Worlds colliding: DEEPEND pelagic program expands to deep-reef environments to examine benthopelagic coupling

The DEEPEND (Deep Pelagic Nekton Dynamics; www.deependconsortium.org) program has been studying the epipelagic, mesopelagic, and bathypelagic fauna of the Gulf of Mexico for the last 14 years (and counting). Given the progress made offshore, we are excited to announce an addition to the DEEPEND research portfolio, a detailed examination of the interactions of mesopelagic and deep-benthic (particularly deep coral) assemblages along the outer continental slope. This new activity, entitled “Deep-Sea Benefits,” will begin field surveys in Sep 2024 and extend four years in total (news release can be found here). This project will run parallel to, and integrate data from, DEEPEND’s sustained sampling further offshore. It will also integrate research efforts from existing “Mesophotic and Deep Benthic” projects in the Gulf (e.g., benthic lander observations, ROV surveys), as well as with concurrent oceanic cetacean studies (e.g., passive acoustic monitoring, airborne observation). We anticipate the end goal to be an integrated assessment of vertical connectivity in one of the most dynamic deep-sea ecotypes in the World Ocean. All future DEEPEND and DEEPEND|Deep-Sea Benefits cruises will be badged under the Challenger 150 project (challenger150.world) North Atlantic Working Group. As always, we welcome input and will be happy to support as many collaborative efforts as possible.

Example echogram of a mesopelagic deep-scatteing layer “splatting” into deep-benthic habitat in the northern Gulf of Mexico. Image courtesy of Kevin Boswell/DEEPEND.

Limnology and Oceanography Article about Cetaceans

A recent research article led by Dr. Matthew Woodstock and two other DEEPENDers, Dr. Tracey Sutton and Dr. Yuying Zhang, was recognized by Limnology and Oceanography, one of the world’s premier oceanographic journals, as one of the most viewed new papers for the journal. In the study, Woodstock et al. developed a computer model that estimated the nitrogen (an important nutrient for primary production) that is vertically transported by cetaceans (dolphins and whales) from deep depths to the near surface waters as they dive deep to eat deep-pelagic (greater than 200m depth) animals and then surface to breathe. The study highlights the important ecological role cetaceans have in biogeochemical cycles and indicates that the mesopelagic zone is a major nutrient source for near surface productivity. It also suggests that dolphins and whales can be a direct link between nutrients on the ocean bottom and the surface waters that are often nutrient limited in the oceanic Gulf of Mexico (and other nutrient-poor regions). The study was the first of its kind for the Gulf of Mexico and one of the few examples of cetacean-mediated nutrient transport in the world.

Matt is a postdoctoral researcher at Woods Hole Oceanographic Institution and specializes in developing ecological models that explore energy, nutrient, and carbon fluxes in deep-sea ecosystems. His work focuses on leveraging existing data and ecological knowledge to develop baselines for current levels of ecosystem functioning and to predict the response of disturbances.

Two DEEPENDERS Exploring Ocean Sciences Meeting

Dr. Heather Judkins and her grad student, Claire de Noyo, both presented new DEEPEND research at the 2024 Ocean Sciences Meeting in February in New Orleans! Heather shared results from her ongoing cephalopod diet metabarcoding study which helps piece together the complex deep-sea food web of the Gulf of Mexico. Of the 63 individuals analyzed, fishes accounted for the majority of prey items.

Claire is a Conservation Biology master's student at USF St. Petersburg and presented the preliminary findings of her thesis research- also on deep-sea trophic ecology! Claire conducted a stomach content analysis on the Hammerjaw (Omosudis lowii) using 574 preserved DEEPEND specimens, making this project the largest Hammerjaw diet study to date. Findings confirm that Gulf of Mexico Hammerjaws prey primarily on cephalopods. They both found that the conference was interesting and learned so much about other ocean science topics!

DEEPEND Researchers and Students Attend GoMCON

Recently, members of the DEEPEND|RESTORE Consortium traveled to the Gulf of Mexico Conference, GoMCON, in Tampa, Florida and had a great experience. GoMCON is a bi-annual conference that brings together scientists, students, stakeholders, industry leaders, and so much more to network and present on research being conducted in the Gulf of Mexico. Nova Southeastern Graduate students from Dr. Sutton’s Oceanic Ecology Laboratory, Hannah Johnson, Katie Lim, and Travis Kirk, students from Dr. Rosanna Milligan’s DEEPSCAPE Laboratory, Sidney Trimble and Ian Areford, as well as Florida International University Postdoc Dr. Pedo Peres were able to be in attendance for this year’s conference. Liberty Juno, a student in Dr. Jon Moore’s Deep Sea Ichthyology lab, attended the conference alongside the NSU students.

 Both Dr. Tracey Sutton and Dr. Rosanna Milligan gave oral presentations on their research during the conference. Students Sidney Trimble and Ian Areford presented their poster on Length Weight Relationships of Mesopelagic fish in the Northern Gulf of Mexico. Student Liberty Juno presented a poster on the “Occurrence, Neuroanatomy, and Morphometrics of Slickhead Leptochilichthys in the Gulf of Mexico.” Students Travis Kirk, Katie Lim, Ian Areford, and Dr. Pedro Peres gave presentations during the pelagic portion of the conference. Katie’s presentation entitled “The Trophic Ecology and Vertical Distribution of the Deep-Pelagic Fish Scombrolabrax heterolepis (Scombriformes: Scombrolabracidae), an ‘Advanced’ Fish in a World of ‘Primitive’ Fishes” looked at the diet of an evolutionarily advanced fish species compared to other deep-sea predators; Travis’ presentation entitled, “Trophic Ecology of Black Swallowers,” examined the diet of a previously understudied genus of fishes finding this fish to be a super predator of the deep sea; and Ian’s presentation entitled Mesopelagic Fish Biomass Patterns in Comparison to Major Oceanographic Features looked at the spatial distribution patterns of various stomiids fishes in relation to different features of the Gulf of Mexico such as, the Mississippi river plume and the loop current. Finally, Dr. Pedro Peres presented on the changes in genomic diversity of three abundant deep-pelagic fish species in the Gulf of Mexico over 10 years. All our members did a fantastic job with their presentations, and we are so proud of all their hard work!

 The graduate students were able to spend three days immersing themselves in new and exciting research presentations, innovations in the field, and more. The conference was a wonderful opportunity for our students to also investigate various fields of employment within the Gulf of Mexico and allowed the opportunity to network with companies and non-profits, both in the private and public sector, and with industry leaders. Students were able to learn different tools in order to look at environmental science as it integrates with policy and management to better plan for restoration and ecosystem resilience. Tools such as, changes to mapping the coastal and offshore systems to data management, broadened our graduate students’ minds to how all the various scientists, stakeholders, and policy makers work together to make informed changes. Overall, this year’s Gulf of Mexico Conference was a wonderful experience! Our graduate students and principal investigators had a great time exploring the wonderful city of Tampa, even visiting the aquarium there, while enjoying all the conference had to offer. We look forward to the next GoMCON in 2026!