 Over the past few years, we've been looking into why Murray crayfish have been disappearing in the Murray-Dylan Basin. And we've discovered they can actually thrive in streams around the snowy mountains, but only if they have just the right habitat that they prefer to live. And that comes with a catch, therefore, because if that habitat disappears, the Murray crayfish go with it. One of the streams that we've been studying since 2009, we found that there was a halving in the habitat that these crayfish like. And as a result, up to 90% of the Murray crayfish disappeared from that river in just a short time. This is really concerning for us because they're an endangered species threatened with extinction. The things we've found is that they really prefer bolder habitats in the streams that they hide under and they really seem to aggregate in areas of the stream covered by lots of stream bank vegetation. Well, I did this research as part of my master's research project and I wanted to look into an animal that both had ecological importance and then also social importance. And once I saw videos of these little creatures, I was completely fascinated with them. Some of them were super cheeky and they would come out of their burrows quite readily and they'd actually tried to defend their patches of territory, which involved a couple of tow slaps and chase-offs. Plenty of people through the Murray-Dylan Basin know the Murray crayfish and think it's quite an iconic species. But ecologically, it's also very important because they do a very important job. They clean up the dead and decaying matter in those streams and they also play a very important part in the food webs of these streams. We did this work in the Snowy Mountains, often in National Park, which is a fantastic country to work in. We did a lot of this while we were camping and that came with a catch because most mornings were freezing cold and the streams themselves were very cold as well, 10 degrees. To survey these Murray crayfish, we actually snorkeled in the streams to actually directly observe what they were selecting for. These crayfish are quite remarkable little characters, really. They've got bright white claws, which are an instant feature that you recognize this species by and each and every one of them had their own way of interacting with us. So we're concerned about Murray crayfish because they're facing a lot of threats. Some of those have been pollution, some of those have been about habitat last like we discovered here. We're also worried about over-harvesting from fishing. There was a commercial fishery on the species many decades ago, which closed down due to the huge collapse in numbers in the Murray River. Our work shows that we should prioritize certain habitats to protect and restore Murray crayfish populations. Things like the riparian vegetation on the stream banks needs to be protected or restored and also things like laying clearing really needs to be halted in these streams if we're going to protect this endangered species.