Marine Biology Commons^™

White Shark Occurrence In Flower Garden Banks National Marine Sanctuary Revealed From Acoustic Telemetry In An Offshore Mpa, Michael A. Dance, Jay R. Rooker, R. J. David Wells, Megan V. Winton, Landes L. Randall, Marissa F. Nuttall, Brondum M. Krebs, Creed C. Branham, Brett B. Sweezey, Richard J. Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

The outer continental shelf of the Gulf of Mexico (Gulf) is characterized by unique bathymetric features that provide critical habitat for marine fauna. Here, we demonstrate the utility of large-scale acoustic telemetry for monitoring an oceanic marine protected area (MPA) and document the first known occurrences of white sharks (Carcharodon carcharias) within Flower Garden Banks National Marine Sanctuary (FGBNMS). White sharks were tagged with acoustic transmitters in the western North Atlantic Ocean off the east coast of the United States and Canada. Nine white sharks were detected along the outer shelf ecosystem associated with FGBNMS over a three-year …

Trawling For Clues: Examining Nefmc Herring Amendment 8, Christopher Santoro

Honors Scholar Theses

In 2007, almost twenty years ago, the Magnuson-Stevens Act changed the landscape of fisheries management in the US. Through the establishment of Fisheries Management Councils (FMCs), it paved the way for top-down management approaches that helped the government combat nationwide declines or collapses in fish stocks. Among the myriad responsibilities of the FMCs was the expectation that amendments to existing fisheries management plans would be a necessity to adapt to modern circumstances. This thesis focuses on New England Fisheries Management Council's (NEFMC's) Herring Amendment 8 (A8). This amendment, passed in 2021, attempts to lay the groundwork for sustainable management of …

All Rivers Reach The Sea: Can We Improve Ocean Conservation Through Improving Public Understanding Of The Connections Between Marine And Terrestrial Systems?, Lauren Hind

The Plymouth Student Scientist

With marine environments facing growing threats and their connections to terrestrial environments often disregarded, understanding public perceptions of these connections is crucial for effective ocean conservation. This study aimed to assess public understanding of the interconnectedness of marine and terrestrial environments and its influence on ocean conservation efforts. To achieve this, two questionnaires (N=560) were distributed among over 18’s (N=301) and under 18’s (N=259) evaluating their knowledge on the connections between marine and terrestrial environments, engagement with conservation and views on education and responsibility. The results indicated a limited understanding and awareness of marine-terrestrial connections, particularly among under 18’s. Current …

Assessment Of Dominant Shark And Ray Species And Their Size At Brondong And Muncar Ports, East Java, Indonesia, Tri Djoko Lelono, Gatut Bintoro, Arief Setyanto, M. Arief Rahman, Desy Setyoningrum, Naufal Hilda Bahtiar, Hanifa Ramadhani, Tawang Firmansyah, Hasan Syaiful Rizal

Journal of King Abdulaziz University: Marine Science

Shark and ray species are both limited in number and distribution and require time to mature and reproduce, making these species extremely vulnerable to mass exploitation as a resource. Based on the identification results, Muncar Port Banyuwangi had 26 species from 490 ray samples, and Brondong Port Lamongan had 28 species from 1830 ray samples. Fifteen species of rays were found only in Brondong, 17 species of rays were found only in Muncar, and as many as 13 were found in the two sample sites. As for sharks in Muncar, 38 out of 679 species were Brondong samples and 22 …

United Seas For Resilient Reefs: A Blueprint For Coral Conservation Through International Cooperation, John J. Bohorquez, Maoz Fine, Dana I. Grieco, David A. Gill, Ali Al-Swalimih, Jacqueline Padilla-Gamino, Isaiah W. Bolden, Margaux Hein, Callum Backstrom, Melanie Mcfield, Raphael Martinez, Benjamin Midberry, Fahd Al-Guthmy, Ellen K. Pikitch, Natalia Benejam, Chen Azulay, Britt Ronen, Oren Levy, Anne Mcelroy, Karine Kleinhaus

School of Marine & Atmospheric Sciences Faculty Publications

Coral reefs are one of Earth’s most vital and threatened ecosystems. They protect coastlines, generate billions of dollars of tourism revenue, support valuable fisheries, and contribute to the development of vital medicines. Yet half of the world's coral reefs have been lost in the last 50 years, and 90% of remaining reefs are projected to die off by the middle of this century, mainly due to warming seas from climate change.

