This symposium is designed to showcase graduate student research, to build awareness of UNH marine research activities, and enhance interdisciplinary connections within the School of Marine Science and Ocean Engineering community. This one-day symposium will include a series of graduate student oral presentations, a keynote address, poster presentation reception and conclude with an award ceremony.
Virtual Symposium Details
The 2021 Graduate Research Symposium has not been scheduled.
Check back in early 2021 for details.
2020 Speaker Information
Fuel from Within: Can resuspended organic phosphorus fuel harmful cyanobacteria blooms in Lake Erie?
Lake Erie, the shallowest of the Laurentian Great Lakes, has been historically plagued with blooms of potentially toxic cyanobacteria despite efforts to reduce external nutrient input. The Great Lakes Water Quality Agreement signed by Canada and the United States of America in the 1970’s sought to decrease the amount of soluble reactive phosphorus (SrP) entering the lakes through rivers and runoff. In the mid 1990’s blooms of the potentially toxic cyanobacteria Microcystis spp. began to reappear in Lake Erie despite the diminished amount of SrP entering the lake, specifically in the western basin. Due to the shallow nature of the basin (average depth 10 m), events such as summer storms have historically been strong enough to resuspend lake sediment, potentially releasing phosphorus sorbed onto organic and inorganic particles (>0.46 m), termed particulate organic phosphorus (POP) and particulate inorganic phosphorus (PIP), respectively. Microcystis, along with all other cyanobacteria, possess phosphatase enzymes that allow the bacterium to effectively cleave the phosphate group off of organic particles and incorporate it into the cell. We hypothesize that wind-driven sediment resuspension events in the western basin of Lake Erie release POP that potentially fuels summertime Microcysits blooms. We first investigated the amount of P released during resuspension events by exposing sediment cores taken from two sites in the western basin to increasing amounts of shear stress. We quantified the amount of SrP, POP, and PIP released from the sediment cores into the overlaying water. In lab experiments, we exposed cultures of Microcystis isolated from the western basin to varying levels of SrP, POP, and PIP and observed growth rates. The hydrolysis rate of the phosphatase enzyme was studied to determine the usage of the POP pool. These experiments allow us to effectively show if sediment resuspension events in Lake Erie release POP, and if Microcystis can use POP to grow.
Movements and feeding of Arctic char relative to summer ice-off in an Arctic embayment
Arctic waters are warming faster than anywhere else on the planet. Increased temperatures are expected to affect the seasonal timing of ice-off, an event that provides productivity booms for consumers. Arctic species are adapted to strong seasonal variations in productivity, but exploiting high productivity events may become more difficult if sea ice phenology changes. The Arctic char (Salvelinus alpinus) is a fish of particular concern, providing sustenance and income to Arctic inhabitants through subsistence fisheries. Although char are known to make seasonal migrations to marine waters to feed, their specific timing in relation to ice-off and the subsequent productivity pulse is unknown. Further, the quantity and quality of food consumed during this period will dictate the importance of the ice-off transition for char. To investigate the movement and trophic ecology of Arctic char, 110 individuals were tagged with acoustic transmitters in 2017 (n=58) and 2018 (n=52) within Tremblay Sound, Nunavut, Canada, with an additional 54 char dissected for stomach content in 2018 (n=23) and 2019 (n=31). Thirty-five acoustic telemetry receivers monitored char movements and recorded 625,483 detections from July 2017 until August 2019. Migration timing was closely linked to the timing of ice-off, with individuals arriving right before ice-off and leaving after a month of complete ice-off. Char that summered within Tremblay Sound exited in two directions: toward the river to the south of Tremblay Sound, and toward the marine environment. Char returning to the Sound from the marine environment were larger, maintained larger homeranges, and entered the region later than those entering from the river within the Sound. Collectively, these results might indicate that several char populations exploit the Sound’s productivity. We hypothesize that the use of Tremblay Sound is linked to food availability, particularly of the amphipod Onisimus litoralis, which was found in 69.6% of sampled stomachs after ice-off. Furthermore, char are eating at high rates, with up to 4.6% of their total bodyweight occupied by stomach content. Thus, Arctic char movements and feeding appear dependent upon the ice-off transition with potential behavioral and growth affects if climate change impacts this species’ ability to exploit the seasonal phenomenon.
Evaluating the performance of a multi-tile macroalgae cultivation structure using physical modeling
Macroalgae cultivation structures must be large scale and structurally robust in order to prove successful in an offshore environment. A multi-tile system consisting of kelp growing lines and a structural grid was designed as part of an ARPA-E funded study, and initial computational modeling of this Phase I design has indicated that it is capable of withstanding storm conditions. Phase II of the project focusses on a field study, with the first step being the fabrication of a physical scale model to be deployed in the UNH wave tank. The physical model is a 3x3 tile array, scaled by Froude number to a 1:180 length scale. Deployment in the UNH wave tank allowed for evaluation of the design’s performance during wave and current conditions. The model was subjected to waves and simulated currents in order to investigate its response to dynamic loading conditions, as well any anomalous behavior such as shock loading or component interaction. The motion of the system during various loading scenarios and orientations was captured with cameras and analyzed via a tracking software. The motion data was then used to identify relationships and trends in the system’s response. A finite-element analysis companion study of the physical model was also executed in order to validate the results of the motion data, thus providing a better understanding of how the full-scale system might behave in an offshore environment.
Subtidal Contributions to hydro- and morpho-dynamics at a wave dominated inlet system
Observations of currents and water pressure obtained at 7 locations within Oregon Inlet, NC, over a 40-day period in the spring of 2019 showed subtidal water level oscillations on the sound side of the inlet with magnitudes often exceeding typical tidal ranges. These oscillations, which are correlated with regional wind patterns, induce cross-shore gradients in sea surface slope from the back bay to the ocean that are strongly coupled to inlet current modulations at subtidal frequencies. Owing to their longer temporal scale, the sub-tidal gradients often combine with typical tidal lows to accelerate one phase while retarding or entirely reversing the other. Concurrent observations of bedform migration on the ebb-tidal delta, obtained with x-band radar, suggest these current modifications at sub-tidal frequencies may be important to sediment transport patterns in the inlet and on the ebb-tidal delta. The role of subtidal oscillations on large scale morphologic evolution is further examined through an idealized numerical model that couples hydrodynamics, waves, and sediment transport through the Delft3D modelling suite implemented at Oregon Inlet over observed bathymetry. The nature of the morphologic development of the inlet is discussed in terms of the presence or absence of subtidal oscillations.
