New Publication

Biogeochemical models predict that ocean warming is weakening the vertical transport of nutrients to the upper ocean, with severe implications for marine productivity. However, this prediction has not yet been observed due to the challenge of detecting low nutrient concentrations across the ocean surface. We analyzed over 30,000 nitrate and phosphate depth profiles observed between 1972 and 2022 to quantify nutricline depths. These depths accurately represent nutrient fluxes, allowing us to assess long-term trends in supply rates. Over the past five decades, upper ocean phosphate has declined worldwide due to stratification. However, nitrate has remained mostly stable. Model simulations suggest that this difference is likely due to nitrogen fixation replenishing upper ocean nitrate, whereas phosphate has no equivalent biological source.

A new Bio-GO-SHIP study was just published today in ISME Journal. Here, Ustick and colleagues use the global metagenome collection to describe the microdiversity of Prochlorococcus – the most abundant phytoplankton on the planet. We find a clear biogeography among closely related lineages including a subclade adapted to low phosphorus conditions. This is the first time we identify a phytoplankton lineage adapted to cope with the limitation of particular nutrient. Once again, Prochlorococcus proves to be an excellent system for understanding eco-evolutionary processes in the ocean.

Check out our new Bio-GO-SHIP paper applying ‘omics to identify the large-scale biogeography of Prochlorococcus and Pelagibacter population-specific growth rates. Observations are from sections I07N, I09N, and C13.5. Congrats to Alyse Larkin, George Hagstrom, Melissa Brock and Nathan Garcia on collecting and analyzing all the data. https://www.nature.com/articles/s41396-022-01332-6

New Bio-GO-SHIP paper describing biome variation in the carbon-to-oxygen ratio of marine organic matter. The study illustrates the power of integrating genomics and ocean biogeochemistry. https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2022AV000679

A new paper using genomics data from GO-SHIP line P15S by Raes and co-workers was published in Nature Communications. They combined sequencing of 16S rRNA and metagenomics with all the hydrographic measurements to assess changes in ecosystem state between polar, subtropical and tropical regions in the South Pacific Ocean. They find that “The ability to query metabolic pathways in existing and future 16S rRNA gene data sets on a global scale establishes the opportunity to test hypotheses regarding how biodiversity influences functional diversity, and how these are related to energy production in the ocean.”