Nightly News | September 14, 2011
>>> for the past few weeks off the coast of southern california , some unusually cold water that's been hanging around and the food that it brings with it has attracted some stunning visitors. blue whales , the biggest creatures on the planet. they were almost hunted to extinction. they're back, and people are watching. miguel almaguer drew the assignment of the day, hands down.
>> reporter: in the chilly waters off southern california 's coast, the hunt is on.
>> there's the tail.
>> reporter: all hands on deck, all eyes on the sea. [ cheers ]
>> reporter: to catch a glimpse of the world's largest creature -- the blue whale .
>> watch for the tail.
>> reporter: these days, there's been plenty of surprises.
>> we live on the california coast, but you don't actually see them like this.
>> like nothing i have ever seen before. they're so huge.
>> whoa, what's that?
>> reporter: biologists say the 200-ton mammals are searching for tiny, shrimp-like krill. this is fertile feeding ground.
>> the krill do well in cold water . last year was the coldest it's been in 30 years.
>> reporter: the length of a basketball court they can live up to 90 years. blues are graceful, elegant and curious. ten years ago, spotting even one would have been rare. but this year, at least 500 sightings so far. researchers saw blue whales courting.
>> what we got to see today was off the charts.
>> reporter: for kayakers, it doesn't get closer than this.
>> hunted primarily for blubber, blue whales for headed for extinction when they were placed on the endangered species list in 1966 . scientists won't say they are thriving but there are 10,000 worldwide. the big threat now is being hit by ships.
>> what concerns us though is because they are so close to shore now they are venturing into the shipping channels.
>> reporter: for stooiss and tourists alike, a reminder of what we almost lost. gentle giants like few have ever seen before. miguel almaguer, nbc news, long beach, california.