A Northern California whale watcher has shared an "epic" encounter between whales and dolphins he captured off the Monterey County coast last week.

The bloody, awe-inducing video, shared on YouTube by Moss Landing-based Sanctuary Cruises, shows eight to ten killer whales attacking a pod of 1,000 dolphins.

"What an incredible encounter I just had," said the man who witnessed the dolphins flying by his boat attempting to escape the whales.

Whale-watching companies are reportedly seeing record numbers of killer whales this spring in Monterey Bay, where the giant animals hunt migrating baby gray whales.