That should have been “competing predators.”

Initially they put orcas in the pool one at a time. The dolphins attacked the orca. When they put 2 orcas in the pool, the orcas could successfully defend themselves against dolphin attack. Orcas and dolphins ended up “calling a truce”. The attacks stopped.

I was interacting with a dolphin, when an orca made a stealth approach and surfaced from beneath the dolphin. The orca sent the dolphin flying backwards thru the air with a flick of his head. He slid between my hands where the dolphin had been. (My 1st meeting with an orca.) Clearly the orcas still didn’t particularly respect the dolphins.

My experience was that the orcas rather assertively sought my friendship. After this 1st orca and I had interacted, all the other orcas recognized me by sight and would come right to me whenever I visited. The orcas involved, in the order I met them were: Canuck 2, Kotar, Kasatka, and Katina. It’s possible that Kandu 5 had originally been one of these orcas.

[Perhaps some 2 dozen visitors formed friendships with these orcas. A couple of us published a peer-reviewed paper on orca behavior as observed from the context of human-orca friendship. Animals 2016, 6(8), 49; https://doi.org/10.3390/ani6080049%5D

Or just maybe, they both eat salmon, and compete for the same food source in the same territory.