A 2024 study did not find a significant difference in shark bites at netted versus unnetted beaches in Sydney since 2000. But that is not necessarily a gauge of the nets’ effectiveness, said Professor Huveneers, the study’s lead author.

Two opposite outcomes could be true, he said: Either the nets did not kill enough sharks to make a difference, or they did and therefore reduced bites at beaches with and without nets.

Because there is no effective way to test which hypothesis is correct, he said, it’s hard to say whether the nets are worthwhile. Many experts argue that newer technologies provide more targeted and less lethal forms of protection.