of and presents relative abundance indices of the silky shark in the Indian Ocean by using logbook and observer data from the Taiwanese large-scale tuna longline fishery between 2005 and 2019. Due to the high zero catch rate, a zero-inflated negative binomial (ZINB) model was used to standardize catch per unit effort. Due to a lack of detailed targeting information, the fishery strategy was identified by using cluster analysis based on …

Accumulation And Bioavailability Of Heavy Metals (Cadmium, Chromium, Nickel, Lead And Zinc) In Water And Sediment Samples In The Musa Creek, Northwest Coasts Of The Persian Gulf, Saghafiankhoo Sedigheh, Battaleb-Looie Sedigheh, Amanipoor Hakimeh, Dravishi Khatooni Javad, Ghanemi Kamal

Journal of Marine Science and Technology–Taiwan

The current study aimed to investigate the total concentrations of heavy metals in water and sediment samples as well as their bioavailability in sediments of Musa Creek. Twenty samples including 10 sediments and 10 water samples were collected from 10 stations. The concentration of heavy metals was measured using inductively coupled plasma–mass spectrometry. The bioavailability of heavy metals was carried out by first step of Tessier sequential extraction method so called single extraction in the manuscript. The results showed that the mean concentrations of cadmium, chromium, nickel, and zinc in water samples was 0.17, 7.44, 43.80, and 8.85 µg/L, respectively. …

Parametric Analyses Of The Dynamic Response And Fatigue Life Of A Compliant Vertical Access Riser With Internal Flow, Fuheng Li, Haiyan Guo, Xiaomin Li, Zhen Liu, Honglu Gu, Peng Cui

Journal of Marine Science and Technology–Taiwan

Subsea interventions on wellheads can be directly performed from a platform using a compliant vertical access riser (CVAR), thereby incurring tremendous economic benefits. The dynamic response and the fatigue damage of a CVAR subjected to regular waves are important for assessing its application feasibility. Therefore, a reasonable numerical model is presented for assessing the damage to a CVAR considering the internal flow using the slender rod theory. The finite element method combined with a Newmark-β scheme is employed to discretize the equations and update the time integration. The Palmgren-Miner rule is applied for fatigue life prediction, focusing on the wave-induced …

Using The Inverse Method To Investigate Flow Models For Mixed Convection Of Annular Finned Tube Heat Exchanger, Han-Taw Chen, Cheng-Hui You, Wei-Lun Hsu, Jiang-Ren Chang

Journal of Marine Science and Technology–Taiwan

The inverse heat conduction method (IHCM) and three-dimensional (3D) computational fluid dynamic (CFD) in combination with are used to select the appropriate flow model and near-wall treatment for the mixed convection of the annular finned tube heat exchanger. Thus, the numerical results obtained by all k-ε models and near-wall treatments are yielded for 4 m/s ≤ Va ≤ 5 m/s. First, IHCM combined with is applied to estimate and Q values. The obtained estimates of and Q are used as reference values for CFD. The results show that the Tk and results obtained by the standard (STD) k-ε model with …

Prediction Of Remaining Useful Life Of Wind Turbine Shaft Bearings Using Machine Learning, Jinsiang Shaw, Bingjie Wu

Journal of Marine Science and Technology–Taiwan

Wind turbines are a major trend in the current green energy market. Wind energy is abundant, and if utilized properly, can result in significant reductions in carbon emissions. Therefore, the development of wind power systems is urgently required. However, wind turbines are mainly built in unmanned areas. Regular inspections require substantial manpower and material resources, and doubts regarding the accuracy of the inspected data may occur. Therefore, it is necessary to establish an automatic diagnostic method for determining the remaining useful life (RUL) of a wind turbine to facilitate predictive maintenance. In this study, a multi-class support vector machine (SVM) …

Supply Chain Management For Superyacht Construction In Taiwan, Chun Pong Wong

Journal of Marine Science and Technology–Taiwan

In the last 20 years, Taiwan’s superyacht construction industry has performed well in the global market; however, numerous yacht builders still practice traditional supply chain management (SCM), which is often inefficient and regularly leads to time and cost overruns. This study aimed to answer two research questions: 1) what SCM challenges does the superyacht construction industry face? and 2) what SCM strategies and practices should be adopted to improve the efficacy and profitability of superyacht construction companies?

