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Relating eDNA concentrations to Brook Trout abundance and biomass across varying spatial scales in Northern Ontario streams
Get PDFEnvironmental DNA (eDNA) detection has been proposed as a potential method for
determining the presence, abundance, and biomass of species within aquatic habitats. However, it
is unclear what spatial scale(s) eDNA detections represent in lotic systems due to uncertainties
surrounding its production and persistence. This study had two objectives: (1) to determine at
what spatial scale(s) (length of stream segments) could eDNA concentration be related to the
abundance and/or biomass of Brook Trout (Salvelinus fontinalis), and (2) to determine if the
relationship between eDNA concentration and Brook Trout abundance/biomass could be
improved by accounting for the contribution of eDNA originating upstream of investigated
stream segments. Concentrations of eDNA were related to the abundance of Brook Trout at the
25m (R2 = 0.22), 50m (R2 = 0.18), and 100m (R2 = 0.42) spatial scales, and to the biomass of
Brook Trout at the 25m spatial scale (R2 = 0.06), suggesting that eDNA concentrations can
represent Brook Trout abundance across numerous spatial scales. Variability observed in these
relationships across spatial scales was likely due to (1) the presumably heterogeneous distribution
of Brook Trout within stream segments causing different concentrations of eDNA to be detected
for similar abundances and biomasses, and (2) the contribution of eDNA from upstream of
examined stream segments to the detected eDNA concentrations. Concentrations of eDNA were
calibrated to 25m stream segments by accounting for the contribution of upstream eDNA
assuming either the constant or conditional deposition of eDNA. Both calibration methods
improved the relation of eDNA concentrations to the abundance and biomass of Brook Trout
within the 25m segments (abundance, R2 = 0.327 and R2 = 0.336 for constant and conditional
calibration respectively). However, both methods incorrectly estimated the persistence and
contribution of upstream eDNA on occasion, suggesting that additional investigation is required
before these methods can be reliably and confidently implemented to assess the abundance and
biomass of Brook Trout in lotic environments
Geochemistry and paragenesis of magnetite bearing gabbros from the Mine Block Intrusion at Lac des Iles Mine, Northern Ontario
Get PDFThe Mine Block Intrusion (MBI) is a 3 km by 1.5 km tear-shaped mafic complex that was emplaced along with
other mafic-ultramafic plutonic rocks of the South Lac des Iles Complex (LDIC) between 2,699 and 2,686 Ma
in the Marmion terrane of the Superior Province. The MBI consists of gabbronorite and magnetite-rich
gabbronorite, and a later series of noritic rocks and their metamorphosed altered equivalents.
Major element data of the MBI indicate that the rocks have a broadly gabbroic composition with protoliths
dominated by plagioclase, a predominance of orthopyroxenes over clinopyroxene, and titano-magnetite, which
is consistent with the petrographic observations. Magnetite gabbronorite rocks in the MBI were derived from
a metasomatized mantle, consistent with the arc setting proposed for the Lac des Iles Complex as a whole.
Plagioclase compositions decrease up the analyzed section, with no sharp change, suggesting a normal
fractionation process with no magma injection events. Plagioclase identified within the magnetite gabbronorite
of the MBI is labradorite-bytownite (An-number ranging from 0.58 to 0.75), which is less evolved than observed
in layered intrusions globally suggesting that saturation of Fe-Ti oxides occurred at an early stage of
differentiation compared with other mafic intrusions. [...
The relationship between multifaceted diversity and functioning of Canadian forests under global environmental change
Get PDFHuman activities have caused biodiversity simplification at local and global scales and raised
concerns about potential effects on ecosystem functions and biodiversity conservation. In the
past decades, there have been increasing efforts to better understand the relationships between
biodiversity (loss) and ecosystem functions, mainly primary productivity, carbon storage, and
temporal stability of productivity. However, there remain important aspects that are still debated
and understudied. Under the ongoing global environmental change, herein, (i) I reviewed and
examined the predictors, drivers and mechanisms of forest background and acute tree mortality
under global environmental change and particularly the interactions between drivers within and
between two mortality modes; (ii) I tested the relationships between multifacet diversity
(functional, phylogenetic and taxonomic) and biomass and stem mortality rates as well as the
underlying mechanisms including biotic damage, stand density index and size inequality in
natural forests, in British Columbia, Canada; (iii) I mechanistically studied the relationship
between multifacet diversity relationship with temporal stability of productivity in natural
temperate and boreal forests across Canada. [...