Despite these challenges there is reason for hope. Some coral reefs – such as in the northern Red Sea and Gulf of Aqaba – have demonstrated remarkable resilience to …

Using Satellite Tracking And Stable Isotopes To Characterize The Movements, Core-Use Areas, And Distribution Of Loggerhead And Green Turtles Nesting In South Florida, Usa: Internesting, Foraging, And Migration, Glenn D. Goodwin

All HCAS Student Capstones, Theses, and Dissertations

The movements of animals in response to environmental variation influence the fitness of individuals and drive major ecological processes, while also varying their exposure level to anthropogenic risks. Understanding the movements and spatial distribution of imperiled species is critical for developing effective conservation strategies. This can be difficult for wide ranging and highly migratory species, such as sea turtles. Throughout their adult life stages, the females of most sea turtle species spend the majority of their time in their foraging areas for multiyear intervals between nesting periods. These foraging areas are typically widely dispersed and variable within nesting populations. To …

Sparse Seagrass Meadows Are Critical Dugong Habitat: A Novel Rapid Assessment Of Habitat-Wildlife Associations Using Paired Drone And In-Water Surveys, Nicole E. Said, Christophe Cleguer, Paul Lavery, Amanda J. Hodgson, Connor Gorham, Julian A. Tyne, Ankje Frouws, Simone Strydom, Johnny Lo, Holly C. Raudino, Kelly Waples, Kathryn Mcmahon

Research outputs 2022 to 2026

Understanding the fine-scale behavioural and feeding ecology of marine megafauna is imperative for effective management of their habitat areas; however, obtaining the relevant data can be both costly and challenging. Here we integrate the use of small drones for dugong surveys with underwater benthic habitat assessment techniques at the local spatial scale (∼30 km2), to determine the drivers of dugong (Dugong dugon) distribution across three locations in the Pilbara, Western Australia. Paired assessment data was collected three times over two years. Benthic habitat (percent cover), seagrass nutritional quality and environmental parameters (temperature, water clarity, water current, water depth) were tested …

Ina Scuba: Mobilization Of French West Indies Scuba Diving Clubs To Rapidly Improve Knowledge On Threatened Marine Species. Case Of The White-Spotted Eagle Ray (Aetobatus Narinari)., Océane Beaufort, Rocio Prieto González

Gulf and Caribbean Research

The White—Spotted Eagle Ray (Aetobatus narinari), listed as Endangered on the IUCN Red List since 2021, is experiencing alarming population declines, underscoring the urgent need for targeted conservation efforts. This species, which plays a vital ecological role in marine food webs, has biological and ecological characteristics that make it particularly vulnerable to habitat degradation and anthropogenic pressures, particularly fishing, tourism, and maritime traffic. In the French West Indies (FWI), the paucity of data on the White—Spotted Eagle Ray remains a major obstacle to the development of effective, island—specific conservation strategies. To address this gap, the INA Scuba participatory …

The First Iucn Red List Of Cold-Water Corals Highlights Global Declines, Julia D. Sigwart, A. Louise Allcock, Renata Carolina Mikosz Arantes, Kelsey Archer Barnhill, Narissa Bax, Julia S. Beneti, Saskia Brix, Gudmundur Gudmundsson, Catherine S. Mcfadden, Severin A. Korfhage, Christi Linardich, Declan Morrissey, Pedro De Oliveira Nascimento, Bárbara De Moura Neves, Steinunn H. Ólafsdóttir, Stefán Ragnarsson, Kaveh Samimi-Namin, Íris Sampaio, Mark E. De Wilt

Biological Sciences Faculty Publications

The most well-known species-based conservation tool is the International Union for the Conservation of Nature (IUCN) Red List of Threatened Species. The current coverage of species in the Red List is known to under-represent benthic marine species. Cold-water corals (CWCs) are increasingly recognised as key to deep-water biodiversity and integral to protected vulnerable marine ecosystems (VMEs), but no deep-sea coral species were previously included in the Red List. We selected 22 cold-water coral species in the Northeast Atlantic, including 4 reef-forming stony corals and 18 octocorals including sea pens and gorgonians, and completed the first IUCN Red List global assessments …

