Physical Sciences and Mathematics Commons^™

Mechanics Of Burrowing In Muddy Sediments, Kelly M. Dorgan

Electronic Theses and Dissertations

Marine muds are elastic solids through which animals move by propagating a crack-shaped burrow. Dilations previously considered anchors serve to exert dorsoventral compressive stresses on the burrow walls that, through elastic behavior of the medium, focus strongly at the tip of the burrow. This focused stress breaks adhesive or cohesive bonds, propagating a crack for the animal to follow. The force exerted by the polychaete, Nereis virens, to propagate a crack has been measured in gelatin, an analogue of muddy sediment, through photoelastic stress analysis. Finite element analysis was used to convert measured forces to those exerted in natural sediments …

Hypoxia In The Northern Gulf Of Mexico: Does The Science Support The Plan To Reduce, Mitigate, And Control Hypoxia?, Nancy N. Rabalais, R. Eugene Turner, B.K. Sen Gupta, D. F. Boesch, P. Chapman, M. C. Murrell

Faculty Publications

We update and reevaluate the scientific information on the distribution, history, and causes of continental shelf hypoxia that supports the 2001 Action Plan for Reducing, Mitigating, and Controlling Hypoxia in the Northern Gulf of Mexico (Mississippi River/Gulf of Mexico Watershed Nutrient Task Force 2001), incorporating data, publications, and research results produced since the 1999 integrated assessment. The metric of mid-summer hypoxic area on the Louisiana-Texas shelf is an adequate and suitable measure for continued efforts to reduce nutrients loads from the Mississippi River and hypoxia in the northern Gulf of Mexico as outlined in the Action Plan. More frequent measurements …

Benthic Mapping For Habitat Classification In The Peconic Estuary: Phase I Groundtruth Studies, Robert M. Cerrato, Nicole P. Maher

School of Marine & Atmospheric Sciences Faculty Publications

Benthic habitat maps of the estuary seafloor will increase our knowledge of range and variability in benthic habitats, will assist managers in their efforts to protect and/or restore commercially and recreationally important finfish and shellfish, will link land usage (e.g. developed vs. undeveloped areas) and water quality data to benthic habitat quality, and will make it possible to utilize faunal data as a long-term indicator of the overall “health” of the estuary. We are developing benthic habitat maps by combining high-resolution remote sensing techniques with detailed study of the physical and faunal characteristics at point locations in different seafloor environments. …

To Live With The Sea: Community-Based Management Of Marine Resources In Southwest Madagascar, Hannah Pitt

Independent Study Project (ISP) Collection

“God intended us to fish, and we will fish until the end,” the elderly Vezo fisherman explained, shrugging his shoulders as if in resignation to an unavoidable truth (Niry). For a people whose history, culture, and economy have revolved around the sea for generations, the idea of preservation is just not palatable, he seemed to be saying. The momentum of tradition, in other words, cannot be stopped. Yet in 23 Vezo fishing villages in the region of Andavadoaka, along the southwest coast of Madagascar, communities have collectively established seasonal and permanent restrictions on critical fishing grounds that together make up …

Ontogenetic Changes In Feeding Ecology And Habitat Of The Damselfish Neoglyphidodon Melas At Lizard Island, Great Barrier Reef, Sai-Wing Chan

Independent Study Project (ISP) Collection

This study examines ontogenetic shift in habitat and feeding ecology of the black damselfish, Neoglyphidodon melas in three patch reef sites at Lizard Island, Great Barrier Reef. This rarely studied species is unique in its coprophagous relationship with the faeces of the giant clam Tridacna gigas. Distribution and habitat composition between three sites and two reef zones was estimated with 48 Visual Belt and Point Intercept Transects. 80 Focal Animal Studies revealed specific foraging strategies and aggressive behaviours. The timing of this study permitted the inclusion of juvenile recruits resulting in a more complete and comprehensive study across developmental stages. …

Investigating A Method To Measure Sperm Transfer In Chelidonura Sandrana (Opisthobranchia: Cephalaspidea), Kate Kunigelis

