Okay so I work with tiny, white salamanders that live in springs here in Austin, TX. Of all of the vertebrates on Earth, these little guys have the smallest habitat - only one little area about the size of a small house; the entire species lives there and has always lived only there. That habitat happens to be called Barton Springs, and it’s a popular swimming hole smack-dab in the middle of downtown Austin (pretty much). At some point, somebody thought it’d be a good idea to clean this swimming hole with bleach and other chemicals…. So this species nearly went extinct. Right now it’s federally protected but still critically endangered and still in a public swimming hole.
These salamanders are called Eurycea sosorum, by the way - The Barton Springs Salamander. There are also a couple of others: E. waterlooensis, E. nana, E. tonkawae, E. rathbuni, E. neotenes… The list goes on.
So a lot of these salamanders live in springs underground, which is amazing when you think about it. The openings to these springs are sometimes only a centimeter across and they can be miles deep - completely dark, completely underwater, isolated in every way. Some have lived there so long that they’ve lost their eyes to evolution. Obviously these guys are extremely difficult to study because it’s basically impossible to observe the insides of these springs. Every few months a new species is discovered when a hole is dug for construction or a well or something. This is a great way to find these species…. while simultaneously destroying their habitat. How, then, can we find and characterize these species if we can’t enter their habitat and see them? That’s the question I’m trying to answer.
I’m trying to apply an idea called Environmental DNA to these salamanders. Everything loses bits of DNA during their lives. You, for example, lose dead skin cells, bleed, spit, excrete… all manner of ways to lose DNA. If you lived in the water, these bits of DNA would - in theory - float around in the environment. So it makes sense that water samples can be taken and looked at to find these bits of DNA. Of course, the amounts of DNA in these water samples is incredibly small. Like… there’s almost nothing there. Most of the time there actually is nothing there. BUT! Sometimes we’ll find something and sometimes it’ll tell us that this particular species lives in this water, and someday we might even be able to tell about how many of them there are. No interrupting their lives or destroying their habitats or anything - just taking water samples that bubble out of the ground in springs anyway.
Anyway, today I realized that that’s exactly what forensic investigators do. They comb the environment for little bits of DNA - the tiniest, most unnoticeable little pieces - and find out information about who left it, what they were doing, etc. It blew my mind to realize that this is what I’m doing. And I’m doing it to save a species.