Transcriptional responses of Trichodesmium to natural inverse gradients of Fe and P availability.

The filamentous diazotrophic cyanobacterium Trichodesmium is responsible for a significant fraction of marine di-nitrogen (N) fixation. Growth and distribution of Trichodesmium and other diazotrophs in the vast oligotrophic subtropical gyres is influenced by iron (Fe) and phosphorus (P) availability, while reciprocally influencing the biogeochemistry of these nutrients. Here we use observations across natural inverse gradients in Fe and P in the North Atlantic subtropical gyre (NASG) to demonstrate how Trichodesmium acclimates in situ to resource availability.

Animals, protists and bacteria share marine biogeographic patterns.

Over millennia, ecological and evolutionary mechanisms have shaped macroecological patterns across the tree of life. Research describing these patterns at both regional and global scales has traditionally focused on the study of metazoan species. Consequently, there is a limited understanding of cross-phylum biogeographic structuring and an escalating need to understand the macroecology of both microscopic and macroscopic organisms.

New insights into the distributions of nitrogen fixation and diazotrophs revealed by high-resolution sensing and sampling methods.

Nitrogen availability limits marine productivity across large ocean regions. Diazotrophs can supply new nitrogen to the marine environment via nitrogen (N) fixation, relieving nitrogen limitation. The distributions of diazotrophs and N fixation have been hypothesized to be generally controlled by temperature, phosphorus, and iron availability in the global ocean.

Phytoplankton transcriptomic and physiological responses to fixed nitrogen in the California current system.

Marine phytoplankton are responsible for approximately half of photosynthesis on Earth. However, their ability to drive ocean productivity depends on critical nutrients, especially bioavailable nitrogen (N) which is scarce over vast areas of the ocean. Phytoplankton differ in their preferences for N substrates as well as uptake efficiencies and minimal N requirements relative to other critical nutrients, including iron (Fe) and phosphorus.

Publisher Correction: Detection of introduced and resident marine species using environmental DNA metabarcoding of sediment and water.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.