LONG BEACH, Calif. (AP) _ A cargo ship collided with a barge Sunday outside Long Beach Harbor, seriously damaging the barge and spilling more than 136,000 gallons of caustic soda from it, the Coast Guard said.

The chemical, which kills fish on contact, ''is heavier than water so it sinks and disperses,'' said Coast Guard spokeswoman Pat Milton.

No injuries were reported in the collision of the 600-foot Israeli container ship Zim California and the 250-foot Dow Chemical barge, said Ms. Milton. The spill was two miles offshore and presented no danger to humans, she said.

The Coast Guard planned to pump the remaining soda out of the barge's rupture tanks to undamaged tanks and tow the craft into Long Beach harbor, about 25 miles south of downtown Los Angeles, Ms. Milton said.