Gigantic sea creatures in Antarctic sea

In early 2008, sea-going scientists probed the seabed of the Southern Ocean near Antarctica and unveiled a diverse and mysterious animal community.

Marine scientist Martin Riddle led the voyage of the research ship Aurora Australis. He told EarthSky there were times that a ‘hushed awe’ fell over the crew as they saw things that had never been seen before.

Video feeds hooked up to underwater cameras broadcast some unexpectedly huge creatures, among them sea spiders, worms and sponges. Sea spiders, for example, are normally measured in centimeters or inches.

But in the Southern Ocean, they can grow 10 times their normal length. Riddle spoke to us from his office in Australia. We asked him…why so big?

Martin Riddle: I’m afraid I don’t have a definitive answer. I’ve got a few ideas. Lobsters and crabs, that whole group, are just not present in the Antarctic. And one possibility is that many of these other groups have taken over the niche that is left vacant, so they’ve become the large wide-ranging scavenger.

The crew also found fields of animals that looked like blown-glass tulips – almost translucent. They’re thought to be early colonizers of areas that have been swept clean by icebergs.

Dr. Riddle noted the effects of global warming may threaten all this underwater life, and he will be back to the Antarctic next decade for a checkup.

Our thanks to:
Martin Riddle
Program Leader
Australian Antarctic Division’s Human Impacts Program