While plastic ingestion has been well documented in sea turtle populations, this study is the first to highlight the issue in freshwater turtles

Littering can have profound impacts on wildlife, causing complications for their health through ingestion or entanglement. Plastic ingestion has been well-documented in all seven species of sea turtles, but the issue is not well understood in freshwater turtles, according to Dr. Greg Pauly, the curator of herpetology and the co-director of the Urban Nature Research Center at the Natural History Museum of Los Angeles County. 

“Plastic ingestion by freshwater turtles: a review and call to action,” co-written by Pauly, was published in Scientific Reports on March 23, 2021, and details results from a field study and a literature review on plastic ingestion by freshwater turtles. This paper was written by Dr. Adam Clause, a postdoctoral researcher at the Natural History Museum of Los Angeles County, Dr. Aaron Celestian, the associate curator of Mineral Science at the Natural History Museum of Los Angeles County, and Pauly. This study is the first to highlight freshwater turtles ingesting plastic—which may be an underappreciated threat to the world’s declining populations of freshwater turtles, according to Pauly. 

Pauly, who earned a B.S. in Evolution and Ecology from UC Davis in 1999 and then returned for a postdoc from 2009–2011, started working with Arboretum turtles in 1998 as an undergraduate and has continued studying that population for several years. Dr. Adam Clause began working with turtles in the Arboretum during his time at UC Davis, where he graduated in 2010 with a B.S. in Evolution and Ecology.

“It’s been fun to work on those turtle populations off and on for the last 20 years,” Pauly said. 

The scientists’ field study examined 65 non-native red-eared slider turtles from the Arboretum and found that 7.7% had plastic inside their stomachs or intestines. One of the ingested plastics was likely a nitrile exam glove. Although the turtle specimens were collected before the pandemic—in 2011 and 2012—this result highlights the potential impacts of increased personal protective equipment (PPE) litter in the environment, according to Pauly. Other ingested plastics likely included a white plastic shopping bag and a piece of disposable cutlery.

“I wasn’t surprised that we were finding these [plastics] because I see animals by these things all the time,” Celestrian said. “It was definitely not a good thing.”

One challenging part of this research was identifying the contents inside the turtles’ stomachs and intestines, as it can be difficult to distinguish plastic from organic material from what the turtles eat, such as crayfish exoskeletons, according to Celestian. To identify the plastic contents, Celestian used Raman Spectroscopy, a chemical analysis technique that details chemical structure, phase and polymorphy, crystallinity and molecular interactions of materials. 

“I have a spectrometer here in the lab called the Raman Spectrometer, which is very good at looking at very small particles and identifying what materials those particles are, even if they’re not recognizable,” Celestian said. “That’s what my main role was, to figure out these bits and pieces of plastics.”

In the scientists’ associated literature review, they found that dietary studies to identify plastic ingestion in freshwater turtles are rarely conducted. Over the past 10 years, nearly 50% of relevant turtle dietary studies have involved only marine turtles, according to Pauly. Marine turtles averaged 15.3 dietary studies per species during this period, whereas non-marine turtles averaged 0.3 dietary studies per species (across the 352 species of non-marine turtles), according to the study. 

The results from the field study and literature review together demonstrate that some freshwater turtle species are ingesting plastic, but researchers have little understanding of how widespread this issue might be because freshwater turtles are not getting the same amount of research attention as their marine counterparts, according to Pauly.

“There’s an increasing awareness of plastic ingestion in lots of marine species, but across the board freshwater environments are much less studied for plastic ingestion,” Pauly said. 

This is not the first study Pauly has conducted on turtles in the Arboretum. Pauly and other researchers at the Natural History Museum of Los Angeles County previously published a study in 2019 that found the living conditions and health of the two primary species found in the Arboretum, the native western pond turtles and the non-native red-eared slider turtles, is greatly improved by removing large percentages of invasive red-eared slider turtles. 