Population Genetic Structure and Mixed Stock Analysis of Striped Bass for Improved Fisheries Management
Striped Bass (Morone saxtilis) is an anadromous teleost with a native range spanning the entire Atlantic coast from the Canadian Maritime Provinces to the St. John’s River in Florida and into the Gulf of Mexico. Substantial spawning populations historically occurred throughout the Atlantic coast but are now limited to four primary river systems, including the Hudson River (New York), Delaware River (Delaware), Roanoke River (North Carolina), and tributaries of the Chesapeake Bay, with many small spawning populations spread throughout the range. While all individuals across the rang spawn annually in fresh to brackish water between the months of April and June, populations north of Cape Hatteras undertake an annual feeding migration to coastal waters as far north as the Canadian Maritimes. These migrating individuals form mixed stocks, or aggregates of fish consisting of individuals from multiple origins, and these stocks support the most popular recreational fishery in the United States. The proportion that each spawning population contributes to the mixed stocks is not known and therefore makes it difficult to manage the species effectively. While considerable research has been recently conducted on the genetic population structure of the non-migratory populations in the southern range, studies identifying the genetic population structure in the migratory range have not occurred since the 1980’s-1990’s. These studies were also conducted prior to the development of high resolution genetic markers and were unable to definitively resolve the genetic population structure within the migratory range of striped bass. The objectives of this study are: 1) to use single nucleotide polymorphism’s (SNP’s) to identify the genetic population structure among the spawning populations of migratory striped bass, and 2) identify the stock composition in 4 areas in the Northeast: New York, Massachusetts, Rhode Island, New Hampshire and Maine. In order to address objective 1 DNA samples from different spawning populations throughout the migratory range were obtained and used to prepare Restriction-site associated DNA (RAD) libraries. The bioinformatics pipeline STACKS was used to call individual genotypes and the population genetics software program STRUCTURE was used to identify the population genetic structure of the spawning populations.
In the coastal ocean, species range boundaries tend to cluster in specific alongshore locations. We used estimates of larval dispersal from a global current model coupled with a simple population model to predict where these clusters are likely to arise due to current-driven larval transport. The locations of the predicted boundary clusters are correlated to observed locations of biogeographic boundaries in the coastal ocean, suggesting that currents play an important role in setting the location of biogeographic boundaries in many locations throughout the coastal ocean. Understanding how currents spatially structure species range boundaries is essential to predicting how species ranges will shift in response to a changing climate and for setting conservation and management goals to respond to those changes.
To predict the locations of species range boundary clusters, we tracked simulated larval particles within 1/12° global velocity fields obtained from the operational Mercator global ocean analysis and forecast system (PSY4V3R1, distributed by the E.U. Copernicus Marine Environmental Monitoring Service) and used the trajectories of these particles to generate estimates of current-driven larval dispersal in the global coastal ocean. We used connectivity matrices from these dispersal estimates in a simple two-species population model which was used to find the location of range boundaries.
UPDATE: Due to the current situation caused by COVID19, the symposium will be held virtually and unfortuantely will not allow the opportunity for poster presentations. We hope that you will join us this Fall during Ocean Discovery day where you will be able to present your poster.
Past Graduate Research Symposium Oral Presentations
Erin Heffron, Earth Sciences/Ocean Mapping
The Distribution of an Acoustic Scattering Layer near Petermann Glacier, Northwest Greenland and its Relationship to Regional Oceanography
Mass loss from the Greenland ice sheet has increased rapidly in the last two decades and has contributed significantly to observed sea level rise. The most pronounced change is occurring where ice sheets are grounded below sea level, due to enhanced interaction with warming ocean waters. However, our ability to predict future sea level rise is hampered by our limited knowledge of these glacial systems, including the regional water mass distribution and circulation responsible for that enhanced ocean-ice interaction. The Petermann Expedition of August 2015 encompassed a broad range of data collection in an effort to characterize the Petermann Glacier system, a marine-terminating glacier with a floating ice tongue that has undergone dramatic changes in the last decade. During the expedition, sonars were used to map the water column, generating a continuous dataset over 30 days. This mapping revealed extensive acoustic scattering layers, so called because the components of the layer – typically zooplankton – cause the acoustic energy to scatter much as it does when it encounters the seabed. The layer was observed to change depth in a spatially consistent manner and corresponded to our general, but limited understanding of the complex circulation pattern in the study area. Shipboard insolation data and satellite-derived light attenuation data were used to rule out response to light as the primary reason for changes in the scattering layer depth. Comparison to salinity and temperature measurements were used to demonstrate a pattern in the scattering layer depth distribution related to circulation, confirming that the continuous record provided by acoustics can supplement point observations of temperature and salinity to provide a more complete picture of regional oceanography and the glacial system as a whole.
Hilary Kates Varghese, Earth Science/Oceanography
The Contribution of 12 kHz Multibeam Sonar to a Southern California Marine Soundscape
An ocean mapping survey was conducted over the Southern California Antisubmarine Warfare Range hydrophone range to characterize the radiation pattern of the R/V Sally Ride's EM 122 (12 kHz) Kongsberg multibeam echosounder. Spanning a 2000 square kilometer area, the 89-hydrophones in the range, combined with the mapping survey, provided the opportunity to study the contribution of this anthropogenic noise to the marine soundscape. The soundscape was characterized and compared at select hydrophones on the range before and during the multibeam survey. One second averages of the sound level were calculated over the data collection period. Sound level percentiles (P1, P10, P50, P90 and P99) were calculated for the full spectrum (1 Hz- 48 kHz) and select frequency bands, and spectral probability density plots were generated for each time period. Frequency correlation matrices were produced for each time period and compared using difference matrices to identify changes in the soundscape. The results are placed in the context of the auditory scene of Cuvier's beaked whales resident on the range by applying a mid-frequency marine mammal weighting function. [Work supported by NOAA, ONR, and Scripps Institute of Oceanography].
