Whale bones on the seabed.
Nick Higgs is on a research cruise off Japan to find out more about the amazing ecosystems that form around dead whales on the seabed.
He is a PhD student at the Natural History Museum and the University of Leeds. Following on from the last scientific cruise in the summer of last year, he has been invited to participate in another cruise with colleagues from the Japan Agency for Marine Science and TEChnology (JAMSTEC) and will be blogging about it at Planet Earth Online.
The team are going to visit the sunken remains of two sperm whales that were experimentally implanted in 2005 at a depth of 925m in Sagami Bay Japan - they had previously died after being stranded on the seashore. These carcasses are diversity hot-spots in the deep sea and one of Nick's supervisors, Adrian Glover, has written for Planet Earth magazine about 'whale falls' and the amazing animals that inhabit them.
Map showing the location of the Natsushima's cruise in Sagami Bay off the Japanese coast. Click to enlarge.
Nick is investigating the bone-eating 'zombie worms', Osedax, and how they bore into the whale bones. He wants to understand what these borings look like in order to learn to find them in fossil whale bones. He also wants to know how much damage these worms do to the bones and how that might have affected the fossil record of whales. Might there be gaps in the fossil record?
Nick's other supervisor, Cris Little, recently wrote a piece for Planet Earth about fossilization at hydrothermal vents, which contain similar types of animals to whale-falls. Samples that the team collects on this trip will help us understand the evolution of whales and the animals that depend on them for food.
Sunset over the bow.
It feels good to be back on dry land. Yesterday we arrived into port and wearily offloaded the ship. Throughout the cruise sleep had been at a premium but the last two nights left us especially exhausted as we stayed up late into the night taking care of the last few samples and packing up the equipment. Being a scientist is not a nine-to-five job and time at sea is precious so we made the most of it.
It has been an eye opening exploration that has left me with lots to think about. I had never seen that many zombie worms in one place before. Little things in large number have big effects.
I am convinced that these little worms are important for the fossil record of whales. It is hard to say just how important now. Over the coming months I will be going through the videos and pictures that we collected looking for patterns and things I might have missed.
Whale bone bearing the scars of zombie worm infestation.
Collecting all the animals and the images is the easy part. Science works by changing all of this information into numbers and analysing them.
How many worms were there on the bone we collected? How many clams live in a given amount of mud? By turning our samples into data they can be compared to other whale falls. This lets us test our ideas and shows others that our observations are real.
Thank you all for following along. I hope you've enjoyed this small glimpse into the alien world of the deep sea. I feel extremely lucky to be apart of this but it's not for me.
Ultimately all of you are my bosses and I hope your eyes have been opened to the importance of ocean science. Half of the earth's surface lies beneath 3 km of ocean. How many more exciting creatures lurk in the 95% of the deep sea that we haven't explored?
Posted on 21 January 2010 | Comments (3)
ROV being launched.
Its all hands on deck here. We are trying to check all the samples we have taken over the last two days for any unusual or strange animals. We've had four dives at whale skeletons since my last post and collected lots of samples; not just bones.
Florence and Hirome are looking at the microscopic life that floats around in the water, Kawa is busy tending to the Osedax in the tank (they are fussy worms) and Miyazaki is making some awful smells with his chemistry bottles bubbling away in the corner.
Meanwhile I have been upstairs in the wet-lab sieving mud and picking out all the tiny animals we find. From bright wriggling worms to slimy snails - we're interested in it them all. All these tiny creatures might seem a bit boring at first sight but up close they are often dazzling. Each has a role to play in ocean ecosystems and we're still finding out new things.
I picked up a small clam from the sieve tray earlier - a species never seen at this type of habitat before! It's the little discoveries that give you a buzz because, in science, it's all the little things that have the big impacts.
There's only a few minutes left of contact time with the computers so I'll leave it there and fill you in tomorrow!
Posted on 18 January 2010 | Comments (1)
Orange spider crabs pick the last scraps of flesh from a whale skeleton
The ship was especially busy this morning as half the scientists were departing. I woke to the clank clank of heavy boots marching through the steel corridors. As I headed down to breakfast I caught sight of the fishing boat that was ferrying the scientists to land. They had got their samples and now more were joining us. Today was the beginning of the second leg of the expedition - the whale fall leg!
As the Hyper-Dolphin descended to the depths we were hastily setting up aquaria in preparation for any bone samples that we might get. I looked up and saw the bottom in sight on the lab's display monitor; it was time to go. I gathered my notebook and camera, going through the checklist of things in my head that I must remember to look out for. I was just a happy observer on last dives but this one was work.
