Heat, Livers and Herbivores: Climate change and wildlife

By Fiona Marcelino

Kurnath shows off the biology lab’s pet woodrat, Charlie.

Increasing global temperatures have the potential to alter ecosystems and the resources they provide one another.

It is estimated that 20 to 30 percent of plant and animal species will be at increased extinction if global temperature rises more than 3.6-5.4 degrees Fahrenheit.

Due to changing climate conditions, University of Utah graduate student, Patrice Kurnath, is examining the physiology of woodrats as a potential predictor of how other herbivorous mammals may react to climate change. 

“I’m investigating the relationship between ambient temperature, plant toxins and liver functions through a sacrifice free assay,” said Kurnath. “I’m interested in looking at how environmental changes affect the woodrat’s ability to metabolize plant toxins.”

Kurnath’s studies in analyzing the relationship between the woodrats’ ability to digest and metabolize plant toxins and also studying how both plants and animals adapt to environmental changes could potentially be applied to mammals and herbivores in different ecosystems as a predictor of how they might respond to climate change.

“Woodrats are great species to study because they’re not endangered and they lend themselves to numerous ecological and evolutionary questions,” said Kurnath. “They also live in the desert which is usually predicted to be affected first and most severely in climate change.”

According to the U.S. Environmental Protection Agency, rising global temperatures can affect the natural world and raise questions of how vulnerable populations will adapt to direct and indirect affects associated with climate change. Higher temperatures require higher energy expenditures, which means more energy is used to obtain food. This means that any change in temperature can cause stress and negatively affect an animal’s metabolic rate.

Findings from Scientific American connect the increase of global temperatures to increased metabolic rates in various animals. While higher metabolic rates in humans is not necessarily troubling, researches are worried about how it might affect future species, especially those living in areas where food and water are limited.

“Plants, trees and other environmental elements have been and are going to continue to change because of increasing global temperatures,” said Kurnath. “By studying the physiology of these woodrats, we can also speculate how other mammals and herbivores not living in the dessert may be affected by climate change.”

Kurnath studies the physiology of Neotoma bryanti, also known as Bryant’s woodrat.

Charlie’s cage in the biology lab.

If you can’t take the heat, get out of the ocean? Or adapt….

By Amanda Jacobson

Coral reefs, also known as the tropical rainforests of the ocean, are refuges of marine diversity. Sadly, bleached white corals have become the poster child for global warming and the effects on ocean life.

Major coral bleaching events occur due to the loss of the symbiotic nutrient-producing algae (zooxanthellae) residing within the corals. Corals themselves are clear, but receive their coloration from the algae living within their tissues.

Loss of the zooxanthellae, and subsequent coral bleaching, can be induced by a variety of factors causing stress to the algae, rising ocean temperature being one of them. Different coral species have variable susceptibility to thermal stress. It has been hypothesized that hardier, slow growing coral will replace less hardy species in the future. The increasing occurrence and magnitude of bleaching episodes have led some marine biologists to believe that corals have exhausted their capacity to adapt. 

There may be hope.  James Guest et al., in a recent article published in the journal, PLoS ONE, describe how one type of coral is adapting to the increasingly warming temperatures of the ocean.

The authors of this paper hypothesized that corals have the ability to adapt to elevated sea temperatures.  They expected to find increases in thermal tolerance on reefs that typically experience more thermally variable environments; corals in these environments would bleach less severely during episodes of elevated sea temperature. 

The study assessed the thermal tolerance of coral in South East Asia that underwent a large-scale thermally-induced bleaching event in 2010. The findings of their work suggest that coral populations that bleached during the last major warming event in 1998 have adapted to thermal stress.

The authors conclude that this study does not suggest that coral bleaching is no longer a problem. Most coral reefs are still threatened by imbalanced ecosystems from overfishing, pollution, disease and acidification.

We need to change our ways; Mother Nature is not always going to be able to bail us out. 

Corals developing resistance to bleaching (colored) thrive in warmer water temperatures relative to those corals that do not (white). Photo credit: James Guest

References:

Guest, JR et al. (2012) Contrasting Patterns of Coral Bleaching Susceptibility in 2010 Suggest an Adaptive Response to Thermal Stress. PLoS ONE 7(3):e33353. 

Loya, Y et al. (2001) Coral bleaching: the winners and the losers. Ecol Lett 4: 122–131.

Hughes TP et al. (2003) Climate change, human impacts, and the resilience of coral reefs. Science 301: 929–933. 