Numerous studies have explored supply chains (SCs) and SCM, but few have focused on the superyacht construction industry. Superyacht construction projects are highly …

The Impact Of Variable Curing Conditions On The Properties And Microstructures Of Mixtures Of Ground Granulated Blast Furnace Slag And Circulating Q1 Fluidized Bed Combustion Ash, Shao-Heng Hsieh, Wei-Chung Yeih, Ran Huang

Journal of Marine Science and Technology–Taiwan

The use of Portland cement, an important construction material, is encountering growing challenges because of its adverse environmental impacts. In this study, a new hydration system without Portland cement, which blends ground granulated blast furnace slag (GGBFS) and circulating fluidized bed combustion (CFBC) ash, was developed and tested. The variables included the effect of different types of CFBC ash, the mass ratios between CFBC ash and GGBFS, and different curing temperatures. The mortar properties were determined through the compressive strength test, absorption test, shrinkage test, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. The main results were as follows: …

A Marine Gis-Based Alert System To Prevent Vessels Collision With Offshore Platforms, Sheng-Long Kao, Ki-Yin Chang, Tai-Wen Hsu

Journal of Marine Science and Technology–Taiwan

How to effectively use an intelligent aid-to-navigation (AtoN) to prevent ships from accidentally colliding with offshore marine platforms (OMPs) is an important issue for maritime environment. This study proposes a novel collision alert system with three components to process Automatic Identification System (AIS) data in the cloud and broadcast AtoNs to ships in order to avoid collision with OMPs. The first component receives as input fuzzy linguistic variables (vessel size, relative speed, and approach distance) from the AIS data and calculates the radius of the guarding ring. The second component serves a Marine GIS (MGIS), where the system simulates the …

Assessing Mangrove Wetland Structure And Function Regulated By Environmental Gradients Under Climate Change And Increasing Human Impacts: A Modeling Approach, Xiaochen Zhao

LSU Doctoral Dissertations

Mangroves are blue-carbon-rich wetlands that can potentially contribute to climate change mitigation policies. However, mangroves are increasingly impacted by both natural and human disturbances worldwide that require restoration and rehabilitation programs to advance their conservation. Yet, there are major knowledge gaps in our understanding of how local resources (nutrients), regulators (e.g., salinity) and hydroperiod gradients interact in controlling mangrove role as carbon sink or source at different spatiotemporal scales under increasing disturbance frequency and climate change.

Here, I developed a mass-balance-based hydrology model to estimate soil porewater salinity (PWS) in riverine mangroves along the Shark River estuary (SRE), South Florida; …

Nutrient Cycling In Tropical And Temperate Coastal Waters: Is Latitude Making A Difference?, Christian Lønborg, Moritz Müller, Edward C. V. Butler, Shan Jiang, Seng Keat Ooi, Dieu Huong Trinh, Pui Yee Wong, Suryati M. Ali, Chun Cui, Wee Boon Siong, Erik S. Yando, Daniel A. Friess, Judith A. Rosentreter, Bradley D. Eyre, Patrick Martin

Biological Sciences Faculty Publications

Tropical coastal waters are highly dynamic and amongst the most biogeochemically active zones in the ocean. This review compares nitrogen (N) and phosphorus (P) cycles in temperate and tropical coastal waters. We review the literature to identify major similarities and differences between these two regions, specifically with regards to the impact of environmental factors (temperature, sunlight), riverine inputs, groundwater, lateral fluxes, atmospheric deposition, nitrogen fixation, organic nutrient cycling, primary production, respiration, sedimentary burial, denitrification and anammox. Overall, there are some similarities but also key differences in nutrient cycling, with differences relating mainly to temperature, sunlight, and precipitation amounts and patterns. …

Beluga Whale (Delphinapterus Leucas) Acoustic Foraging Behavior And Applications For Long Term Monitoring, Manuel Castellote, Aran Mooney, Russel Andrews, Stacy L. Deruiter

University Faculty Publications and Creative Works

Cook Inlet, Alaska, is home to an endangered and declining population of 279 belugas (Delphinapterus leucas). Recovery efforts highlight a paucity of basic ecological knowledge, impeding the correct assessment of threats and the development of recovery actions. In particular, information on diet and foraging habitat is very limited for this population. Passive acoustic monitoring has proven to be an efficient approach to monitor beluga distribution and seasonal occurrence. Identifying acoustic foraging behavior could help address the current gap in information on diet and foraging habitat. To address this conservation challenge, eight belugas from a comparative, healthy population in Bristol Bay, …

Supporting Dataset For Observed And Forecasted Global Warming Pressure On Coastal Hypoxia, Michael M. Whitney

Department of Marine Sciences

This archive contains the supporting dataset for the Biogeosciences manuscript “Observed and forecasted global warming pressure on coastal hypoxia” by Michael M. Whitney. The main objective of the manuscript is studying global patterns exacerbating coastal hypoxia by analyzing linear trends in SST, surface oxygen capacity, and (vertical-minimum) oxygen concentration. Observations from a satellite-derived SST global climate data are analyzed to provide context for coastal SST and oxygen-capacity trends over the last four decades. New analysis of 21st century forecasts from the Community Earth System Model (CESM) Large Ensemble Project is completed for coastal areas. Observed and forecasted coastal SST and …

