Day 26: The final dredge!

By September 1st, 2019

By Olivia Belshaw

Day 26 of our voyage saw the final dredge being deployed into the water – Dredge number 55! This dredge collected mainly limestone/carbonate samples from the sea floor; however, there were a few basalt pebbles hidden within the rocks themselves. The limestones collected were also fossil rich, showing evidence of corals, foraminifera and shells.

Top: RV Investigator and MNF crew work together to safely return the last dredge to the back deck of the ship.

Top: RV Investigator and the Marine National Facility crew work together to safely return the last dredge to the back deck of the ship.
Bottom left: The multitude of mainly carbonate rocks collected in the final dredge
Bottom right: Quinn Anderson (University of Sydney), Chantelle Ridley (University of Tasmania) and Dr Karin Orth (University of Tasmania) inspect rock samples from the dredge, prior to selecting rocks to be categorised and photographed.

 

Different views of a sample of fossilised coral, obtained in Dredge 55.

Different views of a sample of fossilised coral, obtained in Dredge 55.
Image credit: Chantelle Ridley.

 

Basalt pebbles found in a carbonate stone obtained in Dredge 55.

Basalt pebbles found in a carbonate stone obtained in Dredge 55. Photo taken by Edward Clennett, modified by Olivia Belshaw.

It’s hard to believe that in the 26 days we have been on the ship so far, we have categorised, photographed and recorded rock samples from approximately 50 successful dredges. Over our dredging period, we swath mapped multiple sea mounts and underwater geological features in the coral Sea. We’ve collected and analysed almost 700 rock samples, sifted over 50 massive buckets of thick sediment, and collected unique biological specimens including corals and glass sponges. Whilst some of the work has been hard, and at times repetitive, it has certainly been worthwhile, providing Jamie and myself with multiple opportunities to talk to scientists, participate in scientific research and learn about some of the valuable scientific research being led by Australian Scientists.