 Well, thanks everybody for joining us today for this last of our webinars before Christmas. I'm sure you're all ready for a break. But today we have a presentation by Murray Hall, who's the founder and owner of a company called Hall Tech out of Canada. Murray's background started more than 40 years ago when he was trained up in fisheries and wildlife management and he then worked for several years in that industry, learning expertise in ecological monitoring and that side of things. He has since established Hall Tech, which is really specialising in developing technologies for monitoring, particularly aquatic ecosystem type monitoring. But today, Mo is going to present on some of their technologies, specifically electrofishing and also on EDNA, which is being used to characterise species that are present in these ecosystems. So today, just a few administrative things before we get started. If you want to raise a question, the Q&A button is at the top of your screen. You click on that and please do raise questions. It's a privilege to have someone of Murray's expertise and he is going up late in Canada to share with us his knowledge. Next slide, please, Michelle. So HydroTerror is running these webinars really to generate awareness for yourselves in the industry. We see this as part of our role in training industry and various technologies that are out there. But a big part of this is also to get a feel for industry needs and this one's an exciting area for HydroTerror as we are moving more and more into assisting natural resource managers with their monitoring of the environment. So looking forward to some questions there. Next slide, please. So I've dealt with part one of the webinar program. Part two will be a presentation by Murray from Hall Tech and then part three we will run through a Q&A session. Murray has worked all over the world. His business is located in Canada but they've done work in Africa and a lot in the US and South America, for example. So they are a leading company specialising in aquatic research. It is quite a niche industry and we're certainly hoping that Murray is bringing some new knowledge into Australia to help those people dealing with the monitoring of aquatic ecosystems. Hall Tech's core focus is around aquatic research as well as the field data collection services that they provide. They've got some really specialised equipment like boats with electrofishing gear on them and that sort of thing which Murray is going to go through. So they're a bit like a HydroTerror but based in Canada and their core focus has been around this aquatic ecosystem monitoring. So HydroTerror is excited to be levering off their expertise. We've agreed to work with Hall Tech here in Australia as their exclusive distributor both to assist with sales but also to offer integrated services to support yourselves with those aquatic studies. So without further ado, I'd like to hand over to Murray to present. It's very much Murray. Yes, thanks Richard and welcome everyone and good morning to all our friends down under. It's 5 30 p.m. here on Thursday evening. You've got a full day of work ahead of you, ahead of us. So I'm just really excited to present some of our tools and technology and see how it could possibly be a fit for some of your organisations in Australia. So I have been asked to maybe present on the basis and on the assumption that maybe these types of tools would be new to most of you. So if you do have experience in electric fishing or environmental DNA or are skilled at limnological sampling and you have some higher level questions, please post those on the Q&A on your page and then Michelle, our coordinator will be presenting those or I think Richard will be reading them at the end of the presentation. So for most of you, well, electric fishing has been around for 50 years or so. It was very, very crude in the beginning, probably as crude as hooking a couple of jumper cables on a car battery, throwing them in the water and see what floated away. Very dangerous. And then they started just plugging and throwing cables in from AC generators and just walking around without gloves or waders and just highly lethal and extremely dangerous. So we've come a long way since those times. Our backpack, electric fishing systems and boat electric fishing systems have many, many safety and safeguards involved like tilt sensors and immersion sensors, overload sensors, shutdowns. And the whole basis of the technology, its safety is paramount. So on top of the safety features included, actually, I'm sorry, that picture you're looking at right there is actually our Osmos environment and in Canada, North America, you cannot operate a backpack electric fisher or be on a boat electric fishing team unless you have certification and that usually involves a day of theory in class theory and then one or two days of practical training in the field with a certified instructor. Also, in order to go to the field and actually collect fish, you have to apply for and receive a scientific collectors permit issued by the Ministry of Natural Resources in Ontario and then across North America, they'd have similar authoritative bodies that regulate that. You just can't go out and sample and take fish from the system without telling people where or what you're seeing. And in that thing, dovetails because or the amount of debris, water or any number of factors you may not actually roll fish and collect them. You can appreciate in a