Carbon dioxide model could aid in reducing Utah pollution

By Javan Rivera

Salt Lake City, Utah is facing a very serious problem concerning air pollution.

It’s no secret that Utah winters often cause severe inversions that trap large amounts of dirty air in the Salt Lake Valley. However, what’s less widely known is the cause of the problem and what exactly is being done to rectify the situation.

Enter Carolyn Stwertka, a graduate research assistant at the University of Utah who, along with her advisor, are currently developing a model for measuring carbon dioxide movement in the Salt Lake Valley.

Stwertka’s work, which is funded by a GK-12 National Science Foundation grant http://www.gk12.org/ called Think Globally, Learn Locally http://tgll.utah.edu/home.html, is vital to understanding exactly how carbon dioxide circulates through the greater Salt Lake City area and how exactly carbon dioxide emissions can be accurately measured for future Utah policy and legislation.

According to Stwertka, the main cause of Utah’s inversion problem is that the Salt Lake Valley acts as a natural bowl for collecting dirty air. With the Oquirrh and Wasatch mountain ranges hedging in the valley’s south and east sides, the Great Salt Lake trapping air from the west, and the high elevation of the valley’s north end, very little air is able to escape the valley without the aid of significant weather changes such as storms.

“Studying carbon dioxide in an urban environment is of interest to a lot of people because humans are creating a new ‘urban environment’ and this [modeling] provides a way to verify if emissions are decreasing due to [potential future] policy change,” she said.

Salt Lake City provides a very unique testing ground for this research not only because of its natural, inversion-causing barriers, but also because it is home to “the longest standing, consistently running set of [carbon dioxide measuring] stations in a city in the world,” said Stwertka.

The set of stations, mostly owned and operated by University of Utah professor Jim Ehleringer, is the primary source from which Stwertka drew her carbon dioxide measurements of Salt Lake City’s surface layer of air for her case study of the winter of 2010-2011.

Using carbon dioxide measurements along with a set of data points that account for wind forces, biogenic flux as a result of plant life in the valley, man-made emissions, and entrainment http://en.wikipedia.org/wiki/Entrainment_%28meteorology%29, are all input into Stwertka’s model in an attempt to accurately measure carbon dioxide movement through the valley.

“We have our model data and we can see how well it compares to the carbon dioxide observations around the valley [as measured by Ehleringer’s stations],” Stwertka said.

The real core of Stwertka’s work comes into play when it comes to finding an accurate measurement of not only how carbon dioxide circulates through the valley, but more importantly how those emissions eventually make their way out of the city air, and into the higher parts of the troposphere. Ultimately, what effect that has on the global mean of greenhouse gases.

Based on her observations from her own unpublished research, she’s discovered that in urban environments such as Salt Lake City, carbon dioxide tends to form a concentrated dome over the city similar to the “urban heat island effect.”

“In cities you produce a lot of carbon dioxide because it is concentrated,” Stwertka explained. “This essentially means that cities create a lot of carbon dioxide that stays isolated around the city and doesn’t extend into the surrounding rural environment. The question is, how do you relate the surface measurements to the global mean average?”

If Stwertka’s model can successfully measure carbon dioxide emission dispersal into the greater atmosphere, her model could be vital to creating future Utah policy changes regarding carbon dioxide emission regulation.

Salt Lake City is currently in violation of the Environmental Protection Agency’s National Ambient Air Quality Standards, thanks in part, to the valley’s severe inversion problem. With Salt Lake City currently attempting to create a State Implementation Plan (SIP), in order to regulate emissions, Stwertka’s work presents an opportunity to gain accurate carbon dioxide dissemination measurements for the plan.

Not only does Stwertka’s model hold promise for measuring carbon dioxide levels, but it also holds the possibility of measuring additional air pollutants such as PM 2.5 and PM 10 http://en.wikipedia.org/wiki/Particulates.

“Understanding the broad pattern [of carbon dioxide emissions] can help you understand the traveling of other pollutants,” Stwertka said. “We would like to further develop the model to track other pollutants as well so that our model can be used for the SIP.”

http://www.youtube.com/watch?feature=player_embedded&v=3dxx_RNsbLs

An inversion creeps across the city as Carolyn Stwertka hikes up the Grandeur Trail to gather carbon dioxide density measurements of Salt Lake City’s surface air.

