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 Fut