Asterias amurensis potential invasiveness

A new vERSO-related paper was published in collaboration with the University of Sydney.  “From pole to pole: the potential for the Arctic seastar Asterias amurensis to invade a warming Southern Ocean ”  by Maria Byrne et al.  investigates Asterias amurensis, a keystone boreal predatory seastar that has established extensive inva-sive populations in southern Australia, is a potential high-risk invader of the sub-Antarctic and Antarctic. To assess the potential range expansion of A. amurensis to the Southern Ocean as it warms, we investigated the bioclimatic envelope of the adult and larval life stages. We analysed the distribution of adult A. amurensis with respect to pre- sent-day and future climate scenarios using habitat temperature data to construct species distribution models (SDMs). To integrate the physiological response of the dispersive phase, we determined the thermal envelope of larval development to assess their performance in present-day and future thermal regimes and the potential for success of A. amurensis in poleward latitudes. The SDM indicated that the thermal ‘niche’ of the adult stage correlates with a 0–17 °C and 1–22.5 °C range, in winter and summer, respectively. As the ocean warms, the range of A. amurensis in Australia will contract, while more southern latitudes will have conditions favourable for range expansion. Successful fertilization occurred from 3 to 23.8 °C. By day 12, development to the early larval stage was successful from 5.5 to 18 °C. Although embryos were able to reach the blastula stage at 2 °C, they had arrested development and high mor- tality. The optimal thermal range for survival of pelagic stages was 3.5–19.2 °C with a lower and upper critical limit of 2.6 and 20.3 °C, respectively. Our data predict that A. amurensis faces demise in its current invasive range while more favourable conditions at higher latitudes would facilitate invasion of both larval and adult stages to the Southern Ocean. Our results show that vigilance is needed to reduce the risk that this ecologically important Arctic carnivore may invade the Southern Ocean and Antarctica.

Off to the South Orkneys

Two members of the vERSO consortium, Camille Moreau and Bruno Danis (Marine Biology Lab, ULB) will be taking part in the SO-AntEco expedition, led by the British Antarctic Survey (BAS). expedition undertaken in conjunction with an international team of scientists from the Scientific Committee for Antarctic Research (SCAR) AntEco research programme. The team includes participants from 9 different countries and 16 institutes. It also involves scientists from three UK universities (Bristol, Hull, Liverpool and Oxford) and the Natural History Museum in London. The expedition will take place on board the BAS research ship the RRS James Clark Ross in early 2016 and is the sister project of the Krill Hotspots project.

The vERSO team will be focusing on echinoderms (sea urchins and sea stars), and will carry out a series of physiological, biodiversity and genetics measurements, to try and figure out the effects of global change on these ecosystem-structuring organisms.

You can follow our progress on this website and on the expedition’s blog.

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SO-AntEco science cruise location map. HJ Griffiths, BAS.

2015-2016 SEA-GOING EXPEDITION

Alongside the vERSO team working at Carlini station (see previous post[link]), Henrik Christiansen from KUL will be joining RV Polarstern this season during cruise PS 96. Departing from Cape Town this expedition will attempt to advance deep into the Weddell sea, where various samples of benthic organisms shall be collected.