Complete oxidation of trans-4-pentylcyclohexanecarboxylic acid by catalytic ozonation using Cu-Mg bi-metallic catalysts
Get PDFThis thesis studied the use of a bi-metallic Cu and Mg catalyst dispersed on γ-Al2O3 for the
complete oxidation of a naphthenic acid (NA) model compound, trans-4-
pentylcyclohexanecarboxylic acid (4PCH) by ozone. Mono-metallic Cu and Mg, and bimetallic Cu-Mg catalysts were tested for the ozonation of 4PCH. The catalysts were
characterized by ICP-OES, BET, SEM, TEM, XRD, NH3-TPD and XPS. It was found that
bi-metallic catalysts with high amount of surface hydroxyl groups and with pHpzc close to
the pH of the solution at 8.5 were suitable for the mineralization of 4PCH. The catalyst with
1 and 5 wt% of Cu and Mg loading, respectively, had the highest activity with 90% total
organic carbon (TOC) removal at a dosage of 2 g/L in 120 min. The use of tert-butyl
alcohol (TBA) confirmed the involvement of OH•
radicals in the oxidation mechanism of
4PCH. Mg fine-tuned the pHpzc of the catalyst and provided a high concentration of
neutrally charged surface hydroxyl groups to generate reactive oxygen species (ROS) to
break down 4PCH in the liquid bulk. Cu participated in the complete oxidation of smaller
carboxylic acid molecules through complexation and surface reactions with adsorbed ROS.
The by-products of the oxidation of 4PCH were identified and a reaction network was
proposed based on a meta-addition mechanism. The most active catalyst retained its TOC
removal over 5 reusability cycles with an average Cu, Mg, and Al leaching of 0.07, 1.30
mg/L, and 0.2, respectively. The best performing catalyst was also proven effective for the
complete oxidation of a mixture of 4 NA model compounds with an electric energy per
order of 78.1 kWh/m3
Does acute heat stress modulate human milk production in lactating postpartum women?
Get PDFIntroduction: With rising ambient temperatures globally, heat-vulnerable populations are at greater risk
of negative health consequences. Of increasing concern is the potential impact on human milk production
and potential subsequent infant growth and development in our warming climate. While evidence in
animals suggests a negative impact on milk production during periods of heat stress, whether acute heat
stress modulates human milk production in postpartum mothers remains largely unexplored.
Method: Ten lactating postpartum mothers (32 ± 3 years, 24.6 ± 3.5 kg/m², 33 ± 11 weeks postpartum)
completed a 48-h experimental protocol whereby 24-h lactation performance was assessed before and
after a one-hour passive heat stress intervention using a water-perfused suit at 49°C. Throughout the 48-h
intervention, mothers recorded their lactation performance as human milk production using a baby scale
accurate to +/- 2 grams, fluid intake, and wore a FitBit Charge5 to monitor activity levels. Heart rate,
blood pressure, and oral temperature were recorded before the intervention, immediately before and after
the acute passive heating, and at the end of the intervention. Whole-body sweat losses were measured
during the acute passive heat stress.
Results: Passive heat stress resulted in 343mL± 190g of whole-body sweat losses, and increased heart
rate (+12±5 BPM, p<0.0001) and oral temperature (+0.4 ± 0.2°C, p=0.021). 24-h human milk volume
was not different after (335 ± 156mL) compared to before passive heating (333 ± 118 mL) and did not
alter milk production (p=0.921). Additionally, participants consumed more fluid during the 24h after
(1565 ± 70ml) compared to before (1325± 190ml, p=0.005).
Conclusion: Acute whole-body heat stress does not significantly affect the 24-hour human milk
production in breastfeeding mothers likely due to increase fluid intake
Awakening Ontario educators to treaty stories: exploring the possibilities of disruptive treaty scripting as professional development
Get PDFI need to tell you a story. My name is Denise Petitpas and I am a French-Canadian,
Ontario school teacher. Specifically, I am Franco-Ontarian, and my surname Petitpas, comes
from one of the first forty families to settle and establish the New France
colony in present-day Nova Scotia. I am also a descendant of Marie-Thérèze,
a Mi’kmaw woman censused alongside my 7th great-grandfather Claude
Petitpas II, the 30th family of the Sauvages de Mouscadoubet in 1708 Acadia
(see Appendix A) (Petitpas, n.d). My family knows this genealogy and more
from colonial documents and missionary accounts that my distant relatives,
such as my 6th great-grandfather, Bathélemy le sauvage, Claude and MarieThérèze’s son, had extensive knowledge of the Land, its peoples, Indigenous languages, along
with French and English. My ancestors served as interpreters and navigators to the new arrivals.
As Darryl Leroux’s research has shown (IndigenousStudiesUSask, 2015, 17:28), like many
French-Canadians, I descend from a distant Indigenous grandmother. And this is a story I used to
tell.
Fast forward this story 400 years to today. After generations of exile, persecutions, and
inter-marriages (Petitpas, n.d) out of Indigeneity, only the French language and culture have
survived in me. Through a series of complex “colonial happenings” (Madden, 2019, p. 286), I
am not connected to the land (Mi’kma’ki), the people (L’nu), or the language (Mi’kmawi’simk)
of my distant ancestors. Cree Elder Willie Ermine (Sturgeon Lake First Nation) is right; I am
poor, my memory has been erased, and I need an awakening (NCCIE, 2019, 3:05-4:25). [...
