Current Research
Dr. Brooke Weigel is a marine ecologist. Her research focuses on the ecological and physiological responses of primary producers and microbial communities to global climate change, and the consequences of those changes for marine ecosystems and biogeochemical cycles. She is particularly interested in the feedbacks between climate change, kelp forests, microbes & carbon cycling in the ocean. In addition to kelp forests, Dr. Weigel has also studied snow algae in alpine ecosystems, microbial symbiosis in marine invertebrates, and nutrient cycling in freshwater streams.
NSF Postdoctoral Fellowship: Impacts of climate change on snow algal communities in the North Cascades
My current research as a NSF Postdoctoral Fellow aims to improve our understanding of how climate change is impacting snow algal communities in the North Cascade mountains of Washington. This fellowship is co-advised by Dr. Robin Kodner at Western Washington University and Dr. Jodi Young at the University of Washington-Seattle. Snow algae are microalgae that live at near-zero temperatures in alpine ecosystems worldwide. They have bright pigments that color the frozen landscape, darkening the snow surface and lowering its albedo, which accelerates snowmelt. Few studies have quantified snow algal productivity or the factors that drive variation in the intensity of snow algae blooms, which is important to understand as increased biomass leads to faster snowmelt. In addition, we know little about how future environmental conditions, including elevated CO2 levels, will impact snow algae. See this Seattle Times article about our snow algae research from last summer!
My current research as a NSF Postdoctoral Fellow aims to improve our understanding of how climate change is impacting snow algal communities in the North Cascade mountains of Washington. This fellowship is co-advised by Dr. Robin Kodner at Western Washington University and Dr. Jodi Young at the University of Washington-Seattle. Snow algae are microalgae that live at near-zero temperatures in alpine ecosystems worldwide. They have bright pigments that color the frozen landscape, darkening the snow surface and lowering its albedo, which accelerates snowmelt. Few studies have quantified snow algal productivity or the factors that drive variation in the intensity of snow algae blooms, which is important to understand as increased biomass leads to faster snowmelt. In addition, we know little about how future environmental conditions, including elevated CO2 levels, will impact snow algae. See this Seattle Times article about our snow algae research from last summer!
Postdoctoral Research at Friday Harbor Labs: Effects of warming ocean temperatures across the life cycle of bull kelp
My research at Friday Harbor Labs aims to improve our understanding of how environmental stressors are contributing to bull kelp declines in the Salish Sea. My goal is to identify the thermal tolerance limits & nitrogen requirements for successful growth and reproduction of bull kelp in the Salish Sea, from microscopic gametophytes to adult sporophytes. Using temperature-controlled lab experiments (spanning temperatures from 10 to 22°C), my research examines how the interactive effects of thermal stress and nitrogen limitation impact bull kelp physiology, survival & reproductive success across the life cycle. In addition, I am tracking seawater bottom temperatures at sites across the Salish Sea to understand when and where the environment may exceed the thermal tolerance limits for bull kelp growth and reproduction. By working with multiple populations across the Salish Sea that span a natural gradient in seawater temperatures, this research will help inform management of declining bull kelp populations and restoration efforts in the Salish Sea.
Weigel, B.L., Small, S.L., Berry, H.D., Dethier, M.N. 2023. Effects of temperature and nutrients on microscopic stages of the bull kelp (Nereocystis luetkeana, Phaeophyceae). Journal of Phycology. doi: 10.1111/jpy.13366
*Fales, R.J., *Weigel, B.L., Carrington, E., Berry, H.D., Dethier, M.N. 2023. Interactive effects of temperature and nitrogen on the physiology of kelps (Nereocystis luetkeana and Saccharina latissima). Frontiers in Marine Science. doi: 10.3389/fmars.2023.1281104 *Equal contributions (co-first author)
My research at Friday Harbor Labs aims to improve our understanding of how environmental stressors are contributing to bull kelp declines in the Salish Sea. My goal is to identify the thermal tolerance limits & nitrogen requirements for successful growth and reproduction of bull kelp in the Salish Sea, from microscopic gametophytes to adult sporophytes. Using temperature-controlled lab experiments (spanning temperatures from 10 to 22°C), my research examines how the interactive effects of thermal stress and nitrogen limitation impact bull kelp physiology, survival & reproductive success across the life cycle. In addition, I am tracking seawater bottom temperatures at sites across the Salish Sea to understand when and where the environment may exceed the thermal tolerance limits for bull kelp growth and reproduction. By working with multiple populations across the Salish Sea that span a natural gradient in seawater temperatures, this research will help inform management of declining bull kelp populations and restoration efforts in the Salish Sea.
