Dear Colleagues, Following our recent paper demonstrating that whales fertilise the ocean with their nutrient-rich defecations (available free online: http://rspb.royalsocietypublishing.org/content/early/2010/06/14/rspb.2010.08...), we are pleased to announce a paper published today in PLoS showing that marine mammals also defecate microbes which help to break down the nutrients defecated, making them more bioavailable to the food chain. Lavery TJ, Roudnew B, Seymour J, Mitchell JG, Jeffries T (2012) High Nutrient Transport and Cycling Potential Revealed in the Microbial Metagenome of Australian Sea Lion (Neophoca cinerea) Faeces. PLoS ONE 7(5): e36478. doi:10.1371/journal.pone.0036478 Available free online: (http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0036478)A... Metagenomic analysis was used to examine the taxonomic diversity and metabolic potential of an Australian sea lion (Neophoca cinerea) gut microbiome. Bacteria comprised 98% of classifiable sequences and of these matches to Firmicutes (80%) were dominant, with Proteobacteria and Actinobacteria representing 8% and 2% of matches respectively. The relative proportion of Firmicutes (80%) to Bacteriodetes (2%) is similar to that in previous studies of obese humans and obese mice, suggesting the gut microbiome may confer a predisposition towards the excess body fat that is needed for thermoregulation within the cold oceanic habitats foraged by Australian sea lions. Core metabolic functions, including carbohydrate utilisation (14%), protein metabolism (9%) and DNA metabolism (7%) dominated the metagenome, but in comparison to human and fish gut microbiomes there was a significantly higher proportion of genes involved in phosphorus metabolism (2.4%) and iron scavenging mechanisms (1%). When sea lions defecate at sea, the relatively high nutrient metabolism potential of bacteria in their faeces may accelerate the dissolution of nutrients from faecal particles, enhancing their persistence in the euphotic zone where they are available to stimulate marine production. Kind thanks, Dr. Trish Lavery Flinders University. Australia.