Brandon Maingot, Ocean Engineering/Ocean Mapping
High Frequency Motion Residuals: Identification and Estimation
Advances in multibeam sonar mapping and data visualization have increasingly brought to light the subtle integration errors remaining in bathymetric datasets. Traditional field calibration procedures, the patch test, just account for static orientation bias and sonar to position latency. However, this ignores the generally more subtle integration problems that generate time varying depth errors.
Such dynamic integration errors are the result of an unknown offset in one or more of orientation, space, sound speed or time between the sonar and ancillary sensors. Such errors are systematic, and thus should be predictable, based on their relationship between the input data and integrated output. A first attempt at addressing this problem utilized correlations between motion and ping-averaged residuals . The known limitations of that approach, however, included only being able to estimate the dominant signal, imperfectly accounting for irregular sounding distribution and it only working in shallow water.
This presentation discusses a new and improved means of utilizing the dynamics of the integration error signatures which can address multiple issues simultaneously, better account for along-track sounding distribution, and is not restricted to the shallow water geometry. The motion-driven signatures of multiple integration errors may be simultaneously identified through individually considering each sounding’s input-error relationship from extended sections of a single swath. Such an approach provides a means of underway system optimization using nothing more than the bathymetry of typical seafloors acquired during transit. Successful estimation, however, imposes conditions of significant vessel motion, and smooth, gently rolling bathymetry. Initial results of the new algorithm are presented using data generated from a simulator (with known inputs and integration errors) to test the efficacy of the method.
Tyler Menz, Oceanography
Impacts of Temperature and Salinity on Pteropod Abundance and Distribution off the East Coast in the Atlantic Ocean
Pteropods are pelagic, free-swimming sea snails that have a thin aragonite shell that makes them fairly susceptible to the changing ocean chemistry that is associated with ocean acidification (OA). Pteropods are an important part of the ecosystems they are found in as they are a part of the diet of species at multiple trophic levels and help to facilitate the movement of carbon throughout the water column. Previous studies have shown that pteropods are sensitive to OA conditions as they have shown tendencies for shell dissolution, increased shell opacity, and decreased sinking speeds in more acidic conditions. Changes in other environmental conditions associated with OA, such as rising temperature and salinity, may also impact pteropods. Increased understanding about how the distribution of pteropods has changed as temperature and salinity conditions change can provide insight about how sensitive pteropods may be to these variables. The ECOMON dataset from NOAA Northwest Fisheries Department was used to determine if and how pteropod distribution has changed in the Atlantic Ocean off the east coast of the United States. Statistical analyses performed on the dataset determined there is a relationship between temperature, salinity, pteropod abundance, and their location over time. Ongoing research is further exploring the relationship between pteropod abundance and these environmental conditions. Understanding how pteropod populations respond to these changing variables is important in further establishing them as bioindicators for OA.
Brandon O'Brien, Marine Biology
Understanding the spread of two invasive seaweeds using digital herbarium records and distribution modeling techniques
Invasive seaweeds are a potent threat to biodiversity in coastal ecosystems worldwide. Only a subset of all introduced seaweeds have made the leap from being locally problematic to global invaders. Here, we explore the use of species distribution models for analyzing the regional-scale distribution of invasive macroalgae. In particular, we attempted to identify locations that may be vulnerable to the introduction of certain highly successful invaders. Models were built for two species: Undaria pinnatifida and Dasysiphonia japonica. Both species are native to temperate Asia, but have become established in disparate regions of the world. Accuracy of the constructed models was assessed by comparing predicted highly suitable habitat to known occurrence records. They were then used to identify areas that may be vulnerable to introduction by either species in the future: U. pinnatifida is already established in a number of areas worldwide, but has yet to reach the Gulf of Maine. Dasysiphonia japonica is relatively recent to the Gulf of Maine, and is not as globally widespread, but may have the potential to spread beyond its current extent.
Jesse Ross, Civil and Environmental Engineering
Potential Role of Marine Oil Snow in the Fate of Spilled Oil in Cook Inlet, Alaska
The objective of the research is to characterize the potential role of marine snow and suspended minerals in the fate of spilled oil in Cook Inlet, Alaska. While extensive research has been conducted on minerals aggregating with spilled oil, larger organic aggregates, such as marine snow, have only recently been studied as a transport mechanism. This knowledge gap in understanding the fate of oil was highlighted following the Deepwater Horizon (DWH) blowout in the Gulf of Mexico (2010) when a significant percentage of the spilled oil was observed sinking to the seafloor as a result of association with marine snow. Research following the DWH blowout suggests both marine snow and mineral sediment are significant pathways that must be considered during an oil spill response. The U.S. Geological Survey and others have noted that an understanding of baseline marine snow conditions in areas of petroleum exploration and extraction is urgently needed. In the summer of 2018 and in January 2019, sinking particles were collected with a surface-tethered sediment trap in eastern Cook Inlet. The summer particle mass flux ranged from 30 to 220 g m-2 day-1. The particle composition ranged from 19 to 38% organic with little variation between three main sites. The data collected, in addition to local knowledge, was used to develop a procedure for laboratory scale roller table experiments which simulate surface oil and particle interaction. These experiments will be conducted May through August 2019 and paired with sediment trap data to quantify the potential for oil to sink via particle association. This presentation will summarize findings from field and laboratory work, and include a discussion on the relevance of this research to oil spill response decision-making in a larger context.
Angela Sarni, Ocean Engineering
Resolving the Role of the Dynamic Pressure in the Burial, Exposure, Scour, and Mobility of Underwater Munitions
Military testing and training around the United States has resulted in over 10 million acres of property in underwater environments, potentially containing military weapons. The weapons, or munitions, are difficult to locate, capable of sudden movement, and a danger to marine life and the public. Improved understanding of their mobility in underwater environments is vital for safe and cost-effective munition recovery. A pressure-mapped model munition (PMM) was designed and fabricated to resolve the role of dynamic pressure gradients on munition mobility. The PMM is an untethered instrument, containing all electronics necessary to retrieve, time, and store data. The PMM is capable of detecting and measuring surface pressure gradients, orientation and positional changes, and uses an acoustic tracker for retrieval after deployments.
