Fish are shrinking

Fish are shrinking. The average body weight of nearly three-quarters of marine fish populations sampled dropped between 1960 and 2020, a recent study suggests.

The change threatens the food supply of the more than 3 billion people who rely on seafood as a source of protein, The Washington Post reported.

Overfishing is known to reduce fish sizes — fish are larger in protected marine areas — but climate change seems to play a part as well: Researchers found that trout reared in warm water tanks were on average less than half the size of those raised in colder ones.

Scientists speculate that larger fish find it harder to regulate their body temperatures in warm water.