The Baltic ringed seal population has grown fivefold since the 1970s, thanks to bans on hunting and toxic chemicals once common in the region.
Rob Hutchins reports for Oceanographic Magazine.
In short:
- A new model from University of Helsinki researchers estimates that the Baltic ringed seal population has risen from 5,000 in the 1970s to around 25,000 today.
- The recovery is attributed to hunting restrictions and the decline of toxic pollutants like PCBs and DDT, which had once severely impaired the seals’ reproductive ability.
- Despite the rebound, the resumption of hunting in 2015 has slowed the population’s growth rate from a projected 7% annually to under 5%.
Key quote:
“Hunting affects the ringed seal population. We estimate that, without hunting, the population would grow annually by about 7%. However, hunting has lowered the growth rate to less than 5% and even small increases in hunting quotas are likely to cause a further decline.”
— Murat Ersalman, lead author
Why this matters:
The Baltic ringed seal serves as a biological barometer for the health of Arctic and sub-Arctic marine ecosystems. Once decimated by industrial chemicals and overhunting, its recovery offers rare evidence that regulatory interventions — such as bans on DDT and PCBs — can allow species to rebound. But the story also signals caution: Changing ice patterns due to climate change and resumed hunting now threaten to stall or reverse the progress made. Ringed seals depend on stable ice conditions to breed and rest; shrinking ice coverage not only reduces their habitat but also complicates population surveys, making accurate monitoring harder.
Related: PCBs might be sneaking back, despite decades-old ban
