An underwater alarm has reduced the number of whales becoming entangled in shark nets off Queensland, the State Government says.

The alarms, known as pingers, transmit a sonic warning to whales, alerting them they're close to the nets that are designed to protect swimmers from sharks.

From 2000 to 2009, 27 whales were caught in shark control equipment in Queensland. There was just one in 2010 and another last year after the pingers were introduced, Queensland Fisheries Minister Craig Wallace said.

Both of those whales were successfully released, he said.

''Results from the last two years are extremely promising and indicate pingers are helping to warn whales about the presence of the nets,'' Mr Wallace said.

There are 130 pingers between the Gold Coast and Cairns - four on every shark net.