highly turbid system, you could actually be rolling fish. But what we're doing, we're creating an electrical field in the water which creates a taxes or a muscle spasm in the fish and their swim bladder floats them to the surface. And then there's usually two netters on either side of the operator and they scoop, there's a good picture there. They're actually picking up the fish and putting them in a pail and they'll do time transects or 40 meter transects. There's any number of different protocol and then they'll process all the fish at the end of that. So in that particular, there'd be no problem seeing the fish and those clear pristine streams and that's where electro fishing is highly effective. However, if you are working in highly turbid systems, you could be rolling fish and you couldn't be collected them. So environmental DNA will allow you to pick up traces of shredded DNA from their systems, from their tissue, from their gametes, from their excrement and any Greek agitation. So all of these excretions from aquatic organisms contain DNA and if you sample in the proper target area and at the proper depth where you know that species would be, then you can extract that EDNA sample off of the membrane and run it through a QPCR thermocycler to extract that and check it against an assay that you have. So it's not the type of EDNA, it's not the type of technology where you could go and take a sample and it'll tell you all of the biota that's in that system. You have to be looking for something specific. So that's why it's of enormous use when looking let's say in part of an environmental assessment that's involved before any development is done, before any road crossing or road is built or a bridge, crossing of a wetland or a perimeter and there are threatened or endangered species in these habitats. The detection of a threatened or endangered species will definitely halt that development and then either it's halted permanently or there'll be some form of compensation, try to relocate the animals or that's when it starts to get quite interesting in terms of preserving these species here for future generations and not just running haphazard and destroying all the habitat which we have done typically in our past. So tremendous tools for understanding what's in the environment before we make catastrophic changes to those systems. So what you're seeing there is our backpack electric fishing system and what we thought we'd do this is just one of our good colleagues and customers down in New York State in the United States, that's Mark Professor Mark Cromwell and he's just going to give a brief little video here. They've been longtime customers and using our HT2000 backpack electric fisher in their class studies. So maybe Michelle, you could run that video please. I'm Professor Mark Cornwell and I teach fisheries classes here at SUNY Cobalscale. Here we see a typical fisheries lab at SUNY Cobalscale. In order to collect important fish data such as size, community composition, health and survival, fish must first be captured and this is an electrofishing lab. Electrofishing is a fish capture technique often used by biologists around the world because of its efficiency and mortality rate. The most important thing we have to remember in an electrofishing lab is safety. Modern fisheries units such as this Haltech backpack shocker have multiple safety mechanisms to ensure operator and net man safety. Waterproof waders and linemen's gloves are worn by all to ensure insulation from the electric field. Electrofishing works because freshwater fish have a higher salinity than the freshwater they swim in. So the fish is actually more conductive than the water and is the path of least resistance for the electricity. Even though the electric shock is powerful, it won't harm the fish as long as they are not subjected to the electricity for a long time. Once fish are stunned they're easily netted up and placed in a bucket until the sample is complete. Fish collection continues until the target number of fish are acquired or a designated area has been thoroughly fished. Once the fish are processed, which includes weighing and measuring them, they are returned to the water unharmed. Brook trout such as the ones that you see here are very sensitive species and they're indicators of excellent water quality. And by having up-to-date fish data, resource managers such as the New York State DEC are able to make good decisions that will benefit not only the fish but also the aquatic environment and the people who rely on it. Very good. So that is a perfect example of how the technology can be used and it's widely used by educational institutions as well as any science authority or monitoring department federally or provincially or statewide and I know we've had, I believe in the Department of Environmental Sustainability, we've had some backpack systems there but we're looking to break into the Australian market and make a much higher impact with our relationship with Hydrotera. So as I talked earlier on explaining the advantages of electric fishing, EDNA, although it has been around in much cruder forms for many, many, like probably two decades or more, but the ways and means of collecting the sample was quite crude. So you might be using a hand pump or a peristallic pump or even just scooping up water and pulling it through a membrane, but without a lot of thought of the contamination of the sample and this is paramount in environmental