Diversity and oceanic distribution of marine phytoplankton

Changes in marine plankton communities driven by environmental variability ultimately impact the marine food web and global biogeochemical cycles (pathway by which a chemical substance moves through biotic and abiotic compartments of Earth). To predict and assess community shifts and their consequences, we first need to determine the composition of these communities and how they change along environmental and biological gradients, for example latitude or temperature.

With the advent of molecular biology methods such as high throughput sequencing of gene markers (metabarcoding) and an increasing number of sequence datasets, access to the global scale distribution of your favorite “bug” became more feasible. Basically, after acquiring sequence data either in the lab or through public databases, all you need is to determine which sequence belongs to which bug, pretty much like sorting the sequences into boxes where each box represents different individuals. The challenge here is to determine the individual units (like deciding the size of the box) and their close relatives, so you don’t end up sorting the sequences into the wrong compartment.

One common language we all use in biology to define the limits between individuals is the one provided by taxonomy, where the individuals are categorized into species, the different species into genera, etc. Tthe combination of taxonomy and metabarcoding method brings fascinating insights into marine phytoplankton distribution and ecology.