Weigel, B.L., Small, S.L., Berry, H.D., Dethier, M.N. 2023. Effects of temperature and nutrients on microscopic stages of the bull kelp (Nereocystis luetkeana, Phaeophyceae). Journal of Phycology. doi: 10.1111/jpy.13366
*Fales, R.J., *Weigel, B.L., Carrington, E., Berry, H.D., Dethier, M.N. 2023. Interactive effects of temperature and nitrogen on the physiology of kelps (Nereocystis luetkeana and Saccharina latissima). Frontiers in Marine Science. doi: 10.3389/fmars.2023.1281104 *Equal contributions (co-first author)
Biodiversity of sponges (Porifera) in Washington and British Columbia
Sponges (phylum Porifera) are among the most ancient multicellular animals, arising as early as 600 million years ago. They are remarkably diverse, with at least 8,500 described species from marine and freshwater systems worldwide. Despite the exceptional diversity and ecological importance of marine sponges, they are notoriously difficult to identify and remain understudied in marine ecosystems. Sponges have relatively simple and environmentally plastic morphological characters, thus DNA sequencing techniques are necessary to elucidate the cryptic diversity of marine sponges. For example, there are a number of red to orange colored encrusting sponge taxa in the Pacific Northwest that all look similar with the naked eye!
I am collaborating with Dr. Matt Lemay at the Hakai Institute and Dr. Bob Thacker at Stony Brook University to study the diversity of marine sponges in the Pacific Northwest using DNA barcoding of cytochrome oxidase (CO1), 18S and 28S rRNA gene sequences.
Sponges (phylum Porifera) are among the most ancient multicellular animals, arising as early as 600 million years ago. They are remarkably diverse, with at least 8,500 described species from marine and freshwater systems worldwide. Despite the exceptional diversity and ecological importance of marine sponges, they are notoriously difficult to identify and remain understudied in marine ecosystems. Sponges have relatively simple and environmentally plastic morphological characters, thus DNA sequencing techniques are necessary to elucidate the cryptic diversity of marine sponges. For example, there are a number of red to orange colored encrusting sponge taxa in the Pacific Northwest that all look similar with the naked eye!
I am collaborating with Dr. Matt Lemay at the Hakai Institute and Dr. Bob Thacker at Stony Brook University to study the diversity of marine sponges in the Pacific Northwest using DNA barcoding of cytochrome oxidase (CO1), 18S and 28S rRNA gene sequences.