You can follow Henrik here

vERSO team arrival at Carlini Station

This year the vERSO project takes us to Carlini Station (Potter Cove,King George Island, West Antarctic Peninsula) during early spring (October 2015) and will host (rocking!!!) Belgian science till the end of the summer season (March 2016). The scientific “crew” for the campaign will be composed by two Post Doc researchers (Francesca Pasotti, Ghent University UGent, and Antonio Agüera, Free University of Brussels ULB) and a very (very!!) lucky master student from Ghent University (Nene Lefaible). Antonio will join the campaign at a later stage, in early December.
To reach the base this year we (Francesca and Nene) had the chance to join the crew of the expedition vessel Polar Pioneer (Aurora Expeditions Cruise Ship) and be delivered directly to Carlini Base together with our cargo. This vessel has an ice-strengthened keel and it usually works as tourist expeditions vessel. Nevertheless, the ship is directly involved in the scientific logistics needed to allow European research to take place in the far Southern Ocean. In September the ship left from Poland passing by Bremerhaven (Germany) where it uploaded all the scientific cargo (material, food, special clothing etc..) previously sent to the Alfred-Wegener Institute (AWI) harbor headquarters from the various interested research institutes (among which, UGent and ULB). Once loaded the cargo the ship crosses the Atlantic Ocean and reaches Argentine waters.
We joined the ship once the vessel entered the Argentinian territory (on 22nd October) and harbored for one day in Mar Del Plata. The day after, our journey towards the Antarctic started together with other Argentine scientists who also boarded then, and the already onboard Polish research team of the land base Arctowski station.
The trip has been rather lucky. Only two strong storms troubled the sleep of the passengers, the Drake Passage (the most feared part of the travel) went pretty smooth, with no large storms endangering the ship. Once we reached latitude 59 ° S the pack ice showed up in denser and denser zones, obliging the ship to reroute and de-tour the travel to King George Island. Carlini Base (and so Arctowski) are both based on King George Island, the northern island of the South Shetlands Islands, the tip of the West Antarctic Peninsula. The vast white iced Ocean was dominating the landscape for a full all day before being able to reach KGI. The hypnotising silence of these surrealistic ice-covered water masses was only broken by the flapping wings of Albatrosses, Cape Petrels or Snow Petrels, the real masters of navigation in such windy and stormy Seas. Penguins seeking shelter on wondering icebergs were grimly awaited by leopard seals swimming around these giant ice homes. The whole view was utterly breathtaking.
But as beautiful as the pack ice may be to the human eye and soul, as it may result of great hindrance for Antarctic logistics and its successful completion. In fact this time the pack ice troubled us during the unload operations, blocking us from reaching the inner part of the cove and be close enough to the base, not leaving free waters to reach the coast via zodiacs, and requiring more waiting time and longer distances to be managed in between the location of unload on shore and storage places on land. To resume: we worked even harder than usual!
All in all we managed, after a 8 days ship cruise and a total of 3 days of unload (hands-on by each and every one us: from the dedicated ship crew to us, the scientific crew) which delivered goods and equipment to both Arctowski Base and Carlini Base. Eureka!
Here we go! Now me and Nene are ready for the campaign. The unpacking needs to start and soon we will send updates about the proceeding of our campaign, where an acidification experiment will be one of the hot topics of the season!
Stay tuned!
Francesca and Nene

King George Island, West Antarctic Peninsula – Landscape and wildlife

vERSO in Carlini Base, King George Island, West Antarctic Peninsula – let’s start!

02/02/2015

Our travels to the Antarctic are made possible by the valuable German (Alfred Wegener Institute, AWI) and Argentinian logistics. We travel via Buenos Aires, thanks to the Argentinian military logistics of the Dirección Nacional del Antartico (DNA) and in collaboration with the Instituto Antartico Argentino (IAA). The voyage started with one week of delay which we spent in Rio Gallegos (Patagonia, Argentina) waiting for the appropriate weather conditions to cross the Antarctic Convergence on board of an Argentinian Hercules C-130.

We left Buenos Aires on the early morning of  Tuesday 20th January and we arrived in Potter Cove (62° S 58°  W) on the evening of Saturday 24th January after a 3,5 hours flight which landed in a neighbouring base, the Chilean base of Frei.

Potter Cove is a fjord-like embayment on the southern coast of King George Island, one of the South Shetland Islands, at the northern tip of the rapidly warming West Antarctic Peninsula. In Potter Cove the Fourcade glacier has actively retreated since the 1950s and a big part of the inner cove became seasonally ice-free in the last decades. The sediments of these newly ice-free areas are exposed during summer to ice-scour due to glacier calving, to sudden re-suspension due to wave action (at least in the first 20 m depth) and to inorganic sedimentation as a result of summer permafrost and glacial melting. The previously all year-round covered benthic (organissm living inside or in tight contact with the bottom) communities that live in these areas became now exposed to the water-column processes and some studies on macroalgae and megabenthos in Potter Cove already showed how these sites are subject to undergoing colonisation and successional stages.

