Honours Theses

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    Mid-to Late Holocene changes in the hydrographic conditions in the Baltic Sea, as inferred from dinoflagellate cysts assemblages
    (University of New Brunswick, 2017) Manley, Sander; Limoges, Audrey
    Dinocyst assemblages from marine sediments in the south-central Baltic Sea provide a record of changes in the Holocene Baltic Sea hydrographic system for the last 6000 years. A low diversity assemblage of four genera of autotrophic dinocysts is observed throughout, dominated by the species Operculodinium centrocarpum. Dinocyst assemblages, especially process length variation in O.centrocarpum are used to interpret qualitative paleosalinity. The Littorina Transgression, a period of increasing salinity was already underway in the eastern Gotland Deep by 6000 years BP, and continued until 4750 years BP. The highest dinocyst concentrations were observed during Mid Holocene Warming 6000 - 4000 years BP. Littorina Sea A Phase (6000 - 4750 years BP) is defined by an inferred major increase in salinity. From 4750 - 1000 years BP, only minor changes in salinity are reflected in the dinocyst assemblage. From 4000 - 1000 years BP, stable, low concentrations of dinocysts are interpreted as a result of shorter blooming seasons during Neoglacial summers. Littorina Sea B Phase (4750- 1000 years BP) is defined by inferred minor fluctuations in salinity and stable concentrations of dinocysts throughout. Increased dinocyst abundance is observed from 1000 - 800 years BP before declining from 800 - 100 years BP to low concentrations (25 000 dinocysts/g sediment). This is interpreted as caused in part by longer, warmer summers during the Medieval Warm Period (MWP) and shorter, cooler summers during the Little Ice Age as well as increased nutrient runoff into the Baltic Sea from increased anthropogenic land use during the MWP. Dinocyst assemblages indicate gradually decreasing salinity from 1000 - 100 years BP. Late Littorina Sea B Phase (1000 - 100 years BP) is defined by an inferred minor decrease salinity and elevated concentrations of dinocysts during the MWP.
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    Change in occupancy and density of nesting Atlantic puffins and razorbills on Machias Seal Island between 2011 and 2019
    (University of New Brunswick, 2020) Elisseou, Meredyth; H. Major
    At Machias Seal Island (MSI), populations of nesting Atlantic Puffins (Fratercula arctica) and Razorbills (Alca torda) are stable and increasing (respectively). The purpose of my study was to determine whether the increasing Razorbill population has caused a change in the spatial distribution of nesting puffins on the island. I hypothesized that the larger, more competitive Razorbills outcompete puffins for nesting space, resulting in the movement of puffins to alternative regions of the island. Using data from Alcid surveys that occurred in 2011, 2015, 2016, and 2019, I assessed occupancy and density of puffins and Razorbills in each of 1,753 surveyed quadrats. Using generalized linear models in an information theoretic approach, I found no changes in occupancy or density of either species. However, I note the short timespan (eight years) covered in my study and suggest that continued monitoring and analysis of changes in puffin and Razorbill occupancy and density.
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    The genetic population structure of brown trout (Salmo trutta) and rainbow trout (Oncorhynchus mykiss) in New Brunswick river systems (New Brunswick, Canada)
    (University of New Brunswick, 2020) Watters-Gray, Jagger; Pavey, Scott
    Brown Trout (Salmo trutta) and Rainbow Trout (Oncorhynchus mykiss), native to Europe and western North America respectively, now populate New Brunswick rivers after their introduction in the 1900s. Studying the population genetics of these salmonids will help to understand how these introductions took place in New Brunswick and help inform management practices. The objective of this study was to analyze the mitochondrial DNA control region of Brown and Rainbow Trout to determine the genetic structuring of these species. One Brown Trout population revealed substantial genetic structuring; however, low genetic variation in other Brown Trout populations left any interpopulation reproductive interactions unresolved. Rainbow Trout genetic structure supported panmixia, besides two populations above a man-made barrier that displayed significant structuring. This study is the first to explore the population genetics of Brown and Rainbow Trout in New Brunswick, providing a foundation for future work on the genetic population structure of these species.
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    Determination of a link between the taxonomic relationship of Canadian medicinal plants and the exhibited antibiotic activity of their crude extracts
    (University of New Brunswick, 2019) Therrien, Julie K.; Gray, Christopher
    Chemotaxonomy is effective in determining the expected chemical compounds found in extracts from different organisms. However, this is time-consuming and costly, as it is based on purified fractions of a chemical extract. Utilizing biological activity data of extracts and relating it to the taxonomic relationship of plants may be a more effective approach. The aim of this study was to determine if a link exists between the taxonomic relationship of plants and the exhibited antibiotic activity of their extracts. The antibiotic activity of methanolic extracts of 90 plants were evaluated against eight microorganisms. Bioactivity profiles were created and analyzed, using two separate methods. It was found that the lowest taxonomic level that correlated with the bioactivity profiles of the extracts was family.