DNA sampling is using proper sterilizing techniques so you do not contaminate the sample and skew your results. So sterilizing your, the device in our, in our case our aluminum reusable sample housing. There's a one or five or micron membrane contained in that and basically what we're doing with our system is drawing water up through the nozzle and monitoring our pressure and flow so that as the membrane does start to clog with some suspended matter in the water that we can slow the pump down and still meet our target volume. Let's say if we're sampling for one or two liters, if the water becomes, if it is turbid, you're going to get sediment collecting on the membrane. If the pump is, is too high a pressure, you're going to destroy that membrane and you'll have to start over again. So it's very important to slow the pump down and make sure you get your target volume because the sampling technique would require several replicates because they're, they're testing against each other in a lab and you could, it's, it's, it's laborious and there's a lot of logistics to getting into remote areas so you have to maintain and make sure that you, you don't destroy your samples before you actually collect them. So in the field they, the sample membrane would be removed from the housing and put in a lysis buffer and that EDNA is extracted through a number of manufacturers around the world make portable or systems that you could use in the field but traditionally in the past these samples would have been taken back to a properly accredited lab with proper negative pressure and, and strict protocols in their sterilization to make sure that no foreign DNA is infecting your sample. So there's a lot that goes on behind, far more goes on behind the collection of the sample than actually is during the collection of the sample. So our system, as you can see there we've got a tripod and it's designed so that we can use hands-free operation. We can extend a 12-foot pole, just put the end of the nozzle into the system that we're sampling and then start, set our target volume, turn it on and just, just wait until the system does its job. It beeps, you invert the nozzle, the calculations are, our flow meter is calculating how much mud water is still left in that pole, so that everything, we know that within 5% of our target volume that is what's gone, that's the water that's passed through the membrane. So I think we have a little video showing how it works and we've got a little bit of background music but I think Michelle's going to turn that down and I can just sort of talk a little bit over that. Thanks Michelle. So our unit is called the Osmos and these are some, a very brief video here that shows the simplicity of the system. So it's designed, we're running off our 29 volt lithium ion power packs which are very light, the only way three pounds, so it's highly effective for getting into remote areas. So in this, this is a stream system here, so you get to a place where you could set up the tripod and within 12 feet of your sampling area, you have to know what you're sampling for so you, you know that your target species you're going after is going to be in that habitat, so you have to understand the habitat of the organism you're sampling. So we connect our inlet tubes and our outlet tubes, we turn on the system and on this system we have a special bracket and we hang it on the bracket so that count, that acts as the counterweight. So depending on the steepness of the bank, even though we're pushing in the the feet of the tripod, we want to make sure that when you have that pull fully extended to 12 feet that the target tripod isn't tipping over so that's why we anchor it with the backpack. So you're putting your, you're sterilizing all of your, your aluminum holders and you're loading them with your filter housing back in your lab and so you're going into the field with bags full of these as many samples as you're going to do in a day's field work. Simply extend the pole, the hose is running down through the middle of the pole, you slowly slow it down and submerge the anterior end of the pole and then with our, our pivot bracket we can lock it in place so at this point we can go hands-free. We have a remote switch on the front and there you've already, we've, there's a target volume of a one leader, there's a pump is at 16 kilopascals, we've got 15 feet of, of a hose out and, and then we start. So now it's starting the pump and we're just waiting while this ramps up. It's showing you real-time results. You can tell by, if the pump does slow down, you know it's probably clogging. So at this point you enter it out so all the water in the pole does come down and is, we make sure that it's gone through the membrane and it's cycled through the, the, the pump. At this point you would retract the pole and these are all locking knuckles so they're, they're very robust. It's a carbon graphite pole, very reliable and then remove the sample, remove that so it contained inside and there's the membrane contained inside. So using sterilized force nips you delicately remove the, the membrane and then you would have a, which is not shown here, you would have a little vial, a lysis buffer and put it in that. So you can collect these and a lot of people do in-field extraction so that they're, they are minimizing their, the, the possibility of contaminating the samples so they're, they're doing that in the field but if you cannot do it in the field