Global Patterns And Drivers Of Seagrass Biomass, Net Primary Production And Meadow Structure, Nicole R. Foster, Enric Gomis, Diana I. Montemayor, Simone Strydom, Miguel Angel Mateo, Eduard Serrano, Aurora M. Ricart, Martin Dahl, Ines Mazarrasa, Paulina Cisternas, Harry Whiteley, Elliott J. Bates, Viena Puigcorbé, Uxue Moreda, Mar Truc, Karina Inostroza, Rafael Huertas, Roisin Mccallum, Anna Lafratta, Chanelle L. Webster, Caitlyn M. O'Dea, Nicole E. Said, Carlos M. Duarte, Paul S. Lavery, Oscar Serrano

Research outputs 2022 to 2026

Aim: We decipher global patterns in seagrass growth and structure to advance seagrass science, facilitate multidisciplinary research, and promote effective management strategies and policy development for seagrass habitats. Location: Global. Time period: 1975 to 2024. Major taxa studied: Seagrasses—marine angiosperms. Methods: A global data set on seagrass total biomass, total net primary productivity (NPP), shoot density, and percent cover was compiled across 11 genera. We tested how these variables change across seagrass genera, life-history strategy, and geographic location; and then modelled the environmental drivers (temperature, nutrients, light availability) of the patterns observed. Results: The mean (±SE) total biomass of seagrasses …

Rooting For Resilience: Investigating The Success Of Seagrass Restoration Methods, Olivia K. Stockdale

The Plymouth Student Scientist

Seagrasses generate vital ecosystem services to coastal communities, whilst also protecting marine biodiversity. Despite their significance, seagrass ecosystems face a plethora of threats from both anthropogenic and natural sources, causing a 20 % loss of seagrass area over the last century. To combat this, numerous restoration methods exist for seagrass habitats globally, with varying degrees of success. Through a comprehensive systematic review and subsequent meta-analysis, this study illustrates the varying success rates of different transplant and seed-based restoration methods over differing timescales. Accounting for varying timescales, results showed that restoration method had a significant effect on success rate (χ^{2 …}

A Comparative Analysis Of Extant Oceanic Shark Species Using Trait-Based Ecology, Elizabeth A. Johnson

All HCAS Student Capstones, Theses, and Dissertations

Over the past few decades, scientists have been working together to mitigate human impacts on global shark populations, but deciding which species need the most immediate attention can be difficult. This study uses a newly emerging approach to ecology, trait-based ecology, to identify trends in trait expression with depth and determine which species have the most unique sets of traits. While trait-based ecology has already been applied to numerous fields, a trait-based approach to shark research is still in its infancy. A total of 15 traits across 337 oceanic shark species were examined to identify trends in trait expression and …

Ecological And Educational Impacts Of A Living Shoreline On St. Simons Island, Georgia, Usa, C. Tate Holbrook, Cameron Atkinson, Jordan Fountain, Stephanie Knox, Jan Mackinnon

Georgia Journal of Science

Living shorelines encompass a range of nature-based alternatives to traditional coastal armoring structures. In addition to shoreline stabilization and protection, living shorelines are intended to meet conservation goals such as restoring habitat, delivering ecosystem services, and promoting ecological resilience to climate change. While early results have been promising, further monitoring is needed to better understand and evaluate the performance of living shorelines across a range of designs and environmental contexts, thereby informing coastal management. Nature-based shoreline protection is relatively new in Georgia, USA, where in 2015 the state’s fourth living shoreline was constructed of oyster shell and native plants on …

A Computational Profile Of Invasive Lionfish In Belize: A New Insight On A Destructive Species, Joshua E. Balan

The Journal of Purdue Undergraduate Research

Since their discovery in the region in 2009, invasive Indonesian-native lionfish have been taking over the Belize Barrier Reef. As a result, populations of local species have dwindled as they are either eaten or outcompeted by the invaders. This has led to devastating losses ecologically and economically; massive industries in the local nations, such as fisheries and tourism, have suffered greatly. Attempting to combat this, local organizations, from nonprofits to ecotourism companies, have been manually spear-hunting them on scuba dives to cull the population. One such company, Reef Conservation Institute (ReefCI), operating out of Tom Owens Caye outside of Placencia, …

Lessons From An Iconic Grouper: Sex, Science, And Serendipity, Yvonne J. Sadovy De Mitcheson