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    Contribution of variability in embryo development rate and status at hatch to the protracted hatch period of female American lobster Homarus americanus
    (University of New Brunswick, 2018) White, Lydia; Rochette, Rémy; Zou, Liwen
    Female American lobsters typically hatch their embryos over protracted hatch periods of 15-32 days. To investigate the mechanisms underlying this intra-brood variation in hatch time, I reared individual embryos from June to September 2017 at a constant temperature of 9°C, took photos of them at the beginning of the study and prior to hatch, and measured their eye size as a proxy of their development status. A multiple linear regression model explained 74% of the variability in hatch day, and indicated that embryos that hatcher earlier in the summer are (i) more developed come spring (44% of explained variance), (ii) less advanced in development (28%), and (iii) develop at a faster rate (27%). This study suggests that the process of hatching is not strictly associated with a particular role of the brooding female, but rather is perhaps mostly a function of processes or attributes of individual embryos.
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    Cultivation of endophytic fungi inhabiting Abies balsamea using two techniques: a comparative study
    (University of New Brunswick, 2018) Fitzherbert, Tyson; Gray, Christopher; Johnson, John
    Two cultivation techniques: leaf segment cultivation and dilution-series cultivation, were compared for recovery of endophytes from needles of Abies balsamea collected in Saint John, New Brunswick, Canada. Endophytes were cultured on 2% malt extract agar and morphology of the endophytic growth was used to aid identification of distinct isolates. Endophytes were isolated from A. balsamea needles using the leaf segment cultivation method at a frequency of 13%, all replicates of two distinct isolates. Endophytes were isolated form eight of 25 prepared isolation plates for the dilution-series method. All endophytic growth from the dilution-series method was single-celled yeast species, while the endophytic growth from the leaf segment method was exclusively filamentous fungal species; thus, dichotomy was seen between the two methods of isolation.
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    Ionoregulation in the cold: a possible barrier to freshwater colonization?
    (University of New Brunswick, 2018) Dougay, Brett; Speers-Roesch, Ben
    To test if ionoregulation in winter cold is a barrier to freshwater colonization at high latitudes in fishes, I investigated the ionoregulatory responses of euryhaline marine-adapted Mummichogs (Fundulus heteroclitus) and freshwater-adapted Banded killifish (Fundulus diaphanus) held in freshwater at 14°C and 0, 4, 14, and 28 days of exposure to winter temperature of 4°C. I predicted that the Banded killifish would be able to maintain their ionoregulation better then Mummichogs in the cold freshwater. I measured maximal activities of gill Na+-K+-ATPase and H+-ATPase, two key ionoregulatory enzymes, and plasma chloride concentrations as a measure of osmotic status. There were no significant differences between species and no effect of cold acclimation on plasma chloride or enzyme activities. The lack of ionoregulatory perturbation by winter cold in either species, especially the seawater-preferring mummichog, do not support the hypothesis that ionoregulation in winter is a barrier to freshwater colonization in fishes.
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    Isolation and identification of the bioactive natural product A-26771B from an endophytic Penicillium expansum isolate
    (University of New Brunswick, 2020) Forgrave, Kirstyn A.; Gray, Christopher
    Natural products are an important source of bioactive compounds and endophytic fungi derived from marine algae represent an under-investigated source of natural products. The objective of this research was to isolate and confirm that an extract from an endophytic Penicillium expansum contained the natural product A-26771B. The natural product was tentatively detected, using high-resolution electrospray ionization mass spectroscopy data, in a methanolic extract from the endophyte. Despite repeated rounds of high performance liquid chromatography and multiple fermentations of the endophyte, the compound was isolated in sub milligram quantities and identified using proton nuclear magnetic resonance data. However, prior to obtaining carbon nuclear magnetic resonance data that would confirm the identification of A-26771B the natural product degraded. Future work should include isolating more of the molecule A-26771B to determine the bioactivity of the molecule against Mycobacterium tuberculosis and Mycobacterium smegmatis.
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    Changes in body size of Atlantic Puffins at Machias Seal Island (MSI) from 1995-2019
    (University of New Brunswick, 2020) Georgantopoulos, Joy; Major, Heather
    Body size of fledging Atlantic Puffins (Fratercula arctica) at Machias Seal Island have been decreasing over the past 25 years (1995-2019) likely due to climate change. Using fledging size data archived in the Microsoft Access data base “seabird finder” I asked three questions: 1) have puffin fledgers gotten smaller in size (wing chord and mass) over the last 25 years, 2) can small fledgers continue to grow (in wing chord) after leaving the island, and 3) are adult Atlantic Puffins decreasing in size (wing chord). Using linear regressions, I found support for the hypothesis that fledgers are getting smaller with time and that small fledgers grow more after leaving the island than large fledgers. Finally, I found a marginally insignificant result suggesting that adult size is changing in response to fledging size (i.e., adults are becoming smaller with time).
