When Dr Laura Robinson and her team set off from Tenerife to Trinidad on a scientific expedition, they could guarantee that they would see parts of our planet that nobody has ever seen before.
With so little of the deep ocean mapped in detail, the British oceanographer told Explorers: “Every time you go to the sea floor you pretty much find new species and new organisms, and collections of organisms that haven’t been seen together.”
Her voyage on the James Cook research vessel was aimed at taking samples from deep water corals and analysing water around them in order to build a picture of the history of our oceans.
“The corals can live just about anywhere,” says Dr Robinson. “We want to understand where they live and why they live there, because that can help us understand what controls the distribution of ecosystems in the ocean.”
A grant from the ERC (European Research Council) allowed her and colleagues from the University of Bristol to finance the trip and to use a special robot submarine to go in search of these unchartered worlds.
Then the process of finding suitable sites for study began: “We use a big array of echo sounding waves and you make maps of the sea mounts with about 100 metre resolution. And they can have spectacular shapes, for example you may find out that the mountains have flat tops,” she says. Then she studies those low-resolution maps to work out where corals have colonised a particular spot.
Once an interesting target is spotted the ROV (remotely operated vehicle) submarine descends, often over a thousand metres below the surface. Then, sitting in the control room of the ship, Laura directs the cameras to investigate each new location.
“The things that people always love to see and people are distracted by are deep sea sharks,” she says. “We also saw dumbo octopus, beautiful slow moving fish, and a pyrosome. It was just rolling along the seafloor, and we had no idea what it was.”
The pyrosome is a relatively rare long gelatinous tube-shaped organism made up of hundreds or thousands of small animals.
Of course Dr Robinson was there for the corals, and they were there for her. “On the very first dive that we did we landed on absolutely spectacular coral gardens. I’ve seen them before but you can’t help but be blown away when you’re down over a kilometre and you see these metre scale corals and this massive diversity of life,” she explains.
The corals are not only pretty to look at, they offer a very accurate picture of how our oceans change. “What we’ve done is dated nearly 1,000 fossil corals already, and we’re seeing that the corals come and go over time and it looks like it might be related to times of climate change,” explains Dr Robinson.
So have the deep water corals been hit by acidification as sea water absorbs increasing carbon dioxide from human emission? “It’s hard to say, because people don’t visit these places very often,” she tells Euronews. “As you get deeper the water is older in a sense, so it takes a long time for ocean acidification to get down to deep waters.” Some areas of the deep ocean areas may not feel a change in pH for the next 1,000 years.
The scientists have to take into account the different time scales that life can have in the deep ocean. “Some of these corals can grow for 4,000 years,” she says, so we “can get annual records from 4,000 years, and if you take fossilised remains you can go back tens of thousands of years.”
With the research voyage now well behind them, the team at the University of Bristol continues to analyse the data gathered. It should serve as a base line for further research, and against which to judge future changes in the ocean.
But with such a vast area of the planet to explore, Dr Robinson argues the whole adventure should be put into perspective: “You can only scratch the surface. If you carry out five dives of 12 hours each you’re still only seeing a fraction of it,” she smiles.