The 177 red-eared sliders removed from the Arboretum during the 2019 study were the turtles examined in this new project, which began as an investigation into understanding the dietary overlap between western pond turtles and red-eared sliders. However, when Pauly and Clause began to dissect turtles and look at their stomach contents, Pauly said they were shocked to find plastics in some of these individuals. 

“That completely changed the direction of the study to then start thinking about, ‘[…] what’s the number of turtles that might be ingesting plastic, what impact that it’s having on that population, and more broadly, is this a common issue for turtles globally?’” Pauly said. 

Right away, Pauly knew this was a noteworthy discovery, and after looking in the scientific literature, the scientists realized how poorly studied this issue is with respect to freshwater turtles. In their paper, the scientists issued a “call to action” for other researchers to look into this issue for freshwater turtles, Clause said.

Scientists are still unsure why the freshwater turtles consume plastic in the first place, according to Clause.

“Two of the most likely explanations are that [turtles] are either confusing it with a natural food item, or they’re just eating it accidentally while they’re eating normal things in their environment,” Clause said. 

UC Davis’ Arboretum and Public Garden works with multiple departments on campus to reduce pollution in the Arboretum Waterway. Prevention is the first step, according to Nina Suzuki, the waterway steward at the UC Davis Arboretum and Public Garden. Suzuki and other Arboretum employees work with many departments to prevent litter and other pollutants from reaching the Arboretum waterway. Some of these measures include education and signage, improved waste collection bins, promoting reusables and compostables, reducing single-use plastic at campus food service outlets, regular street sweeping, physical barriers at storm drain outlets and regular staff maintenance of the waterway and Arboretum. 

“I think this kind of research is important because it reminds us all that our actions have consequences beyond what we typically think of as our sphere of influence,” Suzuki said via email. “Most people who walk through the Arboretum probably haven’t ever looked a turtle in the eye. They probably also haven’t ever dropped a piece of plastic trash into the Arboretum Waterway. And yet, our use of disposable plastics in everything from beverage containers to utensils to toys, has resulted in tiny bits of plastic making their way into places we would never have expected, like the stomachs of turtles.”

The turtle species living in the Arboretum are commonly studied for research and in UC Davis courses, such as Wild Davis, a course taught by Dr. Laci Gerhart-Barley, an assistant professor of teaching, focusing on urban ecology and urban naturalism. 

Since the turtles in the Arboretum illustrate a number of important aspects of urban ecology, such as how invasive species like the red-eared slider turtles impact native species, Gerhart-Barley includes them in the class. As detailed in Pauly’s previous study, the dumping of non-native animals into an ecosystem, such as the Arboretum, can have very negative impacts on native species as well as the non-native species. 

“That’s an ongoing point of concern with long term management of those invasive turtle species,” Gerhart-Barley said.

Gerhart-Barley plans to include this new study in her Wild Davis course as an example of how human activity in the Arboretum can impact the animals in ways that are less visible; in this case, through the ingestion of plastic, she said. 

“That’s one of the problems with ingesting things is the animal might not look sick, or might not look harmed,” Gerhart-Barley said. “It’s not like the plastic copings around their neck or it’s really visible that there’s a problem. They could appear to be completely normal and still be really negatively impacted.”

Beyond understanding the reasons why turtles ingest plastic, this study brought up many more questions that need to be answered regarding plastic consumption—beyond just freshwater turtles, according to Celestian. 

“This is just the first study of its kind,” Celestian said. “I think more studies are definitely warranted to see how, what the level of pollution is versus what the health of the turtles might be.” 

According to Pauly, the goals of this study were twofold: to highlight the issue of turtles ingesting plastic in an urbanized waterway in California and to emphasize that this is an underappreciated problem for freshwater turtles globally.

“We know across the globe, we know that urbanization is a major threat to freshwater turtles as a group are experiencing—some of the highest rates of extinction of any urban group,” Pauly said. “[Plastic ingestion] is potentially a new emerging threat that freshwater turtles globally might be facing.”
Written by: Margo Rosenbaum — science@theaggie.org

Researches compiled data from a range of sources and determined that malaria is one cause of iron deficiency in African children

UC Davis researchers discovered a correlation supporting the hypothesis that malaria causes iron deficiency in African children. Researchers at the Kenyan Medical Research Institute (KEMRI) led the team that tackled this scientific inquiry alongside Assistant Professor Reina Engle-Stone and Professor Christine Stewart from the UC Davis Department of Nutrition. 

