The Expedition

Determining the species distribution of Mytilus edulis, M. galloprovincialis, and M. trossulus across different vendors in the Greater Vancouver area in British Columbia

Ryan Almhjell, Aron Engelhard, Peter Xin — Mon, 12 Jun 2023 00:00:00 -0700

This study aims to determine the species distribution of mussels across different vendors
in the Greater Vancouver area in British Columbia. To evaluate such distribution, a cohort of 15
individual mussels were gathered from 5 vendors and screened for a genetic barcode that
corresponds to different variants in one of their adhesive protein genes. The test consisted of the
isolation of mussel DNA and subsequent polymerase chain reaction (PCR) amplification to
obtain amplicons of different sizes that can be attributed to a given species. Our results indicate
that 11 of 15 samples could be successfully identified as either M. trosullus, M. galloprovincialis
or M. edulis and that the invasive species M. galloprovincialis was the most abundant with 47%
of confirmed individuals. M. trossulus is the only endemic species to the coast of BC with 20%
in abundance.

The Effects of Cobalt Sulfate on Tetrahymena Thermophila Population Growth Rates

Ethan Cheng, Anderson Kuo, Bryn Murphy, Lauren Rutherford — Mon, 12 Jun 2023 00:00:00 -0700

Tetrahymena thermophila is a unicellular eukaryote found in freshwater habitats.
Substances released via anthropogenic activity can have detrimental effects on aquatic species
such as T. thermophila. Specifically, in British Columbia, there are several copper mines that
release cobalt as a major by-product. Cobalt sulfate, a heavy metal, enters the water and binds to
sediment, resulting in harmful effects on aquatic ecosystems. To study these effects on aquatic
organisms, T. thermophila was exposed to three different concentrations of cobalt sulfate (0
mg/L, 9 mg/L, and 11 mg/L). Cell counts were taken after exposure to cobalt sulfate for 1.5, 3.5,
5.5, 7.5, 24, 26.5, and 28.5 hours and were used to determine cell growth rates (cells/mL/hour)
over 28.5 hours. A One-Way ANOVA test was performed, leading us to reject the null
hypothesis that none of the control nor treatment groups are different from each other. Using the
Tukey-Kramer test, it was found that the 11 mg/L treatment was significantly different from the
0 mg/L treatment. Instead of having a negative effect on cell growth rates, the data support the
idea that increasing concentrations might have been beneficial to T. thermophila cell growth.
However, there are many limitations to our study, thus, further research needs to be conducted to
solidify whether cobalt sulfate is beneficial or detrimental towards T. thermophila.

Eggmosis: Effects of Egg Membrane Permeability on Egg Mass

Gurleen Jammu, Aditi Katyal, Chanpreet Khangura, Aimen Sajid — Mon, 12 Jun 2023 00:00:00 -0700

Osmosis plays a crucial role in multiple aspects of our lives, from digestion to the way we
respond to medications. Osmosis relies on the selectively permeable property of cell
membranes, which allow certain ions and molecules to enter the cell while inhibiting the entry
of others. We tested membrane permeability by exposing de-shelled eggs to different
concentrations of corn syrup (mainly composed of glucose) using an isosmotic, hypoosmotic,
and hyperosmotic solution. We weighed the eggs every 30 mins for 2 hours to generate the rate
of change in g/min for each replicate. The mean rates of change in mass of eggs exposed to the
isosmotic, hyperosmotic, and hypoosmotic solutions were 0.04g/min, -0.18g/min, and
0.090g/min respectively. A one-way ANOVA test and Post-hoc Tukey HSD test determined that
the differences in change of rate in mass (g/min) between the eggs exposed to different
treatments were statistically significant. Following two hours, the eggs exposed to the
hyperosmotic solution were the smallest, while those exposed to the hypoosmotic solution
were the largest. We, therefore, concluded that our hypothesis stating that the rate of change in
mass (g/min) of each de-shelled egg will be significantly affected by the concentration of
glucose solution to which they are exposed to was supported. In future studies, it is
recommended that other molecules are used in the extracellular environment and that the trial
times are extended in order to accurately determine the osmotic concentration inside the eggs.