Independent Study Project (ISP) Collection

This paper investigates possible methods for measuring sperm transfer in the internal fertilizing, simultaneous hermaphrodite Chelidonura sandrana (Opisthobranchia: Cephalaspidea). Comparing sperm amount transferred in copulations has significance for testing the assumption that sperm transfer is linearly correlated with copulation duration as well as providing a tool for future studies. Various methods of preparing, treating, and viewing sperm samples were attempted. Two unsuccessful pilot studies were conducted to test free sperm counts and measuring sperm pellet surface area. Future research should focus on optimizing centrifugation method for surface area measurements of sperm clusters and resuspending sperm clusters to enable sperm counting. …

Distribution Of Ultraviolet-Absorbing Sunscreen Compounds Across The Body Surface Of Two Species Of Scaridae, Elizabeth Cerny-Chipman

Independent Study Project (ISP) Collection

Ultraviolet radiation has far-reaching effects in marine ecosystems, but many marine organisms have UV-absorbing compounds that protect them from sun-induced damage. The mucus of coral reef fish has been found to contain mycosporine-like amino acids that absorb UV light from 309-360 nm. Using UV spectrophotometry, we examined whether fish are able to allocate these MAA sunscreen compounds to areas of the body that receive the most UV radiation. We compared absorbance spectra of mucus from the body surface of dorsal, ventral, caudal and head areas in two species of Scaridae (Scarus schlegeli and Chlorurus sordidus) from Coral Bay, Western Australia. …

Limb Regeneration After Multiple Autotomy And Coxae Removal In The Blue Crab Callinectes Sapidus, Jennifer Ambler

OES Theses and Dissertations

This study investigated limb regeneration in the juvenile blue crab, Callinectes sapidus, specifically the role of the coxa and pedal nerve innervation of the regenerative limb bud over time. The coxa is a leg segment that has been defined as the source of positional, cellular, and neuronal information needed for limb regeneration in brachyuran crabs. This study indicates that removal of coxae under regenerative and non-regenerative conditions did not deter limb regeneration. The coxa is not the exclusive location of limb regenerative information since limbs re-grew with normal positional and functional arrangement in 86% of crabs showing regeneration at removal …

Salt Fluxes At The Chesapeake Bay Entrance, Ruth Lane

OES Theses and Dissertations

Underway measurements of salinity and flow profiles were used to compute salt fluxes at the mouth of the Chesapeake Bay in spring and summer. Waters were sampled along a cross-bay transect over four tidal cycles in 1997: at the end of April, during neap tides, and in mid-July, during spring tides. Data were interpolated onto a uniform grid along the transect area. A least squares regression with semidiurnal and diurnal harmonics was fit on both salinity and flow at each point of the grid to separate tidal from non-tidal influences. The results of the least squares fit were used to …

Summer/Fall 2007, Nsu Oceanographic Center

Currents

No abstract provided.

Assessment Of The Flame Angelfish (Centropyge Loriculus) As A Model Species In Studies On Egg And Larval Quality In Marine Fishes, Chatham K. Callan

Electronic Theses and Dissertations

This project sought to determine if flame angelfish (Centropyge loriculus) could serve as models in examination of environmental and dietary effects on egg quality in marine fishes. Evaluation of 21 marine ornamental species identified flame angelfish as being amenable to egg quality research, due to their rapid conditioning and frequency of spawning. At the onset of this project, accidental copper introduction to broodstock systems required assays to determine the effects of copper exposure on survival and reproduction. Flame angelfish exhibited accute sensitivity to copper, as 60% of fish exposed to 0.25mg/L died within 12 hours of exposure. Likewise, fish exposed …

Annual And Interannual Variability In The Wind Field And The Hydrography Along The Seward Line In The Northern Gulf Of Alaska, Isaac Schroeder

OES Theses and Dissertations

The Northeast Pacific GLOBEC (GLOBal ocean Ecosystems dynamics) program (October 1997 to December 2004) collected hydrographic data along the Seward Line that stretches from the inner shelf (GAM 59.8°N, 149.5°W) and extends over 200 km beyond the continental slope (GAK13 58.1°N, 147.8°W). The complexity of the interannual hydrographic variability in this area stems from the interacting influences of local forcing such as winds, coastal freshwater discharge, eddies, fronts and remote forcing like El Niño-Southern Oscillation. Until now, the influence of winds on the system has been calculated using coarse resolution upwelling index data or spatially sparse buoy data. The coarse …

Mixed Layer Dynamics Along The Seward Line In The Northern Gulf Of Alaska, Nandita Sarkar

