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A summer of stability working groups!

September 2025: With no fieldwork this summer, it was a summer of writing and working groups! I traveled to New Mexico for a Santa Fe Institute micro-working group on diversity-stability relationships in North American birds and to Colorado for a USGS Powell Center working group on how climate change is influencing the stability of foundation species. In Santa Barbara, I continued working on projects from two previous working groups, looking at: (1) how diversity influences multi trophic stability and (2) how macroalgal diversity influences stability on tropical reefs.

Micro-working group participants Reilly O'Connor, Kacie Ring, Gates Dupont, and me at the end of our time at SFI

The press covers our study on coral-associated crabs on the Great Barrier Reef

February 2025: Check out the coverage of our coral-crab 2025 study by: BBC Wildlife, Cosmos, the Nicholas School of the Environment, Earth.com, Oceanographic Magazine, and more!

Presented results at the Moorea Coral Reef (MCR) LTER All Investigators Meeting

November 2024: I learned about new research going on across the MCR and presented the results of a previous experiment in Moorea. As the MCR graduate student representative, I also led a workshop for graduate students and presented an update on the MCR graduate students' year.

Me talking about crabs (of course) to other scientists from the MCR

Two weeks in the south of France for the Santa Fe Institute's Complexity-GAINs International School on Ecological Complexity--I'm a changed woman!

October 2024: As part of SFI's Complexity-GAINs School I got the opportunity to travel to Sète, France, with a group of other students from around world. Over the course of two weeks we got to hear an amazing series of lectures from experts in ecological complexity--an experience that has really broadened and changed the way I see ecology. I also got to meet an amazing group of fellow graduate students and hear about the research they're working on--I'm coming home refreshed and re-inspired! Thank you, SFI!

A group of graduate students from the Complexity-GAINs school out to dinner in Sète

Week at NCEAS for the LTER's Synthesis Skills for Early Career Researchers (SSECR) program

September 2024: I spent a week at the National Center for Ecological Analysis and Synthesis (NCEAS) to kick off the first year of the LTER SSECR program. Thanks to the awesome organizers, mentors, and teachers, we learned a lot about how to collaborate effectively and how to do synthesis research on large scales.

First cohort of LTER Synthesis Fellows on the balcony at NCEAS at the end of our in-person meeting

First in-person working group meeting for a Powell Center project

August 2024: I traveled to Fort Collins, CO, to participate in a USGS Powell Center working group on how climate change is influencing the stability of foundation species. It was an amazing week where I learned a ton from the other group members. I'm excited to see what we do next!

Members of the Powell Center working group at the end of our first in-person meeting in Fort Collins

Oral presentation at the Ecological Society of America's 2024 meeting in Long Beach, CA

August 2024: I traveled to Long Beach this summer to present the results of my first dissertation chapter--in short, nutrient enrichment strengthened the mutualism between Pocillopora corals and their mutualists, which mitigated the negative impacts of nutrient enrichment

Me talking about how multi-species mutualisms may be influenced by nitrogen enrichment--especially when one of the mutualisms is a resource mutualism

Star undergraduates present their research on coral micro and macro mutualists

April 2024: UCSB undergraduates Emma Holm-Olsen and Lauren Rappa present the results of their research at the UCSB Undergraduate Research Symposium--go Emma and Lauren!

Lauren Rappa with her poster on how nitrate influences Trapezia crab feeding rates--Lauren scored hours of crab feeding videos!
Emma Holm-Olsen presenting her work on how nitrate influences coral endosymbionts--Emma counted over 70,000 cells!

Lab work era

March 2024: I'm starting to get preliminary coral histology and physiology results--more details coming soon!

Histology slides of coral samples collected as part of a set of coral lesion surveys
Quantifying the ash-free dry weight of coral tissues, which I use to normalize % protein and % carbohydrate data

Advanced to candidacy and finished my last big summer field season

September 2023: With the help of an amazing committee, I passed my written and oral exams and became a PhD candidate in the spring. Then, I hopped on a plane for the last big summer field season of my dissertation, where I set up a large-scale experiment looking at how structural legacies influence surviving corals.

Experimental coral fragments staged and ready for deployment

Lesion surveys around Moorea

September 2022: This summer of fieldwork was spent: (1) taking down a yearlong experiment that focused on reef mutualisms and (2) surveying the lagoon for signs of coral disease (i.e., coral lesions). With the help of two awesome undergraduates, another graduate student, and the mentorship of Dr. Greta Aeby, we surveyed 13 sites along the north shore, documenting any abnormal coral coloration, growth, or tissue loss. These surveys will be the first of their kind in Moorea and provide valuable information on what kinds of diseases are impacting corals in the region.

Me measuring corals along a transect as part of a broader coral lesion survey

Spring trip to Moorea

April 2022: Labmates and I head to Moorea to work on our lab experiment, RECHARGE, and survey reefs around the island.

Labmate, Kelly Speare (left), and I opening up the top to an herbivore exclusion cage on RECHARGE

Paper published on the role of predators in coral disease dynamics

January 2022: Our paper on how predators influence coral disease was just published in the journal Coral Reefs! We discuss how predators like corallivorous snails can exacerbate coral disease, while certain predators actually slow disease, perhaps through wound debridement.

Figure 1 from the paper showing the number of studies we reviewed through time (a), where they occurred (b), and examples of coral predation on reefs (c,d)

First season of fieldwork with the Burkepile, Stier, and Osenberg labs

September 2021: I spent three months this summer in Moorea, French Polynesia, kicking off the first field season of my PhD. While there, I collaborated with the Stier (UCSB) and Osenberg (UGA) labs, who taught me about the coral-associated fishes and invertebrates that live on the Pocillopora corals in Moorea (and many other things, including how to drive boats around coral).

