Plankton Planet Project Pilot
During the two circum-global Tara Oceans expeditions (2009–2013), scientists aboard the schooner Tara collected over 40,000 samples encompassing the entire plankton ecosystem at 220 sites and three depths. The morphological and genomic analysis of these samples led to the creation of the most comprehensive dictionary ever produced on the biodiversity of a planetary ecosystem.
These findings were featured in a special issue of the journal Science.
But to achieve a truly global picture of plankton composition at the planetary scale, it was necessary to launch a citizen-driven initiative and engage the thousands of sailboats, naval vessels, fishing boats, and cargo ships that crisscross the world’s oceans year-round.
This led to the launch of the Plankton Planet project, with a pilot phase initiated in January 2015 thanks to an exploratory grant from the prestigious Richard Lounsberry Foundation (Washington DC, USA). Plankton Planet (P2) is the first citizen-based biological oceanography program relying on large-scale DNA barcode sequencing (metabarcoding) of plankton community extracts. DNA-based ecology represents a true revolution, allowing scientists to detect and quantify all organisms in an ecosystem (from viruses to animals) from extracted total DNA. This approach is miniaturized, low-cost, rapid, robust, and eliminates the need for years of work by taxonomy experts previously required to analyze large numbers of plankton samples.
The protocols we developed and implemented during the Tara Oceans expeditions were simplified and adapted for citizen use, requiring no particular expertise. The system enables plankton sampling, filtration, and storage via desiccation without electricity or chemicals—ultimately allowing for genomic analysis.
During the 2015 pilot year, 184 plankton samples collected by around fifteen boats along various routes over the course of a year were analyzed.
The DNA of the collected plankton was extracted, and a small region of the genome from the species present in each sample was sequenced using the metabarcoding method. Interestingly, about 96% of the DNA barcodes obtained had already been observed in the Tara samples, and 82% of the barcodes identified by Tara were found again in the P2 samples. Additionally, approximately one thousand barcodes were unique to each boat, representing a kind of genetic signature of each sailboat’s journey.
No contamination by fungi, bacteria, or human DNA was detected. The “planktonauts” did an excellent job, and the method has proven to be robust! This analysis fully validates the principle of collecting plankton under real-life conditions from recreational sailboats.
A big thank you to all the “planktonauts”!
This citizen science work was published in Frontiers in Marine Science on August 17, 2022, in an article titled “Plankton Planet: a frugal, cooperative measure of aquatic life at the planetary scale.“