Are high-end cat and dog food less likely to be mislabeled than low-end pet foods?

Moloud Mazaheri, Ting Gu, Kaileigh Bunting, Persephone Wong — Mon, 12 Jun 2023 00:00:00 -0700

With a pet food market value of 4.5 billion CAD in 2021 and over 16 million cats and
dogs collectively in households across the nation, pets are clearly central to the lives of many
Canadians. With this much monetary value and the clear compassion people have for their pets,
people have been rightfully outraged when multiple studies showed high percentages of
mislabeling of pet foods. While many studies have confirmed high rates of pet food fraud, less is
known about how rates of mislabeling vary with perceived food quality. Thus, using DNA
isolation, polymerase chain reaction (PCR), and gel electrophoresis techniques, this study
compares the rate of pet food mislabelling in high-end pet foods and low-end pet foods. Four
groups were tested with five samples each: High-end dog food, low-end dog food, high-end cat
food, and low-end cat food. We hypothesized that the rate of mislabelling would be significantly
lower in high-end pet food in comparison to low-end pet foods due to the perceived higher
quality of ingredients used in production. Results showed that mislabeling was pervasive in both
high and low-end foods, with more than 60% of foods mislabeled in each group. From lowest to
highest rates of mislabeling, results showed high-end dog food was the least mislabeled (60%),
followed by low-end dog food (80%), followed by high and low-end cat foods, which had the
same rate of mislabeling (100%).

The Effectiveness of Fruit Juices in Preventing Microbial Growth On Plain Bread

Chris Cai, Nikki Ebrahimi-Siaghi, Julie Wu — Mon, 12 Jun 2023 00:00:00 -0700

Food waste has developed into a global issue that plays a significant role, not only for the
economy but for the environment. The considerable amount of edible food lost as waste each
year is mainly due to spoilage thus the aim of our study is to determine whether acidic fruit
juices may be used as preservatives in mould growth prevention of bread. We conducted our
experiment by soaking homemade plain bread slices with 5 different treatments for 17 days. We
placed each piece of bread in a separate seal with a 1 cm x 1cm grid across. During the
experimental period, we determined the microbial growth amount by the number of squares that
had developed mould and recorded results daily. Initial results showed that the number of
squares covered increased overtime for all treatments with pH of 4.3 to 6.3 however, by the 10th
day, the more acidic treatments of pH 2.5-3.3 surpassed others with a significant amount of
microbial growth. Further analysis determined statistically significant results with a p-value less
than 0.05 yet an incomplete rejection of our null hypothesis stating that a more acidic liquid with
a low pH will inhibit mould growth when applied to the bread. These results are not entirely
consistent with previous literature which suggests the fruit juices that we had chosen were not
necessarily the most effective antimicrobial agents thus further experimentation may be done
with other solutions to determine what may be the most effective natural preservative.

Impacts of Various Cleaning Reagents on Mold Growth

Maria Greco, Richard Jang, Liz Nicole Libunao, Dove Uy — Mon, 12 Jun 2023 00:00:00 -0700

Bread is an ideal environment for mold growth due to its high moisture content and optimal pH level. Past research has investigated the effects that cleaning agents have on killing mold-growth inducing spores on various surfaces. It was hypothesized that mold growth on bread would be affected when the surface in contact with the bread was wiped with a cleaning product prior. No condition had consistent mold growth presence among all samples, however Control 1 (bread only) and Lysol® treatment had ⅔ bread slices with mold growth. The highest percent coverage of mold was from sample 1 of Control 1(bread only), at 81.05%. Besides when no growth was detected, the lowest mold coverage was from sample 2 of the bleach treatment (36.74%). The highest mean growth rate was from Control 1 (no wiping) at 11.8%. The lowest growth rate was from the bleach treatment, at 7.26%. Although trends suggest that bleach was the most effective treatment, statistical analysis found no statistical significance among growth rate as p>0.05 (p=0.637). Overall, our study did not support our hypothesis, as there was no difference in mold growth and rates between treatments.