My first sight of the whale was its pale white skull. Orange spider crabs the size of my foot were crawling over it and picking at the last decaying remnants of flesh. These crabs were gathering up the crumbs from one of the biggest feeding frenzies in the ocean. Over 100 years worth of food arrived all at once when the whale carcass hit the bottom. Now all that's left are bones but this isn't the end of the banquet.
The Osedax worm - a creature with a taste for bones
There are creatures that lurk in the dark depths with a taste for bones. These bone-eating zombie worms are no ordinary worms. They look more like little pink palm trees, about the height of your thumbnail, sitting on the bone. You might also imagine their huge jaws needed for chomping on bone. But you'd be wrong. They don't even have a mouth or gut! Instead these weird worms digest the bone using root- like tissues that grow into the bones. Like the clams they also have bacteria living inside them helping to turn the bones into food.
These strange animals are the reason I'm here so I was overjoyed when we found bones that were jam packed with zombie worms. In some places they had completely eaten through the bones! Like grave robbers looking for treasure we snatched up the bone using the ROV's mechanical arms. After stowing our prize, the ROV ascended, treasure in hand, leaving behind a dismayed spider crab whose bone we had taken. Once on deck we took the bone down to the aquarium and just watched as the beautiful worms emerged.
Tomorrow we will be going back to see what else we can find; another day at the bottom of the sea.
Posted on 16 January 2010 | Comments (2)
The Natsushima's ROV control room.
Today saw our first dive to the seabed. At twenty past ten I watched as our robot disappeared below the sea's surface in a torrent of bubbles. Nicknamed the "hyper-dolphin" it descended with speed and agility, true to its name. After the launch I followed the scientists to the control room where we took up our places in front of the display monitors.
The ROV Hyper-Dolphin.
Small jellies whizzed past the camera as we headed for the depths. I sat mesmerised as the giant screens in front of me faded from vivid shades of ultramarine to deep blue and finally to the mirky black as the rays of sunlight become. On arrival at the seabed we were greeted with the image of ghostly conger eels slithering above the muddy bottom. They quickly retreated as the robot glided towards its target.
The aim of the dive was to collect some giant clams that covered great swaths of the sea floor in this area. I sat and watched for the first few hours as the pilots of the robot skilfully went about their work. They used its arms to scoop up clumps of clams and set up experiments for the scientists in charge. My favourite gadget was the "slurp-gun" - a flexible hose that hoovered up animals directly off of the sea bed!
A rattail fish among a bed of clams.
At one o'clock in the afternoon I nestled into the cinema style chair next to the camera control panel to take my shift as photographer. Using the robot's three cameras I snapped pictures of interesting sights and documented the day's work. Once the main objectives of the dive had been completed the pilots carefully packed the gear into the holding tray and made for the surface.
It's now ten pm and there is still lots more mud to sieve and samples to look over. So I'll leave it there and start getting my hands wet.
Posted on 14 January 2010 | Comments (1)
Welcome to the research ship Natsushima! I'm on an expedition with Japanese scientists to find out how some of the weirdest animals on earth make a living in the dark depths of the oceans around Japan. I study the bone-eating "zombie worms" that live on whale skeletons, and I'm here to see the damage they do first hand.
Nick Higgs and a whale bone.
We set sail today after a nail-biting five days of apprehension; a flu outbreak had threatened to scupper the whole trip. The sunny sky that greeted me on my arrival had turned into a blanket of fog and drizzle but it didn't dampen my excitement. I love being at sea. As the ship quietly slipped out of port I got to work stowing my gear and setting up equipment in the labs. The science team gathered after dinner and the chief scientist handed out our jobs for the expedition.
The animals we want to study live over 1km below the sea surface so we will be using a high-tech robot, loaded with sensors and cameras to do our work. I will be on duty for an hour each day in the mission-control room, using the robot's cameras as my eyes in the deep. It'll be my job to snap pictures whenever we come across anything exciting.
As I write we are cruising at a leisurely 14 mph towards the first study site in Sagami Bay. Here dense patches of giant clams live on the muddy sea-bed. Unlike most other animals on the planet, these ones don't rely on the sun's energy for their food.
Instead the clams have bacteria living inside them that turn chemicals seeping from the mud into food. Animals like this have changed our whole perception of how life can function and there's still more to learn.
Over the next week or more I'll keep you updated on what's happening on board and down below. Right now though, jet lag is catching up with me and I'm off to bed.
Posted on 13 January 2010 | Comments (1)