The surface pressure mapping was accomplished using an array of sixteen 3mm-diameter, diaphragm pressure sensors. Orientation changes were recorded using an Inertial Measurement Unit (IMU). All data is stored to an on-board microSD card and recorded with time stamps. The PMM was evaluated through several full-scale laboratory and field experiments to determine its accuracy in detecting hydrostatic pressure changes, orientation changes, passing waves, and environmental changes, such as being submerged in a sand bed. The PMM was able to resolve both the overlying progressive wave signal as well as the deviations due to vortex shedding around the cylinder. Improvements in the original PMM design were implemented into a newly revised PMM 2.0. Further lab and field testing are underway to investigate the increased resolution of vortex shedding due to pressure gradients, and positional changes of the PMM. The results of this research suggest that vortex shedding may significantly contribute to the burial of free-standing objects. Additionally, these results can be more broadly applied to relationships between sediment and fluid structures.
Devin Thomas, Computer Science
New Tech for Old Problems: Building eDNA based solutions for species monitoring in Estuarine systems
Environmental DNA (eDNA), or DNA present in an environmental sample, is emerging as a powerful tool to detect species present in an ecosystem without having to actually capture and identify individual organisms. Fish, invertebrates, and other animals shed DNA through fragments of tissue, reproductive and waste products into the environment they live in. High throughput sequencing of DNA extracted from environmental samples can identify hundreds of plant and animal species at relatively low cost. These methods have the potential to transform monitoring and management of coastal systems, but we are really only beginning to understand how to effectively apply the technology to achieve useful, reproducible results. This talk will focus on emerging eDNA methods for coastal and estuarine monitoring, including potential management applications, examples of relevant research, and development of standardized methods. I will present examples from a pilot environmental eDNA monitoring program being implemented at several National Estuarine Research Reserve (NERR) sites in New England and Oregon, where metabarcoding and single-species PCR methods are applied to species detection with a focus on fish and crabs. Sampling is being conducted in coordination with traditional monitoring programs including seine surveys, fish ladder counts, crab trapping and plankton tows to allow direct comparison to traditional methods. A challenge in implementing eDNA monitoring is the interpretation and analysis of the results, I will discuss our bioinformatics approach, and efforts to provide accessible analysis tools for our end users.
Stephanie Gilooly, MS, Mechanical Engineering
Measurement of Dynamic Pressure Gradients on the Surface of Short Cylinders
Ben Gutzler, Ph.D. candidate, Biological Sciences
Follow your heart: using dataloggers to investigate behavior in freely-moving lobsters
Linas Kenter, Ph.D. candidate, Zoology
Strain evaluation of striped bass (Morone saxatilis) cultured at different salinities
Striped bass (Morone saxatilis) and their hybrids have been well studied and are widely cultured in freshwater ponds as food and gamefish. Recent industry expansion has generated an interest in strain-specific broodstock development for marine netpen and pond culture. In this effort, Atlantic and Gulf coast striped bass strains were cultured in recirculating aquaculture systems (RAS) at different salinities for up to two years and production and morphometric parameters (specific growth, feed conversion, fillet yield, condition factor and stripe patterns) were compared. Striped bass juveniles produced from wild-caught broodstock from rivers in Nova Scotia, Delaware, Virginia, North and South Carolina, Florida, Texas and a selected, domesticated strain were reared in triplicate fresh (0 ppt), brackish (5 ppt) and saltwater recirculating (30 ppt) systems at two separate aquaculture facilities. After one year of age, a subset of fish were implanted with passive integrated transponder (PIT) tags, combined into a larger, “common-garden”, saltwater, recirculating system and monitored over an additional year. Parental broodstock and cultured offspring were fin-clipped and genotyped to identify juvenile family origin. Final weights of fish after one and two years averaged approximately 0.5 and 2.5 kg, respectively and did not differ by water salinity. Growth rates and condition factors differed by strain, but condition factor was not correlated with fillet yield. Consistent with other studies, juvenile fish from South Carolina and Nova Scotia were found to be slow growing compared to migratory Atlantic and Gulf strains. Mixed model analyses showed that family, and family by strain interactions were significant, but accounted for less growth variance than strain alone. These results indicate that family-based selection by strain may be useful in striped bass broodstock development programs.
Logan Maxwell, MS, Wildlife Conservation and Biology
Fitness consequences of hybridization in Saltmarsh and Nelson's Sparrows
Michael Smith, MS, Ocean Engineering: Ocean Mapping
Analysis of the radiated sound field of deep water multibeam echo sounders (MBES) for return intensity calibration using an underwater hydrophone array
MBES are tools used to gather geophysical information on the seafloor and watercolumn which are important for feature detection, identifying gas seeps, and characterizing the seafloor, among others. At high frequencies (>100Khz), MBES can be calibrated for their ensonification patterns in test tanks. However, deep water MBES feature long transmit arrays and varying geometries that make tank calibration impractical. The transmit arrays can be over 8m and have a far field range in the hundreds of meters. In addition, these systems use beam steering techniques to segment the swath into multiple sectors to mitigate ship motions, which complicates the radiated pattern and return intensity. This study will better characterize the radiated sound field of deep water MBES for return intensity calibration. A MBES survey was conducted using a Kongsberg EM122 MBES on the SCORE range, a submerged broadband hydrophone array. Hydrophones were spaced ~5km apart and were continuously recording during the survey. The EM112 is a multisector dual swath system operated at 12 kHz with CW waves. Hydrophone data were analyzed and the resultant radiated sound field was determined at different distances and angles.