The Effects of Cold Temperature Shock on Chlamydomonas reinhardtii Oxygen Production

Daniel Lee, Sofie Levy, Shilpa Shrestha, Yujia Zeng — Mon, 12 Jun 2023 00:00:00 -0700

Chlamydomonas reinhardtii has a photosynthesis process that is multifaceted in its
dependence, as it relies on temperature, carbon dioxide, water, and light exposure. This paper
focuses on the temperature aspect and conducts an experiment where Chlamydomonas reacts to
sudden changes in temperature and examines what kinds of impacts it has on their oxygen levels
and photosynthesis. Nine samples of the stock wewere measured with an oxygen meter to find
their initial oxygen levels, and then equally filled into airtight containers. The samples were
divided into 3 groups, each correlating with a different temperature: 4°, 15°, and 25°C. Each
group was incubated at their corresponding temperature for 60 minutes and was measured again
for final oxygen levels. In addition, the cells of a sample from each group were counted and
compared. The results show that the group placed at 4°C had a significant decrease in oxygen
levels, the group placed at 15°C did not have any noticeable difference, and the group of samples
at 25°C had quite a bit of increase in oxygen. The 25°C group had an average of 115500 cells/ml
while the other two had approximately 176000 cells/ml. However, human error may have
impacted the results as the Chlamydomonas had to be stirred frequently to prevent it from
settling.

Comparison of Meat Contamination in Chicken, Beef, and Pork Samples From Grocery Store and Fast-Food Restaurant Sources

Kartik Bhagat, Mouaz Imdakem, Lyam Lee, Navkiran Takhar — Mon, 12 Jun 2023 00:00:00 -0700

The mislabelling, adulteration and contamination of meat products are part of a growing
issue in the world of food safety. Due to the decreasing transparency behind the source,
production and packaging of meat, the industry is seeing an increase in negligence and poor food
safety practices that result in the sale of adulterated and contaminated meat to consumers. Our
research examined meat samples obtained from pig, beef and chicken products that were
purchased from fast-food restaurants and grocery stores. We isolated DNA and used a multiplex
PCR approach with primers from horse, chicken, goat, sheep, beef and pork. The PCR results
were then analyzed with gel electrophoresis where a comparison of fragment sizes was used to
determine the authenticity of the samples. We observed two cases of chicken contamination in
the beef and pig meat samples purchased from fast-food restaurants, whereas the grocery
store-purchased meat showed no signs of contamination. Therefore, our study found that grocery
store-sourced meat was more accurately labelled, likely due to better hygiene and less handling
by employees.

Effect of temperature on the enzymatic activity of lactase in breaking down lactose

Ellen Choi, Madeline Dow, Helia Jafari, Vani Sharma — Mon, 12 Jun 2023 00:00:00 -0700

This study was conducted to test glucose production in the first order reaction of lactose
hydrolysis with the help of the enzyme β-galactosidase (lactase). Lactose is a disaccharide naturally
found in most mammalian milk and is composed of the two monosaccharides glucose and galactose
(Buller & Grand, 1990). This experiment tested the effect of temperature on the enzymatic activity of
lactase by measuring the glucose concentration of lactose over time. A standardized curve was created to
account for discrepancies between the actual glucose concentrations and the readings from the
OneTouch Ultra 2® blood glucose meter. Lactaid® Extra Strength pills containing lactase were dissolved
in solution and added to 50 mmol/L lactose. Glucose concentrations were measured every 5 minutes
across a 45 minute interval to calculate the reaction rates of lactose hydrolysis at 22ºC and 37.5ºC with
enzyme catalysis. Reaction rate graphs were created to compare the breakdown of lactose at the two
temperatures, and rate laws for the reactions with the two treatments were determined. From the rate
laws, the reaction of lactose hydrolysis at 22ºC produced a rate constant of k = 0.0109s-1, and the group
that received a treatment of 37.5ºC produced a rate constant of k = 0.0150s-1. Ultimately it was shown
that at a higher temperature, reaction kinetics were higher as expected. From this it was concluded that
the human body is at an optimal temperature for the breakdown of lactose.