Past Research
Dissertation Research: The functional role of microbial biofilms in kelp forest ecosystems
Kelp play a vital role in coastal ecosystems, creating habitat called kelp forests and fixing tremendous amounts of carbon, yet we know little about the millions of microbial symbionts that cover their surfaces. My dissertation research explored the identity and functional role of microbes living on bull kelp, Nereocystis luetkeana, in Washington. In addition to characterizing the structure and diversity of the kelp microbiome, my research explored how microbes associated with kelp may influence carbon and nitrogen cycling in kelp forest ecosystems. Kelps release large amounts of dissolved organic carbon (DOC) during photosynthesis, which may provide a food resource to microbes living on kelp blades. In turn, microbes may perform nitrogen cycling functions that could be of importance to the host kelp. In 2017, I was awarded a National Geographic Early Career Grant to study the functional role of microbial communities in kelp forests. To learn more about this research, see the following publications:
Weigel, B.L., Miranda, K.K., Fogarty, E.C., Watson, A.R., Pfister, C.A. 2022. Functional insights into the kelp microbiome from metagenome assembled genomes. mSystems doi: 10.1128/msystems.01422-21
Ramírez-Puebla, S.T., Weigel, B.L., Jack, L., Schlundt, C., Pfister, C.A., Mark Welch, J.L. 2022. Spatial organization of the kelp microbiome at micron scales. Microbiome 10: 52: https://doi.org/10.1186/s40168-022-01235-w
Weigel, B.L. and Pfister, C.A. 2021. Oxygen metabolism shapes microbial settlement on photosynthetic kelp blades compared to artificial kelp substrates. Environmental Microbiology Reports 13 (2): 176-184. doi:10.1111/1758-2229.12923
Weigel, B.L. and Pfister, C.A. 2021. The dynamics and stoichiometry of dissolved organic carbon release by kelp. Ecology 102 (2): doi:10.1002/ecy.3221
Weigel, B.L. and Pfister, C.A. 2019. Successional dynamics and seascape-level patterns of microbial communities on the canopy-forming kelps Nereocystis luetkeana and Macrocystis pyrifera. Frontiers in Microbiology 10: 346. doi:10.3389/fmicb.2019.00346
Pfister, C.A., Altabet, M.A., and B.L. Weigel. 2019. Kelp beds and their local effects on seawater chemistry, productivity, and microbial communities. Ecology 100. doi: 10.1002/ecy.2798
Kelp play a vital role in coastal ecosystems, creating habitat called kelp forests and fixing tremendous amounts of carbon, yet we know little about the millions of microbial symbionts that cover their surfaces. My dissertation research explored the identity and functional role of microbes living on bull kelp, Nereocystis luetkeana, in Washington. In addition to characterizing the structure and diversity of the kelp microbiome, my research explored how microbes associated with kelp may influence carbon and nitrogen cycling in kelp forest ecosystems. Kelps release large amounts of dissolved organic carbon (DOC) during photosynthesis, which may provide a food resource to microbes living on kelp blades. In turn, microbes may perform nitrogen cycling functions that could be of importance to the host kelp. In 2017, I was awarded a National Geographic Early Career Grant to study the functional role of microbial communities in kelp forests. To learn more about this research, see the following publications:
Weigel, B.L., Miranda, K.K., Fogarty, E.C., Watson, A.R., Pfister, C.A. 2022. Functional insights into the kelp microbiome from metagenome assembled genomes. mSystems doi: 10.1128/msystems.01422-21
Ramírez-Puebla, S.T., Weigel, B.L., Jack, L., Schlundt, C., Pfister, C.A., Mark Welch, J.L. 2022. Spatial organization of the kelp microbiome at micron scales. Microbiome 10: 52: https://doi.org/10.1186/s40168-022-01235-w
Weigel, B.L. and Pfister, C.A. 2021. Oxygen metabolism shapes microbial settlement on photosynthetic kelp blades compared to artificial kelp substrates. Environmental Microbiology Reports 13 (2): 176-184. doi:10.1111/1758-2229.12923
Weigel, B.L. and Pfister, C.A. 2021. The dynamics and stoichiometry of dissolved organic carbon release by kelp. Ecology 102 (2): doi:10.1002/ecy.3221
Weigel, B.L. and Pfister, C.A. 2019. Successional dynamics and seascape-level patterns of microbial communities on the canopy-forming kelps Nereocystis luetkeana and Macrocystis pyrifera. Frontiers in Microbiology 10: 346. doi:10.3389/fmicb.2019.00346
Pfister, C.A., Altabet, M.A., and B.L. Weigel. 2019. Kelp beds and their local effects on seawater chemistry, productivity, and microbial communities. Ecology 100. doi: 10.1002/ecy.2798
Sea cucumber evisceration and regeneration to study gut microbiome community assembly
The gut microbiome is pertinent to many aspects of animal health, and there is a great need for tractable experimental systems to study gut microbiome assembly. Sea cucumbers have the remarkable ability to eviscerate most of their internal organs, including the gut. After evisceration, sea cucumbers can regenerate their lost gut in less than 3 weeks. I studied the process of gut microbiome community assembly during regeneration using the sea cucumber Sclerodactyla briareus. Despite immersion in a diverse consortium of environmental microbes, a specific subset of microbes proliferated in the gut, including taxa that likely conferred energetic and immune advantages to the host.