Shannon-Morgan Steele, MS, Ocean Engineering: Ocean Mapping
End-fire Synthetic Aperture Sonar: A new technique for seafloor sub-bottom studies
The deep sound penetration desired for many acoustic seafloor sub-bottom investigations restricts sonar operation to low frequencies, as higher frequencies are rapidly attenuated with depth. Low-frequency sonar systems are characterized by large beam widths (typically 30-40 degrees), which limit their angular resolution and thus, significantly diminish their ability to detect small-scale lateral variations of the sub-bottom. This talk will introduce end-fire synthetic aperture sonar (SAS), a new method for obtaining high-resolution measurements of the sub-bottom. End-fire SAS coherently combines multiple acoustic pings as the sonar moves through the water column, towards the seafloor, forming a narrow beam on the sediment that can be thought of as an “acoustic core”. This talk will discuss proof of concept for the end-fire SAS technique using results from simulations and the first end-fire SAS field experiments conducted this past winter.
Andrew Stevens, Ph.D. candidate, Computer Science (Best Oral Presentation for 2018!)
3D Habitat Analysis via Finite Element Modeling of Invasive Macroalgae
Outside environmental influences and invasive species are changing the makeup of ecosystems on the land and in the sea at an unprecedented rate. Right here off of the coast of New Hampshire and the Gulf of Maine, invasive macroalgae (also known as seaweeds) are rapidly displacing native species and in some areas completely transforming the seafloor habitat. We have developed a new analysis technique to measure and compare the 3D spatial architecture of seaweeds so that we may better understand the refuge spaces they can provide to small aquatic organisms. This information can then be used to predict changes in organism populations that rely upon these seaweeds for protection as invasive varieties crowd out native communities. Our analysis of three seaweed species models showed a high diversity of habitat within their 3D spatial structures, and by collecting field samples we have been able to validate our approach and demonstrate its viability. By further developing this new analysis technique, we can begin to model entire communities of seaweeds as they change over time to learn how they might affect the entire food chain in a marine ecosystem.
Gregory Gilbert Taylor-Power, MS, Mechanical Engineering
Experimental investigation of the turbulent wake generated by wind turbine models in a large boundary layer wind tunnel
Katherine Vera von Krusenstiern, MS, Oceanography
Predicting Bathymetric change in dynamic estuaries
Sediment transport is investigated at Hampton-Seabrook estuary, NH to evaluate the applicability of the Coupled-Ocean-Atmospheric-Waves and Sediment Transport (COAWST) numerical model to simulate the bathymetric change over annual timescales. The study area spans the near coastal region that includes the adjacent beaches and extensive back-bay channels extending inland for several kilometers. In this hindcast, the Regional Ocean Modeling System (ROMS) and the Community Sediment Transport Model (CSTM) are coupled within the COAWST to track the temporal stability of the seafloor. The model is forced by observed water levels at the seaward open boundary, and is verified with observations of sea surface elevation and vertical variation in currents at sensor locations, deployed in fall 2017. Model results are compared to an in situ bathymetric survey completed in fall 2016. Differences between the field and model simulated bathymetric change will be discussed in terms of hydrodynamic variations on spring-neap tidal cycles, specification of bottom boundary conditions, and sediment grain size distributions.
Hampton-Seabrook estuary is a vital economic, recreational, and ecological asset to New Hampshire. Due to the dynamic nature of the sediments, navigational channels and harbors are dredged regularly from infill of sediments by the Army Corp of Engineers. Numerical modeling offers a robust capability to predict morphologic change in dynamic environments and provides an important tool for assessing coasting resilience to vulnerable shorelines. This work is supported by the National Ocean and Atmospheric Association and the Office of Naval Research.
Wilton Burns, MS, Earth Sciences
Effects of small-scale turbulence on phytoplankton growth and metabolism.
Our current understanding of how turbulence affects small planktonic organisms is based on fluid dynamic theory, ocean models, and laboratory experiments that often have conflicting results. Atmospheric models predict that global temperature rise associated with climate change will affect turbulence patterns within the marine photic zone, where phytoplankton reside. To investigate how small-scale turbulence affects growth (growth rates, cell counts and extracted chlorophyll, and nutrient quotas) and metabolism (production of transparent exopolymer particles (TEP)) of marine primary producers, phytoplankton in monoculture and natural assemblages were incubated under a range of turbulent treatments. Results indicate that early in exponential growth of the monocultures, cell-specific TEP was higher with increased turbulence. During mid- and late exponential growth, there were no measurable differences in phytoplankton growth and TEP production as a function of turbulence. However, nutrient quotas were higher in the more turbulent tanks in phytoplankton cells >15 µm in length. Data from this study suggest that changes in turbulence in marine photic zones could result in increased nutrient storage in larger phytoplankton cells, as predicted by numerical models, but may not greatly affect the global carbon cycle via changes in TEP production.
Melissa Gloekler, MS
Movement and Erosion of Alberta Bitumen along the Bottom as a Function of Temperature, Water Velocity and Salinity
While many trajectory models exist to predict the movement of oil floating in or on water, few are designed to address heavy oil on the bottom of water bodies. In addition, remobilization (erosion) of the material into the water column is also difficult to predict. While properties such as adhesion, viscosity and density of oil may be readily measured, the critical shear stress (CSS) and the effect of (current) velocity, salinity, and temperature are virtually unknown for most heavy oils. The Center for Spills and Environmental Hazards (CSE) has a 4,000 L annular flume, with a water depth of 0.43 m. An inner rectangular flume (1.2 m length, 0.2m width, 0.9 m height), placed inside the annular flume, was preceded by two flow straighteners to reduced turbulence and produce a uniform, one dimensional flow field. The current is generated by an electric thrust motor and measured in 3D by a Nortek AS (Norway) Vectrino II Profiling Velocimeter. A 20g circle of Alberta bitumen (SG = 0.998) was placed on a laminated grid (1cm2 square pattern) at the bottom of the straight flume. A total of 2.3m3 of water was then gradually added to the flume. The electric motor was started and the profiler began collecting data. Two cameras, placed along the side and above the oil, collected video of the erosions and length/width changes of the oil. Conditions were held steady for one hour once the desired current velocity was achieved. Temperatures, current velocity (X, Y, Z), and digital videographic data were collected during each run. Erosions and percent lengthening of the oil was monitored as a function of water temperature, salinity and velocity. The turbulent kinetic energy (TKE) method was used to calculate the bed shear stress (BSS). In addition to the expected impact of higher temperature on the movement along the bed and erosion into the water column, the viscoelastic and shear-thinning properties of the bitumen played a role in its behavior (lowering of viscosity at higher BSS slowing erosions and movement) and must be considered when predicting its behavior during a spill.