The Effect of Temperature and Salinity on the Growth Rate of Tetrahymena thermophila

Sukham Kahlon, Yoomin Kim, Quinnie Lai, Joy Zhao — Mon, 12 Jun 2023 00:00:00 -0700

Tetrahymena thermophila are ciliated unicellular eukaryotes that inhabit freshwater
habitats and use the same food supply as salmon species. Its simple cellular structure, ability to
adapt to different environments, and availability of genetic information make it an ideal organism
for studying a wide range of biological phenomena. T. thermophila feed on bacteria which in turn
are eaten by zooplankton, a primary food source to salmon species. The objective of our study was
to determine the effects of temperature and sodium chloride (NaCl) on T. thermophila while
keeping these interactions in mind. There is a global increase in temperature and freshwater salt
content driven by human activities over the years. This study measured the growth rate of T.
thermophila in 0mM and 50mM of NaCl that were incubated at 25°C and 35°C. For each
temperature and salinity treatment, there were three replicates. Cell counts were taken at 0, 3, 6,
22.5, 25, 30 hours after incubation and cell concentrations were calculated from those counts. The
results of this experiment showed that in the 0mM salinity treatments, the growth rate of T.
thermophila increased from 25°C to 35°C. For the 50mM salinity treatments, the growth rate of T.
thermophila decreased from 25°C to 35°C. Based on a two-way ANOVA, we can infer that
temperature has little to no effect on growth rate of T. thermophila, salinity has a significant effect
on growth rate of T. thermophila, and the interaction between temperature and salinity has a
significant effect on the growth rate of T. thermophila.

Physella acuta growth in response to varying concentrations of Zinc

Calvin Pan, Cassidy Barraca, Islam Hassan, Parneet Sarai — Mon, 12 Jun 2023 00:00:00 -0700

Bladder snails, Physella acuta, are well-known for their fast maturation and reproduction as well as having higher tolerance to heavy-metal polluted stream. We investigated the effects of heavy metals, specifically zinc, on the growth of P. acuta by exposing them to 3 different zinc concentrations (200, 400, and 800 μg/L) and a negative control (0 μg/L) for 20 days. We quantified the shell length (SL) and body mass (BM) growth rate of P. acuta as a proxy of the effect of zinc concentrations. The 800 μg/L zinc treatment yielded both the highest mean growth rate of SL (0.0466±0.0013 cm/day) and BM (0.095±0.007 g/day). A general trend of increasing SL and BM growth rates of P. acuta was observed with increasing zinc concentrations. Statistical tests proved significance in variation in both BM (p=.001) and SL (p=.015) growth rates, while only 800μg/L treatment against the control showed significance on SL and BM growth rates (p=.001, p=.01). Furthermore, survival rates varied between the highest 76.7% in control and the lowest 28% in 800 μg/L treatment. The cause of mortality and therefore varying survival rates are not specified with possibilities including but not limited to; acclimation, overfeeding, and handling. Any egg masses observed were recorded by count and size (small, medium, large). Overall, the varying concentrations of zinc in this experiment did not negatively impact P. acuta as they were still able to thrive, reproduce with viable egg masses, and adapt to the varying levels of Zinc.

Exploring the effects of temperature on the growth rate of Tetrahymena thermophila

Heather Cathcart, Diana Dadkhah, Mingzeng Qin, Raman Sandhu — Mon, 12 Jun 2023 00:00:00 -0700

The objective of the study was to determine the effect of temperature on T. thermophila growth
rate. T. thermophila are free-living unicellular eukaryotes that are found in freshwater lakes, ponds, and
streams. We measured the growth rate of T. thermophila at temperatures of 20°C, 35℃ and 41℃. There
were three replicates per temperature treatment. Cell counts were taken at 0, 3, 21, 24, 27, and 45 hours
and were used to determine the growth rate. Our results showed that the 20°C treatment had the highest
growth rate, followed by the 35°C treatment, and the 41°C had the lowest growth rate. One-way ANOVA
and Tukey's multiple comparison test were performed to determine the significance of the results. The
one-way ANOVA was run on samples, including hour 3, which showed no statistical significance
between the groups (p = 0.0575). Hour 3 was then excluded from the data due to human error during cell
counting, and another one-way ANOVA was run, which was found to be statistically significant (p =
0.0157). Based on Tukey’s multiple comparisons test, there was statistical significance found between
20°C treatment and 35°C treatment (p= 0.0407) and 20°C treatment and 41°C treatment (p=0.0169).
There was no statistical significance found between 35°C treatment and 41°C treatment (p=0.7429).
Given these results, we can reject the null hypothesis that temperature will not affect the growth rate of T.
thermophilia at various temperatures and accept the alternative hypothesis for the dataset excluding hour
3. Thus, we can conclude that temperature has an effect on T. thermophilia growth rate.

