Jordan is a postdoc at Simon Fraser University. She is an ecologist with an interest in resource management. Jordan shares how she and her colleagues have used a remotely operated vehicle to survey marine biodiversity in the Mexican Pacific.

Jordan Hollarsmith.
Personal links. Website | Twitter
Institute. Simon Fraser University
Academic life stage. Postdoc
Major research interests. Resource management and ecology as it relates to multiple stressors.
Current study system. My research currently focuses on how we manage resources given the cocktail of threats facing nearshore marine ecosystems. In addition to comparing decision-making frameworks used across North America, I am using kelp forest ecosystems of the Salish Sea as a case study into modelling threats using expert opinion instead of more traditional data sources. This work is beautifully collaborative and very urgent given the pace of ecosystem decline we are observing in the Salish Sea and around the world.

Jordan Hollarsmith, Kyle Neumann, and Tallulah Winquist, prepare for a dive in large swell of the coast of Socorro Island in the Revillagigedo Archipelago. Photo taken by Tamara Arenovich with the Sea Shepherd Conservation Society.

Jordan Hollarsmith and Georgina Ramírez Ortiz with the ROV. The photo was taken by Arturo Bocos at El Bajo in the Bay of La Paz.
Recent paper. Hollarsmith JA, Ramírez-Ortiz G, Winquist T, Velasco-Lozano M, DuBois K, Reyes-Bonilla H, Neumann KC, Grosholz ED. 2020. Habitats and fish communities at mesophotic depths in the Mexican Pacific. Journal of Biogeography 47(7), https://doi.org/10.1111/jbi.13842. [content link here]
Motivation for this paper? Ecosystems found below 30 m depth in the ocean are some of the least known in the world, in part because it is so difficult to access them. However, advances in ROV (remotely operated vehicle) technology means they are now smaller and cheaper than ever before. Colleagues and I decided to seize this opportunity. With the help of National Geographic, the Explorers’ Club, the Sea Shepherd Conservation Society, and other generous partners, we built our own small ROV to survey continental and oceanic islands in the Mexican Pacific. We chose these locations based on the high biodiversity and endemism found in shallow areas around the islands. Moreover, the complex mixing of water masses in the region provides increased potential for highly diverse habitats and fish communities below 30m.
Key methodologies. This paper is among the first to use small and economic ROV technology to survey fish communities at mesophotic depths. Our approach was highly collaborative, involving early career researchers and students from the United States and Mexico, multiple academic institutions in both countries, non-profits, funding sources, and direct-action environmental organizations. Thanks to the combination of diverse collaborations and affordable technology, we were able survey a wide range of islands, depths, and habitats for very little money.

The ROV.
Unexpected challenges. Driving the ROV from small boats in huge open-ocean swell under a stifling tarp surrounded by curious boobies and sharks was difficult, to say the least! It was hard to see many details when driving the ROV, so often we would only realize what we had surveyed when we reviewed the footage later. Thankfully, despite the difficult field conditions and the constant battle with sea sickness, we were able to identify the majority of fish we observed and elucidate ecological and biogeographical patterns from our data.
A soft coral reef at mesophotic depths around the Revillagigedo Archipelago.
Major results. Out of the 81 species we identified in our surveys, we observed nine fish species deeper than they’ve ever been recorded and one fish species, the Galapagos snake eel, thousands of kilometers away from anywhere it had previously been observed. Our surveys included large undocumented rhodolith beds (free-living coralline algae) and mesophotic algal communities, in addition to diverse communities of soft corals and sponges. These findings increase our knowledge of the natural history of these fish species, and increase our understanding of the ecosystems within the two Mexican National Parks that we surveyed.
A mesmerizing school of hunting jurel (Seriola rivoliana) at Clarion Island.
Next steps for this research. One of the undergraduate students involved in the video analysis is using these data for his senior thesis at the Universidad Autónoma de Baja California Sur. Watch out for his paper on the differences in fish functional diversity at mesophotic depths across continental and oceanic islands, currently in revision at Ciencias Marinas!
If you could study any organism on Earth, what would it be? I would study kelp! Kelp is a beautiful and diverse family of brown algae (Laminariaceae) that forms critical habitat in temperate rocky reefs around the world. Kelp is also found in the mesophotic zone in tropical and subtropical regions where a clear surface layer allows light to penetrate deep into the ocean where it illuminates cold, nutrient-rich water, thus providing the perfect conditions for kelp. These habitats have been observed in the Galapagos, New Zealand, and the Mediterranean. We were hoping to find another one in the Revillagigedo Archipelago, but we will have to save that for another mission!