Meghan Hartwick, PhD candidate, Molecular, Cellular, and Biomedical Sciences
Estimating Seasonal Variation of Vibrio parahaemolyticus concentrations in Oysters from the Great Bay Estuary
The recent emergence of Vibrio parahaemolyticus disease in the Northeast US is a challenge for public health safety, resource management and industry regulation. Most V. parahaemolyticus strains are believed to be non-pathogenic and those that do cause disease are contracted from the consumption of raw or undercooked seafood and shellfish from warm water environments. It is believed that co-occurring climate change associated environmental trends may be an underlying factor behind this new disease pattern. Surveillance of V. parahaemolyticus concentrations and coincident environmental conditions in the Great Bay Estuary has produced a long-term data set that can be applied to identify to conditions that may contribute to V. parahaemolyticus population dynamics in this region. Non-linear, temporal and multivariate analysis were applied to environmental and climatic data to determine that surface water temperature, average pH, average chlorophyll a, maximum turbidity and salinity were key variables to estimate V. parahaemolyticus concentration in oysters from the GBE. Focused studies into plankton dynamics suggest season specific plankton communities that are significantly associated with the variation that is observed in V. parahaemolyticus populations in oysters. The application of these results provides the basis to characterize ecological relationships for V. parahaemolyticus in this region and will be used to develop forecasting models of risk conditions for industry, shellfish resource managers and public health agencies in the Northeast.
Joshua Humberston, PhD candidate, Earth Sciences
Estimating surficial seafloor mud fraction in the tidally dominated Little Bay using principal component analysis of acoustic backscatter envelope properties
Field observations from an Odom Echotrac vertical-incidence 200 kHz echosounder were used to estimate seafloor mud fraction (fractional sediment size distribution less than 62.5 mm) in a tidally-dominated estuary with sediment distribution ranging 0–78% mud. Observations were obtained in water depths ranging 0.5–24 m in the Little Bay, New Hampshire. Backscatter waveform envelopes associated with the first acoustic interaction with the seafloor were analyzed and defined by seven properties: maximum and mean intensity, waveform width, area, skewness, kurtosis, and leading edge rise time. The spatial variability in these properties were decomposed into orthogonal eigenvectors using standard principle component analysis. The spatial weighting of the first principal component (representing 95% of the variance) was compared to observed surficial mud fraction. A simple logarithmic curve fit to the data accounted for 41% of the variability and well estimated (13% RMS error) the spatial pattern of mud across the bay from deep channels (no mud) to the flats (high mud content). The calibrated logarithmic function is used to estimate mud fraction spanning the estuary. Systematic deviations from the model are associated with regions with lower sediment porosity. When these anomalous data are removed from the analysis, the logarithmic model accounts for 62% of the variance. Application of the model along two cross-estuary transects in the Great Bay (independent from model development) resulted in similar RMS errors (15%) in predicted mud fraction showing that the empirical model works well for the Great Bay region provided the same sonar and settings are used.
Christopher Hunt, PhD candidate, Natural Resources & Earth Systems Sciences
Coastal Alkalinity: What we know (and don’t know) about neutralizing Ocean Acidification
Ocean Acidification (OA) is a complex problem in coastal waters, affecting a variety of stakeholder groups (commercial, environmental, governmental) across a wide range of spatial and temporal scales. Assessing and projecting OA impacts is difficult given the contributions of several processes, a lack of recent historical baseline data in many areas, and the dynamic nature of the coastal environment. Alkalinity is the ocean's primary buffer against climate-driven acidification. While the alkalinity of the ocean has long been studied, the variability of alkalinity in the coastal zone and the processes affecting alkalinity have received less attention. However, new technological advancements coupled with improved understanding of the chemistry of alkaline species may offer new insights into buffering against OA. Researchers in the UNH Ocean Process Analysis Laboratory are currently conducting two projects examining coastal alkalinity across a variety of settings. This presentation will discuss the state of knowledge regarding coastal alkalinity, outline the approach of each OPAL project, present new data and maps, and synthesize how these projects will advance our understanding of coastal alkalinity and acidification.
Kara Koetje, MS, Ocean Engineering
Boundary Layer Dynamics in the Great Bay: Working Towards Resolving Estuarine Nutrient Fluxes
Quantifying the coupled physical and geochemical processes in the fluid-sediment interface is critical to managing coastal resources. This is of particular importance during times of enhanced hydrodynamic forcing where extreme tide or wind events can have a significant impact on water quality. A combination of field and laboratory experiments were used to examine the relationship between large-scale fluid shear stresses and geochemical fluxes at the fluid-sediment interface in the Great Bay Estuary, New Hampshire. Sediment geochemical measurements paired with flow field observations over several tidal cycles provide nutrient load estimates for the Bay. Sampling during typical tidal flow conditions along estuary-wide transects, an unexpected rotational flow field in the near-bed region of the water column was observed, which could have significant impact on the resultant nutrient release and nutrient budget estimates.
Meghan Owings, MS, Biological Sciences
Effects of the biomedical bleeding process on the behavior and physiology of the American horseshoe crab, Limulus polyphemus.
The hemolymph from the American horseshoe crab, Limulus polyphemus, is used to produce Limulus Amebocyte Lysate (LAL), which is used to test medical devices and vaccines for Gram-negative bacteria. This process has a 10-30% mortality rate, as well as several sublethal impacts. The goals of this study were to: 1) investigate the effects of the bleeding procedure on the behavior of horseshoe crabs in their natural environment and; 2) determine which bleeding process stressors (blood loss, air exposure, or increased temperature) have the most deleterious effects. For the field study, 14 control and 14 bled animals were fitted with ultrasonic transmitters and released into the Great Bay Estuary, and their depth preferences and locomotor activity were recorded from May-December of 2016. Lab experiments were conducted in outdoor tanks where animals were exposed to combinations of stressors. Accelerometers were attached to 64 animals to measure activity; and blood samples were repeatedly drawn to monitor hemocyanin levels. The telemetry study showed that control and bled animals exhibited similar activity patterns and seasonal migrations with females being slightly more impacted by the bleeding process in the first few weeks after they were released. In the lab, hemocyanin concentrations and activity were significantly impacted by different combinations of stressors, but not individual stressors. We hope that when this study is completed, the findings can be utilized to more sustainably bleed horseshoe crabs.