According to the recent study, malaria has an estimated parasite prevalence of 24% with 213 million cases reported in 2018 in sub-Saharan Africa. Iron deficiency is responsible for over 60% of anemia cases and was found to be associated with impaired cognitive development and the leading cause of  disability among children living in Africa.

Malaria can cause anemia through the destruction of parasitized and non-parasitized erythrocytes. When interrupting malaria transmission in a trial done in the Kenyan highlands, iron deficiency cases were reduced, while iron deficiency cases increased during the malaria season in Gambian and Kenyan children.

The research enabling the discovery of the correlation between iron deficiency and malaria is an example of involving larger groups of people to acquire more data sets to answer complex questions, according to Engle-Stone. The topic has been a challenge in the global field of nutrition, especially in studying the relationship between iron, infection and inflammation.

KEMRI is known for being involved with clinical, social, laboratory and epidemiological research on a local and international level, according to Chief Research Officer Dr. Norbert Peshu. Their mission is to “to deliver high quality research relevant to global health and to build local capacity for undertaking research,” according to their website. For this study, the organization needed many diverse data sets, so they reached out to different investigators who already had data from various studies that would be appropriate to include in their research efforts. The information from the shared data would make it possible for the KEMRI research team to analyze their data more efficiently. 

“This is when they reached out to me about a study that we conducted in Cameroon,” Engle-Stone said. 

The Cameroon study took place in 2012 when the country decided to address micronutrient deficiencies by fortifying wheat flour and cooking oil with vitamins and minerals. The researchers involved also studied inherited hemoglobin disorders, such as the sickle cell trait, and were interested in learning about anemia in Cameroon.

Studies on the sickle cell trait were instrumental in the most recent study because they allowed the researchers to avoid observation, which would put the results at risk of reverse causation and confounding. The sickle cell trait, which protects an individual against malaria, is used as a variable in the Mendelian randomization approach to reduce the bias in a researcher’s observations. 

Mendelian randomization, the process of taking measured variations of genes where the function is known, makes it easier to explore the causal effect on the genes when exposed to a disease in a controlled setting, according to the CDC.

Being a part of the UC Davis Department of Nutrition has allowed Engle-Stone to be aware of iron deficiency problems in sub-Saharan Africa. The nutrition department studies many nutrient deficiencies, including iron, and many cases are located in sub-Saharan Africa. The goal of researching iron deficiency problems is to discover factors that contribute to iron deficiency and to develop interventions that safely reduce iron deficiency, according to Engle-Stone.

The safety of iron deficiency interventions are discussed among many scientists because of the growing concerns that these interventions are being provided to individuals who are not iron deficient or in areas where infection is common. The supplementation of iron can increase the risk and severity of infections, but deficiency can lead to anemia so nutritionists must work on balancing these considerations, according to Engle-Stone. 

 Dietary intake is a risk factor for iron deficiency in sub-Saharan Africa, according to Engle-Stone. Animal products contain more available iron than plants, and the economic barrier in sub-Saharan Africa in accessing animal products prevents individuals in the region from getting the sufficient iron required for their health.

According to Engle-Stone, subclinical infections, where a person may not experience a lot of the symptoms of malaria but will have their metabolism affected, have been reported as well. Malaria is so common in the area that standard care for pregnant women in most of sub-Saharan Africa is prophylactic treatment with anti-malarial medication. The World Health Organization recommends distributing iron supplements along with anti-malarial drugs to fight both conditions simultaneously.

“Ideally if people have access to both, the nutritional interventions will result in good prevention and treatment for malaria,” Engle-Stone said.