OES Theses and Dissertations

The northern Gulf of Alaska marine ecosystem is very productive with a "nutrient paradox". Primary producers require light and nutrients for photosynthesis. A primary source of nutrients is the deep ocean, while light is available in a relatively shallow layer in the upper ocean. In most productive parts of the world oceans, nutrients are brought to surface waters by upwelling. However, in the northern Gulf of Alaska, the winds are generally downwelling inducing and the mechanism(s) by which nutrients are brought to the euphotic zone are not known. One mechanism that might bring nutrients into the euphotic zone is the …

Collaborative Proposal: Form And Function Of Phytoplankton In Unsteady, Low Reynolds-Number Flows, Peter Jumars, Lee Karp-Boss

University of Maine Office of Research Administration: Grant Reports

Small-scale flow dynamics at low Reynolds numbers (Re) are important to phytoplankton cells in delivery of nutrients, sensory detection by and physical encounter with herbivores, accumulation of bacterial populations in the "phycosphere" or region immediately surrounding phytoplankton cells and coagulation of cells themselves as a mechanism terminating blooms. In nature most phytoplankton experience unsteady flows, i.e., velocities near the cells that vary with time due to the intermittency of turbulence and to discontinuous, spatially distributed pumping by herbivores. This unsteadiness has not previously been taken into account in models or measurements with plankton. Moreover, there have been decade- and century- …

Sensors: Collaborative Research: Aloha Mooring Sensor Network And Adaptive Sampling, Emmanuel S. Boss

University of Maine Office of Research Administration: Grant Reports

The PIs propose to develop a moored deep-ocean sensor network that will first be installed at the Hawaii Ocean Time-series (HOT)/ALOHA Observatory (AO) and then at other cabled observatory sites as they are implemented. This moored sensor network is based on a profiler that will move between near-surface and fixed abyssal sensors under program control. The PIs feel that this project will demonstrate the scientific potential of combining adaptive sampling methods with a moored series of profiling sensors. The PIs will also develop optimization software tools to maximize overall information return given the constraints of competing scientific objectives, the continually …

Mechanics Of Suction Generation During Feeding In Little Skates, Danielle Duquette

Senior Honors Projects

Feeding mechanisms of aquatic vertebrates has been extensively studied in the past, while that of elasmobranchs remains limited. Skates and rays are believed to have evolved from a shark ancestor, thus they represent the most derived group. All skates are dorsoventrally compressed, have a unique jaw suspension type and head skeleton and live in benthic environments. It is unknown whether these derived features of skates have altered the ancestral shark feeding mechanism. Comparing feeding mechanisms in skates and sharks may shed light on morphological transformations that have arisen after the evolutionary split of these two groups. In this study prey …

The Sensitivity Of The Southwest Monsoon Phytoplankton Bloom To Variations In Aeolian Iron Deposition Over The Arabian Sea, Jerry D. Wiggert, Raghu G. Murtugudde

CCPO Publications

[1] A coupled, 3-D biophysical ocean general circulation model is used to investigate how aeolian iron deposition affects the Arabian Sea ecosystem. Two separate aeolian iron deposition fields, derived from the GISS and GOCART atmospheric transport models, have been applied as surface boundary conditions. The model results exhibit widespread biogeochemical sensitivity to the choice of deposition field. With GOCART deposition, SW Monsoon phytoplankton blooms in the western and central Arabian Sea are enhanced and exhibit greater realism. The central Arabian Sea bloom is supported by supplemental input of horizontally advected iron from a pool that undergoes a yearlong progression that …

Remote Assessment Of 4-D Phytoplankton Distributions Off The Washington Coast, Brandon S. Sackmann

Electronic Theses and Dissertations

Satellite-based optical measurements were coupled with physical and optical measurements from Seaglider – a long-range autonomous glider – to study interactions between biological and physical processes off the coast of Washington, USA, and to evaluate space-time variability of regional phytoplankton and particle distributions. Using satellite ocean color data variability in near-surface chlorophyll a was characterized across a range of spatial and temporal scales ranging from 1 – 500 km and from days – years to assess region-wide responses by phytoplankton to changes in environmental conditions. Results from 1998 – 2002 revealed both strong negative and positive anomalies associated with lingering …