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    An inside look at a professional modern dance company
    (University of New Brunswick, 2016) MacMillan, Marissa; Burns, Janet Mary Christine
    This thesis explores the experiences and collective activity of participants in the art world of Bodies in Motion, a local modern dance organization from Hartford, Chilton. This qualitative research uses Becker’s (1982) framework for studying social organizations, in conjunction with Unruh’s (1979) theory of social worlds and social types, to understand how participants create and maintain the functioning of their social world. The research followed a symbolic interactionist, theoretical approach, where data was collected through interviews and participant-observation. Through these techniques, eleven participants were asked about their experience with Bodies in Motion and the art sphere within Hartford. The research found that Becker’s framework and Unruh’s social types can help to determine the dynamics of social worlds.
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    A retrospective assessment of marine ecological research using optimal α
    (University of New Brunswick, 2020) Zhao, Chuhan; Houlahan, Jeff
    Null hypothesis significance testing (NHST) is and has been for many decades broadly applied across disciplines, NHST’s shortcomings have been identified and discussed since its introduction. Optimal alpha is a better method for setting statistical thresholds in NHST because it minimizes the overall probability of making errors. However, we don’t know how often using optimal α would result in a different conclusion than NHST. I calculate optimal α for 433 tests from 2009-2018 published marine biology papers and compare conclusions with NHST. I find totally 24 % of conflicting results (small ES: 22 %; medium ES: 22 %; large ES: 29 %). For disagreement, optimal alpha has 97 % significant results at small ES, 54% at medium and 24% at large. Low observed p value tends to have disagreement. These results mean that failing to use optimal alpha may be inflating the probability of making wrong conclusions in marine biology.
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    The effect of exhaustive exercise on the thermal tolerance of brook charr (Salvelinus fontinalis)
    (University of New Brunswick, 2020) Traynor, Emma Mary; Kieffer, James
    This study examined whether exercise influences acute thermal tolerance in brook charr (Salvelinus fontinalis). To address this, fish were assigned to one of 4 groups (i) control; (ii) 5-minute exhaustive exercise; (iii) thermal stress only; and (iv) 5-minute exhaustive exercise prior to thermal stress. Blood samples were also taken from the fish to measure stress parameters (plasma lactate and glucose) between the groups. Acute thermal tolerance, measured as the temperature where the fish lost equilibrium, were similar between fish exposed to thermal stress only and fish exposed to exercise prior to the thermal stress (30.2 ±0.5C and 29.6±0.8C, respectively). However, blood lactate and glucose were about 25% higher in charr exercised prior to the thermal stress (lactate 8.2 mmol/L and glucose 9.5mmol/L). These findings show that there are no differences in the thermal tolerance between groups, but there are additional physiological effects in fish exercised prior to thermal stress.
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    Effects of environmental conditions on egg-laying dates in Atlantic puffin Fratercula arctica
    (University of New Brunswick, 2019) Fana, Natalia; Major, H.L.; Whidden, S.E.
    Climate change trends may have an impact on the timing of seasonal activities, and in particular the phenology of Atlantic Puffins. The purpose of this study was to investigate if changes in environmental conditions, such as Sea Surface Temperature (SST), are responsible for the observed delay in egg laying at Machias Seal Island (MSI), New Brunswick. I used monthly means for SST and egg laying dates over a period of 24 years (1995-2018) from MSI. I used general linear models in an AICc framework and found a positive relationship between egg laying dates and SST over time. I suggest continued long-term monitoring to assess future changes and the puffin’s ability to continue to adapt to those changes.
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    Identification and DNA taxonomic analysis of a library of endophytic fungi
    (University of New Brunswick, 2019) Stack, Ryleigh A.; Gray, Christopher; Johnson, John
    Endophytes represent a largely untapped source of natural products. Despite a growing body of research, data and knowledge relating to endophyte biology and chemistry, one of the difficulties in endophyte research remains the accurate identification of endophytes. The advancements and development of molecular methods have provided researchers with tools that allow them to obtain an identification based on the endophyte’s DNA sequence, rather than its morphological and/or phenotypic characteristics. In the present study, the DNA extracted from 155 endophytes was analyzed following a DNA taxonomy methodology and compiled to give phylogenetic trees to obtain identifications based on the molecular properties of the endophytes, rather than their morphology. Of the 155 endophytes; 57 were identified to the species level, 65 to genus, 5 to class, 2 to subdivision, 10 to order, 15 to family, and 1 to subclass.
