Wild Ocean Blue

If you’re a tweeter and you’ve been following my tweets lately, you might have noticed a fair few stories from the cetacean world showing up. Reason being, there have been lots of whale and dolphin studies out in the last few weeks.

And here is a selection of the recent stories I think are most interesting, important, or both.

Photo by kaladrakas

For starters there was news that dolphins are picky eaters.

Previously, scientists thought that common dolphins (Delphinus delphis) pretty much eat whatever they find. But now it turns out they prefer eating certain fish with a high fat content, presumably because with their active lifestyle they need all the energy they can get.

To find out what they have been eating, Jerome Spitz from the University of La Rochelle rummaged around inside the stomachs of dolphins caught by tuna drift nets in the Bay of Biscay.

Common dolphin. Photo by Chris Gray

He discovered that dolphins ignore common fish with a low energy content, and make a b-line for less abundant lanternfish.

So it turns out for common dolphins only the best will do.

Leviathan lives – or at least it did 12 million years ago

New fossils have been found in Peru of a very scary sea monster that patrolled the seas until it went extinct several million years ago.

It looked rather like a sperm whale, only it was much more dangerous. Sperm whales don’t have upper-teeth, so they have to suck up their food. These ancient whales came fully equipped with two bristling rows of enormous fangs, the size of a machete (up to 36 cm or around 10 inches) – all the better for gobbling down large prey, probably other whales.

It roamed the oceans at the same time as Carcharocles megalodon, the 15m / 50foot and now extinct version of a great white shark – together they would have been a pair of serious ocean troublemakers.

The folks who discovered this new oceanic beast – which probably had the biggest, scariest mouth of any 4-legged creature we know of – have rather sweetly named it Leviathan melvillei, after their literary inspiration.

We also heard that sperm whales are carbon neutral

Talking of sperm whales… iron in modern sperm whale poo fertilizes the oceans, triggering a bloom of carbon-sucking phytoplankton, some of which end up as whale food. A neat cycle indeed.

Sperm whale tail. Photo by Adrian Midgley

The iron boost from each whale stimulates enough plantlife to counteract their own exhalations of carbon dioxide. The key is that the whales eat squid down in the dark depths and defecate nearer the sunny surface, bringing lots of iron with them. In the Southern Ocean alone, sperm whales bring up 50 tonnes of iron a year.

Sadly, whale hunting may have already reduced the ability of the oceans to lock away carbon dioxide from the atmosphere.

Bad news for finless porpoises

And finally, there was bad news for the finless porpoise (Neophocaena phocaenoides) – an odd looking fellow (unlike most other dolphins and porpoises, it doesn’t have a fin on its back).

The problem is, what we thought was one species could well be at least two. The small population of less than a thousand porpoises living in China’s Yangtze River could be headed the way of the Baiji river dolphin which three years ago was pronounced extinct in the wild.

Finless porpoise. Photo by ori2uru

Finless porpoises live across the Indo-Pacific, but it turns out the Yangtze porpoises have very different genetics to all the others, suggesting they are somewhat isolated and should be protected as a separate population. The Yellow Sea and South China Sea populations also appear to be distinct from each other.

The jury is still out over whether they are different enough to count as a separate species.

Sorry to end on a gloomy note, but it looks like – if we’re not careful – the Yangtze River could be the site of the next cetacean extinction that happens during on our watch.

If you’ve been watching my tweets lately, you’ll probably already have noticed I like to link to ocean stories from around the web.

So I thought I’d give you some thoughts on my favourite ocean tweets from the past week.

For starters, it seemed to be a week of great seahorse fecundity with the announcement of baby seahorses being born in two English aquariums. We had spotted or yellow seahorses in Chester – a species native to the Indo-Pacific.

And then the patter of tiny fins could be heard in Hastings with the arrival of 200 baby short snouts. These are European seahorses that live around the UK coastline and down into the Mediterranean.

Seahorses have been having babies in British aquariums since Victorian times, so this is nothing especially new. But it obviously still exciting.

