Whale Populations Decline as Climate Change Alters Southern Ocean

Nature Scientific Reports, 11 February 2026

The reproductive rate of southern right whales has declined in the last decade as warming waters and shrinking sea ice reduce nutrient and prey availability. The average time between births has increased over the past three decades, growing from each female producing a calf every 3 years to now having one every 4 or 5 years. Longer calving intervals are linked to environmental changes in whale feeding areas, including declining Antarctic sea ice concentration and warming sea surface temperatures. Both of these factors alter krill habitat and productivity, a key food source of the whales. These combined climate conditions explained about 55% of the variation in calving intervals, indicating strong associations between environmental change and reproduction. This reproductive decline has slowed population growth and represents a warning sign for the species, as human-driven climate change is reducing Southern Ocean ecosystem health.

Paper | News Coverage | Summary by Flinders University