Blue Whales in the Bay to Feed on Krill - Central Coast News KION/KCBA

MONTEREY, Calif- Blue Whales making a rare return to the Monterey bay to feed, and they are eating tens of thousand of krill at day, "If you could take all of the water out of Monterey bay and just leave the animals there you would see these clouds miles long of krill right along Monterey Canyon," said Don Croll and Ecology Professor at University of California Santa Cruz.

But if you're not a scientist the life cycle may be complicated. In simple terms the North West winds push water filled with nutrients to the top of the ocean. Those nutrients attract krill,whales follow and eat the krill, "When we get large concentrations of whales its hard not to get excited. It's just the most spectacular thing to ever happen on the planet," said Croll.

Researchers around the bay try to tag the animals to help track their behavior. the overall goal is to see where the whales travel throughout the year, "Where do they go to breed where do they go to eat the blue whales that we see here we know from our satellite tracking that they go as far as Costa Rica," said Croll. Scientist also monitor krill to see when the whales are likely to show up.

When I was out whale watching we also got a great look at some Humpback Whales, which are also in the bay feeding on krill, and other small fish. These whales are a little more flashy, some might say they are show offs compared to the mellow blue whale."It's not really clear why they breech but the Humpbacks breech and I think the blue whales they may not breach because that's a lot of whale to get out of the water so I've never seen a Blue Whale breach," said Croll.

Researchers are not sure how long the Blue Whales will stick around.