Gulf and Caribbean Research

From a common little damselfish and spectacular grouper aggregations, to disappearing reef fishes and the dark side of the international seafood trade, my journey has passed through a fascinating and worrying period of change in the way we view and treat our oceans. Although much of my career has been in the Indo—Pacific, I focus here mainly on my professional ‘roots’ in the Caribbean and on the Nassau Grouper Epinephelus striatus, a species that kept me curious, taught me patience, never to assume and always to stay hopeful. This fish is almost an obsession; why can we not better safeguard …

Half Of Atlantic Reef-Building Corals At Elevated Risk Of Extinction Due To Climate Change And Other Threats, Luis Gutierrez, Beth Polidoro, David Obura, Francoise Cabada-Blanco, Christi Linardich, Emma Pettersson, Paul Pearce-Kelly, Krista Kemppinen, Juan Jose Alvarado, Lorenzo Alvarez-Filip, Anastazia Banaszak, Pilar Casado De Amezua, James Crabbe, Aldo Croquer, Joshua Feingold, Elizabeth Goergen, Stefano Goffredo, Bert Hoeksema, Danwei Huang, Emma Kennedy, Diego Kersting, Marcelo Kitahara, Petar Kružić, Margaret Miller, Flavia Nunes, Juan Pablo Quimbayo, Andrea Rivera-Sosa, Rosa Rodríguez-Martínez, Nadia Santodomingo, Michael Sweet, Mark Vermeij, Estrella Villamizar, Greta Aeby, Khatija Alliji, Daniel Bayley, Elena Couce, Benjamin Cowburn, C. Isabel Nuñez Lendo, Sean Porter, Kaveh Samimi-Namin, Tom Shlesinger, Bryan Wilson

Biological Sciences Faculty Publications

Atlantic reef-building corals and coral reefs continue to experience extensive decline due to increased stressors related to climate change, disease, pollution, and numerous anthropogenic threats. To understand the impact of ocean warming and reef loss on the estimated extinction risk of shallow water Atlantic reef-building scleractinians and milleporids, all 85 valid species were reassessed under the IUCN Red List Categories and Criteria, updating the previous Red List assessment of Atlantic corals published in 2008. For the present assessment, individual species declines were estimated based on the modeled coral cover loss (1989–2019) and projected onset of annual severe bleaching events (2020–2050) …

Flujos De Servicios Ecosistémicos En Un Área Marina Protegida Del Atlántico Sur: Perspectivas Desde El Análisis De La Teoría De Redes, Mitch Porter

Independent Study Project (ISP) Collection

En cuestiones de gestión de áreas protegidas, los servicios ecosistémicos se tienen cada vez más en cuenta junto con la conservación de la biodiversidad. Sin embargo, las decisiones que se toman sobre la conservación de los servicios ecosistémicos no suelen incluir los posibles efectos en cascada de la pérdida de biodiversidad sobre la provisión de servicios. Los conocimientos de la teoría de redes y los estudios de robustez pueden proporcionar una metodología para evaluar la vulnerabilidad de estos servicios frente la estructura trófica de los ecosistemas que los proveen. A través de una serie de simulaciones de extinción para la …

Applications Of Environmental Dna (Edna) To Detect Subterranean And Aquatic Invasive Species: A Critical Review On The Challenges And Limitations Of Edna Metabarcoding, Sakib Tahmid Rishan, Richard Kline, Md Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

The world is struggling to solve a devastating biodiversity loss that not only affects the extinction of treasured species and irreplaceable genetic variation, but also jeopardizes the food production, health, and safety of people. All initiatives aimed to conserve biodiversity rely heavily on the monitoring of both species and populations to get accurate spatial patterns and overall population assessments. Conventional monitoring techniques, such as visual surveys and counting individuals, are problematic due to challenges in identifying cryptic species or immature life stages. Environmental DNA (eDNA) is a relatively new technology that has the potential to be a faster, non-invasive, and …

Practical Solutions To The Invasion Of Lionfish In Utila, Honduras: Science, Education, Food, And Jewelry, Carolyn Corley

Undergraduate Honors Theses

Lionfish (Pterois sp.) are invasive species capable of devastating coral reef ecosystems due to their lack of predators, large appetites, generalist diet, high fecundity, and rapid spawning rates. As lionfish have expanded their distribution across the Caribbean, many conservation groups have taken it upon themselves to systematically remove these predators from environments where they are threatening native species. However, few have involved the community the way I observed while interning with the Whale Shark and Oceanic Research Center in Utila, Honduras. Protecting coral reefs is extremely important, especially in small communities like Utila, where the majority of people’s …

