The Weddell Sea: A Vital, Vulnerable Biodiversity Hotspot

The Southern Ocean is a realm of exceptional biodiversity, often poorly understood, shaped by extreme cold, seasonal ice cycles, and deep-ocean currents. At its heart, the Weddell Sea stands out as a critical sanctuary—a “biodiversity hotspot” harbouring everything from vast krill swarms to spectacular sponge and coral gardens, massive icefish breeding colonies, and iconic species like the emperor penguin and Weddell seal. This unique life is facing growing pressure from climate change, particularly the decline in sea ice, which serves as a vital habitat.

Launching a Monitoring framework: the WOBEC expedition

The research icebreaker Polarstern, operated by the Alfred Wegener Institute (AWI), has set sail for the Antarctic Weddell Sea on December 15th, embarking on an ambitious expedition to establish the groundwork for long-term biodiversity monitoring. The expedition’s primary goal is to understand how this unique ecosystem is evolving and, specifically, how the rapid decline in Antarctic sea ice is impacting these delicate communities. The “Weddell Sea Observatory of Biodiversity and Ecosystem Change” (WOBEC) is an EU Biodiversa+ project that aims to develop a long-term monitoring plan integrating traditional and innovative observational techniques. Gathering this data is crucial for understanding the region’s unique biodiversity and how it’s changing, which is necessary for creating effective preservation plans, especially for a potential future Marine Protected Area (MPA).

Expedition leader and marine ecologist at the University of Rostock, Heike Link, emphasises the urgency:

“We want to understand how this unique ecosystem is developing and what effects the decline in Antarctic sea ice is having on the communities. The expedition is a crucial test for our joint observation concept, which we are setting up for the coming years.”

The researchers will study unique environments like the Maud Rise seamount near the Greenwich Meridian, where special currents support a rich and diverse community, and the species-rich shelf area off Kapp Norvegia, close to the German Antarctic station Neumayer III. Crucially, the scope of the investigation will capture the entire web of life. As Anton Van de Putte notes:

“The Southern Ocean is home to unique biodiversity; however, we often examine only small parts of it. With this expedition, we have researchers looking at all trophic levels from the air, ice, water and seafloor. The data we collect will serve as an essential benchmark to track and understand changes in this unique ecosystem.”

A Legacy of Data: Making Antarctic data available to all

A major pillar of this work is data accessibility. Beyond collecting new biological, chemical, and physical data, the WOBEC team is committed to making all new and historical datasets publicly available. This effort is in close cooperation with international partners and the SCAR Antarctic Biodiversity Portal.

Anton Van de Putte highlights the essential work of standardising this vital information:

“We have been working hard with our team to provide templates and instructions that will make it easier to make the data we collect available through OBIS (Ocean Biodiversity Information System) and GBIF (Global Biodiversity Information Facility).”

With the Polarstern now en route to the ice, fieldwork will soon begin, greatly enhancing our understanding of one of the planet’s most sensitive and valuable marine environments and ensuring that its data are prepared to support protection efforts for generations to come.