you can carefully transport those on ice or dry ice back to a lab and do your extractions there. Basically just tying up the hoses, throwing on the backpack and collecting your tripod and pole and onto your next site. So that would take all of, that's probably real time so in five minutes you can collect but you'd never just take one sample you would take two or three samples at each site before moving on. So that's a brief introduction to the Osmos EDNA Sampler. Thank you. Oh Bob McLean he's a local musician here in Guelph and a good friend so thanks Bob for the music. So in 2018 we worked with the University of Guelph and the Bio Diversity Institute which our world were known for their barcoded life project and grad students working in the Robert Hanna lab, Hanna lab here and a joint project with Trout Unlimited their worldwide organization focused on the conservation and preservation of trout species around the world. So what the point of it was we were, it was a combined effort to just confirm the presence of of brook trout in, in the case of Guelph, a beautiful urban stream that actually runs through the south, an urban area of Guelph but beautiful cold water stream running through some undeveloped forest in the south end of the city as well as a site in Niagara Peninsula down near Niagara Falls, the world famous Niagara Falls. So the they're interested in validating the EDNA sampling techniques and confirming the the the the presence of the species also and confirming that with actually detection and collection using electric fishing equipment. So we we we went to the field and sampled this is the site in Guelph on Hanlon Creek so we went to the field and so that we were not disturbing the sites because electric fishing is quite intrusive so you actually have to get into the water and you typically work upstream but that would disturb the the the substrates significantly so the the EDNA sampling was done prior to that at all of these sites, five sites along this stretch of creek and then after that was done then the then those sites were electric fishing using our HT2000 electric fisher and then the report basically goes into detail of of the extraction and the sampling results of both techniques and and if anyone is interested with that I have forwarded a draft copy of that it hasn't been finalized yet with unfortunately with COVID a lot of these university labs are shut down and very hard to get access to and and we're just coming into a possible another shutdown here locally so this isn't going to change in the short term but so but the draft report is available and I've I have permission to share that with you through from the university and Trout Unlimited to if you're interested so just let Richard and Michelle know so one thing to note here on our Osmos nozzle so you'll see three stages there there's one stage that's missing so on the right hand side we have the upper so that's connected to the pole and then the middle stage there you don't have if you're a sampling in very pristine environments and non-turbid environments that's actually a pre-filter so we can have the the the inlet stage on the left connect right to the the final stage on the right and eliminate that stage in the middle but in some areas that are highly turbid if we don't have a pre-filter taking some of the sediment so it would be a coarser micron if we're collecting for EDNA sample membrane is one or five micron then you may be putting a 10 or 20 or 100 micron filter in the pre-filter just to allow to stop the sediment from clogging the nozzle but still coarse enough to allow the EDNA they're microscopic and they can still pass through that pre-filter and still get captured on the final membrane so that's why we do that and we also do use precision machining of aluminum so that these can be used time and time and time again so we don't have reoccurring costs we're not filling landfills up with single use plastic nozzles so we're conscious of that so the next day or the next slide Michelle I think if you could advance that okay so we're just this is the other sampling site down at Niagara basically this was quite different in that we have two reaches of this system so it was interesting to see they weren't spatially collected so completely different communities of of Brook Trout and they we we did have detections at both and it was interesting to see that in all of the sites the Osmos EDNA detector did can confirm the presence or aligned with our the electrophishing detections as well so a lot of people are they often think whether EDNA could be used as an indicator of abundance of a species and to date that's that's still being discussed the this particular report does not see a correlation between presence of EDNA and abundance so some sites for example some sites we collected maybe 10 Brook Trout but the EDNA signature wasn't significantly higher than in sites that we collected to Brook Trout but EDNA is interesting in that you don't know exactly where the that DNA is coming from it could be coming from upstream in the system so these are the things that are still being explored in the science and the people are using this all over the world and extremely bright people so vastly more qualified than I am to talk to this but it's they I would defer to Dr. Bob Hanner at the University of Guelph or some of his publications and and his his many associates so if you're interested in delving into this further I can contact us