Antarctic diving team

During the Tango 1 expedition, an important part of the projects relies on samples and data collected by SCUBA divers. Our diving team is composed of Francesca (UGent), Martin (ULiège), Lea and Camille (ULB).

Antarctic waters are a first for all members but Francesca, and previous training was an important part in the planning of the expedition. First, all divers needed to obtain a European Scientific Diver certification to be able to carry on research underwater. The team then trained in Belgium using the same tools they would use here, around the Antarctic Peninsula.

Diving in Antarctica mainly requires the ability to cope with freezing-cold water. For this, the dry suit is a must and is completed by multiple layers of thermal underwear and warming equipment. Luckily, Belgian weather can offer extreme diving conditions, with quarries and lakes reaching down to 4°C during the winter. Our team was therefore well prepared and did not suffer from more than a few cold fingers.

On-site they collect specimens, sediments cores along with pictures and videos to document the expedition.

TANGO 1 in a nutshell

The Team is leaving tomorrow for the first expedition of the TANGO project, to the Grandidier Channel, in the West Antarctic Peninsula, onboard the RV Australis (A motor sailboat operated by Ocean Expeditions, Capt. Ben Wallis).

RV Australis, in front of Mount William. Photo: Bruno Danis (CC-BY)

TANGO1 is about understanding ecosystems responses to climate change in the Southern Ocean, and in particular trying to identify tipping points (at which ecosystems can drastically change in terms of structure and function) using a holistic scientific design.

Seastar, Odontaster validus. Photo: Quentin Jossart (CC-BY)

TANGO1 is about exploring areas which are poorly documented, understood and inventorized, in an informed fashion and yet are undergoing accelerating environmental pressure.

RV Australis during the Belgica 121 expedition. Photo: Bruno Danis (CC-BY)

TANGO1 is about coherence in terms of environmental impact. We want to lead by example, as we use a sailboat to carry marine science work in an extreme environment. RV Australis will allow us to reach particularly low levels of GHG emissions and habitat disturbance during sampling operations.

TANGO1 is about agility. Our sailboat allows us to reach shallow areas, and make fast decisions as we adapt to the conditions we will be meeting in the field.

SCUBA operations during the Belgica 121 expedition. Photo: Bruno Danis (CC-BY)

TANGO1 is about commitment. We pledge to be in complete immersion in the environment we will be studying as we are convinced this will contribute to raise awareness about the importance of nature conservation.

Working in the snow during the Belgica 121 expedition. Photo: Bruno Danis (CC-BY)

We are leaving tomorrow, crossing the Drake Passage to the Western Antarctic Peninsula for a month of fieldwork.

Team ROV is ready to go!

After a full year of training, I am very excited to bring the ROV to Antarctica and finally explore the Southern Ocean seafloor.

The BlueROV2, equipped with a GoPro HERO 10 – Quarry of Barges

When buying the BlueROV2 last year, we had no idea how much technical problems we would encounter. After 3 pool sessions (thanks to the David Lloyd and our dear Fabienne), multiple sessions in the “Vrouwenpolder” and the “Spuikom” (with thanks to Watersport Ostende Spuikom), a trip to Chile, another to Corsica and a final dive in the quarry of Barges, I think we pretty much discovered all possible problems and fixed them, learned about best practices and of course the importance of making check-lists (and reading them before departure…).

Let’s hope everything goes well once we’re there!


B121 cruise report is now available!

If you are interested in a full report about the expedition, it is now available for download here. We give a full review of our activities during the expedition and publish a set of preliminary results.

