On average by 13%!

Gray whales in the Pacific are getting smaller according to study

The body size of gray whales in the Pacific has decreased by an average of 13 percent in just two decades.

(Bild: stock.adobe.com/slowmotiongli)

According to a new study, the body size of gray whales in the Pacific has decreased by an average of 13 percent in just two decades. This "shrinking" could threaten the reproduction and survival of the marine mammals, according to the study.

For their study, the researchers focused on a small group of around 200 gray whales in the northeastern Pacific. These marine mammals, which are considered "guardians of the ecosystem", generally stay close to the coast and feed in shallower and warmer waters than other gray whale populations.

Shrunk by 13 percent on average
The researchers analyzed drone images and found that the size of adult whales decreased by 13 percent on average between 2000 and 2020. This is "possibly an early sign that the population is declining", says scientist Kevin Bierlich.

Females in particular are getting smaller
According to the study, the trend is particularly clear in the case of female gray whales: These were on average larger than the males in the past and are now the same size on average. The researchers cited the disruption of the ocean circulation caused by climate change as a possible cause for the shrinking of the whales.

In particular, the scientists referred to changes in ocean currents, which are important for the growth of plankton, the whales' food.