Illuminating the hidden connections that drive ecosystems

As told to Katie Jewett

I 've always been curious about things we can't naturally see at first. Growing up, I spent every summer on Auburn Lake in rural Wisconsin, where I was constantly looking beneath the surface with my swim goggles.

When I was 15, I googled “scuba diving in Wisconsin,” found a dive shop, and convinced my parents to let me scuba dive. I went shipwreck diving in the Great Lakes to see something other than the green pea soup consistency of the local lakes. In the winter, I went ice diving. The most beautiful thing was looking up from underneath to see sunlight filtering through little bits of algae trapped in the ice. 

I attended St. Olaf College in Minnesota and spent the summers studying stream and estuarine ecosystems around the world. After my first summer studying nitrogen-fixing algae in Northern California streams, I was hooked on ecology. My interest in microbial ecology flourished while studying marine sponges for my master’s degree, as sponges host extremely diverse microbiomes. 

During my PhD at the University of Chicago, I began studying kelp forests. I realized that we knew almost nothing about the microbes that live on kelp, their diversity, and functional role. I collaborated with an imaging expert at the Marine Biological Lab in Woods Hole to produce the first-ever visualization of the kelp microbiome that included multiple bacterial species. I had already characterized the diversity of kelp-associated bacteria through DNA sequencing, but the image revolutionized our understanding of their micron-scale interactions. Sequencing the genomes of kelp microbes revealed important functions such as nitrogen cycling and vitamin B12 synthesis. 

As a postdoctoral researcher at Friday Harbor Laboratories, I was tasked with understanding why kelp are declining in Puget Sound, Washington. Half of kelp’s life cycle is microscopic, so understanding the impacts of climate change stressors at each life stage is critical. I grew kelp from multiple populations across seven different temperatures in the lab to find the upper thermal limits for growth and reproduction.

In addition to microscopic kelp and bacteria, I study the invisible drivers of the carbon cycle. When kelp photosynthesize, they release dissolved sugars into the water known as dissolved organic carbon. Approximately half of all carbon sequestered by marine macroalgae like kelp is in this dissolved form, yet we know very little about how much carbon the kelp releases, let alone where it goes. My research program will improve our understanding of carbon cycling in kelp forests to better evaluate the ability of kelp to sequester carbon dioxide from the atmosphere.

Here at Stanford, my lab will also study the impacts of temperature and other climate stressors on kelp physiology to predict how we can have resilient kelp forests in the future. Being at Hopkins Marine Station is a dream come true. I can see kelp forests and sea otters right outside my window. I can’t wait to design courses that make use of the diverse environment here. 

I also feel a sense of urgency as climate change accelerates. We need creative approaches to understand invisible and impactful processes like carbon cycling that occur within the ocean. I’ve always been drawn to measuring how hidden connections keep ecosystems functioning. I hope that by illuminating these processes I can contribute to conservation and restoration solutions, and help ensure a sustainable future for kelp forests. 

Related: Brooke Weigel, Assistant Professor of Oceans