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    The effects of temperature on food consumption, growth rate, and somatic indices in the winter-dormant cunner (Tautogolabrus adspersus)
    (University of New Brunswick, 2020) Watson, Melina; Speers-Roesch, Ben
    As fish are ectotherms, temperature is an important environmental factor, making the cold and poor food availability of winter a critical constraint. Winter dormancy (sheltering, inactive state involving reduced or no feeding) can be a strategy utilized to survive winter. I investigated a winter-dormant fish, the cunner (Tautogolabrus adspersus), to test the hypothesis that fasting is an obligate behavior of dormancy. I predicted that cunner exposed to temperatures below the dormancy threshold (~7.3°C) will have a higher thermal sensitivity to food consumption than those held above the threshold. I recorded the daily food consumption and growth rate in cunner over 28 days at several seasonal temperatures (15°C, 12°C, 9°C, 6°C, and 3°C). Even when food was available below the dormancy threshold, cunner did not feed or fed at an extremely low level, which constrained growth at approximately 9°C. Thus, appetite and growth are greatly, or even completely, suppressed during dormancy.
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    Influence of mineralogical composition and texture on induced polarization effects in gold-bearing rocks from the Hebert-Brent Showing, Yellowknife Greenstone Belt, Northwest Territories
    (University of New Brunswick, 2017) Richardson, Mark; Butler, Karl; Lentz, David
    In June 2015, geological mapping discovered significant concentrations of gold in the Hebert-Brent (HB) Showing situated within an 11 m-wide highly sulphidized sericite-ankerite schist shear zone, hosted in a 10-15 m-wide, quartz-feldspar porphyry. The HB gold showing is located within the Barney Deformation Corridor of the Yellowknife Greenstone Belt (YGB), Northwest Territories. On July 29th, 2016, two 400 m long IP/resistivity surveys, with 5/10 m electrode spacing were acquired using a multi-gradient array. The survey identified zones of high IP response (chargeability) where expected, in areas of known disseminated sulphide mineralization. In addition, the IP survey exposed a previously undiscovered anomalous IP source. In this study, a prototype two electrode laboratory apparatus was used to investigate factors influencing electrical resistivity and IP effects in selected mineralized and non-mineralized rocks from the survey area. The study revealed information that may be utilized in future geophysical exploration in this area. It was determined that samples from Hebert-Brent are generally less resistive than non-mineralized rocks within this area. However, as a consequence of preferential alignment of silicate layers with foliation, anisotropic effects should be anticipated in this area. The IP response of the mineralized samples was in general greater in magnitude than the non-mineralized samples. It was also determined that there are some IP effects related to highly resistive, non-mineralized rocks in this area. These anomalous IP effects are likely a result of some uncertainty in the measurement apparatus. Normalizing the PFE IP effect by resistivity served to make the mineralized samples standout from highly resistive ones that also exhibited elevated IP responses. Comparison of mineralized and non-mineralized spectral curves were shown to be characteristically different. In addition, the peak phase angle between 0.1 - 10 Hz was found to correlate with increased percent frequency effect. It is recommended that surveys which sense the conductivity of an ore body should be used to aid in delineating massive and electrically conductive parts of a sulphide body. In addition, it is recommended that future IP and resistivity surveys in the area use a measurement of IP effect normalized by resistivity (such as the Metal Factor; MF) to highlight anomalous bodies that are prospective for elevated sulphide (and associated gold) content. Based on the findings in this study, spectral induced polarization (SIP) surveying may aid in identifying mineralized rocks in HB, as the phase maximum (between 0.1 and 10 Hz) is in general greater than that of the non-mineralized country rocks. Testing of the two electrode apparatus was shown to provide accurate and repeatable measurements on both the mineralized and non-mineralized rocks used in this study. However, more testing of the measurement apparatus is recommended to assess its reliability for very highly resistive samples.
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    Grimm origins: Fairy tale intertexts in Margaret Atwood's short fiction and poetry
    (University of New Brunswick, 2018) Cormier, Kayla; Maier, Sarah; Creelman, David
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    Does land-use affect bird abundance?
    (University of New Brunswick, 2019) Prosser, Jacob; Houlahan, Jeff
    Over the last 50 years many species have seen negative population trends and scientists have identified habitat loss, change, and fragmentation as possible causes. I investigated the ability of random forest and boosted trees models to predict bird abundances based on land-use throughout the United States. Bird abundance data was acquired from the North American Breed Bird Survey (BBS) and land-use data was gathered by the Multi-Resolution Land Characteristics (MRLC) consortium. The models had a mixed transferability between the training and test data with 14 of 21 models better fit the training data. The models were mixed in their ability to accurately predict abundances based on land-use compared to the mean; 14 of 21 models more accuracy predict abundance compared to the mean suggesting an effect of land-use on abundance. Six models were classified as “good,” 11 as “cautious,” and 4 as “poor.”