Photo by Kelly Graham/Marine Photobank

As I discuss in Poseidon’s Steed, keeping seahorses in aquariums helps spread the word about these extraordinary creatures and of course raises awareness about the problems they face in the wild. And with breeding programmes like these two, and many others around the world, aquariums don’t have to rely on wild caught seahorses for their displays.

On a more worrying note, if you haven’t already, then take 30 seconds out of your day to watch a video on the Guardian website showing the sea ice at the north pole shrinking from 1978 to 2008.

Back in the late seventies, satellites first started taking pictures from space of the extent of sea ice over the arctic. Since then, the sea ice has fluctuated annually but overall has been contracting, with 2009 being the 3rd lowest extent on record.

And despite the slight recovery from 2008, scientists are still convinced that in the next few years the arctic will become completely ice-free during the summer.

Arctic Sea ice age in February 2008 compared to the average for 1985-2000. NASA.

Believe what you will about climate change, but this to me is stark evidence of the changes that have been taking place in the environment in the past few decades, and a worying sign of the changes still to come.

And finally…

This week we saw a cheery bit of ocean trivia. A video of bottlenose dolphins getting up to some strange jellyfish tricks has been doing the rounds.

Bottlenose dolphin (Tursiops truncatus). NASA.

The footage came from Tremadog Bay in Wales, and you can see the researchers onboard laughing themselves silly at the spectacle.

It’s not too obvious on the video clip but when the dolphins got a good aim, they flipped  the jellyfish clear out of the water.

It’s behaviour that’s never been see before, but perhaps goes some way to explaining why captive dolphins know what to do when a beach ball is thrown at them.

And why are they doing it? Well, who knows. I’d like to think they were just having a bit of fun.

Thanks for reading. More from me and the ocean world soon.

Today the BBC screened the first episode of their latest landmark wildlife series. This time around they’ve called it, quite simply, Life.

I must admit that back in 2006 when trailers for Planet Earth came out I was a little skeptical that we were really about to witness ‘planet earth as we’ve never seen it before’ as was promised. Surely we’ve seen it all by now?

But no. I was swept away from the opening scene to the closing credits. Planet Earth is undeniably stunning and when I watch it again and again on DVD there are still bits of my mind that get blown away.

And now we have Life. Once again, a little part of me is whispering ‘we’ve seen it all before, we’ve seen it all before’.

And once again, I have to admit that we obviously haven’t seen it all before.

Take, for example, the giant pacific octopus.

Perhaps I should already have known this, but the pregnant female finds herself a safe crevice deep down somewhere out of sight, lays a hundred thousand eggs and slowly starves as she tends and cares for them. By the time the tiny, spotty babies hatch, mother octopus has passed away. Yes it does sound a little sad, but that’s semelparity for you.

Giant Pacific Octopus (Enteroctopus dolfeini)

The first episode offers up other oceanic treats like bottlenose dolphins stirring mud rings off the Florida coast and extraordinary slo mo shots of flying fish as they try to escape sailfish (with footage that for the first time convinces me where the sailfish get their name from). These guys alone are definitely worth tuning in for (it’s on again tomorrow and on Saturday) or watching again on BBC iplayer.

This episode did feel a little bit like a quick fire round.  We see a carnival of snippets without going into too much detail. For example we whiz through madagascar and catch a tantalizing glimpse of a leaftail gecko’s foot with no mention of who it belongs to.

Mossy leaftail gecko from Madagascar. Helen Scales.

But perhaps this was a starter show parading things we’ll see later in the series. We’ll see next week.

And there were a couple of things that I’m sure we have seen before, like the poison arrow frog carrying its tadpoles one-by-one up a tree and plopping each one in a different water-filled bromeliad. These guys hopped through another BBC show a while back I think. But nevertheless they are still quite extraordinary.

We get some gnarly scenes of a leopard seal eating young chin strap penguins, flinging them about like rag dolls. But we are left with the oh-so-cute images of a baby orang utan with its mum while David Attenborough reminds us what life is all about.

So, in my humble oppinion, Life was good. I wonder if next week will be even better. I look forward to finding out.