Marine Biology

Discovering life in the icy deep – secrets of the Weddell Sea

Hello all! My name is Betina Frinault and I am a Marine Biologist.

Here on the Weddell Sea Expedition 2019 (the “Expedition”) I represent the University of Oxford and the Nekton Mission. Together with Dr Michelle Taylor and Dr Lucy Woodall we form the Expedition’s “Marine Biology Team”.

The following intends to provide an introduction to marine life we are assessing on the Expedition, what we are aiming to explore and why.

Since joining the Expedition in Antarctica on January 1st, we have been observing a plethora of marine life: penguins aplenty from majestic Emperors standing proud to petite yet feisty Adélies that nipped at our kneecaps whilst atop sea ice; Weddell, Crabeater and Leopard seals happily springing in and out of the water and taking snoozes on floes; and goliath Humpback and Southern Minke whales ejecting their misty blows nearby our great ship, SA Agulhas II, seemingly to alert us to their presence. It is undeniably wondrous.

That said, our marine biology research on the Expedition intends to newly explore the life of the much deeper, darker and unfamiliar waters of the Weddell Sea. To discover the “critters of the benthos”; remarkable communities of organisms that live in, on, attached or close to the seabed.

 

In particular, we will be investigating deep-sea benthos dwelling near to and directly underneath ice shelves. Our target area is the environs of the Larsen C ice shelf, situated in the north-western zone of the Weddell Sea.

The Larsen C ice shelf is targeted as it recently incurred calving of a huge iceberg, the A-68, exposing marine areas to sunlight after being cloaked by ice for millennia. With this uncovering of ice, sunlight can newly penetrate the surface layers, plus wind-surface interaction and nutrient supply is enabled. As such, it is expected that tiny light-dependant photosynthetic plankton will come to reside and bloom in these areas. This will potentially generate vast cascades of marine snow and ultimately modify food delivery to the very bottom of the water column, and hence its occupants.

Essentially we are aiming to investigate how such changing ice conditions on the surface may impact the biology in the depths of the Weddell Sea. We aim to explore community patterns of the benthos, including types of animals present and their abundances. This will be done across differing study locations encompassing seafloor with completely open water above, and seabed near to and under the Larsen C ice shelf. We will also aim to identify environmental, geological and oceanographic drivers and parameters of such communities. As you can imagine, there are many factors to consider.

To give examples of animals we suspect we may observe in the benthos, would be sea cucumbers (a wider group of animals to which sea pigs belong!), starfish, sea squirts, sea anemones, sponges and corals - where some individuals may be decades to centuries old! There may also be unfamiliar and downright baffling species too, and it is highly likely novel species will be encountered. After all these are unexplored territories.

Our scientific adventure into the deep-sea and unknowns of Antarctica is by no means without risk. Accessing, and staying within targeted study zones may prove inherently challenging with considerably changeable ice conditions posing a threat not only to the start but to the continuation of our seafloor investigations. In respect, we are very lucky to have vital expertise from the Scott Polar Research Institute (SPRI) and Stellenbosch University, and Captains Knowledge and Freddie plus crew, keeping a close eye on the sea ice and checking for leads (fractures) within, to best smooth our passage to and from exploration sites.

Overall the Expedition is very much about teamwork excellence, and our marine biology research is very much a collaborative effort enabled by a network of partnership institutions and their highly-skilled people. For example, we will be using underwater robots/drones, comprising of remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs) provided and piloted by the Eclipse Group and Ocean Infinity, respectively. This will help obtain footage of the never-been-seen-before biology and pick up specimens for DNA analysis. The Royal Netherlands Institute of Sea Research (NIOZ) has supplied a multi-corer to take soft sediment samples (in an undisturbed manner) so we can evaluate small “infauna” critters living within the benthos, and headed-up by the University of Cape Town (UCT), a CTD (conductivity, temperature and depth), in addition to other instruments, will be used to measure environmental parameters.

As well as new discoveries and lessons to learn, from a marine biology perspective our work will allow us to create key baselines from which we can predict and assess change. This is important in view of future climate change and further incidences of Antarctic ice shelf collapse, as well as other alterations to the environment which may influence marine life from the top to the very bottom of the water column.

Our work will be shared and it will also allow us to feed into policy and protection frameworks.

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Affiliated to The Queen’s College, University of Oxford, Betina Frinault participates on the NERC DTP (NPIF) Programme working with the Departments of Zoology and Physics. She is a research scientist at the Nekton Foundation, a contributor to the citizen science platform Zooniverse, and in coordination with the Pew Charitable Trusts is a member of the “Antarctic Futures Project”. On the Weddell Sea Expedition 2019 Betina has enjoyed sharing her work via Reach the World bringing live interactive seminars from Antarctica to class rooms across North America.

Betina Frinault and the Eclipse Group’s ROV “Lassie”, Antarctica, 6th January 2019; WSE 2019