What is e-DNA?

I have a question. I have not been able to find an answer so I thought I would ask my readers to see if someone knows. The question is this: What is e-DNA?

I know m-DNA and mt-DNA, which is mitochondrial DNA. I know r-DNA, which can be either ribosomal or recombinant, depending on your interpretation. I know about ss-DNA (single-stranded) and ds-DNA (double stranded), too.

There is right handed DNA and left-handed DNA, also known as A DNA and Z DNA. I think there is even a B-DNA. And there is E. coli DNA, but I cannot find any references to e-DNA, except on the discussion about the genetic material of Asian Carp being found in Lake Michigan.

Please understand that I do not doubt the urgency of the carp question, but if we are going back to the Supreme Court arguing that they didn’t know the first time around that DNA was present in Lake Michigan, the justices may ask for more of an explanation on what this new information means. How was this e-DNA detected, they might ask. I would if I were a judge.

Can someone help me on this?