Alex Primo (a graduate student from the Osenberg lab) and me setting up the first experiment of my PhD

Manuscript accepted for publication in Marine Ecology Progress Series on the nature of top-down control in Georgian salt marshes

November 2020: In our new paper, we look at how the density of the marsh periwinkle snail (Littoraria irrorata) affects snail grazing impacts on salt marsh cordgrass (Spartina alterniflora). We found that increasing densities of snails exponentially increased the grazing intensity per stem, but linearly decreased Spartina biomass.

Very cute photo of L. irrorata on a blade of grass. Photo credit: Brian Silliman

New paper out in Scientific Reports on how protected areas may influence corallivores and their potential predators

October 2020: In a paper led by Liz Shaver (scientist at The Nature Conservancy and Silliman Lab alumn), we show how protected coral reefs in Florida have fewer corallivorous snails (Coralliophila abbreviata), which we propose may be because of increased predator diversity inside protected areas.

Differences in the number and length of corallivorous snails based on site protection status (protected versus non-protected) and coral cover. Panel (a) shows the relationship between coral cover and snail abundance. Panels (b) and (c) show mean snail density (per m2) and length inside versus outside of SPAs

Review on positive interactions in oyster reef ecosystems accepted for publication in Frontiers in Marine Science

July 2020: In a review led by The Nature Conservancy's Simon Reeves, we examine oyster reef research and identify potential positive interactions on reefs that may be useful for reef restoration. Read the whole article here

Schematic depiction of the seven categories of positive interactions on oyster reefs that we synthesized: (A) physical reef creation, (B) positive density dependence, (C) refugia from abiotic stress, (D) refugia from biotic stress, (E) biodiversity enhancement, (F) settlement improvement, and (G) long-distance facilitation

Master's thesis defended!

July 2020: I orally defended my Master's research at Duke and submitted the written thesis on how a Xanthid crab, simulated wounding, and algal contact can influence disease occurrence in branching corals on the Great Barrier Reef! More details on what we found coming soon.

Scoping review on living shorelines published in Frontiers in Marine Science

July 2020: In a review led by Silliman lab postdoc Carter Smith, we look at what research has been done on living shorelines and the current state of living shoreline research.

Conceptual figure from our paper showing different forms of shorelines

Forum published in Trends in Microbiology on the coral meta-organism

July 2020: In collaboration with the Ainsworth lab at UNSW and the Silliman lab at Duke University, we talk about about how "interstitial associates" (i.e. organisms that spend most or all of their lives on/within corals) influence the coral holobiont in our new paper out in Trends in Microbiology.

Conceptual figure from our paper showing how coral-associated fishes and invertebrates can affect corals and their microbial communities

NSF-INTERN grant awarded to spend the summer working at the Smithsonian Institution's National Museum of Natural History

June 2020: NSF-INTERN grant awarded to spend the summer researching invertebrate biodiversity on North Carolinian oyster reefs using metabarcoding data from Autonomous Reef Monitoring Structures deployed in conjunction with the Global ARMS project.

Jason Dinh (Patek lab graduate student) and I heading off to collect the Autonomous Reef Monitoring Structures we deployed around Beaufort, NC, in collaboration with Smithsonian scientists

Salt marshes protect shorelines: new paper out in Current Biology

June 2019: Through a combination of field experiments and meta-analyses, we show that salt marshes do reduce shoreline erosion and remain an important component of coastal protection in our recent paper, led by Brian Silliman

Conceptual figure from our paper showing how marsh edges are influenced by eutrophication, drought, overfishing, and other environmental factors

First paper in collaboration with the Silliman lab published in Frontiers in Ecology and Evolution

April 2019: In my first paper as a part of the Silliman Lab, we look at how positive species interactions can be leveraged to enhance salt marsh and mangrove restoration.

Conceptual figure from our paper showing ways in which positive species interactions can improve mangrove restoration

Undergraduate thesis published in the American Journal of Botany

February 2019: In collaboration with Kathy Gerst of the USA-National Phenology Network and local expert Bill Peachey, the work from my undergraduate thesis is out in print! You can read about how the flowering of a keystone desert species, the saguaro cactus (Carnegiea gigantea), may be influenced by climate here.

Photo of the study site. Photo credit: Bill Peachey

$30,000 Bass Connections grant awarded to study whether sound can be used as a proxy for oyster reef biodiversity

December 2018: Our proposal was funded to assemble a team of undergraduate students, master's students, PhD students, postdocs, and faculty to study whether we can use bioacoustic metrics to estimate oyster reef diversity. Learn more on our website: https://ecometrics.webflow.io/

Undergraduate student and I excavating an oyster reef quadrat in Beaufort, NC

Undergraduate research on a common Moorean algal species published in the Marine Environmental Research

October 2018: The work from my undergraduate summer research was just published in Marine Environmental Research! In the paper, led by Cat Fong, we examine how epiphytes on a common macroalgal species, Turbinaria ornata, provide food for young fish in Moorea, French Polynesia.

NSF-Graduate Research Fellowship awarded for three years of graduate study

April 2018: In exciting news, I was awarded a three-year NSF fellowship to study marine ecology as a part of the Silliman Lab at Duke University. I'll start in North Carolina this fall, where I'll study salt marshes and coral reefs.

Silliman lab members walking out towards a long-term lab experiment on Sapelo Island, GA

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Email: jrenzi(at)ucsb.edu