Award: OCE-1829812

The deep pelagic ecosystem is earth’s largest habitat yet many of its inhabitants are poorly known to the general public, and in some cases, even to scientists. Siphonophores, for example, are soft-bodied animals that swim freely throughout shallow and deep ocean environments. They are abundant predators and include numerous species – with many more to be described and discovered – but generally their gelatinous bodies comprise elongate strings of stinging tentacles.

This project was an exciting collaboration between three biology and oceanography research labs, and together we trained a talented team of graduate students and a postdoc. We deployed a range of tools to study how siphonophores feed, who they feed upon, and how they have evolved into their significant food web roles across the shallow and deep ocean. We used deep-diving robots tethered to research ships to observe siphonophores feeding on a range of prey in the deep, cold ocean just off the central California coast. In shallow waters, a team of trained scientific SCUBA divers were tasked with finding and carefully collecting siphonophores.  We looked at how specialized feeding structures evolved in siphonophores to best equip them for feeding on certain types of prey. We better described the diets of different siphonophore species by sequencing their numerous gut contents. And, we looked at the stable isotope compositions of siphonophores to see their placement in the food web and how this changes across shallow to deep layers of the oceanic water column.

The field work for this project was an exciting challenge and we were lucky to bring many students and scientists out on research ships to study the deep sea together. Although our research cruise coincided with the early height of the COVID-19 global pandemic, we were privileged to sail together for two weeks and help to train the next generation of more diverse oceanographers and biologists.

We were thrilled to share many parts of this project with teachers and students of many ages. We worked closely with the Birch Aquarium in San Diego to develop open-access lessons and labs about deep-sea food webs and organismal biology, and the threats that these ecosystems face, such as plastic pollution. These materials are freely available online and help to increase scientific and environmental literacy within California communities and beyond.

Last Modified: 01/10/2024
Modified by: Anela Choy