Weigel, B.L. 2020. Sea cucumber intestinal regeneration reveals deterministic assembly of the gut microbiome. Applied and Environmental Microbiology: 86 (14): e00489-20.
The gut microbiome is pertinent to many aspects of animal health, and there is a great need for tractable experimental systems to study gut microbiome assembly. Sea cucumbers have the remarkable ability to eviscerate most of their internal organs, including the gut. After evisceration, sea cucumbers can regenerate their lost gut in less than 3 weeks. I studied the process of gut microbiome community assembly during regeneration using the sea cucumber Sclerodactyla briareus. Despite immersion in a diverse consortium of environmental microbes, a specific subset of microbes proliferated in the gut, including taxa that likely conferred energetic and immune advantages to the host.
Weigel, B.L. 2020. Sea cucumber intestinal regeneration reveals deterministic assembly of the gut microbiome. Applied and Environmental Microbiology: 86 (14): e00489-20.
Microbial symbiont diversity and function in marine intertidal sponges
Marine sponges host complex and host-specific communities with thousands of unique microbial taxa. For my Master's thesis research, I investigated how tidal exposure shapes the microbiome of the sponge H. heliophila using sequencing of 16S rRNA genes, and I examined nitrogen cycling genes in the sponge holobiont.
Weigel, B.L. and Erwin, P.M. 2017. Effects of reciprocal transplantation on the microbiome and putative nitrogen cycling functions of the intertidal sponge, Hymeniacidon heliophila. Scientific Reports 7: 43247.
Weigel, B.L. and Erwin, P.M. 2016. Intraspecific variation in microbial symbiont communities of the sun sponge, Hymeniacidon heliophila, from intertidal and subtidal habitats. Applied Environmental Microbiology 82: 650-658. doi: 10.1128/AEM.02980-15
Marine sponges host complex and host-specific communities with thousands of unique microbial taxa. For my Master's thesis research, I investigated how tidal exposure shapes the microbiome of the sponge H. heliophila using sequencing of 16S rRNA genes, and I examined nitrogen cycling genes in the sponge holobiont.
Weigel, B.L. and Erwin, P.M. 2017. Effects of reciprocal transplantation on the microbiome and putative nitrogen cycling functions of the intertidal sponge, Hymeniacidon heliophila. Scientific Reports 7: 43247.
Weigel, B.L. and Erwin, P.M. 2016. Intraspecific variation in microbial symbiont communities of the sun sponge, Hymeniacidon heliophila, from intertidal and subtidal habitats. Applied Environmental Microbiology 82: 650-658. doi: 10.1128/AEM.02980-15
Linking invertebrate grazers, algal communities, and nitrogen fixation rates in streams
During my undergraduate research, I examined how grazing and physical factors mediate the source of nitrogen to stream ecosystems. We conducted an in situ grazer exclusion experiment by removing crawling invertebrate grazers from epilithon-covered rocks in three streams of varying drainage area within the Eel River network in California. In the largest stream, grazers increased the proportion and biomass of nitrogen-fixing cyanobacteria, which increased nitrogen fixation rates. Check out the publication here:
Weigel, B.L., Welter, J.R., and P.C. Furey. 2020. Invertebrate grazing and epilithon assemblages control benthic nitrogen fixation in an N-limited river network. Freshwater Science 39 (3) doi: 10.1086/710023.
During my undergraduate research, I examined how grazing and physical factors mediate the source of nitrogen to stream ecosystems. We conducted an in situ grazer exclusion experiment by removing crawling invertebrate grazers from epilithon-covered rocks in three streams of varying drainage area within the Eel River network in California. In the largest stream, grazers increased the proportion and biomass of nitrogen-fixing cyanobacteria, which increased nitrogen fixation rates. Check out the publication here:
Weigel, B.L., Welter, J.R., and P.C. Furey. 2020. Invertebrate grazing and epilithon assemblages control benthic nitrogen fixation in an N-limited river network. Freshwater Science 39 (3) doi: 10.1086/710023.