Throughout the hike, the inversion managed to spread all the way to the base of Grandeur Peak, and even enveloped part of the mountain.

Carolyn Stwertka hiked ¾ of the way up the Grandeur Trail during the winter of 2010, carrying a backpack full of electronic equipment designed to take measurements of carbon dioxide emissions throughout the trek.

What Do Women Really Think?

Profiles of Female Scientists at the University of Utah

By Kirstin Roundy

In the science, technology, engineering and mathematical (STEM) fields, career progression is similar to the steps of a ladder; you have to climb the lower steps if you want to advance to the top. However, according to statistics from the National Science Foundation (NSF), most female scientists don’t make it to the top of the academic ladder. Although women represent 41 percent of awarded STEM doctoral degrees, female scientists occupy only 28 percent of full-time professor positions.

In an academic setting, the basic steps of the ladder are undergraduate student, graduate student, post-doctoral fellow, assistant professor and professor. This series of articles profiles female scientists, at various points in their careers, striving to climb the ladder in the Department of Pathology at the University of Utah.

Betsy Ott – Post-Doctoral Fellow

Betsy Ott

Science is cool. 

At least that’s the message that Elizabeth (Betsy) Ott wants to share. Ott is a post-doctoral fellow at the University of Utah, researching how bacteria that cause urinary tract infections are able to infiltrate host cells.

Her interest in science has been a life-long pursuit.

“Probably the earliest memory I have of really loving science is in the fifth grade,” said Ott. “We had to do our first research project. I did marine biology. I was infatuated with Jacques Cousteau and oceanography…I remember bioluminescence was amazing to me and just knowing that it’s a chemical reaction done by these cells in the skin of these animals was so exciting to me. I couldn’t wait to learn more about it, all aspects.”

This desire to learn about every aspect of what she studies has led Ott through a very diverse research career.  From pumping fish stomachs to document dietary choices in stocked versus unstocked lakes to analyzing urine samples in infants for defects in metabolic pathways, Ott dabbled in several arenas during her undergraduate career.

It was the repetitiveness of analyzing urine samples every day that led Ott to apply to graduate school.

“The idea (analyzing urine samples) was cool, but actually you just did the same thing over and over again,” she said. “I guess that was the biggest motivation for me to go to graduate school. So it was a very good experience for me because it wasn’t research and it was very clear to me that I wanted to be in research.”

Ott’s graduate research focused on following the degradation and movement of cellular membrane proteins in yeast. During her research, she discovered that the degradation pathway also regulated the multivesicular body (MVB) pathway during the starvation response. The interesting thing to Ott was “that these proteins that do the sorting of the MVB pathway are hijacked by HIV in human cells to get out.”

The combination of knowledge gained during graduate school and a desire to apply that knowledge to infectious disease is what led Ott to her current position studying uropathogenic bacteria. “Now I can still apply all my trafficking knowledge to a new problem that’s much closer to infectious diseases,” she said.

Ott talked about her transition from graduate student to post-doctoral fellow by stating, “the expectations are different, which is gratifying. I’m expected to, if I don’t know something, go figure it out, which is great. It’s kind of freeing to have somebody have that confidence in me.”

Ott hasn’t witnessed blatant displays of gender discrimination in regards to the NSF statistics stated previously.

“In college, our class essentially was more women than men. Also, the NIH (National Institutes of Health) does not discriminate [between] male or female post-docs. So I feel like that is equalizing. There’s no bonus for a PI (Principal Investigator) to hire more males than females,” she said.

However, in looking to the future, Ott does have one issue when it comes to gender equity. What happens when she wants to have children?  Ott has a right to be concerned. According to the NSF, women who were single and without children showed the greatest gains in terms of obtaining full professorships than did women who were married and had children.

“Thinking about kids, I’m very nervous about that because I do want a family,” Ott said. “I do know that that will sacrifice my salary, it will sacrifice my position…it could very well sacrifice some of the respect that I think I deserve.  I’m nervous about walking that delicate line.”

Regardless of the complications, Ott plans to stay in research. “I think I’d have to spend my time searching for the right job in order to be happy. I might have to look around a few times in order to find it and I’m willing to do that.” 

Until that time, Ott continues with her own research and strives to find opportunities to share her love of science with others.

“I like judging science fairs because it’s just so fun to see kids get involved in science. They do these projects where their eyes just pop open and they’re like, ‘This is so cool!’ and I say, ‘I know! Just wait, you don’t even know,’” she said.