MISSION BEACH, Calif. -- The three-decade tradition of nightly fireworks at SeaWorld will resume Saturday night, now that environmentalists and the park have agreed to test Mission Bay water to see if the pyrotechnics actually cause any pollution.

The popular fireworks show, visible throughout Mission Bay Park and the nearby beach communities for more than 30 years, ended abruptly last summer, when a self-appointed group called San Diego Coastkeeper said it intended to file suit.

Environmentalists had said they thought hundreds of pounds of unexploded explosive powder and other harmful chemical leftovers from exploding rockets and shells was falling into Mission Bay.

If that was happening, that would be a major violation of federal and state clean water laws.

SeaWorld officials have convinced members of San Diego Coastkeeper that their rockets' red glare -- and other fireworks -- are not adversely affecting water quality in the bay.

San Diego Coastkeeper director Bruce Reznick said no suit will be filed if SeaWorld applies for a clean-water permit, and continues to clean up paper and other scraps of unburned pyrotechnics from the park after the nightly shows.

"We do not really know what is in SeaWorld's fireworks," Reznick told the San Diego Union-Tribune. "By monitoring the water, we can figure out if there is any harm."

Aerial fireworks shows are largely unregulated by the various federal and state agencies that enforce clean air and water laws.

The move against Sea World last summer was the first time that a fireworks show was cancelled over environmental concerns, officials said at the time.

The San Diego Regional Water Quality Control Board has asked state and federal officials what to do about claims from the Coastkeeper group that the exhibitors need water and air pollution permits.

In nearby Mission Beach, reaction is mixed towards the return of the shows, which usually went up at about 9:40 p.m. every night. One resident told the Union-Tribune that residents along Bayside Walk are affected by the shows, which can frighten dogs.