Scientists have a new tool to identified species; by sequencing environmental DNA (eDNA) to find all the species that lives in the environment
I want to use today’s post to write a bit about a new tool that could potentially be one of the best tools available to both ecologists and conservationists. As you probably know from the title, the things we are going to be looking closer at is called Environmental DNA, from here on shortened to eDNA.
Whenever an organism interact with the environment, it does shed some DNA in one form or another. It can be in saliva, blood or other fluids, but the most common source for mammals is skin that is shed. You can find your own DNA in pretty much all the areas you spend some time, and getting rid of all of it can be a huge task.
Some test tubes with DNA. Image is Public Domain.
What eDNA does, is that it allowed researchers to collect a sample from the area where this organism have been, and analyze this sample for genetic material that originates from the organism. While DNA will disappear after a while, most soil, water, or sediment samples will contain traces of genetic material from several different organisms.
In order to be able to use eDNA, we need other DNA from the species to compare it against. What it boils down to is matching the DNA found in the environmental sample with a database that host DNA data about the species we believe is in the area, and then we can see which species of organisms are in that area by looking at matches between the sample and the database.
What can we use eDNA for?
eDNA could have a lot of potential uses, but they are mainly believed to be either scientific, or used as an argument for or against protecting areas based on the species that are found in the location. It should also be useable for doing things such as finding out if your house is infected by a species of bugs or another pest animal that is difficult to directly observe.
I’m sure there are also some other uses for eDNA, and keep in mind that it’s still fairly new, so there could still be lots of innovations that makes it useable for solving other problems in the future.
Using eDNA for conservation purposes
As I said in the beginning of the post, this tool could easily turn out to be incredibly powerful for both ecologists and conservationists, and it will open possibilities of monitoring species that are difficult or impossible to directly monitor.
Just imagine if you want to protect an area in the ocean that you believe hosts some interesting species. Before anyone is willing to donate money to protecting this, you will need to prove that this area is actually worth protecting. You might have individuals who claim that they have seen very rare species there, but you really need better evidence than that if you want to get funding!
Monitoring species underwater is obviously a difficult task, and you really need to get lucky to stumble upon the species you are looking for without spending years in a scuba suit. However, an eDNA analysis could make this a quick and easy matter.
Instead of monitoring the species or looking for waste products from it, just imagine that you can instead take a small water sample and send it to a lab. Now they will run it for genetic material and compare it against a database. Ideally you get a list of several species that all have shed some form of DNA in the area you sampled, and you have your direct proof of the species being there.
It sounds almost like science fiction, right? But let me assure you, it’s not, and I even have a good real-life example of it being used in this particular way!
Case study: eDNA found six extra species of sharks in water samples!
A group of international scientists collaborated on a project to figure out which sharks were still found in New Caledonia, an ocean territory in the Pacific Ocean that belongs to France. After years of using visual observations as the primary way to check for sharks, the scientists feared that some species of sharks had actually been regionally extinct, meaning that they were no longer found in this part of the ocean.
As the eDNA technology got better, the team wanted to try it out to see if they could find any genetic material from the shark species they were surveying, and found a method that allowed them to analyses traces of DNA in both shark skin, excretions and even blood from the water sample. All they needed was to fill a bottle of water from the area, then let the lab run it to detect genetic material within the sample.
The team collected a total of 22 water samples, and the results were pretty amazing. It turned out that these 22 water samples gave them more information about which sharks were found in the area, than what they had already learned from over 3,000 dives and 400 baited videos!
A grey reef shark (Carcharhinus amblyrhynchos), one of the sharks that were found in almost all the eDNA samples. Image by Albert kok, posted with the Creative Commons Attribution-Share Alike 3.0 Unported license.
A total of six extra shark species were found in the area, for a total of 13 species identified by their eDNA alone.
It’s worth mentioning that the team found a total of 16 shark species by combining eDNA, cameras and dives, meaning that 3 of these species were not picked up by the eDNA analysis. However, since eDNA were responsible for finding an additional six species, we could argue that this method was more accurate than the other methods.
eDNA is still very new
There has not been done a lot of research using eDNA like this yet, but there is a huge potential here. Just imagine when we can find evidence of endangered species by taking a soil or water sample instead of having to spend thousands of dollars on cameras, divers, rangers and other costly methods of finding evidence.
There’s still a long way to go before eDNA becomes a quick and easy way to do this, but as you can see from the research paper with the sharks, the potential benefits of developing this method is huge.
Thanks for reading
Thanks for checking out my post about environmental DNA, and how we can use this to find which species are found in an area. I hope you found it interesting, and make sure to check out the comment section below!
About @valth
Hey, I'm @valth - the author of this post. I love to write about nature, biology, animals, nature conservation, ecology and other related branches of science, and I occasionally write about my life, about Steem or about random stuff as well. I'm trying my best to write at least one post every day, so make sure to give me a follow if you enjoy my content and want to see more of it.
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Mange takk for ny informativ artikkel @Valth
Ja, her lærte eg noko nytt igjen. At det er noko som heiter miljøDNA (Environmental DNA),visste eg ikkje før eg las artikkelen din.
Det er eit svært breitt område du har kunnskap om. Du skriv ôg om kva nytte me kan ha av denne teknologien og at den kan vera meir effektiv enn andre metodar å skaffa seg kunnskap. Til dømes skaffa 22 vassprøvar med å undersøkja eDNA gjev meir info enn 3000 dykk og 400 videoar med beite.
Heilt fantastisk kva ein kan finna ut med slik undersøking.
