Using a submersible robot to penetrate depths of up to 4000m, a joint US-Australian team have reported some extraordinary organisms off the coast of Tasmania.

“Our sampling documented the deepest known Australian fauna, including a bizarre carnivorous sea squirt, sea spiders and giant sponges, and previously unknown marine communities dominated by gooseneck barnacles and millions of round, purple-spotted sea anemones”

However, a news report by the AFP suggests that even at 4km beneath the surface, there is cause for concern:

“Modern-day deep-water coral reefs were also found, however, there is strong evidence that this reef system is dying, with most reef-forming coral deeper than 1,300 metres newly dead,” he said.

Though close analysis of samples was still required, Thresher said modelling suggested ocean acidification could be responsible.

“If our analysis identifies this phenomenon as the cause of the reef system’s demise, then the impact we are seeing now below 1,300 metres might extend to the shallower portions of the deep-reefs over the next 50 years, threatening this entire community,” he said.

The lead researcher Dr Ron Thresher from CSIRO is blogging the voyage from the Research Vessel ‘Southern Surveyor’ in incredible detail, and is well worth a read.

The submersible vehicle "Jason" pictured on board the RV Southern Surveyor, exploring the deep reefs of the Tasman Fracture Zone, southern Australia.