If you are in a hurry, your can read the summary below:

The Belgica121 expedition (B121) ventured to explore the marine biodiversity of the West Antarctic Peninsula (WAP) to test the concept of using a nimble sampling platform, the R/VAustralis, a steel hulled, fully rigged motor sailor. Named as a tribute to the first international scientific expedition in Antarctica lead by Adrien de Gerlache in 1897-99 (onboard the Belgica), B121 took place between February and March 2019, sampling 15 stations in 22 working days in an area extending from the Berthelot (65°19.751 S, 64°08.263 W) to the Melchior Islands (64°19.246 S, 62°55.375W). Deploying 20 different types of gear (both traditional and modern), the B121 team gathered over 1700 samples that will be brought back to Belgium for further identification (by taxonomic experts) and analyses (isotopes, population genetics or genomics…). The team focused on biodiversity assessments, from the intertidal to subtidal zone (20 m) in coastal areas with contrasting characteristics regarding their exposure to glaciers, oceanographic characteristics and intensity of touristic activities. Other projects included population genetics studies, trophic ecology, environmental DNA, microplastics surveys and more (see full report below for details).

The use of R/V Australis for coastal studies deemed to be extremely efficient, in terms of environmental impact (ca. 150x less CO2 emissions than a Polar class icebreaker) and reactivity, allowing the team to adapt the sampling efforts in function of the weather or anchoring conditions. Fully devoted to the expedition, the ship allowed the B121 team to sample in shallow areas, not accessible to icebreaker and too far away from research stations, and which have been under sampled.Regarding the biodiversity census, the B121 expedition worked on various realms/taxonomic levels including the intertidal, soft sediments, macro- and megabenthos, fish, birds and marine mammals. Seven stations were investigated for the intertidal (MI, NH, UI, SK, HI, GR and FH) with a total of 121 measurements in quadrats. The average number of species per station was 18. Kidderia bicolor (bivalve), Obrimoposthia wandeli (flat worm) and Laevilitorina caliginosa (gastropod) were the most abundant organisms (up to thousands of individuals per m2).
Sediment type (9 to 22 meters depth) ranged from complete silt in the anoxic inner basin at the anchorage site of Hovgaard Island or Neko Harbor, to sandier and well oxygenated sediments of Green Reef. At a first glance the macrofauna pre-sieved samples showed very poor communities in the anoxic sediments, with only small gastropods and few motile taxa such as amphipods, which were present in small numbers. A qualitative analysis of macrofauna will be carried out and biomass will be estimated for both soft sediment metazoan size classes and referred either to surface (for the core and Van Veen sampling) or to sediment volume (for the scooping sampling method).

Regarding the mega/macro benthos (9 to 20 meters depth), 53 common species were identified. They were frequently observed directly in situ during the 38 dives performed at the nine sites, or after the dives when watching the 12 video transects… In total, 164 fish specimens were collected, most of them belonging to five species, i.e. Trematomus newnesi,Notothenia coriicepsHarpagifer antarcticusTrematomus bernacchii and Notothenia rossii. The spatial distribution of samples is patchy with most specimens collected at Føyn Harbor and Useful Island. Several localities yielded less than a dozen fish preventing spatial comparisons of fish catches. Fish samples collected represent a valuable collection of the Antarctic shallow water fish fauna, which is dominated by notothenioids. Regarding the birds and marine mammals, a total of 46 standard counts were carried out all along the cruise track (from the Beagle channel to the southernmost visited site of the cruise at Berthelot Islands along the Antarctic Peninsula and the Drake passage. 26 species of birds, 3 species of cetaceans and 4 species of pinnipeds were observed. Finally, several attempts (in 4 different locations) were unsuccessfully ran to sample snow petrel feathers for a project on this species phylogeography and taxonomy.

Other projects were carried out during the expedition, focusing on habitat mapping, population genomics and eDNA sampling to gain further insights into the region’s biodiversity levels. Twelve video transects were carried out, one or two at each station, to characterize the shallow habitats. Although Antarctic shallow benthic communities are usually considered depauperated with very low biomass and abundances compared to deeper communities of the Antarctic continental shelf, preliminary results suggest the occurrence of highly diverse shallow communities depending on local conditions. A preliminary correspondence analysis of common taxon distribution suggests marked differences between the considered stations. An in- analysis of the video transects and the relative surface mapped will help further describe biotic interactions and community composition and diversity. The population genomics project was carried out to advance a technological pilot study undergoing in the framework of the RECTO project. A range of organisms were sampled for this purpose, including 83 ostracods, 227 amphipods, 65 bivalves, 16 sea stars and 81 fish.The pilot study focuses on the evaluation and optimization of reduced representation sequencing protocols, more specifically RADseq.. Eventually, RADseq should yield thousands of genotypes per specimen, which will help to identify any potential local adaptation patterns possibly linked to the contrasting environmental and community conditions. For the eDNA project, 8 sampling events were conducted at four major stations that correspond roughly to the widest spatial extent of the expedition. DNA will be extracted from the filters in dedicated eDNA lab spaces at the KU Leuven. Subsequent high-throughput sequencing of the obtained metabarcoding libraries should enable species-level presence-absence detection.

