**Distinct Populations of Turquet’s Octopus in West Antarctica**
Ocean bays in West Antarctica are home to two separate populations of Turquet’s octopus (Pareledone turqueti). Recent DNA analysis reveals that these populations were once part of a single familial group. This suggests that around 125,000 years ago, the West Antarctic ice sheet that separates the two bays had completely collapsed into the sea, allowing for gene flow between the octopus populations.
**The Ancient Connection Between Octopus Populations**
Scientists have conducted genome sequencing on octopus populations in the Weddell and Ross Seas and discovered evidence of ancestral gene flow between the two populations approximately 70,000 years ago. This indicates that an ancient seaway may have opened across the West Antarctic Ice Sheet, directly linking the present-day Weddell Sea and Ross Sea. Researchers suggest that this occurred during an interglacial period when the West Antarctic Ice Sheet collapsed, estimated to have happened between 68 and 265 thousand years ago.
**The Risk of Future Ice Sheet Collapse in West Antarctica**
Currently, it remains uncertain whether West Antarctica is at risk of a complete collapse due to the climate crisis. This is one of the major uncertainties in climate models. While some experts predicted disaster in the region several decades ago, more recent climate models predicted no significant ice loss in Antarctica within the century. However, the reality is proving to be different, with West Antarctica discharging melting icebergs at a faster rate than the rest of the continent.
**The Potential Impact of a Collapse**
If the entire West Antarctic ice sheet were to collapse due to human-induced global warming, it could result in a severe environmental catastrophe. Sea levels could rise by 3.3 to 5 meters (11 to 17 feet) globally, leading to the overturning of water circulation in oceans and a significant reshaping of coastlines worldwide. Currently, the collapse of the West Antarctic ice sheet on a centennial timescale is considered a low likelihood process. However, even the most optimistic future models predict that air temperatures could reach levels potentially within the tipping point for the collapse of the ice sheet.
**The Fragile State of West Antarctica**
Currently, more than half of the ice shelves supporting the Antarctic ice sheet are at the risk of collapsing. If these ice shelves crumble, it could lead to irreversible losses. The potential reunion of Turquet’s octopuses with their long-lost family members would signal that our planet has entered troubled waters.
The distinct populations of Turquet’s octopus in West Antarctica provide evidence of a historical connection between the Weddell and Ross Seas. The collapse of the West Antarctic Ice Sheet in the past suggests that similar events could occur in the future, especially with rising global temperatures. The potential collapse of the ice sheet would have catastrophic consequences for sea levels and coastlines worldwide. The fragile state of West Antarctica, with melting icebergs and vulnerable ice shelves, highlights the urgency to address the climate crisis and mitigate the risk of further environmental damage.