An Assessment Of The Use Of Sediment Traps For Estimating Upper Ocean Particle Fluxes, Ko Buesseler, An Antia, Sw Fowler, Et Al, Deborah K. Steinberg, T Trull

VIMS Articles

This review provides an assessment of sediment trap accuracy issues by gathering data to address trap hydrodynamics, the problem of zooplankton “swimmers,” and the solubilization of material after collection. For each topic, the problem is identified, its magnitude and causes reviewed using selected examples, and an update on methods to correct for the potential bias or minimize the problem using new technologies is presented. To minimize hydrodynamic biases due to flow over the trap mouth,the use of neutrally buoyant sediment traps is encouraged. The influence of swimmers is best minimized using traps that limit zooplankton access to the sample collection …

Spring 2007, Nsu Oceanographic Center

Currents

No abstract provided.

The Observation, Modeling, And Retrieval Of Bio-Optical Properties For Coastal Waters Of The Southern Chesapeake Bay, Xiaoju Pan

OES Theses and Dissertations

The primary purpose of this study was to develop an inverse method to retrieve the inherent optical properties (IOPs) and biogeochemical parameters (e.g. chlorophyll a concentration and salinity) appropriate to monitor the water quality and biogeochemical processes from remote sensing of the coastal waters in the southern Chesapeake Bay and coastal Mid-Atlantic Bight region (MAB) dominated by Case 2 waters. For this purpose, knowledge of the relationship between remote sensing reflectance (R_rs) and IOPs and the effect from bottom reflectance on R_rs, is required.

A substantial investigation of IOPs has been conducted for the coastal …

Interactions Between Phytoplankton And Bacteria In The Uptake Of Organic Compounds, Andrea Michel Rocha

OES Theses and Dissertations

The most common methods for estimating bacterial productivity are [³H]-leucine and [³H]-thymidine incorporation. Uptake of these compounds has been attributed primarily to bacteria; however, because dissolved organic nitrogen may be an important N source for some phytoplankton, the use of these compounds to estimate bacterial productivity needs to be reexamined. In order to ascertain whether phytoplankton could compete with bacteria on relevant timescales and thereby bias bacterial productivity estimates in estuaries, I examined the ability of cultured phytoplankton and size-fractionated natural populations to take up leucine and thymidine in systems seasonally dominated by phytoplankton mixotrophs. In …

Globec Nep: Satellite-Observed Ocean Climate Variability, Andrew C. Thomas

University of Maine Office of Research Administration: Grant Reports

The PIs will extend in time and expand in scope the satellite data development and satellite-based analyses of ocean climate variability in the Northeast Pacific (NEP), begun during the GLOBEC Pilot Project phase (1997 - 00). The overall scientific problem is to characterize and quantify the dominant modes of variability in the NEP as embodied by satellite measurements of surface transports, temperature and chlorophyll patterns. Our analyses address multiple spatial and temporal scales using merged satellite data products over GLOBEC target study regions in both the California Current (CCS) and the coastal Gulf of Alaska (CGOA).

GLOBEC NEP field studies …

The Lability Of Riverine Particulate Organic Carbon Delivered To The Ocean, Lawrence Mayer

University of Maine Office of Research Administration: Grant Reports

The large annual flux of organic carbon from land to the ocean largely disappears in the sea. Reasons for this loss are not clear. Under this award, the PI will examine abiotic and biotic aspects of the lability to loss of riverine particulate organic matter. Work will focus on the Mississippi, as it demonstrates the clearest loss of particulate organic material of any North American river upon deposition in the ocean. Photochemical experiments will follow up on initial work showing significant dissolution of particulate organic matter subjected to solar levels of radiation. Interactions with metal cycling will be studied, as …

Sger-Exploring The Use Of Quantum Dots To Detect The Physiology Of Intact Phytoplankton Cells By Flow Cytometry, Karen Orcutt

University of Maine Office of Research Administration: Grant Reports

The PIs will to apply the emerging technology of Qdots in biological oceanography, particularly in studying phytoplankton. Qdots have unique fluorescence properties with tremendous potential for probing cell structure and function. They are inorganic fluorophores that can be conjugated to biological materials such as antibodies or DNA for use in cell detection. Molecular conjugates of Qdots offer a wide spectrum of applications such as multi-labeling of proteins and fluorescent in situ hybridization of DNA. The PIs will explore a new approach to an established research topic and venture into the emerging research area of nano-materials.