Complimentary projects were ran during the expedition, including a microplastics survey,oceanographic measurements in selected sites, biogeochemistry and trophic ecology as well as macrophotography. For the microplastics survey, a total of 36 samples of sediment and organisms were taken at eight sites between 5m and 20m depth. Sea stars and filter feeding bivalve were sampled for the biotic part of this project. Analyses will be performed in collaboration with Heriot Watt University (Edinburgh, UK) as a part of a PhD thesis ongoing at the ULB Marine Biology Lab. With regards to the oceanographic measurements, 17 CTD casts were carried out in ten sites to characterize water masses parameters. A deep (400m) cast was carried out before Arctowski Peninsula (AP) in conjunction with an eDNA sampling effort. Biogeochemistry analysis will be carried out on soft sediment from the different sampling sites. Sediments will be characterized at the University of Ghent analyses to determine the granulometry (median grain size, size fraction%), total organic matter content (TOM), Total Organic Carbon (TOC%) content, Total nitrogen content (TN%), and pigments content. For trophic ecology, 156 samples counting 24 different species and over 650 specimens were collected at seven sites between 8m and 20m depth. Water and sediment samples were collected at each site. Specimens of seaweeds were sampled as potential food sources while other organisms were collected from different trophic guilds, among primary and secondary consumers, filter feeders, predators/scavengers and terminal consumers. Isotope analysis of ∂13C, ∂15N, and ∂34S will be carried out at the University of Liège. Trophic models will be developed to characterize species trophic niches and plasticity, as well as the main structures of trophic networks in shallow coastal habitats of the visited sites. Finally, 143 specimens were macro-photographed during the expedition. The most photographed phyla were Arthropoda (56 specimens) followed by Echinodermata (23), Mollusca (18), Polychaeta (14) and Chordata (10). Both overview and close up pictures of the specimens were captured.

From the initial results, in terms of sampling diversity of projects and fuel efficiency, it appears that the B121 expedition was extremely successful. Further analysis is of course needed to better characterize the biodiversity and run the multiple analysis, but it is recommended that the concept of using a more nimble platform for shallow biodiversity works in the Southern Ocean should be more widely considered, as a complementary approach to traditional approaches which are either based in research station, or along logistics-driven polar icebreaker routes.

“Playing with Mud at 64° S – so much fun!” – Francesca Pasotti

When people ask me what I do for work, I reply “I am a marine biologist”.The excitement then brings about the second question “oh wow! What do you study?” and often this initial excitement is soon killed off by my second answer : “sediment and worms” 😉 but not always though, I still manage to convince people of how awesome my job is!  Yes, I am one of those scientists to whom sand can speak and who find delight exploring a hidden world which cannot be fathom by the eye, but it needs a microscope and lots of patience to be witnessed and discovered. I work with soft sediments and a size class of organisms that live in them known as MEIOFAUNA…animals – yes, animals : they are multicellular, have organs and “limbs” a bit like us but are super tiny and they pass through a mesh sieve of 1 mm!!. Since the beginning of our cruise B121 I have explored during my dives the shallow bottoms of each location we have been visiting seeking for sand and mud. I have set out to collect sediment either by means of cores (plexiglas tubes which use vacuum to bring back on land a perfectly intact piece of the sea bottom!) or simply by scooping the surface of the sea bottom where sediment patches could be found.  What do I wish to find out by looking at these communities? I want to see what is their overall biodiversity in between the different sites we study since there are many different animals that live in the sediments in that size range, and their presence or absence from one location can tell us a lot about the health of the sea bottoms, for instance about how well is the recycling potential of the sediments doing in relation to the glacier retreat activity. It sounds very scientific right? But at the end of the day, I am just a girl having fun underwater and playing with mud on the surface! Look at this picture of me and Ryan (first mate on board) setting up my outdoor laboratory in the back of the Australis where I was dedicated  a little space to where to make it dirty for a little while!​

