Antarctica: A Small Shift with Enormous Consequences
In the heart of Antarctica's summer, the ocean surrounding the Rothera research station maintains a chilling -1 degree Celsius. This region, teeming with microscopic plant and animal plankton, presents a unique and murky diving environment that few would consider ideal.
Yet, the divers accompanying me are brimming with enthusiasm as they prepare to plunge into these depths. Pati Glaz, a marine biologist with the British Antarctic Survey's dive team, shares her excitement over the distinctive starfish with 40 arms that call this place home. Her dive partner, fellow BAS marine biologist Matt Bell, is equally captivated by the phenomenon known as "polar gigantism."
"Polar gigantism" refers to the intriguing fact that species exclusive to cold polar oceans often grow larger than their counterparts in warmer waters. The colder the water, the more oxygen it can hold, which in turn supports the growth of larger animals. As Professor Lloyd Peck, who leads marine biology research at BAS, explains, "Because it's cold, the biology is very different. Things live a long time."
However, in a rapidly warming Antarctic, this longevity may become a liability. Animals here have adapted to live long lives due to their slow growth and reproduction rates. An Antarctic starfish, for instance, may take hundreds of days to reproduce, compared to a few weeks for its UK cousins. Even a slight increase in temperature can disrupt this delicate balance, causing their larvae to hatch earlier, during winter when food and light are scarce.
"We're concerned that many species could fail due to the detrimental changes in the timing of their life cycles, caused by just a small amount of warmth," Prof Peck warns.
The dive research team's strength lies in their long-term commitment to surveying the same sites on the seabed for nearly 30 years. This consistency is crucial for understanding the winners and losers in an ecosystem that has already warmed by an average of almost a degree since the research began.
Diving in Antarctica comes with its own set of challenges. In addition to specialist dry suits and thick gloves, spotters on the surface keep a vigilant eye out for wildlife, particularly predatory leopard seals and curious killer whales. Following a fatal encounter in 2003, any sighting of these marine predators before or during a dive results in an immediate abort.
After a 20-minute dive, the divers return, surprisingly warm and cheerful, carrying samples of wildlife for their laboratory aquarium. The urgency of their research is palpable as they strive to understand how marine ecosystems are coping with climate change and explore sub-zero biology, a field where science knows very little.
"If you take the cells of animals that live at warmer temperatures and cool them down to zero degrees, they don't work," Prof Peck explains. Biologists believe that the way proteins fold and stick together plays a crucial role in this process. Warm-water animals experience protein sticking when cooled, but evolution has found a way to allow life to thrive in freezing oceans.
"Understanding why our animals don't have problems with their proteins sticking together will shed light on these mechanisms," Prof Peck adds. This knowledge could have significant medical applications, potentially offering insights into diseases like Alzheimer's and CJD, which are caused by abnormal protein sticking in the brain.
The team's new collaboration with the Centre for Engineering and Biology aims to develop microscopes capable of operating in sub-zero temperatures, allowing them to explore this unique biology for the first time. Back on the dive boat, there are other reasons for optimism. Whales, once a rare sight at Rothera, are now a common presence, with at least 30 and possibly as many as 40 humpback whales counted in the bay, setting a new record.
Populations are recovering following the ban on whaling 40 years ago, and the receding sea ice has allowed whales to swim here for the first time in millennia. How ocean ecosystems respond to warming is of critical importance. In the past, these ecosystems absorbed vast amounts of carbon from the atmosphere, contributing to the onset of ice ages after periods when Antarctica was even warmer than today.
Fossilized palm trees on the continent provide evidence of this warmer past, a fact often cited by those skeptical of climate change. However, the current warming trend in Antarctica appears to be far more rapid than in previous aeons, potentially outpacing the ability of its slow, cold biology to adapt.
The tiny changes we make today could have enormous consequences for the future of this unique and fragile ecosystem.