through Richard at Hydrotera and and we can help you make some connections and help you understand how this could be beneficial to some of your your research so we are interested after after this and perhaps it can be discussed in the Q&A do you do you see some of this technology of being of use and what you're doing and if not right now certainly in the future you see where this is going so yeah these are the some of the conclusions here that the Brook Trout work were identified at both sites and the use of environmental DNA monitoring validated with electric fishing so if yeah it's going to be interesting to know so in perhaps in in South Australia yeah I guess you can you can do we're polling you right now and our and Michelle is can share the results of the poll I have no idea how many people are actually joining in this joining us on this webinar I hope I'm not just talking to myself and it'd be interesting to see some of the responses to some of these so if maybe at this point I don't know where we are in the time schedule Michelle if you want to tell us where we're at it's it's 10.05 am Murray so you've got a bit more time if you like or you can hand back to yourself for questions well I actually let's just talk a little bit more about some of the products that Haltec can offer so on top of our electric fishing so backpack electric fishing boat electric fishing equipment also the backpacks we have conversion kits that can be used for electro anesthesia and narcosis so if you want to sample fish in your in your your for your in your lab studies or your hatcheries then we can sedate this fish so that you can actually handle them maybe to install some pit tags or do some fin clipping or extract some roll so you can safely handle the fish and then they gently recover from the from the sedation and then you can return them back into your your hatchery or back into the stream so typically before electro sedation came along people were using clove oil so clove oil sedates the fish but you cannot return the fish it takes them a couple of days actually to recover from that if you release them to a stream before they were fully recovered they could be subject to predation they wouldn't have all their wits about them to to escape high order predators so the nice thing about electro fishing once they recover from from the taxes then they're completely ready to be returned to the stream so we also have conversion kits to use in small john boats for streams that are slightly deeper where you could they're not weightable with your waders or tote barges where you can you can put the equipment in a tote barge and still walk around and then right up to very powerful boat systems where uh you know we're putting up to 12 000 volts in the water and sampling species at depth in large water bodies on top of that we we manufacture a complete line of limnological equipment so from sampling benthic organisms and like nets plankton nets kicknets ekman dredges ponar type dredges vandoren bottles camera bottles we make custom apparatus some of our our most fun project is when scientists come to us and ask this is this is a project this is what i need to do nothing exists can you build this for us we love projects like this and we do projects like that and prototypes like that for projects all over the world so if you have research and something does not exist to do what you want to do uh that is uh that's one of our our foretaste um custom application yeah so we can make anything and um uh we're looking forward to to working with you all so maybe at this point um um if richard wants to delve into maybe start the q and a's if you have any or maybe we have some q and a's ready now sure murray thanks firstly thanks very much for that presentation very interesting i think um judging by the the feedback from the audience uh you're educating us all um and i think that's that's the important thing to be aware of so a lot of our customers at hydratera deal a lot with things like ecological risk assessments and with uh environmental monitoring but often those uh studies are based more on things like water quality and that sort of thing with less of a focus on the actual ecology that's uh really what it's all about right protecting the environment so i think it's great to get a perspective on how we can monitor the actual flora and fauna of the world and you know hopefully use trend analysis to see if we are making a real impact from all those efforts um so i do have quite a few questions for you murray actually um one of which you you did answer which was um around whether or not we can use edna to quantify you know the recovery of the quantity of uh fish in a particular river system but um maybe if you could just share a bit there in terms of how how uh people in canada have looked at monitoring the success of say restoration of the lakes and river systems using edna you know what's the frequency of monitoring that they've actually used for the edna uh sort of things well it's um again it's a it's a new science really uh it's although it's been around for a while it's been it's been crude so where we're seeing it now and it's it it has to be accepted and we're just getting um accepted by the regulatory bodies as an accepted sampling tool and this has been through the enormous efforts of um a lot of university um and uh private consultants um that have proven that um through their efforts that you can actually detect the presence of a species