Growth Rate of Euglena Gracilis in Response to Different Incubation Temperatures

Jonathan Hao, Kaitlyn Le, Daniel Lee, Henry Payette — Mon, 12 Jun 2023 00:00:00 -0700

Global warming is the world’s largest unsolved problem with rising temperatures
affecting many organisms. As Euglena gracilis is an essential species in the Fraser
River of Vancouver, British Columbia, this study aimed to determine if increasing
temperatures like those predicted to occur due to climate change, has an effect on the
growth rate of E. gracilis. Its growth rate was compared in three treatments
(representing current temperature conditions (20 ºC), predicted temperature conditions
(25 ºC), and a control (30 ºC) based on optimal growth temperatures) with three
replicates per treatment. Over the course of 20 days, eight 20 μl samples were obtained
from each replicate and cells were counted on a haemocytometer grid. Adjusted results
showed that temperature does not affect the growth rate of E. gracilis. It also
contradicted our prediction that the closer the temperature was to 30 ºC, the higher the
growth rate would be. Instead, the highest growth rate was found in the 25 ºC treatment,
followed by the 20 ºC treatment, and lastly the 30 ºC control. This discrepancy may be
due to study errors as cell concentration was not calculated correctly. Overall,
temperature was not found to have a significant effect on the growth rate of E. gracilis,
which is counter to the broader literature.

The Effects of Copper on Euglena gracilis ’ Oxygen Production

Jiny Lee, Shraddha Patki, Hana Salehi, Albana Vukaj — Mon, 12 Jun 2023 00:00:00 -0700

Understanding the effects of heavy metals such as copper on various organisms in an ecosystem
is essential to protecting their habitats in an efficient manner. The following study was conducted
to measure the oxygen production of the primary producer Euglena gracilis in various copper
concentrations. Fifteen samples of E. gracilis were left in an incubator for a span of three hours
in various copper concentrations. Cell count as well as oxygen production was measured
previous to, and after incubation and recorded. Even though it was expected that the highest
oxygen production would be from samples with lowest copper concentrations, it was found that
the treatment with 0.15 mg/L copper concentration had the greatest median for oxygen
production. Both 0.15 mg/L and 1.5 mg/L treatment types showed greater oxygen production in
comparison to the control group. However, it was concluded that there is no significant
correlation between various copper concentrations and oxygen production by E. gracilis.

Mushroom Debacle: Can Store-Bought Mushrooms Match Natural Mushrooms in Protein Content?

Arman B., Avin E., Sanaz N., Uzak T., Anson Z. — Mon, 12 Jun 2023 00:00:00 -0700

Mushrooms are the reproductive spore-bearing structures produced by fungi. There are
both inedible and edible mushrooms, and different types of mushrooms have different chemical
compositions. We engineered an experiment to test a large variety of mushroom types for protein
concentration. The experiment involved 12 wild and 9 store-bought mushrooms, as well as
Ninhydrin solution, a reagent that forms a purple compound in the presence of amino acids. We
applied Ninhydrin solution to slices of mushrooms, and heated them to expedite the reaction. We
analyzed the protein concentrations in the mushrooms by comparing the shades of purple on the
mushrooms to a purple hue rubric. We found that the store-bought mushrooms generally turned
darker shades of purple than the wild mushrooms; some of the wild mushrooms did not turn
purple at all. Additionally, mushrooms that were more fresh and softer seemed to observe a
purple colour at a faster rate and developed a darker purple shade after heating. These results
mean that commercially cultivated mushroom species generally had higher protein
concentrations than those found in the wild, demonstrating that overall protein availability affects
the eligibility of a mushroom to be considered food.

