A California agency has approved a $100 million expansion of the tanks SeaWorld uses to hold killer whales in San Diego — but it has also banned the park from breeding captive orcas.

The California Coastal Commission added that amendment on Thursday as it approved an expansion that would triple the size of the current killer whale enclosures. The expanded "Blue World" exhibit is set to open in 2018.

The plan drew heated opposition from animal rights groups who say the new tanks will lead to more captivity for orcas.

However, the commission's approval comes with the provision that no new whales from the wild will be kept there.

SeaWorld says it hasn't captured wild orcas in more than 30 years.

Park attendance and income have suffered since the release of the popular 2013 documentary "Blackfish," which suggested SeaWorld's treatment of orcas provokes violent behavior.

The SeaWorld parent company is based in Orlando. The ruling would not affect the husbandry program at the Orlando park. SeaWorld is planning a similar tank expansion at its Orlando and San Antonio parks.