LONG BEACH, California (AP) -- SeaWorld wants to greatly expand the tanks it uses to hold killer whales in San Diego, but animal rights activists fear the plan would pave the way for breeding the animals in captivity -- something they say is cruel no matter the size of the tanks.
The California Coastal Commission on Thursday was considering the $100 million proposal for the marine theme park.
The panel has been flooded by tens of thousands of emails against the project that opponents also say represents a marketing ploy to boost plummeting park attendance.
Dozens of protesters, including actress Pamela Anderson, stood outside the meeting at the Long Beach Convention Center, holding signs urging a no vote on the tank and condemning SeaWorld and its practices.
They moved inside for the beginning of the meeting that's expected to be contentious and last much of the day.
The staff of the commission that regulates land and water use along the California coast has recommended approving the expansion under nine conditions that include forbidding SeaWorld from housing recently captured orcas in San Diego.
SeaWorld says it has not collected any orcas in the wild in more than three decades, its animals are well treated and park shows help generate support for conservation.
Under the proposal, SeaWorld would demolish portions of a 1995 facility that included a 1.7-million gallon (6.5-million liter) pool and replace it with a 5.2-million gallon (20-million liter) tank and 450,000-gallon (1.7-million liter) pool.
The Orlando, Florida-based company has said the orca population at the San Diego facility -- which currently numbers 11 -- would not significantly increase due to the "Blue World" project it wants to open in 2018, even though the capacity of the tanks would jump.
Attendance at the California park has declined since the release of the population documentary "Blackfish" in 2013, which suggests SeaWorld's treatment of captive orcas provokes violent behavior. The company's stock price also has dropped over the past two years.
SeaWorld says negative media attention is partly to blame and there is also increased competition among Florida theme parks and other factors.
Animal rights activists fear SeaWorld will use the expanded tanks to breed orcas in San Diego and send them to other marine theme parks. They say captivity has cut the life spans of the highly intelligent animals that should be transferred to ocean sanctuaries on the coast.
SeaWorld says its animals have normal breeding interactions in the healthy environment provided by the park, and not allowing its killer whales to breed would be inhumane.
SeaWorld helps the plight of orcas, which were hated and feared before SeaWorld began opening its parks, spokesman David Koontz said in an email to The Associated Press.
"Nearly a half-billion guests to all our SeaWorld parks, and other marine parks around the world, have gotten the chance to experience killer whales firsthand, learn about them and come to appreciate them for the wonderful animals they truly are," Koontz said.