An Evaluation Of The Organic Carbon Content Found In Fucus Vesiculosus And Ascophyllum Nodosum From Skutulsfjörður And Eyjafjörður, Iceland, Sylvie Alexander

Independent Study Project (ISP) Collection

In response to global warming and changing climate, carbon sequestration through macroalgal cultivation has emerged as a possible climate change mitigation technique. Macroalgal cultivation’s relationship to carbon sequestration however is still not well understood. It is imperative to understand macroalgae’s connection to carbon sequestration to evaluate if macroalgal cultivation can help combat climate change. There is a gap in literature regarding the carbon content of Icelandic macroalgae and therefore the contribution of Icelandic macroalgae to national and global carbon sequestration estimates. This paper aims to address this knowledge gap by evaluating organic carbon content of Fucus vesiculosus and Ascophyllum nodosum …

Beach Suitability For Nesting Olive Ridley Sea Turtles (Lepidochelys Olivacea), Playa Malena, Azuero Peninsula, Panama, Soleil Foy

Independent Study Project (ISP) Collection

Sea turtle species all over the world are facing continuous declines in their populations partly due to diminished viable nesting habitat. Understanding sea turtle nesting preferences and the suitability of beaches for reproductive success is necessary in order to sustain their populations and ensure their conservation. Olive ridley sea turtles (Lepidochelys olivacea) are one of the species experiencing this trend, especially in the Eastern Pacific. This study examined the beach suitability of a site known as Playa Malena in the Azuero Peninsula in Panama for Olive ridley nesting. This site was compared to the suitability of 7 other …

Abundance, Foraging Levels, And Dietary Preferences Of Chaetodon Capistratus On Reefs Surrounding Porvenir Island In The Guna Yala Comarca Of Panamá, Eleanor Ann Casement

Independent Study Project (ISP) Collection

Reef fish are a physically and functionally diverse group of organisms that live in close association with coral reef habitats. Chaetodontidae represents the most species rich family of corallivorous fish, and their reliance on corals as food resources has led to their designation as indicator species of coral cover and health. However, the majority of research on the foraging ecology of Caribbean Chaetodontids dates back several decades, and therefore does not account for recent changes in coral community composition as the result of disease, climate change, and other stressors. As the novel and deadly stony coral tissue loss disease (SCTLD) …

The Influence Of Bottom Type And Water Column Stratification On Reef Fish Community Structure At Gray’S Reef National Marine Sanctuary, Bridget Campbell

Honors Theses

Understanding the physical and oceanographic differences across reef habitats can help researchers assess how those differences influence fish distribution and community structure, which leads to a better understanding of what a healthy reef system looks like. The traditional methods used to assess fish communities on temperate reefs are limited and often focus solely on either the reef structure or water column conditions alone. An assessment of both data sets yields a more complete understanding of the ecosystem as a whole. In this study, Gray’s Reef National Marine Sanctuary (GRNMS) was surveyed both inside and outside a Marine Protected Area (MPA) …

An Eventful Past Predicting A Bizarre Future: Assessing The Influence Of Ocean Circulation On Key Fish Species In Icelandic Waters. An Analysis Of Past Circulation Records In Order To Predict The State Of Demersal Fish Stocks In Future Climate Scenarios, Matthew Engfer

Independent Study Project (ISP) Collection

Feedback-driven changes in North Atlantic Ocean circulation are affecting marine ecosystems off the coast of Iceland and are predicted to have differing outcomes by 2100. In this study, data reflecting Icelandic fish stock distributions was compiled on a map with oceanographic temperature and depth in order to observe patterns of population changes with changes in ocean currents. After evaluating past temperature effects on demersal fish stocks, future habitat predictions were estimated in weaker ocean circulation scenarios. A number of assumptions were made in order to pinpoint a correlation between ocean temperature and fish habitat. Iceland’s unique location and climate offers …

Effectiveness Against White Sharks Of The Rpela Personal Shark Deterrent Device Designed For Surfers, Craig Blount, Dan Pygas, Marcus P. Lincoln Smith, Daryl P. Mcphee, Colby Bignell, Ocean Ramsey

Journal of Marine Science and Technology–Taiwan

Many shark bites to humans, including fatalities, have involved surfers. Various personal shark deterrents are commercially available to surfers, including Rpela v2, which is a battery-powered device fitted to a surfboard. It produces an electric field around the surfer aimed at deterring sharks from approaching or biting by disrupting their electro-reception organs. The device was tested on white sharks (Carcharodon carcharias) at Salisbury Island, Western Australia. In total, 46 trials were done with the Rpela v2 either active or not active to determine the device’s effect on sharks’ response to a floating board with fish bait attached (to tempt a …