Carousel feeding refers to the hunting technique commonly employed by orcas. An individual or small group of orcas will release bursts of bubble or flash their white undersides to round prey such as salmon or herring into a tight defensive ball close to the surface. The orcas then slap the ball with their tail, stunning or killing up to 10-15 herring with a successful slap. Carousel feeding has only been documented in the Norwegian orca population and with some oceanic dolphin species.