...and don't be a herring either!

Oh joy, more bait balls on the BBC!

This time its the herring, swarms and swarms of them off the coast of Alaska feeding on the algae blooms. And there's a lot to feed on - according to David Attenborough (and who would doubt him) there is more mass of living things there than in the Amazon rain forest.

All those algae is great news if you are a hungry sea bird, seal, dolphin or hump back. But alas they do make the water a bit murkier than the previous sardine run (shame), and there are no armadas of gannets diving for their dinner (double shame).

But there was this great bit during the birds-eat-bait-ball-frenzy scene (above) when, as the camera man explained, "it all went quiet" as the gulls made their escape until.... WHAM!!!! as a monstrously big hump back stormed through the scene swallowing thousands of herrings in one go:

I'm guessing the camera man's heart rate is only now beginning to get back to normal!

In the "making of" program the Beeb uses to pad out a 50 min program to an hour we watched the divers, including the man behind the camera in the scene above, seriously debating what would happen if the whale ate them.

Ok, maybe they were semi serious, but it clearly was a bit of an issue, but apparently the whale does spit out things it doesn't like, clever thing.

And they really are particularly clever hump backs. About a hundred of them have worked out this real neat way to go fishing, whereby they round up their prey by circling round blowing bubbles (below, from above). The herrings get confused and fearful of the bubbles, so the loop acts like a net.

Then half a dozen whale rise up through the centre to eat some of the tonne of fish they consume every day.

And if that seems like a lot, well they were very very hungry. They head off to Hawaii which is a good place to hang out and have children (some lovely shots of a mum and her son below) but alas not much to eat if you're a whale, so actually the mother whale is near starvation after 6 months without food and a young mouth to feed.

The daddy whales mean while are out there impressing the ladies with their stunts:

Remember that's a fully grown hump back whale leaping out of the water!

Pretty good stuff and worth looking out for. The BBC site can be found here with video clips and stuff.

An amazing series - the sardine run in particular was stunning.