Here, we explore the influence of wind-forced variations of the nutricline on coccolithophore export production from upwelling affected NW Africa to the the Caribbean, highlighting the importance of considering phytoplankton- and carbonate production across the entire photic zone when projecting the effects of ocean warming on future primary production.
The last months were crazy busy getting all set for implementing our very first Saharan wet dust fertilization experiment on a monoculture of Emiliania huxleyi, probably the most opportunistic and cosmopolitan of the coccolithophores. Here are some updates regarding what we were looking for with this experiment!
The expedition is now almost ending and we are heading back to Punta Arenas, where everything started nearly 2 months ago. It was a long and fulfilling experience, resulting from the enthusiasm of all the participants and of the overall good conditions during the expedition. We have high expectations from this scientific collaboration, anticipating many discoveries regarding the effects of climate change on the Antarctic pelagic ecosystem.
The last weeks of January 2019 were spent monitoring the surrounding marine environment north of the Antarctic Peninsula. On board the “Oncle Max” Polar Ship, we work in shifts of 12 hours in order to maximize the navigation and sampling time of this remote region. The water column has been sampled almost every day since, to investigate the distribution of biomass and composition of phytoplankton communities, including the biogeochemically important coccolithophores.
After crossing the stunning Patagonian channels of Chile and Argentina, we arrived at the Drake Passage expecting a more difficult navigation, given the strength of the currents and waves typical of this region. The ship rocked a bit more, leading some of our travel mates to "seasick" or to take refuge for longer periods in their cabins. But the DUSTCO/PROPOLAR team members withstood the swing, remaining awake and enthusiastic at the triumphal entry into the Antarctic Zone, crossing the 60ºS :-)
We are starting the New Year with a great new adventure! On the 2th January 2019 we will sail from Punta Arenas (southern Chile) all the way south, through the Drake Passage, to reach the Antarctic Peninsula, on board the polar ship Almirante Maximiano in the context of the project PHYTO-NAP (“Phytoplankton response to climate trends in the Northern Antarctic Peninsula”). Why are we interested in the Antarctic Peninsula? Click here to know more about it :-)
We are pleased to announce that the most recent work from Laura Korte - “Effects of dry and wet Saharan dust deposition in the tropical North Atlantic Ocean” - is on Biogeosciences Discussions! In her paper, Laura shows results from three incubation experiments comprising Saharan dust additions to study the phytoplankton response to nutrient release in oligotrophic seawater in the tropical North Atlantic. Keep posted during the on-line scientific discussion! :)
Over the past week, some of DUSTCO’s team members gathered together in The Netherlands, to take part in the successful PhD public defense of Laura Korte, at the Vrije Amsterdam University, entitled “Saharan dust deposition in the equatorial North Atlantic Ocean and its impact on particle export fluxes”. Congratulations Frau Doctor Laura! :-)
We are currently preparing a coccolithophore batch-culture in which we will test the potential of Saharan dust as a nutrient fertiliser, in which we will use dust samples collected from the Saharan desert pre-adjusted to resemble dust that is naturally deposited in the ocean and leached in acidified ‘artificial rainwater’ for mimicking acid cloud processing. We started with Emiliania huxleyi – probably the most opportunistic of the coccolithophores – but hope to investigate other species as well in the future.
The departure day for the AMT28 has finally arrived! On the past 22th September, our young scientists Andreia Tracana and Afonso Ferreira have board the RRV James Clark Ross to start this amazing cross-Atlantic adventure. For the next 5 weeks, they will be daily monitoring the ocean and the atmosphere across the entire Atlantic Ocean.
We have just finished packing our beautiful old iron-boxes containing all the lab material for collecting coccolithophores (and dust!) all across the Atlantic Ocean, on board the RRS James Clark Ross (JCR) during the next AMT28 (Atlantic Meridional Transect). We will sail only later in the fall, but we are already super excited about all the discoveries yet to come! :)
Today I am sharing this wonderful image of a coccolithophore bloom! It was taken using and Scanning Electron Microscope (SEM) and shows a view of the surface of the ocean (10m water depth) at 2000x magnification. This plankton sample was collected offshore Cape Blanc (NW Africa) and represents the easternmost side of our transatlantic array!
Over the past week we had this amazing opportunity to be part of the Marine Biogeochemistry Training School on: Biogeochemical and Ecological Dimensions of a Changing Ocean", nicely organised by IPMA and CCMAR and hosted by The University of Algarve (Portugal). During the course we could learn from and discuss scientific ideas directly with big names in science such as Adina Paytan, Jerry McManus and Susanne Neuer.
The past few weeks were very busy preparing the plankton samples for the taxonomic microscope analysis and doing the first observations and counts. More than 100 slides were mounted at the Laboratory of Calcareous Nannofossils (Nanolab) at the Instituto Dom Luiz of the University of Lisbon, for the identification and quantification of the coccolithophore species thriving all along the the photic layer of the tropical North Atlantic.
A recent new article of the Journal of Geophysical Research, by A. Torfstein and S. Keenest, shows the the very first continuous comparisons between of daily atmospheric dust and ocean productivity in the Gulf of Aqaba’s nutrient-limited ecosystem, and concluded that they appear not to be correlated in this region.
Later in the fall of 2018, our colleague Andreia Tracana will have the amazing opportunity to join the forthcoming AMT28 expedition which will take place on board the RRS James Clark Ross (JCR) in the fall. AMT (Atlantic Meridional Transect) is a well-known scientific research programme hosted at the Plymouth Marine Laboratory in conjunction with the National Oceanography Centre.
MARE-FCiências.ID (Marine and Environmental Sciences Centre), a centre for research, technological development and innovation, will be hosting DUSTCO for the next couple of years. MARE’s fields of research traverse marine and environmental sciences aiming at understanding the patterns and processes influencing the functioning and evolution of biological diversity on the planet.
A reminder of when our transatlantic expedition was out in the science section of the Dutch NRC newspaper, back in May 2016, in a very special article by Gemma Venhuizen, our journalist onboard! I cannot really read because it is not written in English, but just seeing it already brings back a lot of nice memories!
Since we were in Chile, we couldn't miss to travel further north and visit the amazing Atacama Desert, one of the most arid places on Earth. Dust lifted from the Atacama Desert is known to be incorporated into higher air layers and carried by the SE trade winds over and into the Pacific Ocean, similarly to what we known for the Saharan desert and the Atlantic.
We started 2018 in the best way possible by taking of the DICE workshop "The Role of Dust in Climate Change: A biogeochemistry perspective", in Las Cruces, Chile, 8-10 January. Scientists from all over the world and from different fields were participating, from biogeochemists, ocean and climate modellers.... to us, the "Dusty Gang" from the tropical North Atlantic!