Food web studies

Among the many research projects conducted during the B121 cruise, trophic ecology has taken an important place for divers and fish specialists all along the campaign. But what is it about ? Beyond the formal and bit severe words, trophic ecology can be simply and instinctively recapped by the famous idiom “you are what you eat” ! Every single piece of snack each of us ingests or drop of liquid we are happy to sip not only contributes to maintaining our whole body in good shape but also, and insidiously leaves its indelible mark in our organs. This holds true for all living beings and for isotopes as well ! Analyzing the composition of organisms in Carbon, Nitrogen and Sulfur stable isotopes can tell us a lot about the long story of what they usually eat and where they have been living. Eventually, analyzing the isopotic composition of organisms living in close vicinity to each other in a same place can help unreveal biological interactions between them in the food chain that is, who’s eating whom and what. That’s why specimens of some common and key species of the visited sites were sampled at the sea bottom, from seaweeds to sponges, worms, starfish, sea urchins and fish, to caracterize main food web elements and compare them between sites. The complexity of food webs is also a condition of ecosystem resilience facing climate change, the more redundant and complex biotic interactions are in a food web and the more likely the ecosystem is to resist to change. Let’s wait a bit and see what isotopes will tell … !


Through the eye of the needle

On March 20th, we were working in Foyn Harbour, our latest station, and completing the sampling. Everything is fine, and now the team’s work has reached an optimum in terms of fluidity and efficiency. But the time has come to leave. With Ben, we are keeping a close eye on the weather forecast, and the time is right to head back to the mighty Drake. First, we were planning to leave on the next day, but then we felt it would be best to set sails earlier, late afternoon or in the evening  at the latest. This was a bit earlier than anticipated, but very strong westerlies are forecasted in a few days, as well as headwinds towards the end of the crossing, next to Cape Horn. No time to waste anymore. After a last dive in Enterprise Islands (right next to Foyn Harbour), on a shipwreck, we pack all our gear and get ready for the crossing. Done in a little more than an hour. We prepare the ship, and by the time we are ready to go, snow starts falling heavily, significantly reducing the visibility. We still need to cross the Gerlache Strait, and pass by the Melchior Islands to make our way to the open ocean. Not that easy with no visibility, icebergs and reefs all around us. The radar is our eyes, and we sail very slowly… At 0:30, we hit something, and the familiar noise of the hull against ice sounds really loud. Close encounter with a big iceberg. The hull of the Australis was spared this time, but not the anchor, properly bent. 

But we manage to reach the Drake Passage at the end of the night and start the crossing. A long crossing again.

The Drake Passage gives me this strange impression of being in a time capsule. Everybody gets ready and braces for the crossing. Our bodies go in standby for 3 days. I’ve spent most of the time in bed, probably seasick. Any normal life task is very demanding and you struggle to get your ideas together. The final part of the crossing, once we’ve reached Cape Horn is tricky as well: the ocean is still rough, and we get the false impression that the crossing is over, when there is still a full night of navigation, this time closer to land, closer to rocks. 

At that point, and this is why I called this blog “Through the eye of the needle”, we checked the weather again and realised that 2 hours behind us, the storm was closing the path with very strong winds, the kind you don’t want to find yourself in. Lesson is, and probably for the rest of the expedition: always listen to your instinct. When it tells you its time to leave, leave!

The Beagle channel brings serenity after the crossing, and we reached it at the end of the crossing, enjoying a very peaceful ending to the expedition, reaching our final destination, Ushuaia.

Final relief for all.

