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This is one of the best times of the year to spot a gray whale off the coast of Southern California. That's because they're migrating south for the winter. Recently, lots of other whales have also been sighted there, including one of the rarest, a sperm whale, off the coast of Long Beach. As NPR's Kirk Siegler reports, scientists are puzzled but whale watchers are thrilled.
KIRK SIEGLER, BYLINE: Not five minutes out of the nation's busiest commercial port and you're in a marine wonderland.
DAN SALAS: Just do me a favor. Secure your cameras, sit down, hold on. I need to get up the coast here. I'm going to show you...
SIEGLER: The captain of this boat that's just setting out from Long Beach is Dan The Whale Man Salas. Seriously, that's what they call him.
SALAS: We've had so many whales. We've had - we had orcas. This is all in the last two weeks. We've had orcas. We had...
SIEGLER: It's a like a whale traffic jam off this coast right now and Captain Dan isn't about to disappoint his guests.
SALAS: Right there.
UNIDENTIFIED MAN #1: Oh.
UNIDENTIFIED MAN #2: Oh, my God.
SIEGLER: One of the marine biologists aboard this vessel is Dave Bader of the Aquarium of the Pacific.
DAVE BADER: It's my favorite part of the whale watches, that collective experience when you see the ridge of the back and everybody's sort of...
UNIDENTIFIED WOMAN #1: Oh.
UNIDENTIFIED WOMAN #2: Oh.
UNIDENTIFIED WOMAN #1: Oh.
SIEGLER: Bader has been studying the annual gray whale migration here off the tip of the Palos Verdes Peninsula for the past 15 years. Not far from these cliffs, the ocean floor drops off 1,000 feet and gray whales park along the contour for a few days on their way south. They like to keep the land in eyeshot, Bader says.
BADER: And right up along the edges of that drop-off is where the food can be concentrated, where the whales can find it easier.
SIEGLER: This year, scientists have also been spotting pods of orca whales, humpbacks, a sperm whale - the list goes on.
BADER: The thing you would expect to see are gray whales migrating through. And the fact that we're getting a chance to see at this time of year fin whales, blue whales, is really a mystery.
SALAS: Now you can see the whale right in front of us. This is kind of like the friendly handshake. I'm letting the whale know that we're here...
SIEGLER: Scientists, like Dave Bader, looking to solve this mystery are considering a few early theories. One is that climate change is causing currents to shift, sending billions of tons of squid and krill to this part of the coast. Basically, the whales have pulled off the highway and bellied up to the buffet.
Another theory is that this bay is getting cleaner and it's supporting more marine life again. It used to be one of the most polluted bodies of water in the U.S.
BADER: We knew they came through here and we knew that they were there, but to see them in this abundance, we really don't know why. You know, it could very well be that we've done a great job and the waters are better here off the coast and somehow that's attracting them. Maybe the populations themselves are growing. But the honest answer is, we don't know.
SIEGLER: The only certainty is that this is an amazing place to be right now. That is, if you can manage to see one of these creatures through all the giddy whale watchers snapping photos with their iPhones and some with their hulking camera lenses.
JILL WALSH: I've always wanted to see a whale. I've never got a chance. This was really...
SIEGLER: You've never seen one before?
WALSH: Not up close like that, no.
SIEGLER: Jill Walsh is taking the day off from school to celebrate her birthday out here.
WALSH: Oh, I think we'll be back, yeah. Definitely. I'm going to take information to all the teachers and the students.
SIEGLER: A classroom in the ocean. It's exactly what marine biologist Dave Bader wants to hear. The high number of whale sightings are drawing more people onto boats like this and bringing more attention to the ocean as a whole. And that's good for conservation.
BADER: I think in Los Angeles, we think of the wild as being a place that's very far away from us. You know, we have to travel to Alaska or Hawaii or South America, Central America - some place, to get to the wild.
SIEGLER: When all this time, it's right here, a few miles from a metro area of 20 million people.
UNIDENTIFIED WOMAN #3: The tail! The tail! (Laughter)
SIEGLER: Kirk Siegler, NPR News.