Dear All, This is a follow up on a previous announcement of several new thematic Research Topic collections that are currently being considered in the journal Frontiers in Marine Science. Many thanks for the considerable interest received thus far. Based on the suggestions and enquiries received, the number of topics under consideration has been expanded and some of the previously indicated topics have been slightly modified; please see below. Topic 1: Conservation ecology of marine mammals in southeast Asia and western Pacific Topic 2: Behavioural ecology of island-associated cetaceans Topic 3: Population processes of apex marine predators: ecology, demography and behaviour Topic 4: Conservation ecology of marine mammals in coastal seas of sub-Saharan Africa The intended host section of the journal is “Marine Megafauna”, but the topics will be cross-listed with multiple other sections, such as “Marine Conservation and Sustainability”, “Marine Biology”, and “Marine Evolutionary Biology, Biogeography and Species Diversity”. At this early stage, we welcome expressions of interest so that we can prioritise topics that are currently under consideration and potentially suggest new ones. We would like to hear from anyone interested in contributing a manuscript to any of the above topics. Please send us (i) your tentative title, (ii) email address of the lead or corresponding author, (iii) indicate which topic you are interested in participating, and (iv) an approximate time when you may want to submit your manuscript. Please note, the expressions of interest are not a commitment but simply an indication of interest which may or may not result with a manuscript submission. Anyone interested, please contact us at: FrontiersMarSci.MarMam@gmail.com Note please that as Frontiers is an Open Access platform, standard manuscript processing fee will apply to all accepted articles. Thank you all in advance for your interest. Bill Richards Assistant to Guest Editorial Team