North Atlantic right whales have shrunk by an average of a meter over the past 30 years due to intensive fishing. This is the conclusion reached by scientists who monitored their population.
Using aerial photogrammetry measurements from airplanes and remotely controlled drones over a 20-year period a team at the National Oceanic and Atmospheric Administration (NOAA) in California studied their size changes.
The photographs taken during aerial observations in the 1980s and 1990s show that the average length of these marine mammals was 14 meters. By the 2010s, the average length of the North Atlantic whale was one meter shorter, and some individuals were even several meters shorter.
According to scientists, this may be due to the entanglement of whales in fishing nets, leading to stress, reduced food supply and other side effects of human activities.
North Atlantic whales are listed in the Red Book, they are the rarest whales on Earth, and, despite the fact that hunting for them is prohibited, the population of these giants has not yet been able to recover. In the Middle Ages, there were more than 100 thousand of them, at the beginning of the 20th century - about 5 thousand, by 1980 their number had decreased to 100, and by now there are only 365 individuals.
The new study is published in the journal Current Biology.
