Student Research

How Do Salmon Find Their Way Home?

Marcus Welker, PhD Student, Ecology and Evolutionary Biology

Marcus Welker studies salmon and how they find their way home. Salmon are born in rivers, migrate to the ocean or lakes, and return again years later to the place they were born with incredible precision.

Specifically, Marcus is measuring amino acids in rivers that are believed to give each river a unique chemical fingerprint that salmon learn as juveniles, remember as adults, and use to discriminate their home streams. Marcus wants to know if these chemical fingerprints are unique to ever river and if they are stable over time – the two criteria necessary for salmon to use them as a signal.

Additionally, Marcus is conducting an experiment in a hatchery to determine if salmon can learn amino acid patterns as juveniles and use these to remember patterns as adults to make decisions in a large fish-maze. While doing the experiment, Marcus is also measuring the genetics of amino acid sensing receptors in salmon noses – the sensory system believed to be critical for home stream selection.

"Cool Robot" Uses Ground Penetrating Radar To Save Lives

Benjamin Walker, PhD Student, Engineering Sciences

Ben Walker studies ways in which to conduct safe crevasse detection for sup¬ply traverse personnel through robotics research. Each year a heavy equipment resupply is conducted between Thule, NEEM and Summit Camp, Greenland, and this resupply must traverse heavily crevassed sections of the Greenland Ice Sheet to complete the job. Ben’s research is developing a robot and instrument combination that will automatically collect and interpret this data.

During his fieldwork season at Summit Camp in June of 2013, Ben increased the reliability of the solar power system of a robot—the “Cool Robot.” This robot tows the Ground Penetration Radar, which is used to detect crevasses. Ben and his colleagues performed multiple long-distance runs in order to determine the solar power available and the daily range of the system.

Temperature and Pollination in Greenland

Christine Urbanowicz, Ph.D. Student, Ecology and Evolutionary Biology

Christine Urbanowicz studies the pollinators and plant-pollinator interactions that are beneficial for flowing plants in Greenland’s tundra ecosystem. She is interested in how variation in plant density and temperature influence the number of pollinators that visit flowers and the number of fruits a plant produces. She is also collecting data on parasites of bumblebees in Greenland.

In 2013, Christine counted the numbers of insects visiting flowers in six sites around Kangerlussuaq, Greenland, that were subjected to different wind conditions. She collected and identified insects at these sites, and collected and identified pollen off their bodies to determine the plants that each insect visits.

During the summer of 2014, Christine is determining how variation in temperature in Kangerlussuaq affects the pollination and fruit set of blueberry as well as a few other plants. Climate change is expected to cause drastic changes in vegetation in Greenland, and many of these changes will be mediated by the availability and composition of pollinators.

How Does Climate Change Affect High Latitude Aquatic Ecosystems?

Jessica Trout-Haney, Ph.D. Student, Ecology and Evolutionary Biology

Jess Trout-Haney studies how climate change affects high latitude aquatic ecosystems, specifically their physical, biochemical, and biological properties. She studies how differences in lake chemistry and morphometry of low-nutrient Arctic lakes affect the abundance of cyanobacteria and cyanotoxins in southwestern Greenland.

In the summer of 2013, Jess surveyed 19 lakes of varying size and depth between Kangerlussuaq and the Greenland Ice Sheet in southwestern Greenland. She ran sonar transects across each lake in order to generate maps of lake basins. Additionally, she collected lake water, phytoplankton, and zooplankton samples in order to examine how nutrients, species composition and cyanobacterial toxins vary among lakes.

Soils Biologist Studies Past and Present Erosion in South Greenland

Ruth Heindel, Ph.D. Student, Earth Sciences

Ruth Heindel studies soils, a valuable resource for Greenland that supports natural ecosystems and also agricultural activity in South Greenland. Specifically, she studies past and present wind-driven soil erosion, a process that threatens soil resources by removing soil and disturbing vegetation.

During the summers of 2012 and 2013, Ruth collected spatial data describing eroded areas in the Kangerlussuaq region. Additionally, she measured lichen diameters in order to estimate past and present rates of soil erosion. In the spatial analysis lab at Dartmouth, Ruth has developed a land cover classification for the Kangerlussuaq region that identifies eroded areas from satellite imagery. She has found that eroded areas generally occur on steep south-facing slopes, and are much more common closer to the Greenland Ice Sheet.