Written by: Francheska Torres— science@theaggie.org

The Center for Simulation and Education Enhancement helps design engaging learning environments despite the barriers presented by the pandemic

Amid difficult learning conditions, UC Davis Health faculty have been brainstorming tactics to keep doctors, medical students and nurses engaged and motivated throughout their training. As a part of the pediatric intensive care unit (PICU) nurse training program, one session designed by Michelle Linenberger, a UC Davis Children’s Hospital nurse educator and professional development specialist, has made progress in helping nurses learn in a fun environment: an escape room-style simulation.  

“Especially with the stress of the pandemic and intensity level so high at the hospital, it’s nice to come together and create a fun learning environment to keep people excited and renewed for work in healthcare,” Linenberger said.

Having worked in the PICU nurse training program for several years, Linenberger described the program to include lectures from PICU physicians and nurses in addition to the simulation portion. She ran her first escape room session last year and continued to add on to her design to help students through the often stressful simulations.

“Simulations sometimes can be a stressful learning environment, and you want to balance supporting them but you want to try and create that real patient environment as best you can,” Linenberger said. 

Linenberger explained that the intensity of the escape room simulates what it’s like performing under pressure when taking care of a sick child while also allowing the new nurses to apply what they have learned from lectures. She emphasized how she enjoyed seeing the participants learn how to problem-solve, collaborate and communicate effectively through the simulation.

Courtini Sladek, a nurse in the PICU at UC Davis Health, explained that she was excited to experience an escape game related to nursing, as she often enjoys escape-style games with her husband. She explained that the escape room simulation challenged her knowledge and taught her new aspects about her position in a way that was enjoyable and entertaining.

“The escape game took the pressure off and turned what is normally a stressful activity into something that was fun and engaging, and it left me wanting to do another,” Sladek said.

Sladek explained that at the beginning of the session, the nurses were given a brief description of asthma patients that they would be treating. Once the nurses were situated in the simulation room, the timer began and music began to play as the nurses went on to assess the patient—a high-fidelity mannequin—in front of them. As she assessed the patient, Sladek described finding puzzle pieces with vital signs or symptoms that gave them clues to their next steps. She also worked together with other nurses to find a key to a lockbox which contained a blacklight, allowing them to gain access to more information that ultimately helped them treat the patient. 

Linenberger described working closely with the Center for Simulation and Education Enhancement to prepare props for the session. Ian Julie, the director of the Center for Simulation and Education Enhancement at UC Davis, explained that the center had to make multiple changes to training curriculums due to the pandemic. 

“The issue that we encountered is simulation training for doctors and medical students and nurses and all the other healthcare workers involves a lot of hands-on learning,” Julie said. “Because of social distancing rules, we really had to cut down on what we were doing in person.”

To overcome these barriers, Julie explained that they had to broadcast much of their curriculum through online platforms, where a small number of students were able to conduct the simulations in person while the rest of the class was able to watch. The center also used 360-degree cameras to create interactive environments where students could walk through scenarios virtually.

Not only did these virtual platforms allow simulations to be run safely, but they also received a fair amount of positive feedback from students. Julie explained that many doctors and students are unable to attend training exercises due to clinical duties at unprecedented hours. He expressed that because of their success in increasing the amount of participants in these activities, the center will continue using the screen-based content they developed throughout the pandemic and will experiment with new technology to help those who are still unable to attend in-person simulations post-COVID-19. 

“By being able to participate online and being able to do things asynchronously, we were actually able to include a lot more people who otherwise would’ve either been but been dead tired or would have skipped the activity entirely because they wouldn’t have been able to make it given their clinical responsibilities,” Julie said.

Linenberger said that being able to design the escape room simulation was rewarding as an educator, and to see the level of collaboration and excitement in learning was all worth the effort. She explained that other faculty members have reached out to her for help in creating escape rooms in other disciplines as well. She hopes to continue expanding her design in the future.

“It was probably one of the most enjoyable teaching moments that I’ve had in my 25 years here,” Linenberger said. “It was quite nice to see people excited, something different.”

Written by: Michelle Wong — science@theaggie.org