Canadian researchers have found find that the population of bowhead whales which overwinters in the Amundsen Gulf and Eastern Beaufort Sea did not make the 6,000km round trip in 2018-2019.  Click here.

Bowheads are the only baleen whale endemic to the Arctic.  They live near the polar ice edge for much of the year and although sea ice dynamics are not the only driver of their annual migratory movements, it likely plays a key role. Given the intrinsic variability of open water and ice, one might expect bowhead migratory plasticity to be high and linked to this key environmental factor. Using a network of underwater passive acoustic recorders, the researchers have documented the first known occurrence of bowheads overwintering in what is normally their summer foraging grounds in the Amundsen Gulf and eastern Beaufort Sea. “The underlying question is whether this is the leading edge of a phenological shift in a species’ migratory behaviour in an environment undergoing dramatic shifts due to climate change.”  Royal Society Open Science (open access)

At the other end of the planet, satellites reveal ocean currents are getting stronger, with potentially significant implications for climate change.  Swirling and meandering ocean currents that help shape the world’s climate have gone through a “global-scale reorganisation” over the past three decades, according to new research published in Nature Climate Change (paywall).

Using available data from 1993 until 2020, analysis of changes in the strength of eddies across the globe were analysed found that regions already rich in eddies are getting even richer and, on average, eddies are becoming up to 5% more energetic each decade.  One of the regions with the biggest change is the Southern Ocean, where a 5% increase per decade was detected in eddy activity. The Southern Ocean is known to be a hotspot for ocean heat uptake and carbon storage and increasing energy in these eddies could affect ability of Southern Ocean to absorb CO₂.  Click here and here