Impact of urbanization on McVicar Creek, Thunder Bay
Get PDFUrbanization has significantly altered natural ecosystems, particularly impacting
waterbodies like streams and creeks. In Thunder Bay, Ontario, the urbanization of McVicar
Creek has led to increased impermeable surfaces and reduced riparian shading, resulting in
changes to stream characteristics and water temperature dynamics. This thesis investigates the
adverse effects of urbanization on McVicar Creek, with a focus on water temperature variations
as a key indicator. Through the collection and analysis of water temperature data from urban and
non-urban study sites, this research aims to assess the impact of urbanization on stream thermal
regimes.
Results indicate elevated water temperatures in urbanized segments of McVicar Creek
compared to rural areas, suggesting the influence of an urban heat island within the city of
Thunder Bay. Additionally, the study reveals significant differences in stream depth and width
between urban and non-urban sites, highlighting the morphological alterations induced by
urbanization. These findings underscore the importance of stream restoration projects and long-
term monitoring to mitigate the adverse effects of urbanization on stream ecosystems. By
understanding the impacts of urbanization on waterbodies, policymakers and environmental
managers can develop effective strategies to protect and rehabilitate urban streams, ensuring the
health and sustainability of aquatic ecosystems in urban environments
Identifying significant groundwater recharge areas and modelling surface and subsurface water balance of the Neebing River
Get PDFThis study provides a hydrological function assessment of the Neebing River, a stream that starts
in a rural context and transitions to an urban environment that has historically been prone to flooding.
Hydrological function assessments have been widely used across the globe, but there is limited
information on many rivers in northern Ontario's watersheds. Previous hydrological function assessments
provide a basis upon which to develop models based on thematic mapping, surface water and
groundwater interactions and isotope sampling to enable the mapping of significant groundwater
recharge areas (SGRA) in the Neebing watershed. Infiltration rates were modelled based on available
topographic, soil and land use data sets. Statistical analyses of climatological and hydrological variables
were used to examine surface-subsurface water interactions on a seasonal and annual scale. Stable
isotope sampling was used to investigate groundwater-surface water interactions in some detail. Results
of the study show that the Neebing River is highly dependent on the contribution of groundwater to
streamflow, especially during dry periods and during the winter. The flow dependency on groundwater
highlights the relationship between the Neebing River and the SGRAs within its watershed. The present
study advances knowledge of the hydrological function of the Neebing River and provides baseline data
for future studies of the impacts of climate change and urbanization on this watershed
From Manomin to ‘Wild’ Rice and Back Again: Understanding the Transformations of a Native Ontario Grain and Indigenous Cultural Resurgence
Get PDFManomin (also called manoomin) is a native Canadian grain (Zizania palustris) that was the main carbohydrate food for many Indigenous people in Ontario for many generations and over a million pounds were harvested per year in the 20th century. However, changes to the landscape, especially the construction of dams, have destroyed much of the habitat of this plant. This project is a knowledge synthesis of the archaeological evidence and ethnohistorical information about manomin in Ontario, along with an introduction to the cultural traditions and local histories of partner First Nations. It serves as a starting point for further investigations into the relationship between people and manomin in Ontario. The main applied conclusion was that water level management in Ontario needs to include Indigenous governance for the support of manomin growth. This report was funded by the Social Sciences and Humanities Research Council of Canada and conducted in in partnership with Obishikokaang (Lac Seul First Nation) and members of Alderville First Nation in Ontario.Social Sciences and Humanities Research Council in partnership with Canadian Heritag
The relationship between sex, gender, and workplace accommodations among workers with mental health disorders
Get PDFIn 2022, over 5 million Canadians (18%) reported having a mood, anxiety, or substance
use disorder over the last 12 months (Stephenson, 2023). These disorders can be attributed to
environmental, physiological, genetic, chemical, and social influences. Globally, mental health
disorders have been projected to cost the economy $16.1 trillion USD in lost productivity
between 2010 and 2030, while also being a main contributor to noncommunicable disabilityadjusted life years lost (Bloom et al., 2011). These economic costs underestimate the full extent
of the human suffering experienced by individuals and their families due to mental illness.
Workplace accommodations are essential to support individuals with mental health
disorders. Almost 40% of employees aged 25-64 with mental health and/or physical disabilities
require workplace accommodations. Of these, women have a higher unmet need for
accommodations than men, in addition to requiring more accommodations than men (Morris,
2019). Accommodations for mental health disorders are critical in helping employees cope with
transient or temporary mental health issues, resulting in longer job tenure, being able to work
more hours, and remain employed (Chow, Cichocki, & Croft, 2014; McDowell & Fossey, 2015;
Zafar, Rotenberg, & Rudnick, 2019). These accommodations often include flexible work
arrangements, job duty modifications, job coaching, feedback from supervisors, and gradual
return to work (Bastien & Corbière, 2019; Corbière, Villotti, Lecomte, Bond, & Goldner, 2014;
McDowell & Fossey, 2015; Villotti et al., 2017; Zafar et al., 2019). [...