NSF Postdoctoral Fellowship in Biology FY 2021: Neutral buoyancy in deep-sea squid: mechanisms of ammonia rich, low density fluid formation and impacts of ocean acidification

Durant, Andrea, Toronto

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2021, Broadening Participation of Groups Underrepresented in Biology. The Fellowship supports a research and training plan for the Fellow that will increase the participation of groups underrepresented in biology. The research will examine how deep-sea squid produce a unique fluid for buoyancy. Deep-sea squid produce and store a fluid internally that is the same density as the external seawater, an important strategy for buoyancy that limits the energetic demands of locomotion. The Fellow will examine the cellular processes that lead to this fluid formation in specialized buoyancy organs of deep-sea squid. Furthermore, carbon dioxide (CO2) emissions from human activities are absorbed by oceans and consequently, the deep-sea is projected to experience the most significant decreases in pH (i.e., ocean acidification) within the next century. Therefore, this research will also examine the impacts of ocean acidification on deep-sea squid buoyancy. The proposed research will provide a novel framework of buoyancy processes in deep-sea squid, which play critical roles in the food web of marine ecosystems both as predator and prey. The Fellow, who is African American, will promote greater inclusion of underrepresented undergraduate students at the University of Miami through meaningful mentorship involving the proposed research activities. The Fellow will also coordinate an annual World Ocean’s Day program to engage Miami-Dade elementary school children in ocean sciences. Many species of deep-sea squid use some form of ammonium (NH4+) retention to achieve neutral buoyancy, a very poorly understood physiological adaptation allowing for a low-energy lifestyle. This research will examine physiological mechanisms underlying NH4+-rich fluid formation in deep-sea squid and determine the effect of ocean acidification on buoyancy, as NH4+ regulation is generally linked with acid-base homeostasis in animals. Field collections of live specimens combined with powerful molecular approaches, including next-generation sequencing, will be used to (1) characterize the ion-transport mechanisms allowing for NH4+ retention in the buoyancy organs of squid and (2) examine alterations in the NH4+ retention mechanisms in response to acidified seawater. Main findings will describe the first ion transport model in ammoniacal squid and identify changes in physiological endpoints (i.e., buoyancy) in the context of ocean acidification. The Fellow will receive training in the fields of bioinformatics and cell culturing systems as well as implementing an annual World Ocean’s Day event aimed at broadening participation through the involvement of elementary school students from the Miami-Dade area. 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.