In the oceans, almost no older fish
A study of commercial fish in the seas around the USA and Europe showed that the number of old individuals declined on average by 72%, causing the population of commercial fish may suffer greatly.
The work was published in the journal Current Biology.
Scientists from the University of Washington in Seattle studied 63 species of commercial fish.
To determine the age of fish, the researchers relied on otoliths — solid education, perform the role of ears, which grows annual rings.
During the work the researchers used data on population for 24-140 years.
It turned out that the rate of decline of populations of the fish increased by 180%. In some species, such as Pacific cod, Pacific hake, red snapper and Atlantic cod, the number of old individuals declined by more than 95%.
While older fish tend to produce more caviar and better adapt to environmental changes, so the lack of old commercial fish can cause the extinction of entire species.