Rising Temperatures Affect the Number of Mosquitoes in the Arctic

Lauren Culler, Ph.D., Ecology and Evolutionary Biology, Dickey Center Arctic Fellow and Outreach Coordinator

Climate change is causing temperatures to rise in the Arctic and Lauren is studying how these changes in temperature affect mosquito emergence from freshwater ponds.

During the summers of 2011 and 2012, Lauren Culler counted the number of mosquitoes in several ponds near Kangerlussuaq, Greenland, every few days and measured how many mosquitoes emerged from each pond. (See picture of individually wrapper mosquitoes.) She also used lab studies at Kangerlussuaq International Science Support to measure how temperature affects the number of days it takes a mosquito larva to grow into an adult.

So far, she has leaned that warmer temperatures are likely to increase the number of mosquitoes that emerge because the larvae grow much faster when it’s warmer and thus spend fewer days exposed to predators. She has also discovered that the amount of rainfall in the spring is a crucial factor because very dry weather leads to the death of mosquito larvae as their habitat dries.

How Climate Warming Alters Soil Carbon Content

Julia Bradley-Cook, Ph.D. Student, Ecology and Evolutionary Biology

Julia Bradley-Cook is studying how climate warming is altering the biological processes that control carbon flow through natural ecosystems. She investigates microbial decomposition in tundra soils where permafrost and cold soil temperatures have allowed for the buildup of large stores of carbon.

In 2011 and 2012, Julia collected samples from soil pits to measure soil carbon content across two spatial scales:  the local area near Kangerlussuaq and the regional area of western Greenland (Kangerlussuaq, Sisimiut, and Nuuk). She used a combination of field experiments and laboratory studies to measure how decomposition rates vary with moisture and temperature.

Soil organic carbon storage varies substantially at local and regional scales and she will soon be able to describe how the “quality” of carbon varies as well. This determines the biological availability of the carbon and how sensitive it is to warming.

Alden Adolph, Ph.D. Student

Engineering Sciences

Alden is studying how the Greenland Ice Sheet keeps records of historical atmospheric composition in the tiny bubbles of air trapped within the ice.

She focuses on understanding how the gases in the atmosphere travel through the snow and firn (snow that is more than one year old) so that we know how long the air has been trapped within the ice.

In 2007, Alden and her colleagues collected a firn core from Summit Station on the Greenland Ice Sheet and have since been studying how gas travels through the firn. The first step has been determining the best method to measure gas transport, which is important for correctly reconstructing the history of atmospheric composition and relating that to past temperature.

Once Alden and her colleagues understand the way that the earth has behaved in the past, they can hopefully improve predictions about what might happen with regards to future changes in the atmosphere, as well as the implications for the Greenland Ice Sheet, ecosystems, and people.

Kayaking Siberia's Lake Baikal to Evaluate the Effect of Climate Change

by Anna Gleizer ‘14, Stefansson Research Fellowship, Lake Baikal, Russia

During summer 2012, I became the youngest woman to kayak the circumference of Siberia’s Lake Baikal. The journey through Russia and into eastern Siberia took two weeks and the circumnavigation itself lasted 45 days, during which I collected hydrology data for an independent research project aimed at evaluating the effect of global climate change and localized anthropomorphic pollution on the quality of Baikal water.

Fieldwork in Denali National Park

by Sam Streeter '13, TH '14

Watch Sam's video about his work

During the spring-summer 2013 interim and continuing through the summer 2013 term, I performed research in the Dartmouth College Earth Sciences (EARS) Department as an engineering senior honors thesis student, Stefansson Research Fellow, and John Lindsley Fund grant recipient. The first portion of my experience involved fieldwork on the Kahiltna Glacier in the Alaska Range in Denali National Park, Alaska, and the second portion was laboratory-based in the Dartmouth EARS Department.

My research experience involved fieldwork with Professor Erich Osterberg and his team on the Kahiltna Glacier in Denali National Park. At the Kahiltna Glacier basecamp, I helped transport from the field all ice cores drilled on the slopes of nearby Mt. Hunter, helped setup a remote weather station on the Kahiltna Glacier, and helped organize, collapse, and transport research team supplies from the field.

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