Dear colleagues, My coauthors and I are excited to announce the publication of our new paper in Conservation Physiology, outlining 11 key unanswered questions in marine mammal bioenergetics. We also discuss existing tools to address these key questions, and highlight particular areas where development of new methodologies are needed. The impetus for this effort was to provide a guiding framework to set research priorities that would help increase the utility of bioenergetic approaches for addressing management and conservation of marine mammals. The abstract is pasted below and the paper can be found at https://doi.org/10.1093/conphys/coac055 (it is open access). Many thanks to all of the people who participated in this exercise and made this publication possible. Please don't hesitate to reach out with questions (emchuron@uw.edu). Best, Liz McHuron Abstract Bioenergetic approaches are increasingly used to understand how marine mammal populations could be affected by a changing and disturbed aquatic environment. There remain considerable gaps in our knowledge of marine mammal bioenergetics, which hinder the application of bioenergetic studies to inform policy decisions. We conducted a priority-setting exercise to identify high-priority unanswered questions in marine mammal bioenergetics, with an emphasis on questions relevant to conservation and management. Electronic communication and a virtual workshop were used to solicit and collate potential research questions from the marine mammal bioenergetic community. From a final list of 39 questions, 11 were identified as ‘key’ questions because they received votes from at least 50% of survey participants. Key questions included those related to energy intake (prey landscapes, exposure to human activities) and expenditure (field metabolic rate, exposure to human activities, lactation, time-activity budgets), energy allocation priorities, metrics of body condition and relationships with survival and reproductive success and extrapolation of data from one species to another. Existing tools to address key questions include labelled water, animal-borne sensors, mark-resight data from long-term research programs, environmental DNA and unmanned vehicles. Further validation of existing approaches and development of new methodologies are needed to comprehensively address some key questions, particularly for cetaceans. The identification of these key questions can provide a guiding framework to set research priorities, which ultimately may yield more accurate information to inform policies and better conserve marine mammal populations. Elizabeth McHuron, PhD Research Scientist, UW CICOES