Abstract Description

Marine biodiversity influences the efficiency and stability of global nutrient cycles. This is exemplified by the role of keystone species, which shape and maintain marine ecosystem health. Despite this, the precise mechanisms underpinning the roles of keystone species remain under-researched. In the Southern Ocean, the contribution of Southern Hemisphere humpback whales (Megaptera novaeangliae) and southern right whales (Eubalaena australis) to nutrient recycling via their nutrient-rich faeces is well studied. However, insight into the taxonomic and functional contributions of their gut microbiomes remains largely undefined. The gut microbiomes of these baleen whales are of particular interest due to their influence on the micro- and macro-nutrient content of faeces in both aphotic and euphotic zones of the ocean. Using shotgun metagenomic analysis, insights into the diverse consortia of bacteria and archaea can be obtained and integrated with physicochemical data. This study aims to provide a deeper understanding of the role of baleen whale microbiomes in enhancing productivity within nutrient-limited marine ecosystems.