Studying stable isotopes at IsoCamp
The name of the course is IsoCamp: Stable Isotope Biogeochemistry and Ecology. Could this be the nerdiest summer camp ever conceived?! Perhaps. But if you’re like me and get excited to talk about science for two weeks straight with like-minded curious individuals and get a full night’s sleep most nights, this is the camp for you!
The projects that people were involved in were fascinating and included studying paleontological marine mammals, Egyptian mummies, nutrient uptake in trees, rocks from Mars, archeological remains from the Napoleanic wars, or the diets of bats in redwood forests or polar bears in the Arctic.
This annual camp has been going on since 1996 at Utah University, and is an intense two weeks of education and hands-on lab training with an amazing array of knowledgeable and friendly instructors. I would highly recommend the course to anyone interested in using stable isotopes in their ecological research.
Our class making the delta symbol,
a central notation in isotope research.
But what are stable isotopes? “Aren’t those radioactive?!”
This is a common question for people studying stable isotopes. But good news! Studying stable isotopes will only cause a glow of happiness, not one of radioactivity. The field of stable isotopes generally studies the elements hydrogen (H), oxygen (O), carbon (C), nitrogen (N) and sulfur (S). Each of these elements naturally have different numbers of neutrons and protons in their nucleus, or isotopes. The lighter versions are more common than the heavier versions and studying the ratio of heavy to light isotopes can reveal some really cool things about nature!
Lectures were each morning with an attentive audience,
covering a wide variety of topics.
How are they used in ecology research?
In so many ways! There’s an important word in stable isotope research: fractionation. This essentially occurs when some process directs the heavy and light isotopes in different directions. For example, in partially evaporated water, the molecules with the lighter isotopes would evaporate first. This is why it’s possible to use stable isotopes to detect if water came from a desert versus a temperate rainforest. You can use your understanding of natural processes to uncover many different things from isotope research.
Our team collecting samples to process in the lab.
Here are a just few examples:
Connecting breeding and wintering grounds of Neotropical migrant songbirds using stable hydrogen isotopes: a call for an isotopic atlas of migratory connectivity.
Millennial-scale tree-ring isotope chronologies from coast redwoods provide insights on controls over California hydroclimate variability.
Comparing compound-specific and bulk stable nitrogen isotope trophic discrimination factors across multiple freshwater fish species and diets.
Exciting applications for my work
I am planning to use the skills I learned at IsoCamp directly in my Ph.D. research at UC Davis. I will be using them to detect migratory connectivity for both Golden-crowned Sparrows (Zonotrichia atricapilla) and sea turtles. Using an array of isotope signatures (generally C and N for the ocean and O and H for land) I will create isoscapes that predict from where the animals originated prior to migration. For the birds, this means identifying summer breeding grounds in Alaska and British Columbia and for the turtles this means identifying foraging grounds in the Gulf of Mexico and Caribbean. For both systems, the animals will also be tagged with either GPS or satellite telemetry in order to validate the isoscapes and make better predictions for the populations.
Left: Extracting water from soil samples – each afternoon was spent on group projects, learning different lab techniques, and Right: Data analysis and preparing presentations!