Dolphin Behavioral Responses To Uncrewed Aerial Systems As A Function Of Exposure, Height, And Type, Savannah Damiano

Electronic Theses and Dissertations

Uncrewed aerial systems (UAS) are becoming a standard tool in the study of cetaceans, however, a comparative assessment of animal responses to UAS has not been established to gauge the most effective systems for cetacean study. We utilized Dolphin Quest Bermuda’s eleven bottlenose dolphins as subjects for such an investigation taking place over five weeks in 2022 and five weeks in 2023. The dolphins were evaluated for investigative behavioral responses to six off-the-shelf UAS types and a custom fixed wing system. Each UAS was flown in decreasing height vertically above the main dolphin lagoon to evaluate dolphin behavioral responses in …

Using Podcasts To Bring National Estuarine Research Reserves Into The Classroom For Grades 6-12, Kaitlyn M. Dirr

Senior Theses

In a typical classroom setting, there are significant challenges to exposing students to concepts related to earth sciences and the environment. These challenges are exacerbated when conveying lessons about geographic areas with limited access, such as oceans and coastlines (Louv, 2010). It is now more important than ever for environmental education to improve and adapt to our changing world. Educators may have the opportunity to bring these subjects to life by using media content such as podcasts to introduce students to new places and the scientists, managers and educators that work in those spaces. In the United States, there exists …

Eavesdropping On Animals: Can Bioacoustics Help Save Species?, Zoe Grueskin

Capstones

Around the world, scientists are using sound to study the natural world in a growing field called bioacoustics. Researchers are eavesdropping on frogs and fish, elephants and earthworms, and many hope what they hear can inform and inspire conservation action around the world. From the field’s auspicious beginning with accidentally-recorded whales, to researchers today listening to locations as diverse as the Arctic seafloor and India’s Western Ghats mountain range, this capstone project explores the potential — and limitations — of conservation bioacoustics. Read the story, see photos and listen to audio pieces featuring three bioacousticians and their field recordings here: …

List Of Fish Species Present In Galápagos, Ecuador, And California, U.S.A., With Notes On Their Commercial Importance And Conservation Status, Erin J. Hanson, Jose R. Marin Jarrin

IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt

No abstract provided.

Determination Of Atlantic Shortfin Mako Shark (Isurus Oxyrinchus) Population Genetic Structure And Comparison Of Mitogenomic Markers, Marissa Mehlrose

All HCAS Student Capstones, Theses, and Dissertations

This study provides the first genomics-level, population structure and genetic diversity assessment of the shortfin mako (Isurus oxyrinchus) shark. The assessments were based on mitogenome sequences from makos distributed throughout the Atlantic Ocean, with Pacific mako mitogenomes used as a comparative outgroup. In addition to complete mitogenome-based analyses, I assessed individual mitochondrial coding gene and non-coding (Control Region) sequences for their comparative resolution properties as markers for revealing matrilineal population structure and genetic diversity. Sequencing of 125 makos in the western and eastern Atlantic across northern and southern hemispheres yielded 92 complete mitogenomes (16,698-16,702 bp) and 33 partial …

A Genomic Investigation Of Divergence Between Tuna Species, Pavel V. Dimens

Dissertations

Effective management and conservation of marine pelagic fishes is heavily dependent on a robust understanding of their population structure, their evolutionary history, and the delineation of appropriate management units. The Yellowfin tuna (Thunnus albacares) and the Blackfin tuna (Thunnus atlanticus) are two exploited epipelagic marine species with overlapping ranges in the tropical and sub-tropical Atlantic Ocean. This work analyzed genome-wide genetic variation of both species in the Atlantic basin to investigate the occurrence of population subdivision and adaptive variation. A de novo assembly of the Blackfin tuna genome was generated using Illumina paired-end sequencing data and …

Defining The Current Distribution Of The Imperiled Black-Spotted Newt Across South Texas, Usa, Padraic S. Robinson, Drew R. Davis, Sean M. Collins, Richard Kline