The effects of glucose concentration on the glucose-induced chemotaxis of Tetrahymena thermophila

Caroll Gao, Ava Kornum, Sean Liu, Alvin Wong — Mon, 12 Jun 2023 00:00:00 -0700

Tetrahymena thermophila is a free-living, unicellular eukaryote (Collins & Gorovsky, 2005) that lives in freshwater environments, using its cilia to move through water and sweep food into its oral grooves (Bozzone, 2000). Chemotaxis is the movement of an organism in response to a chemical gradient of a particular substance. The glucose-induced chemotaxis of T. thermophila was investigated to identify which concentration of glucose solution elicited the greatest chemotactic response. T. thermophila were starved and incubated at 25 °C for 24 hours. After the starvation phase, T. thermophila were cultured in 1x10-1 M and 1x10-6 M glucose solutions for 5 and 30 minutes. Following fixation of the cells using IKI, the cells in each replicate were counted using a haemocytometer. A one-way ANOVA test was conducted for both time trials with the glucose concentration as the factor, which obtained p-values that were statistically insignificant. Therefore, the concentration of glucose solution does not have a statistically significant effect on T. thermophila’s chemotaxis. We fail to reject the null hypothesis that the concentration of glucose will not affect the chemotaxis of T. thermophila.

Effect of intertidal terrain surface aspect on Mytilus Species Complex distribution after the 2021 Pacific Northwest heat dome (PNWHD)

Subin Kim, Kaylee Li, Bonnie Liang, Kyla Terenzek — Mon, 12 Jun 2023 00:00:00 -0700

In June 2021, the Pacific Northwest heat dome (PNWHD) impacted British Columbia
(BC), leading to unprecedented heat-induced mass mortality of blue mussels (Mytilus spp.).
The invasive species, Mytilus galloprovincialis (Mg) and Mytilus edulis (Me), may threaten
the native species, Mytilus trossulus (Mt) because Mt has a lower heat tolerance - resulting in
a shift in BC’s marine ecosystem dynamics. In this observational study, we examined four
cardinal aspects (north, south, east, and west) of Pasley Island, B.C., to understand the
distribution of Mytilus species’ post-disturbance recruitment, as each aspect reflects different
solar radiation levels. We expect to see Mt being the worst competitor of the species complex
at the south and west aspects, where mussel beds were more exposed to solar radiation at
daylight low tides during the PNWHD. We collected 40 mussels (10 from each aspect) from
Pasley Island. To identify the Mytilus species, DNA isolation, Polymerase Chain Reaction
(PCR), and gel-electrophoresis were performed. Our observational data showed higher counts
of non-native mussels (Mg and Me) than native juvenile mussels (Mt) in all aspects, with
higher differences in the south and west aspects. Me was found only in south and west
sample locations. Our findings suggest that Mg has the highest tolerance to direct solar
radiation relative to Me and Mt.

Effects of freezing on the metabolic rate of the bay mussel, Mytilus trossulus

Josh Yang — Mon, 12 Jun 2023 00:00:00 -0700

Mussels that live in intertidal zones of temperate regions risk freezing at every
winter low tide as they are exposed to sub-zero temperatures. Therefore, they have
evolved the ability to tolerate freezing with a hefty energetic cost, as tissue and cellular
damage incurred must be repaired afterward. The metabolic costs of freezing have yet
to be investigated in an intertidal species, specifically whether a metabolic cost is
associated with crossing the freezing threshold. I hypothesized that animals that freeze
will experience relatively more damage than those which do not and will therefore
demonstrate a higher metabolic rate associated with repair immediately after freezing. I
exposed the intertidal mussel, Mytilus trossulus, to -5.5°C for 6 hours and found similar
oxygen consumption rates regardless of the outcome. This may indicate that the driver
for metabolic shifts is not attributed to the crossing of the freezing threshold but rather
the percentage of body water converted to ice. With the predicted increasing frequency
of cold snaps due to climate change, we can better predict how mussel populations will
respond to these events by understanding the fundamental mechanisms of freeze
tolerance.