It is within this complex environmental context that we identified three sites which are contrasting in terms of glacier influence (ice impact, inorganic sedimentation, time since the glacier retreat/ice-free age). Here we will study the functioning of the smaller components of the benthos, the meiofauna (32-1000 µm) and macrofauna (1000 µm- few cms). As measure of ecosystem functioning we will measure oxigen production and consumption, nutrient fluxes and other biogeochemical parameters, so to say the biological activity of these organisms and how they affect the environment in which they live, sequestrating or producing carbon and other important basic elements of life on Earth..

We will measure all this in situ!!! quiet an amazing portfolio for the Antarctic!! In fact doing this in such extreme places is quiet challenging. The weather till now has been pretty bad since that beautiful day that welcomed us in the Antarctic Peninsula…wind has been mostly too high for diving activities in the cove (we need less than 20 knots of wind a rather gentle gusts) but in the past three days we finally got the chance to start…we performed our check dives and identified and marked one of the three sites where we will deploy the benthic chambers and the in situ profiler…The diving is really “extreme” here : cold water, bad visibility (often less than 30 cm), cumbersome equipment, tethered diving, leopard seals hazard and so on…all this makes it a hard task to complete, but we are determined to gather such important “in real” information to increase our understanding of the ecosystem functioning in this rapidly changing ecosystem.

more post to come when the work will be started with the chamber

deployment!

wish us good weather folk!

Francesca, Ulrike and the wonderful people in Carlini

Laboratory experiments in Carlini Base, King George Island.
Laboratory experiments in Carlini Base, King George Island. Ulrike Braeckman on bottom left, divers Ralf Hoffman (top right, most left person) and Francesca Pasotti (right person driving the boat)
Benthic chambers deployment via zodiac
Benthic chambers deployment via zodiac

24/03/2014

EUREKA!

WE made it!

The diving and the laboratory work has been successful! We finally had enough good weather days to perform all the needed dives. We deployed the chambers to each and every studied site and we have been able to collect water samples for oxygen concentration from inside the chambers before and after the 24h incubation time and we collected as well sediment samples from the same area where the chambers were located, in order to study the fauna and biogeochemistry of the sites and related these characteristics to the fluxes measured within the benthic chambers. It really feels good when a campaign starts as a huge challenge and ends as a successful scientific campaign, which has been enriching from the professional and human point of view. Eureka! Now our samples are waiting to be sent back to Europe via Polar Pioneer, and soon we will be abel to process the >2000 samples in order to unravel what we have already roughly observed during our field work…very exciting!! Therefore more to come…in form of publications and small updating posts…

 

Follow us up folk!

 

Francesca and Ulrike @Belgium

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Pasotti Francesca, Advanced Belgian Scientific Diver, Ghent University, Belgium, ready to dive to collect the water samples from within the benthic chambers (Photo: Anders Torstensson)

 

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Anders Torstensson, University Gothenburg, Sweden (underwater photographer of the dive team) (Photo: Francesca Pasotti)
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Anders Torstensson (left) and Ralf Hoffman (right, AWI, Germany) tethered and ready to dive in buddy system for the deployment of the benthic chambers (Photo: Francesca Pasotti)
Benthic chambers (Photo: Anders Torstensson)
Benthic chambers (Photo: Anders Torstensson)
Pasotti Francesca taking water samples from within the chambers by means of glass syringes (Photo: Anders Torstensson)
Pasotti Francesca taking water samples from within the chambers by means of glass syringes (Photo: Anders Torstensson)

 

 

 

 

2014-15 expeditions

This year, 3 concurrent expeditions will be heading south to address a series of scientific questions identified by the vERSO consortium.

Our teams will be joining the RV Polarstern SIPES (PS 89) expedition (Anton Van de Putte, RBINS), and also working in land-based stations: Dumont D’Urville (Philippe Dubois, ULB and Loïc Michel, ULg) and Carlini (Francesca Pasotti, UGent). The main objectives of these concurrent expeditions are to setup and test new experimental procedures, gather samples, run experiments and organise large amounts of data.

We wish them good look in this endeavour. We’ll keep you posted with new updates on the respective blogs.

Learn more about the vERSO project here!

Follow Anton on RV Polarstern here!

Follow the ULB teams on the Marine Biology Lab website here!

Ecosystem Responses to global change: a multiscale approach in the Southern Ocean