Primary Industries says it has no choice but to impose further limits on snapper fishing in South Australia.

A statewide snapper fishing ban will be 15 days longer this year, ending in mid-December for commercial anglers.

Recreational anglers face lower bag limits.

The longer ban is to apply for all anglers from next year.

Professor Mehdi Doroudi from Primary Industries said extending the no-take period was critical to protect stocks, even if it pushed up fish prices.

"The main concern is about abundance of fish. If we don't have fish we wouldn't have any fish in the market, we need to always considering that fact as well," he said.

The department says there will be more work and community consultation done in an effort to protect the main spawning aggregations in Spencer and St Vincent Gulfs, with further announcements expected early next year.