The Department of Conservation's Coastal Otago biodiversity ranger Jim Fyfe told Morning Report there were 31 pups born in the area this year, up from 21 last year.
"The populations really turned a corner around Dunedin and we're looking forward to having them around full time."
However, people need to "make space" for them.
Fyfe said roads were the biggest danger for sea lions. Some roads had been temporarily closed during breeding season when they came further inland.
"We ask people to keep the speeds down when they're travelling on coastal roads around Dunedin at the moment."
The re-introduction of a sea lion population on the mainland was an "amazing story", he said.
"A female called Mum came up from the Auckland Islands some 30 years ago and all the breeding females we have here a descendants of this one female.
"As they do recover on the mainland we're learning more about their habitat needs and there is almost complete overlap between humans and sea lions around Dunedin."
