The Labrador Sea is characterised by hostile winds, bone-chilling waters and ethereal, almost otherworldly ice floes. Its summers are brief and its winters long. At its most frigid, around two-thirds of the sea is covered with ice, with the other third only just above freezing. Sitting as it does between eastern Canada’s Labrador Peninsula and southeast Greenland, it is, rather unsurprisingly, the coldest part of the subpolar North Atlantic. Through it, between the months of May and June, exists an artery known as ‘iceberg alley’ due to its plentiful supply of icebergs. Indeed, the iceberg that collided with the ill-fated passenger liner Titanic in 1912 travelled along this aquatic highway.

It is a place that, at first glance, appears altogether inhospitable and bleak, but the Labrador Sea’s conditions make it the ideal home for scores of creatures. Various species of whale, for example, including humpback, minke, orca, sei, and the northern bottlenose – designated as endangered in 2006 – live in and around the sea, largely owing to the plentiful supply of herring and shrimp. 

Below its surface also reside squid, lobster, flatfish, capelin and haddock, making the sea the perfect natural pantry for a diverse range of predators, from seals to sea lions, polar bears to sea eagles. These hunters are a relatively common sight along Greenland’s southern shores, while on the sea’s Canadian boundary, caribou – which are fond of devouring coastal sedge and moss – live in close proximity to the Arctic fox, snowshoe hare and black bear.

The Labrador Sea, and the coastlines that border it, are part of a delicate and finely balanced ecosystem. The flora and fauna have evolved to survive, and in many instances thrive, in an environment that, for the majority of life forms on the planet, would present abundant difficulties. 

Yet the long-term survival of the plants and animals that inhabit the Labrador Sea and its surrounding regions is far from certain. The impacts of climate change are starting to be felt in earnest, and the consequences of a rapidly warming planet could be catastrophic. The Labrador Sea, an area easy to overlook or ignore entirely, is very much on the frontline of climate change. 

A sea of substance

Dr Jon Robson, an expert in ocean dynamics, climate variability processes and climate predictions based at the University of Reading, is fully aware of the Labrador Sea’s global significance. “One of the reasons the Labrador Sea is important is because it has a key role in a globally important ocean current called the Atlantic Meridional Overturning Circulation (AMOC),” Robson says. 

“This plays a part in regulating climate through its movement of heat and carbon through the ocean. Essentially, the AMOC is a huge system of currents that move warm water from the subtropics into the polar region in the North Atlantic. It is part of the reason why Europe is relatively warm. Although the Labrador Sea may only contribute a small amount of the total strength of the AMOC, simulations with ocean and climate models suggest that changes there over the past few decades – in particular, the amount of dense sea water formed – may have played a vital, perhaps larger role than one might expect, in shaping how the AMOC and the North Atlantic has changed from decade to decade.”

And, Robson notes, modifications to the AMOC aren’t something to be taken lightly. “Changes in the strength of the AMOC have been implicated in a range of climate-related impacts, including Atlantic hurricanes, coastal sea level change along the US and in Europe, and even monsoon rainfall over India and North Africa. Models suggest this will happen gradually over the 21st Century, but the worry is that the AMOC could weaken suddenly over just a few decades.”

“Although this is probably an unlikely scenario,” Robson adds, “we are fairly certain that similar AMOC weakening events occurred in the past, especially during periods of large climate change.” And, given we are on the verge of a period of ‘large climate change’, these are history lessons that need to be carefully considered.