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Black-spotted Newt (Notophthalmus meridionalis) is a chronically understudied salamander species, with many aspects of its natural history, ecology, and distribution poorly known. Previous studies using traditional methodologies have had limited success documenting N. meridionalis on the landscape, detecting individuals at 6% (7 of 114) and 1% (2 of 221) of sites surveyed. A novel environmental DNA (eDNA) assay was designed and implemented with the goals of assessing the current distribution of N. meridionalis across south Texas, USA, and better understanding the conditions for positive eDNA detections. We conducted eDNA sampling and traditional surveys at 80 sites throughout …

Overfishing Drives Over One-Third Of All Sharks And Rays Toward A Global Extinction Crisis, Nicholas K. Dulvy, Nathan Pacoureau, Cassandra L. Rigby, Riley A. Pollom, Rima W. Jabado, David A. Ebert, Brittany Finucci, Caroline M. Pollock, Jessica Cheok, Danielle H. Derrick, Katelyn B. Herman, C. Samantha Sherman, Wade J. Vanderwright, Julia M. Lawson, Rachel H.L. Walls, John K. Carlson, Patricia Charvet, Kinattumkara K. Bineesh, Daniel Fernando, Gina M. Ralph, Jay H. Matsushiba, Craig Hilton-Taylor, Sonja V. Fordham, Colin A. Simpfendorfer

Biological Sciences Faculty Publications

The scale and drivers of marine biodiversity loss are being revealed by the International Union for Conservation of Nature (IUCN) Red List assessment process. We present the first global reassessment of 1,199 species in Class Chondrichthyes-sharks, rays, and chimeras. The first global assessment (in 2014) concluded that one-quarter (24%) of species were threatened. Now, 391 (32.6%) species are threatened with extinction. When this percentage of threat is applied to Data Deficient species, more than one-third (37.5%) of chondrichthyans are estimated to be threatened, with much of this change resulting from new information. Three species are Critically Endangered (Possibly Extinct), representing …

Genetic Population Dynamics Of The Critically Endangered Scalloped Hammerhead Shark (Sphyrna Lewini) In The Eastern Tropical Pacific Ocean, Sydney P. Harned

All HCAS Student Capstones, Theses, and Dissertations

The scalloped hammerhead shark, Sphyrna lewini, is a Critically Endangered, migratory species known for its tendency to form large aggregations of mostly adult females, especially in the heavily-fished Eastern Tropical Pacific (ETP) Ocean. This species forms iconic, visually spectacular, seasonal aggregations in the northern Galápagos Islands, and it is hypothesized based on telemetry studies that pregnant females from these aggregations migrate to mainland coastal nurseries for parturition. This study investigated the population genetic dynamics of the scalloped hammerhead across most of its coastal and offshore distribution (Mexico to Ecuador) in the ETP, focusing on young-of-the-year animals sampled from nursery …

Assessing The Occurrence Of Trichechus Manatus Latirostris In Mobile Bay, Alabama Using Edna, Elora Pierce

Honors Theses

In the past several decades Florida manatees (Trichechus manatus latirostris) have begun to expand their summer range into the northern Gulf of Mexico. Because this is a recent occurrence, not much is known about their habitat use and distribution in this region. Citizen-sourced sighting data suggests that Florida manatees frequent subembayments of Mobile Bay, Alabama, reaching a sighting peak in August. To assess the occurrence of manatees in this area environmental DNA surveys were used from winter (February 19-20) and summer (August 21-22) of 2018. At each of the 21 sites ranging from the mouth of Mobile Bay, …

Environmental Drivers Of Mesophotic Echinoderm Assemblages Of The Southeastern Pacific Ocean, Ariadna Mecho, Boris Dewitte, Javier Sellanes, Simon Van Gennip, Erin E. Easton, Joao B. Gusmao

School of Earth, Environmental, & Marine Sciences Faculty Publications

Mesophotic ecosystems (50–400 m depth) of the southeastern Pacific have rarely been studied because of the logistical challenges in sampling across this remote zone. This study assessed how oxygen concentrations and other environmental predictors explain variation in echinoderm assemblages at these mesophotic systems, where this group is among the predominant fauna. We compiled data on echinoderm taxa at 91 sampling stations, from historical and recent surveys (between 1950 and 2019), covering a longitudinal gradient of approximately 3,700 km along with the Nazca, Salas y Gómez, and Juan Fernández ridges. Uni- and multivariate model-based tools were applied to analyze the patterns …