Now that we are back to the connected world, we will feed this blog and our website, so keep up with us.

The B121 expedition in a few figures:

22 sampling days

226 gear deployments

1739 samples

38 scuba dives

1727 nm

4280 l of fuel

Mission accomplished.


Macro-photography or “how to see the samples differently”

Alongside the numerous samplings done every day during the expedition, a timeframe is also dedicated to macro-photography. There, a different world can be revealed from what we cannot see with our poor human eyes…

“Wow, this little guy was a flatworm and not a leech“ or “Hey, look at this structure on the right, it is key for the identification “ are just two examples of B121 exclamations associated to someone looking at a macro-picture. 

That’s the key advantage of macro-photography: it gives you precious information to identify the organisms onboard (or after the expedition). Last but not least, this is also a good resource for future scientific publications and outreach activities.

That’s why Quentin (Jossart) is spending few hours every day to capture the most common or interesting species collected throughout the day. Photographing them alive is an asset because some structures or colors can deteriorate after preservation. A lot of patience is thus sometimes needed as some animals are constantly moving… “Please mate, stay here a seecccooonnddd” is the most polite exclamation that has been heard from the dedicated photo-area onboard.

…and thanks for all the fish?

Four men in a small rubber boat. Drifting away and fishing. Tied to a
small iceberg. Somewhere in a channel with ice-cold water, between 5 and
150 meter deep. To the north, rugged, steep mountains, interspersed with
glaciers that look as if they may topple any second. To the south, a
very shallow and flat archipelago with two penguin rookeries. Our
operating base, the Australis, is anchored there.

We haven’t caught a single fish all day. Suddenly, a pack of crabeater
seals surfaces directly next to us. They play around in the turquoise
water of the iceberg and loudly recharge their lungs with fresh air.
“Where are all the fish?” we ask. The seals snort and shoot perhaps one
or two curious glances at us, but otherwise we’re being thoroughly
ignored. We value their company nevertheless.

A few hours later – the sun has already dropped behind the horizon – 
our final effort at this locality pays off: the small net we set out in
the morning brings us ten fish. At last. A happy moment, because these
are valuable samples that will allow us to conduct detailed studies on
the diet and genetic make-up of this species. Such information is
ultimately important to understand and protect the unique Antarctic fishes.

Living in 23 meters by Franz

When it comes to spending four weeks with 11 persons on a small vessel
such as the “Australis”, details, compromises and organisation are key
to enjoy the voyage to Antarctica.
Finding your own space in tiny cabins, sharing one shower or dealing with your cabin mate snoring are all details that become part of a daily routine that we all (have to) embrace.

Working on such an unusual platform requires good organisation to
satisfy every project and person that is part of the expedition. Sharing
“laboratory” space, zodiacs, sorting trays, etc., … can be tricky when
many operations happen at the same time and good coordination and
communication among the team is important to avoid any conflict. Our
daily routine therefore always ends with a debriefing to discuss science
as well as planning or personal feelings.

The most important assets to live on the “Australis” can be summarised
into three major points that, as we all agree, make the success of our

First is Katie, who’s in charge of everyone’s happiness inside the boat.
She is the one we will have to blame if we put on too much weight during
these four weeks. She is the British sister of the boat, always asking
if everything is fine and offering goodies for comfort. She also proved
herself a brilliant biodiversity catcher on Antarctic shores.

Then comes Ryan, mostly dedicated to outdoor activities, he is always in
for a zodiac lift, assisting the divers, going fishing and making sure
we are all safe when conducting our science. Never short on a funny
comment or joke, this New Zealander and Katie are like cats and dogs in
the galley.

Last but not least is Ben, captain of the “Australis”. His huge
experience of the surrounding environment ensures the success of
location picking while satisfying every project on board. Entirely
dedicated to the Belgica121 expedition he always finds a way to help us
achieving our goals.

These aspects are certainly only the tip of the iceberg – the three of
them work day and night to run the “Australis” without us noticing and
all this work in the shade is probably the most important part of the
success of the Belgica121 expedition.

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