Lindsey Williams, PhD candidate, Natural Resources & Earth Systems Sciences
Information needs of coastal decision-makers and resource users: an exploration of information flow, timescale, and systems perspectives
Despite increasing calls to connect science with decision-makers, challenges remain in facilitating the flow of information across sectors. In some cases, these challenges stem from lack of resources or other capacity limitations, in others from a fundamental lack for awareness of what information is most needed by decision makers and how information flows between groups. In this study, we focus on the information needs and sources as reported by business and government decision makers in coastal New England. Through analysis of semi-structured interviews, we focus on what types of information needs are identified and what sources of information business and government decision-makers rely on for their jobs. Within these sectors, we also explore 1) the timescale of the information needs as context for understanding how the different sectors conceptualize the challenges they face, and 2) the systems scale as context for understanding conceptualization of the system within which they operate. If we are to meet the calls for management relevant science and science based decision-making, understanding these factors of information flow will be a key component.
Kaitlin Van Volkom, MS, Biological Sciences
Effects of introduced prey species on the growth and reproduction of the blood star, Henricia sanguinolenta
Henricia sanguinolenta is a native generalist predator that consumes sponges during the fall and spring months. Historically, in the summer and the fall months, these animals feed on detritus and filter particles from the water column. However, after the invasion of several tunicate species, these animals had the opportunity to feed on another prey species during the warmer months when food is less abundant. The goals of this study were to 1) monitor the percent cover of prey species throughout the year 2) determine sea star feeding patterns, and 3) evaluate the effect of diet on growth and reproduction. A field site was surveyed monthly to evaluate the percent cover of tunicate species, and instances of feeding were recorded. In a lab setting, sea stars were fed four different diets for six months. They were fed a combination of sponge and tunicate species that represented the historical and proposed current diet. They were weighed every two weeks, and at the end of the experiment the gonads and pyloric caeca were weighed.
Elizabeth Weidner, MS, Earth Sciences (Best Oral Presentation for 2017!)
Estimation of Marine Seep Flux on the East Siberian Arctic Shelf
An estimated 1400 gigatons of methane are held in subsea reservoirs on the shallow (<50 m average depth) Eastern Siberian Arctic Shelf (ESAS). Marine gas seeps and high methane concentrations in surface waters indicate these reservoirs are releasing methane via ebullition. Bubbles ebullated from the ESAS seafloor have a relatively short pathway through the water column and can facilitate the transport of methane directly to the atmosphere without oxidation. Methane seeps were mapped with a calibrated broadband split-beam echosounder on the ESAS in order to directly and quantitatively address the magnitude of methane flux and the fate of rising bubbles. Acoustic measurements were made over a broad range of frequencies (16 to 29 kHz), which allowed for very high range resolution and the identification of single bubbles in the water column. Seep bubble size distribution (BSD) were determined by exploiting bubble target strength models over the broad range of frequencies. By coupling BSD with bubble rise velocity measurements, made possible by split-beam target tracking, gas flux can be estimated.
Jessica Carloni, MS, Natural Resources, Wildlife Conservation & Biology
Identifying Foraging Locations of a Pelagic Seabird in Coastal New Hampshire
Joshua Carloni, MS, Zoology
Factors Influencing the Distribution of Ovigerous American Lobsters
Eric Doherty, MS, Ocean Engineering
The Memorial "Living Bridge" Project: Tidal Energy fron the Piscataqua River
Steve Eayrs, PhD candidate, Natural Resources & Environmental Studies
Facilitating Change in the New England Groundfish Fishery: Application of the Kotter Model for Organizational Change
This study applied organizational change management theories and principles to understand the appetite and attitudes of fishermen to change, including the Paradox of Fishermen. It also evaluated the efficacy of industry groups that serve to facilitate change on behalf of fishermen against the renowned Kotter model for organizational change, and it developed a new, comprehensive change management model to facilitate change in the New England groundfish fishery.
Sara Edquist, PhD candidate, Zoology
Spatial and Temporal Distribution of a Fish Parasite and its Intermediate Hosts in Great Bay Estuary
Ian Gagnon, MS, Mechanical Engineering
The UNH Living Bridge Tidal Energy Conversion System
A tidal energy conversion system was designed to power an array of smart infrastructure and estuarine sensors on Portsmouth, NH’s Memorial Bridge. The purpose of this tidal energy conversion system is to demonstrate an emerging renewable energy technology, serve as a research tool, and increase public interest in S.T.E.M. as well as the United States’ critical energy and transportation infrastructure. The tidal energy conversion system consists of a crossflow hydrokinetic turbine, a floating turbine deployment platform, and two vertical guideposts that provide a mooring point between the turbine deployment platform and one of the bridge’s piers. A resource assessment was performed to determine the available energy that could be converted from the tidal currents at the deployment site. An energy management system was simulated to determine the potential for providing continuous power to the sensors. Expected loads were calculated to ensure that the tidal energy conversion system would perform as expected under local gravitational, wind, wave, and tidal current loading. As a part of a senior design project, a 1:13 Froude scaled model of the tidal energy conversion system and bridge pier was constructed and tested in a tow/wave tank to experimentally verify these loads.
Onni Irish, MS, Earth Sciences (Best Oral Presentation for 2016!)
