June 3, 2017

Izwandry Idris and Asher Flatt
Izwandy Idris and Asher Flatt take their turn on the giant tweezers during sample sorting on the CSIRO RV Investigator.

Blogging the abyss iconDay 20: Asher Flatt, onboard communicator, and Izwandy Idris, Universiti Malaysia Terengganu

The CSIRO RV Investigator voyage to Australia’s eastern abyss is primarily a sample-gathering expedition from an almost entirely unknown region of Australia. The seafloor is mapped using multibeam sonar so that specialised equipment can be sent to retrieve myriad lifeforms from the abyssal plain. Then the hard work begins. Above the water and waves, in the science labs of the ship, all the samples (even rocks!) are sorted and catalogued to be sent to museums in Australia and around the world.

Scientists wait for the all clear to collect samples
Scientists wait in the ‘garage’ at the back of the deck until the Brenke sled is landed and secured by the ship’s crew. Image: Robert Zugaro

Sorting the catch from beam trawl, Brenke sled and box corer is an arcane art of mysterious symbology and lined paper, unknown to all but the most fastidious of minds. First, check the board outside the operations room for information on the daily operations. Second, turn on the ice machine so there is a good supply of iced seawater to keep all the abyssal beasties cold and fresh. Also prepare chilled filtered seawater in the fridge to accommodate surface, or planktonic, species. Third, prepare the sorting trays and weigh them before and after to tally total biomass. We are now ready to retrieve our samples!

Scientists sort the catch into tubs on deck
We're all over it . . . Scientists in the ‘receiving party’ venture forth onto the deck equipped with hard hat, steel-capped boots, gloves, waterproofs and life jacket, to counter blows to the noggin and toes, seabird guano and/or fierce gusts of wind, among other things. Image: Asher Flatt

The rest of the science crew will be hanging back in the wings, waiting to put things on ice and quickly ferry precious samples back and forth from the deck into the lab. The collecting process needs to be done quickly yet carefully: the organisms are now out of water and some of them may possess sharp or venomous spines, and we also want to avoid damaging them. Keeping animals cold in containers of ice is very important at this stage. They have made the journey from the frigid abyssal depths to our alien world of light and warmth. If not kept cold, they will quickly lose their shape.

Sea cucumbers and brittle stars in the net
A catch of brittle stars and sea cucumbers awaits disentanglement from the beam trawl net. Image: Asher Flatt
A tub of invertebrates
A tub of assorted invertebrates. Image: Asher Flatt
Eels on the deck
Eek! . . . eels on the deck. Image: Asher Flatt 
Maggie Georgieva, Izwandry Idris and Maylene Loo
Even the rocks have stories to tell. Maggie Georgieva of the Natural History Museum, London, UK, Izwandry Idris and Maylene Loo of CSIRO. Image: Asher Flatt

Now the sorting frenzy begins! First, all the animals are placed into general categories, such as sponges and starfish (refer to our previous Kombi post for more details!) then into more specific categories of the lowest possible taxa (family, species, or just a common group, such as Gastropoda.

Melanie Mackenzie sorting sea cucumbers
Hmmm . . .  can we be more specific? Melanie Mackenzie of Museums Victoria sorts sea cucumbers.
Sorting samples into containers
Sorting samples into containers. Image: Robert Zugaro
Taking tissue samples from fish
Tissue samples are taken for chemical and genetic analysis, to study food webs, identities, evolution, and geographic links between deep-sea populations. Images: Asher Flatt
Melanie Mackenzie, Tim O'Hara and Phoebe Lewis
Panning for biological gold . . . Melanie Mackenzie and Tim O'Hara of Museums Victoria, and Phoebe Lewis of Victoria's Royal Melbourne Institute of Technology. Image: Asher Flatt

In the meantime, smaller samples from the Brenke sled will be graded by size and sieved to remove the remaining mud. Before this, a certain amount of samples will be put aside to be inspected for microscopic foraminifera. The cleaned samples are then sorted using a stereo microscope (remember the ship is continuously rocking!).

Tim O'Hara at the microscope
Tim O'Hara takes a close up look at a deep-sea brittle star. Image: Asher Flatt

Special finds are photographed by Karen Gowlett-Holmes (invertebrates), and Alastair Graham and John Pogonoski (fish). Specimens, along with lengthy taxonomic information (identification numbers, destination, weight, preservation method etc.), are then listed in a records sheet. Correct labelling is very important. To avoid missing labels (a great sin for a biologist!), two levels of labelling (internal and external) are made. The internal label is made using special paper that can withstand ethanol or formalin solutions, and the external label is written with marker pen.

John Pogonoski photographs a tripod fish
John Pogonoski of the CSIRO Australian National Fish Collection prepares a tripod fish to be photographed. Image: Asher Flatt

The samples and their papers are then sent to the aptly named 'pickler': the person in charge of placing our placid ocean pals in ethanol, formalin, or frozen: whatever other medium best prolongs the slow decay of time.

Lupita Bribiesca-Contreras of Melbourne University and Museums Victoria
Lupita Bribiesca-Contreras of Melbourne University and Museums Victoria with 'picked' seastars. Image: Asher Flatt
A labelled crustacean
A crustacean from the deep, packed and ready for its post-voyage journey to Museums Victoria. Image: Asher Flatt

With this careful processing they can be available for reference and research for years to come. Finally the preserved specimens are boxed for sending to museums and institutions around Australia and even the world! While most specimens will be sent to CSIRO, Museum of Victoria, a numbers will go to Australian Museum, Geosciences Australia, Queensland Museum, Tasmanian Museum and Art Gallery, and Natural History Museum, UK, and University of Vienna for further works after the voyage ends.

Sounds easy? Well, sometimes we have to spend the whole shift just processing specimens from one deployment. In other instances, three deployments were made within a 12 hours shift!

Martin Gomon and Alastair Graham
Martin Gomon of Museums Victoria and Alastair Graham of the CSIRO Australian National Fish Collection indulge in some onboard research. Image: Asher Flatt


Voyage date: 
Saturday, June 3, 2017