without actually collecting it and where it's very interesting is that and here's here's a perfect example of um a success story where a large development was slated to uh um on a on a large piece of property you know let's say a hundred acres and uh previous conservation or conservation authorities and had uh had seen and identified this area as a um as habitat for an endangered species of turtle here called the Blandings Turtle um although no one had seen like monitoring efforts going out at times when they had seen them in the past hadn't detected them for I think two or three years and the developers were rubbing their hands together thinking that the the only obstacle between them and and building this uh this large uh uh residential block was uh was disappearing because there were no visual detections uh over um some time until um a group went in and with um DNA sampling so they were sampling the the the problem with reptiles is that they are habit their habitats are verner pools or shallow areas that may dry up later on in the year and they move on and they're constantly on the move and or in turtles they're bearing themselves in the mud and it's a tremendous effort to actually see them but sampling of verner pools in this area detected positive positive detection of Blanding's DNA at the site so they said uh they went back with a much greater um visual effort and actually did find uh the animals present so and uh there's a number of stories uh that that rings true Jefferson Salamander again you know virtually impossible to find or very difficult to find but by sampling their habitat we know they're there and uh this is now being um accepted as a science verified sampling technique and tool and uh it's it's all focusing around the methodology so the the methods used to do it have to be have to be certified you have to follow us a protocol and if that is done and that's proven then that science is accepted by the regulators so that's where we are at in in North America and in Europe too actually uh Europe is quite advanced on on um on their EDNA research so we're very excited it's a it's a it's another tool in our toolbox and going forward and it's far less intrusive than some of our other sampling techniques and we see it as a massive growth area and uh it's going to be an outstanding opportunity for um companies that are delving into this space and uh and um and need to find these these animals and just can't detect them in any other manner I think um in Australia one of the hot topics at the moment is around groundwater surface water interaction and the potential impacts of um the contaminated groundwater discharges to freshwater ecosystems and we had recently had a workshop um on that that was run by the Australian land and groundwater association one thing that's of interest to myself is the ability to use um these devices to to screen across areas of sort of known groundwater discharge to try and compare the ecological health of those discharge zones versus uh those areas that are considered not to be impacted by the discharge of groundwater so I think uh this EDNA approach might might provide part of the answer in terms of trying to characterize the differences but I suppose the question is um you know how far does DNA drift and how long does DNA last um like you mentioned that turtle study um you know is it possible that it's uh a lot of the time it's residue from a turtle that might have died five years earlier do you have any uh actually that's that's yeah that's an excellent question so definitely um in a flowing system so you're going to the DNA will flush out through the system um and definitely uh through the decay of an animal there's massive amounts of uh uh DNA um uh left in the residue or left in the the substrate so absolutely that that could be a possibility so I to my knowledge they I'm not sure if they can detect if the so this is the this is a question for the scientists can they determine whether the DNA collected is historical DNA or if it's actually from an organism that's recently passed through the sample site so um absolutely those are those are things that you can't tell you can't tell when the the the organism has been there but the technology is is improving and I could see that being something that could change in the future um probably last question for you Murray just um around electrophishing um I know we are the science has improved a lot um as you mentioned started off with car batteries and things and then in uh since in progress in levels of sophistication um so it was interesting to see you you've worked out a sort of voltage that stuns fish but but brings them back to uh to life I was just wondering about some of our other uh mammals and things that live in in the water too um like in particular in Australia the platypus for example is a is a very shy and creature but how vulnerable are the mammals to uh being um zapped if you like versus the fish species has there been uh studies done to work out if if they're more sensitive or less sensitive for example than the fish themselves yeah so the the larger the organism whether it's a fish or a mammal or an invertebrate the largest surface area they have to absorb the electricity so um like a large fish will feel a higher voltage gradient than a smaller fish smaller fish are much harder to to shock so most definitely um the platypus would not be happy about being in the electrical field and um you'll probably get him uh