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USU undergrad studying invasion of African zooplankton into Willard Bay By
Will Bettmann
It doesn't take a rocket scientist to figure out that Olivia Lester is an extraordinary student. If one was needed, however, her father is just down the highway in Brigham City. "I kind of knew when I was young I was into biology," said Lester, a sophomore at Utah State University. "I was always interested in science. My dad is a rocket scientist for Thiokol so he encouraged me. In elementary school, I was in Young Astronauts. Then in high school, I started doing my own research, and competing in science fairs all across the country. I won a lot of awards nationally," said Lester. While many high school students in Brigham City were probably congregating in parking lots on weekend nights, Lester was designing a "more efficient stove that could be used in Third World countries." This year, Lester received an URCO (University Research and Creative Opportunities) grant, in addition to a much larger grant from the Utah Division of Wildlife Resources (UDWR), to study the "invasion of the exotic cladoceran, Daphnia lumholtzi, in Willard Bay, and its effect on the pelagic food web." She presented the results of her research at the URCO Student Showcase on April 19 in the Taggart Student Center. Lester decided to come to Utah State University because she knew the College of Natural Resources encouraged student research. "They've been really supportive," said Lester. "They really encourage students to do research like mine. I just think a lot of undergraduates aren't aware of that option." According to Lester, Daphnia is a cladoceran, which belongs to a broad category called zooplankton, which, in her words, are basically a bunch of tiny critters. Willard Bay has a native Daphnia species, but recently a foreign invader (known as an exotic species) has arrived. The invader, known as Daphnia lumholtzi, is just 2 millimeters long, barely visible to the naked eye. It was discovered in Willard Bay by Dr. Chris Luecke, who is supervising Lester's work in the bay. An exotic (or alien) species is any species that is not native to a given ecosystem. Some exotic species can exist harmoniously in their new environment. However, some are a nuisance, and others spread so quickly that they choke out many native species and seriously alter the ecosystem. According to the U.S. Fish and Wildlife website, activities to prevent and control invasive plant and animal species that severely impact the lands and waters of the United States have become a priority for the U.S. Fish and Wildlife Service. It's not just wildlife people who are concerned about exotic species. For example, the zebra mussel, an invasive species in the Great Lakes region, can cause damage to industrial and municipal water delivery systems; it can threaten hydropower and irrigation systems; it can threaten other mussels and damage sport fisheries; and it can cause boat engines to seize up and fail. Not bad for a creature about the size of an adult's thumbnail. "In Willard Bay, there hasn't yet been a serious negative impact from Daphnia lumholtzi," Lester said. She said a problem could occur if the exotic Daphnia spreads so rapidly that it chokes out the native Daphnia. "Dr. Luecke brought a water sample from Willard Bay back to the lab and said, 'Whoa! What is this?' He suggested that I research it. This is the first report of Daphnia lumholtzi in the Mountain West. It's pretty common on the East Coast. We guess that it was first introduced in 1995 when wiper fish were stocked in Willard Bay. Wipers are a type of bass, and the ones they used came from North Carolina," Lester said. Willard Bay is a freshwater reservoir, created by being walled off from the Great Salt Lake. In the last few years it has become a popular sport fishing destination, which has lead the UDWR to import new varieties of fish, such as the wiper. Luecke said he first noticed Daphnia lumholtzi a couple of years ago. "We brought some samples back from Willard Bay, and some of my students were looking at various microorganisms under the microscope and using charts to classify them," Luecke said. "The students were getting frustrated because they couldn't identify this one species. I was yelling at them and telling them they needed to work harder, but then when I took a look, I didn't recognize it either. A few nights later, I woke up in bed and remembered a paper I had read about something like this, and it turned out to be Daphnia lumholtzi. This species originated in Africa, and was introduced into the southeastern U.S. by fisheries stocking African fish." Knowing that Daphnia lumholtzi has had an impact on southeastern fisheries, Luecke made a proposal to the Utah Division of Wildlife Resources to study the population in Willard Bay. He said this year's grant, which covered Lester's and another student's salaries and some equipment, was about $14,000. Lester said Luecke, who is the interim head of the department of fisheries and wildlife at USU, has not previously worked on research with an undergraduate student on a research project. "I think it's worked well," said Lester. It's less expensive for the department because graduate students usually get a big stipend. It's been a really cool experience for me." Luecke said, "It's been fun watching her develop as a scientist. She's an undergraduate student and she's working on a national level. I've never had an undergrad that seemed to be able to take charge so much." Some of Lester"'s research consisted of studying the reaction of Willard Bay fish to the exotic Daphnia. "I did experiments with juvenile fish, and they really prefer the native Daphnia. I think it's because the exotic daphnia have an elongated head, and large spiky tail spines, which the small fish choke on. If enough of the small fish can't get food, then that could have an impact all the way up the food web," Lester said. Lester's fieldwork mainly took place this past autumn, and involved long days scooping samples of zooplankton and fish out of Willard Bay. "It was really exciting," she said. "A few days were really windy. One time, a girl got thrown overboard. In fieldwork, nothing goes according to plan so you just have to adapt and deal with it." Since late October, Lester has been analyzing the samples. Both Lester and Luecke said one factor could help mitigate the effects of Daphnia lumholtzi in Willard Bay: the exotic species doesn't seem to thrive until late in the summer, when most fish have grown large enough to eat them. Luecke said fish smaller than 50 millimeters (about the length of an adult's little finger) don't like the exotic species, but fish bigger than that can eat it with no problems. Lester said it has been difficult balancing graduate-level research with her undergraduate course work. She has missed three weeks of classes this semester traveling around the country presenting her research. At one conference, hosted by the American Society of Limnology and Oceanography, Lester was one of a small handful of undergraduate presenters among about 1,000 presenters. At that conference, she also met with a man widely regarded as one of the world's experts on Daphnia. "It was a little nerve-wracking, but he ended up being really nice. It was kind of scary beforehand because I've barely had any course work in the subject and I was worried he'd ask me something I didn't know," she said. In addition to her research and 16 credit hours of classes, Lester is a member of the Wildlife Society, a leader of a science quiz team which competes all over the West, a teacher's assistant, and a member of a couple of student committees. Despite her busy schedule, Lester said she is glad to be working with Luecke. "He"s like the best person to work for," she said. "He"s a great teacher and researcher. He's known by ecologists all over the country. He went out on a limb with me, and I'm really grateful. He's taken time to teach me everything -- he just goes the extra mile.
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