The novel approach may improve …

Investigating Coastal Processes And Nitrate Levels In The Elkhorn Slough Using Real-Time Data, Lisa G. Adams, George I. Matsumoto

Faculty and Research Publications

The primary objective of this activity is to predict how coastal processes, such as tides, affect salinity, temperature, and nitrate levels in a type of estuary, called a slough. Real-time data from the Elkhorn Slough National Estuarine Research Reserve in Monterey, California, will be used to test predictions. In addition to collecting, graphing, and interpreting real-time data, students will learn how nitrates enter the estuary, and they will gain a better understanding of the interconnectedness of all bodies of water, especially estuaries.

Generation Of Internal Solitary Wave By Gravity Collapse, Chen-Yuan Chen, John Rong-Chung Hsu, Cheng-Wu Chen, Hsin-Hsun Chen, Ching-Feng Kuo, Min-Hung Cheng

Journal of Marine Science and Technology

Laboratory experiments were conducted to investigate the generation of an internal solitary wave (ISW) in a two-layer free surface fluid system in wave flume (12 m × 0.5 m × 0.7 m), which included wave channel and compartment. There is filled with stratified twolayer fluid system in the channel and small compartment, respectively. These two regions in the wave flume are separated by a movable vertical gate at one end of the flume for generating the ISW (internal solitary wave). An ISW generation is thus caused by gravity collapse upon raising the vertical gate. Given positive potential energies, an elevation-type …

Wave Propagation At The Interface Of A Two-Layer Fluid System In The Laboratory, Chen-Yuan Chen, John Rong-Chung Hsu, Cheng-Wu Chen, Ching-Feng Kuo, Hsin-Hsun Chen, Min-Hung Cheng

Journal of Marine Science and Technology

A series of laboratory experiments on internal solitary wave (ISW) had been conducted in a two-layer fluid system. Internal solitary waves were generated in laboratory which was controlled by several variables, including different layer thickness ratios H1/H2, interface differences ηo, and the density ratios ρ1/ρ2. The wave flume used in this experiment was 12 meter long with a cross-section 0.5 m wide by 0.7m in height. Five ultrasonic probes placed at equidistance recorded the interface fluctuations, and one density probe measured the change of density across the interface. Data collection and processing were carried out via control software. This paper …

Volcanic Eruptions At East Pacific Rise Near 9°50'N, James P. Cowen, Brooke Love, Brian Glazier, Daniel J. Fornari, Timothy M. (Timothy Mitchell) Shank, S. Adam Soule, Alexander Treusch, Kyle R. Pomranig, R. Chadwick Holmes, Maya Tolstoy, Edward T. Baker

Environmental Sciences Faculty and Staff Publications

Evidence for recent volcanic eruptions along the fast spreading East Pacific Rise (EPR) crest near 9°50'N spanning about 4 to 5 months of activity was discovered in April and May 2006 as a result of studies related to the U.S. National Science Foundation's (NSF) Ridge2000 (R2K) program. In April, during routine recovery and redeployment of ocean-bottom seismometers (OBS) at the EPR R2K Integrated Study Site (ISS) near 9°50'N, eight of 12 OBS could not be recovered [Tolstoy et al, 2006]. Anomalous turbidity and temperature structure in the water column along the ridge axis confirmed scientists' suspicions that the OBS were …

Ner: Exploratory Research On Developing A Nanoscale Sensing Device For Measuring The Supply Of Iron To Eukaryotic Phytoplankton In Natural Seawater, Mark L. Wells

University of Maine Office of Research Administration: Grant Reports

The long delay in recognizing the potentially key role of Fe in coastal marine systems has been in large part because of the complexity of microbial:Fe interactions in seawater. There still is no analytical method for determining biologically available Fe for either prokaryotic or eukaryotic phytoplankton. However, there is evidence that Fe availability to eukaryotic phytoplankton can be regulated by additions of the fungal siderophore desferrioxamine B (DFB) to coastal waters. The DFB-Fe complex not only is unavailable for uptake at significant rates, but also outcompetes the natural organic ligand classes in seawater for Fe. Measurement of DFB-Fe concentrations in …