exiting the area very quickly um I'm not sure whether a mammal would actually go into taxes become immobilized I think they would probably feel the shock and they would exit very very quickly but yeah and I and I would be I would be concerned about that so if I knew that there were platypus and they're an endangered species then I would be quite concerned about using electric fishing to technology in that environment I would I would put very very very low voltage and um and maybe encourage them to leave before we actually turned it up so we could achieve taxes in the fish I did have one more question sorry and then uh then we probably let you have a rest but the you mentioned that the the reason it works well is that there's a difference in how the electric current moves through the freshwater versus their fish themselves and just wondering in as we get into more of our estuarine systems and quite a few of Australia's streams are actually you know they have some saline groundwater discharges and that sort of thing we don't have as many beautiful freshwater streams as Canada that's for sure what what are the repercussions for electrophishing of increased salinity in the water yeah so that's uh that's a game changer so uh as you increase salinity then the the environment is more productive than the fish species so electricity always takes the past least resistance so unless you have massive power so we our primary power supply would be a generator and then through our pulse boxes so it's depending on the conductivity of these brackish systems you are you may not be able to achieve any results at all just the electricity is going through the water rather than the fish so the first thing you would do is do your conductivity and if we are in a situation that's you know 6000 microseemons 7000 microseemons per centimeter then you're probably not going to be very effective with electrophishing so in these environments then you have to go back to traditional net netting uh trap nets and gill nets okay so it's been a very interesting presentation Murray do you think uh just in summary that the future of characterizing the health of these sort of aquatic ecosystems is going to be more of a staged approach where you might start with edna as a sort of standard and then once you know what species are there set up and almost um customize your sampling with the electrophishing after that no it would probably be the other way around so remember edna you can't take a sample of a water and it and then extract it and identify all of the species there it's it's not a tool for identifying species abundance and diversity all edna can do is tell you whether you have to have a sample of edna of a target species that you're looking for and then the sampling technique will tell you whether that species is presence or absent from that environment um electrophishing on their other hand is that's why it's been so popular and effective for decades in that it is the only way the most effective way without exception to go in and do a complete biodiversity study you can look you're going to capture every single organism in that system all of the species of fish invertebrates crayfish and that's how we're going to that's how we do our classification so you're looking your species identification and and density and diversity that's where electrophishing works far better than anything in the past we used nets same nets with highly damaging when not done properly there was high mortalities but when electrophishing is done properly we have virtually no mortality and you just return the fish happily to the stream after you've collected them you can do all your biometrics you do your weights your lengths your ids you can look at fish health you can handle them like there's things you can do with the electrophishing that you can't do any other way so any any any study where you actually have to see what's there electrophishing is the way to do it okay so that was interesting it wasn't actually the answer I was expecting Murray so that you're continuing to educate me uh but um look I think we'll wind it up there um what I what I'm very interested in is uh has hydrater is moving more and more into this area of monitoring natural resources is probably to set up a forum for sort of best practice characterization of natural systems and we'll be looking to do that in the new year but certainly what you've described today is two technologies that sound pretty critical in terms of helping us to get a better handle on uh the health of eco systems sounds like electrophishing might be a bit challenging in some of our estuarine environments um that's certainly great to know of it as an effective tool in those freshwater systems where the ec is sort of below 6 000 so many thanks for your time it's been it's been very informative and um look forward to hearing more from you in the new year no it's been wonderful uh speaking with you all and I'm looking forward to continued conversations and uh I just want to wish everyone there um uh safe and and health during this pandemic and um and still hope we can all have a wonderful Christmas holiday and uh maybe get our mind off some of this uh that's going on in the world today and get our minds back in the new year to to protecting our our environments and preserving um preserving our uh the world for our future generations so thank you very much once again and Merry Christmas everybody thanks Murray okay bye bye for now