Feb. 19—A science fair is an opportunity for young learners to dip their toes into the scientific process through a fun experiment.

The baking soda volcano is probably the most classic example.

The 60th annual Howard County Science Fair saw elementary students have fun with science Saturday by making slime, building simple robots, and in one case, seeing if one could filter sugar out of soda.

But in the senior division, older students took their experiments a step further, relating them to real-world issues.

Ava Prather, a sophomore at Northwestern High School, spent 48 days observing the effects of an increasingly salty environment on daphnia, a freshwater crustacean.

Daphnia, also called common water fleas, are present in most freshwater environments. These bottom-of-the-food-chain organisms are eaten by others.

Their prevalence makes them important, especially if the environment undergoes changes, such as the salinity level.

“They’re kind of the canary in the coal mine,” Prather said.

Prather tested the impact of adding sodium chloride, magnesium chloride and sodium bicarbonate (baking soda) to water with daphnia. These are common road salts.

Over the course of 48 days, Prather observed that daphnia exposed to sodium chloride turned brown and cloudy. Their intestines appeared shriveled.

“I saw that in all daphnia in the sodium chloride group,” she said.

Daphnia are clear, allowing one to see their organs and measure their heartrate, with the help of a microscope.

The sodium bicarbonate daphnia had slower heartrates and slower movements. Magnesium chloride had a more corrosive effect on the organisms.

Prather increased the amount of salt gradually over the course of the experiment. She also tested what happens when daphnia are put directly into a salty environment.

When exposed gradually, daphnia still reproduced but experienced health side effects. Those that were thrown right in died.

For her efforts, the Northwestern sophomore was the top prize winner at Saturday’s science fair. Prather won $2,500 in Indiana University Kokomo scholarships and a $100 cash prize. IUK hosts the annual science fair.

Prather was a participant in last year’s science fair, where she studied the effects of saltwater erosion on limestone, a common building material of ancient ruins. She said her project led her down a rabbit hole where she discovered the United States is expected to face a freshwater crisis in the next 20 years.

“That got me thinking, I’ll only be 36 in 20 years,” she said. “This is my future, and I kind of have to do something about it.”

Prather said salt can infiltrate freshwater aquifers through snow melt, like from road salts, and fertilizers, especially when water is pumped out at a high rate.

“This is especially a concern in Florida,” she said.

It’s also a concern in agriculture-heavy states where surface runoff of fertilizers is common.

Prather’s takeaways from her experiment were alternatives to road salts are needed as are ways to control excess runoff.

The scholarships Prather won Saturday are stackable if she continues to participate in the science fair. She plans to do it again next year.

Prather’s experiment was just one of many that impressed those who judged the projects.

“I find our students seem extra excited this year about science,” said Deb Jaworski, science fair committee member and IUK math lecturer. “The senior division, they’re looking at significant issues we face and trying to figure out a way to address it.”

Adam Lesko was among those in the senior division. The Northwestern freshman looked at how different acidities impact the health of a sweet corn kernel.

He fertilized seeds with vinegar, water and agricultural lime, commonly used on farm fields. Water served as the control group.

Lesko found that lime resulted in the longest root lengths but vinegar produced more roots. This indicates two things.

“It taught us sweet corn can live in a basic soil (lime),” Lesko said. “(And) it tells us roots can survive in an acidic soil.”

However, there’s a big catch with the vinegar results. Nematodes like acidic soil, and they like corn.

Lesko’s experiment also observed nematode activity.

While an acidic soil can produce more root systems for corn, it might also attract organisms that could damage the crop. It’s something to consider before planting and using any fertilizer.

Megan Broeker said she was pessimistic leading into her project about learning types and critical thinking skills.

There’s a strong argument that learning types do not exist. Part of her expected that to be the case when she surveyed people about their preferred learning method.

“I kind of thought the learning types would not exist,” Broeker said. “The data kind of proves it does exist.”

This was one of the results of her project where people answered a 10-question survey about how they learn then did a sudoku.

Learning types consisted of auditory, kinesthetic, reading and those with multiple. Broeker surveyed 112 people.

Kinesthetic and auditory learners scored best on sudoku. Broeker also categorized respondents by careers. Top performing careers were health and service.

For the Northwestern freshman, the results could help students in the long run.

“What I found showed students most applicable careers can be figured out though learning type and critical thinking skills,” Broeker said.

Linda Wilson, a science teacher at Northwestern High School, spends countless hours with her students as they prepare for the science fair.

On Saturday, she served as judge for the junior division. She had high praise for Eastern Elementary teacher Sarah Bonesteel and her students’ “well-designed” projects.

“Eastern does a great job with their projects,” Wilson said. “Mrs. Bonesteel does a fantastic job.”

Spencer Durham can be reached at 765-454-8598, by email at spencer.durham@kokomotribune.com or on Twitter at @Durham_KT.