Collaborative Research: Adaptation to changing oceans by the most abundant vertebrates on earth

The world's oceans are changing rapidly, resulting in still poorly understood impacts on ocean ecosystems, fisheries yields, and carbon storage in the deep ocean. One obvious place to start investigating these impacts is on the most abundant vertebrates on earth, yet these taxa are so obscure that even most biologists are unaware of them. Lanternfishes and bristlemouths dominate the twilight zone in oceans around the world and make up nearly half of all vertebrate biomass on earth. They number in the quadrillions or higher and form a crucial link in the marine food web as primary consumers of zooplankton and food for commercial fisheries. They also connect surface waters where they feed at night with carbon export to the deep ocean during the day through the sinking of their fecal pellets and dead bodies. This organic carbon that reaches the deep ocean then remains stored for hundreds to thousands of years. Therefore, it is vital to understand any impacts on these crucial links in the marine food web. This research will provide the first investigation of how our rapidly changing oceans are affecting foundational vertebrate taxa in global marine food webs. This will create fundamental knowledge about how the most abundant vertebrates are adapting, changing population sizes, shifting their diets, and contributing to carbon storage in response to changing oceans around the world. In addition, the outcomes of this research will be shared through the Berkeley Center for Ocean Futures and K-12 outreach. Research-based courses will provide experimental design and statistical training to undergraduates. All specimens and associated data will be catalogued in the Museum of Vertebrate Zoology and Scripps Institute of Oceanography Ichthyology collections for use by the global scientific community. This research will create genomic and phylogenetic resources for lanternfishes and bristlemouths, determine how they are adapting to changing oceans, and predict the resulting impact on marine food webs and carbon sequestration in the deep ocean. The investigators will use large-scale genomic sequencing of samples from around the world to determine if populations are adapting to warming or acidification from shared signatures of selection on related genetic pathways, such as calcification, thermal tolerance, or heat shock proteins. This research will also produce a genome-scale tree of life for these groups, new de novo genome assemblies, and reconstruct recent changes in their population sizes. The investigators will additionally use µCT scans of specimens from museum collections to detect changes in bone density through time associated with ocean acidification and predict how it will affect their feeding ability. Stomach contents from modern and historical museum specimens will be compared to detect changes in marine food webs over time. Finally, the investigators will develop a new approach to understand how much carbon these taxa are exporting to the deep ocean by DNA-barcoding their gut microbiomes and comparing the unique signatures of lanternfishes and bristlemouths to the composition of free-floating particulate organic matter, known as marine snow, at different depths. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.