It all started in the spring of 2016, when the dusty-team decided to cross the tropical North Atlantic for the fourth and last time. On the 19th of March we sailed from St. Johns (Antigua) on board of the British research vessel James Cook, heading to Sta. Cruz, Tenerife, where we would arrive one month later. The expedition was dedicated to recover the transatlantic array of instruments that had been collecting Saharan dust in the ocean between Africa and the Caribbean since 2012, in the context of TRAFFIC and DUSTTRAFFIC projects.
In addition to the recovery and redeployment of the sediment trap moorings, we also sampled the upper ocean for all kinds of marine life, including viruses, phytoplankton and zooplankton, while also sampling the atmosphere for mineral dust. We even carried out a shipboard incubation experiment to test the bioavailability of dust-born nutrients via dry- vs. wet dust deposition!
Amongst the phytoplankton communities, we were especially interested in calibrating our recent findings regarding the coccolith export production across the transatlantic array (see Guerreiro et al., 2017) with new observations of the modern coccolithophore communities thriving in the photic layer of this region. To that aim, we collected seawater samples between the surface and 250m and measured vertical water profiles if temperature, sanity and fluorescence at each sampling station between the Caribbean Sea (Antigua) and the region offshore Cape Blanc (Mauritania).
At the end of our transatlantic expedition, we were surprised to find that buoy Carmen, which had been deployed perfectly clean offshore Cape Blanc (NW Africa) in November 2015, was now completely covered by gigantic barnacles - in Portuguese the so-called "percebes", most likely reflecting the spring bloom off this highly productive upwelling region.
Besides all the exciting data and sample material that we collected from the expedition, and of the interesting and multidisciplinary discussions onboard..., the truth is... we had lots of fun too! And when you're lucky enough to be part of a really friendly and cooperative scientific team and ship crew, this is the kind of happy atmosphere that you get! :)