Bare hyggelig det, @siggjo. Jeg er glad for å høre at du likte den :)
Det er veldig nytt ennå, og jeg vet ikke engang om det er noen som bruker det i stor grad her i Norge, men jeg ser for meg at det kan ha store bruksområder her til lands. For eksempel er det mange som jobber med å kartlegge hvilke arter av fisk vi har i forskjellige innsjøer (og vi har jo veldig mange innsjøer her i Norge), og tenk hvor mye raskere dette kan gjøre når vi kun trenger noen få vannprøver istedenfor å måtte fysisk fiske med garn for disse undersøkelsene.
God illustrasjonpå korleis teknologien kan koma til nytte her til lands ôg @Valth
I'm only passingly familiar with eDNA, but it seems like it a useful tool for a lot of applications, particularly conservation, as you wrote.
As far as I understand, it's basically a presence/absence thing, right? So it might not be ideal (at least in the microbial systems I deal with) for doing things like population turnover, differentiating live/dead populations, or gene expression. Still a very interesting tool, though.
Yes, I believe that is correct. From what I read, it will not really be able to be used to determine concentrations of the different species at this point.
I would imagine that it could be very useful for microbiology, but it might not be as precise as you might need it to be yet. But I could see that it might be useful for quickly determining if a soil or water sample has a presence of a certain microbe, like if you want to quickly find out if there's a dangerous organism in your drinking water. I'm far from caught up in the latest microbiology technology, but don't they often still grow cultures on agar to find out if a species is present?
This was easy to follow--it could have been loaded with jargon and obtuse sentence structure, but no, you made everything perfectly clear. eDNA, an interesting development, but I do have a question:
Could this not have application in law enforcement? Could it not be another tool to trace the activities of people? This might be useful for catching criminals but also (too bad) for increasing surveillance of civilians.
Now I'm going over to read one of your earlier blogs, one that describes insects committing suicide. That looks truly fascinating.
I'm glad you found it easy to follow, @agmoore! And that's an interesting question. I would say that it might not be very useful for criminal forensic right now, because the soil or water sample would probably include lots of people who are not involved, so it would probably give a lot of false-positives in its current state.
As for surveillance, I would guess that it could have some potential, but we're still a pretty long way from being able to use this tool for this purpose. It is probably also a lot less effective compared to using more commons means of surveillance.
Thanks for stopping by with some very interesting questions, @agmoore! I'm sorry I could not really give you a better answer though.
This is quite an interesting perspective of DNA analysis. And the fact that it deals with DNA residues in a particular area or environment suggests that the eDNA can be applied to solving crimes too. By identifying DNA or perps of crimes through eDNA, can it be compared to or applicable to forensic analysis in crime fighting?
Thanks for sharing @valth
It might work, but I think it will provide lots of false-positive results unless the crime has been committed in a place where almost no people go to. But the technology is still very new, so maybe it will evolve to be used for this purpose in the future.
Oh Yea! That's true. You are quite right about the false positives. Thanks @valth, I get your logic now.
Hehe, that's good! It might still be useful for forensics in some form or another, but there's a few problems to be solved first :)
Great post.
discovery of scientist in eDNA is a good news.
with eDNA we can know the various organisms that exist in a habitat. So at one time found fossils of mosquitoes trapped in the snow at the south pole we can know what animal was last sucked his blood. and we can traverse the life that exists through eDNA.
scientists can also use it to determine how many rhinoceroses rhinoceros in the area of native habitat, or look for the existence of Sumatran tigers and Javan tigers that have been declared extinct or almost extinct.
thus we can be more conscious and aware of the environmental sustainability and cultivate a caring attitude to the diversity of living things around us.
i believe this invention is not a fiction and certain that will be very useful for us in the future
Yep, it will for sure we a useful technology. It would be really cool to see it used to find evidence of species that are believed to be extinct, but that would require a huge amount of luck to get a sample with their DNA in it.
Very innovative indeed...
Imagine saving of millions of dollars spent on observation posts, collecting data, cameras, scuba dives and so on....Now all those dollar spendings can be directed to actual conservation efforts.
Yep, there is potential to save so much money with this method!
Amazing tool to find EDNA and it's already producing a great result. Marine life is still un discover able. The way the tool helps to detect 16 species of shark from 22 water sample is an amazing figure when consider that result of 22 sample is more informative than 3,000 dive and 400 baited videos. It will not save a lot of money but hopefully the tool will become better with new advancement and give fruit full result for conservation of nearly extinct species.
Indeed a handy tool for better human health. Hopefully the tool will bring revolution in ecologists and conservationists life. Thanks for sharing @valth
Yes, I also hope it will be able to revolutionize these fields in the future :) Thanks for stopping by, @kamchore!
In my opinion, eDNA is very useful for researchers and can be used as a security tool from threats.
I hope this eDNA can grow better.
I like your blog @valth
It is interesting.
Thanks! Yeah, eDNA is very useful, and will probably grow to have many more uses in the coming years :)
I think this method will allow us to find every specie that live on earth, i will also revolitionize the field of genetic, we shall have more DNA's for test!
Hopefully scientist will get some huge help from this tool!
Hmm, maybe it will in the future, but right now it needs a DNA sample to compare it against, so it will not be able to find new or unidentified specie. But much can happen when the technology evolves!
A very useful discussion, by reading it I get a lot of information about eDNA and its usefulness.
Thankyou for share @valth
I'm glad you liked the post about eDNA, @muksalmi :)