Analysis of CLCS Reccomendations in Light of their Relevance to the Delineation of a United States Extended Continental Shelf (ECS) in the Arctic
Article 76 of the United Nations Convention on the Law of the Sea provides a mechanism by which a coastal State can extend sovereign rights over resources of the seafloor and subsurface outside of its 200 nautical mile exclusive economic zone. In order for a coastal State to delineate this region, often referred to as the extended continental shelf (ECS), bathymetric, geophysical and geological data must be collected and analyzed to apply the mandates defined within Article 76. The coastal State must present its ECS delineation to a commission, called the Commission on the Limits of the Continental Shelf (CLCS). The CLCS reviews coastal States’ submissions and publishes recommendations as to whether they believe that the proposed ECS boundary is in accordance with Article 76. The United States has a potential ECS in the Chukchi Borderland region north of Alaska. This thesis examined two coastal States’ CLCS recommendations, the Kerguelen Plateau (Australia) and Vøring margin (Norway), to assess what criteria the CLCS utilized to classify seafloor highs, to forecast the impact these recommendations may have on a potential submission of the United States in the Chukchi Borderland region. This thesis has found that the CLCS requires a coastal State with seafloor highs that are connected to its continental margin to show that these features are (or not) morphologically and geologically continuous with the continental margin and landmass. If the coastal State can prove the seafloor high under question satisfies both of these criteria, it could potentially increase the coastal State’s final ECS outer boundary. Application of these criteria to the Chukchi Borderland region found that available data today could substantiate an argument that the Chukchi Borderland fulfills both criteria; however, further geological data needs to be collected from the northern extension of the Chukchi Borderland to support an Article 76 seafloor high classification.
Damian Manda, MS, Ocean Engineering
Autonomous Surface Vessel Developments for Hydrographic Survey
Maria Marin, MS, Oceanography
Observations of Surface Mixed Layer Variability in the Equatorial Pacific along the Coast of Ecuador
Melissa Melendez, PhD candidate, Oceanography
Local and Remote Forces Affecting the Carbonate Chemistry of Enrique Mid-shelf Reef at the Southwest Coast of Puerto Rico
Corey Sullivan, MS, Zoology
Design of an Integrated Multi-trophic Aquaculture Raft
John Turner, PhD candidate, Mechanical Engineering
Very Large Experimental Wind Farm Array
Offshore wind proposal and installment is growing at a fantastic rate. In these necessarily large wind farms located near densely populated coastal cities, the governing fluid dynamics is not completely understood. An experimental study of a large offshore wind farm array is being conducted at the UNH Flow Physics Facility to better understand the flow around these devices.
Meagan Wengrove, PhD candidate, Ocean Engineering
Mightily Mobile Morphology at a Mega-nourishment
Observations of wave orbital ripples and current driven mega-ripples at two cross shore locations within the sub-tidal area of a mega-nourishment were made as part of the MEGA-Perturbation EXperiment (MEGAPEX). MEGAPEX was an internationally collaborative field experiment that took place in the fall of 2014 at the Sand Engine mega-coastal nourishment in the Netherlands. Installed in 2011, the purpose of the 4.5 km alongshore and 700 m cross shore perturbation is to use currents to naturally nourish the southern Dutch coast for a period of 20 years. Over the past 4 years the Sand Engine has dramatically changed shape as seen in Fig. 1a (initial shape in 2011) and Fig. 1b (shape today) (Stive, et al. 2013). On the large scale, the mega-nourishment is very dynamic; raising the question of the dynamic nature of its small scale morphology. This research investigates the forcing mechanisms behind small scale temporal and spatial morphologic change of ripples at the tip of the Sand Engine. Morphologic patterns were observed with two stationary rotating pencil beam sonars with a 3 m diameter footprint positioned with a 100 m cross shore spacing, just seaward of the shoreline and just shoreward of the sub-tidal sandbar. Concomitant hydrodynamic forcing was measured using an array of ADVs and ADCPs. Measurements were collected over a month long period, capturing two significant coastal storms, one of which was the remnants of Hurricane Gonzolo. Two-dimensional spectral analysis determined ripple orientation, wave length, and height (Fig. 1c and 1d). Results show ripples changing orientation and regime between orbital and anorbital bed states as a function of hydrodynamic forcing, a rarely observed phenomenon in previous works. Ripple wave length varied between 14 cm and 1.2 m (Fig. 1c and 1d) dependent upon the phase of the tide, sometimes complete transformation took place within as little as 20 minutes. Finally, during the passing of the remnants of Hurricane Gonzolo, with a 5 m offshore wave height, ripple wave lengths of 2.5 m were observed within this relatively shallow nearshore area.
Peter Bachant, PhD candidate, Mechanical Engineering
Studies of Cross-Flow Turbines at Large Laboratory Scale in the UNH Tow Tank
Eric Bajor, MS, Mechanical Engineering
High-Frequency Broadband Seafloor Backscatter in a Sandy Estuarine Environment
Emily Carlson, MS, Ocean Engineering
Near Bed Coherent Structures and Rippled Sea Bed Evolution Due to Short Waves
Anna Chase, MS, Zoology
The Influence of Substrate Material on Marine Fouling Community Development
Salme Cook, PhD candidate, Oceanography
Simulating Hydrodynamics on Tidal Mudflats
Tobias Dewhurst, PhD candidate, Mechanical Engineering (Best Oral Presentation for 2015!)
Dynamics of a Submersible Mussel Raft
Robert Eckert, MS, Zoology
Spatial Patterns of Spat Density in Relation to Distance from Native Oyster Reefs in Great Bay Estuary, New Hampshire
Shelley Edmundson, PhD candidate, Zoology
Channeled Whelk Research
Fiat Eren, PhD candidate, Mechanical Engineering
Pose Detection of Unmanned Underwater Vehicles (UUVs) Utilizing an Optical Detector Array
Meg Hartwick, PhD candidate, Natural Resources & Earth Systems
Marine Microbiology, Vibrio Ecology and Population Dynamics in the Great Bay Estuary
Scott Loranger, PhD candidate, Oceanography
Acoustic Properties of Submerged Oil Droplets
Elizabeth Morrissey, MS, Zoology
Clash of the Crustaceans: Interactions Between Green Crabs and Lobsters in the Great Bay Estuary
Ashley Norton, PhD candidate, Earth and Environmental Sciences
Developing Acoustic Methods for Characterizing Eelgrass Beds in Great Bay