(úupbeat music) ú- Hi everyone, welcome to today's SciPub.

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(chirping) (chirping) (screeching) (screeching) (chirping) (chirping) (screeching) (chirping) (chirping) (screeching) (chirping) All right, well, I hope you enjoyed the speed trivia.

And thank you for joining us tonight for the Science Pub BING.

This is a monthly lecture series exploring the exciting world around us.

I am Jessica Hua.

I am an Associate Professor of Biological Sciences at Binghamton University, and am hosting for this evening.

- And I'm Kristine Kiewser, co founder of Science Pub BING, along with Nancy Coddington of WSKG.

Nancy can't be with us tonight, but she will be back to host this program in June.

In the meantime, we're so grateful to Dr. Hua for being our guest host tonight.

And as usual, I'll be behind the scenes fielding audience questions.

So please leave those in the chat.

Again.

Thank you, Jessica and Nick.

- Thank you, Kristine.

And one additional player, we have WSKG's science intern, Julia Diana, who is joining us from Binghamton University.

She will be live tweeting the event.

You can follow the conversation on Twitter using the hashtag #WSKGscipub.

So without further ado, tonight's talk is called Frogs, Frozen Roads, and Human Safety, keeping animals and humans safe through the seasons.

And road salts, road salt is a lifesaver in winter for humans, but what about our amphibian friends?

Come spring, these salts can run to wetlands and ponds causing harm to communities of wildlife that rely on these habitats to survive and thrive.

Today we'll explore the latest research on the impacts of commonly used deicing salts on frogs, toads, and salamanders, as well as conservation efforts.

Nick Buss is a doctoral candidate pursuing a PhD in biological sciences in my lab at Biological Sciences Department.

And together we perform research at Binghamton University's ecotoxicology and disease ecology lab.

Nick will share his findings on how environmental pollutants affect local wildlife with a special focus on amphibian hosts and parasites.

So welcome, Nick.

Thank you so much for your presentation today.

And without further ado, Nick will go ahead and share his screen.

- Wonderful.

Thank you so much, Jes, and thank you to all of you for coming out this Tuesday evening to join in on some, hopefully what you will find to be an interesting talk on road salt pollution and its impacts on amphibians.

So, to start us off for this evening, I just wanna give a topic overview very briefly on what we will be talking about this evening.

We're going to be starting off here by talking about the benefits and the costs of road salt usage, primarily with regard to humans and human health.

Then I'm going to segue into the toxicological impacts of road salt usage on wildlife and its impacts on environmental health, particularly of aquatic ecosystems.

And then rounding out the evening, I'm going to be telling you about some ways in which you can help to monitor and potentially curb road salt impacts in the local Binghamton area through some local citizen science efforts that Binghamton University is currently undertaking.

So without further ado, I'll start on the benefits and costs of road salt usage.

I'll start off here with just giving a rundown of what salinization is and its primary causes.

So salinization of aquatic systems comes in two forms.

The first of which is primary, or natural salinization.

So this is salinization that can occur over broad ranges of time from evaporation and subsequent rainfall from ocean waters.

So once again, this takes a very long time to occur.

There's also impacts of primary salinization from the retreating of ocean waters, which can leave salt deposits behind, creating a very arid landscape once the waters have receded.

This is actually a very big issue within the Western portions of Australia currently, where arid land is the norm, or the majority of the land in Western Australia due to retreating ocean waters.

And then there's also the weathering of bedrock containing salts.

And this is the primary way in which primary salinization occurs.

And for those of you tuning in here locally, you may know about the history of Syracuse, New York, just about an hour north here of Binghamton, which has gotten the moniker of the Salt City.

And this is because of the natural halite bed subcrop as shown here in this figure, which contains naturally occurring bedrock of sodium and chloride ions.

Here we can see in this left hand photo, some salt workers in Syracuse in the Salt City, who have taken salts from the aquifer.

So this aquifer contains the natural halite bed and weathering of this rock from groundwater.

And what they would do is take this water from the earth, from the aquifer, and then let that evaporate.

And once evaporation occurred, they had salt left behind.

And this occurred in Syracuse from the 1700s to 1900s.

Nowadays, salt mining is the norm.

You may notice this name, the Morton Salt Co. from your dinner table.

This is halide mining, and this is the primary way in which we acquire salt for our everyday uses nowadays, rather than from the evaporation of aquifers.

So this is, once again, primary or natural salinization.

So what we're going to be spending much of our night talking about is secondary or human-induced salinization, which comes from a variety of different pathways.

For instance, agricultural crops are commonly irrigated with waters containing salts.

Due to the massive amounts of water that can be put onto crops, these salts can be deposited into the soil.

Following really intense rain events or storm events, these salts can them wash off of the cropland and inundate nearby streams and other water bodies with high concentrations of sodium and chloride ions.

There's also the issue surrounding salt brines from hydraulic fracking, where engineers and others put salt or put water down into the ground to frack the bedrock, and then this wastewater has to come back up, and this wastewater, in some cases, contains natural salts, plus other things of environmental concern I won't jump into or delve too deep into this evening.

And these can be applied or are sometimes applied to roadways.

Pictured here is a hydraulic fracking site in Pennsylvania, which is a state that utilizes hydraulic fracking fairly frequently.

And the majority of what we'll be discussing tonight, and one of the main pathways by which secondary salinization occurs is through the application of roadway deicing salts in the winter months to keep us safe going to school, going to and from work.

This is typically in the form of sodium chloride, and these salts can rush off of impervious surfaces, such as pavement, after their application from things like snow and ice melt, spring rains, and can inundate nearby water bodies with salt concentrations that can be quite high.

So with that being said, there are some benefits to road salt, despite the fact that these ions can end up in our freshwater systems.

Pictured here is a modeling study undertaken on Highway 401 from 31 sites.

Highway 401 goes from Michigan to Montreal, Canada.

And what we see here on the y-axis is the mean number of accidents across time.

And we have two different line plots here.

One is without roadway maintenance and one with.

And when we compare these two lines, we can see that there's up to a 30% reduction in traffic collisions across this highway.

So there's also some additional benefits to this other than just a reduction in vehicular crashes.

There's also the economic impacts of getting to work, school, and other engagements.

When we can't do these things, the estimated costs, for instance, in the nor'easter of 2013 in Massachusetts was estimated to be about 300 to $700 million per day due to impassable roadway conditions.

So we do gain benefits from reduced traffic collisions and also economic gains in this sense.

Since the 1940s, we've been applying road salts.

Because of these benefits, it has increased over time, and just simply because our reliance on our roadway infrastructure has increased to get us Amazon delivery packages, interstate travel, all the things that we rely on in our society.

And because of this current usage in America, it's actually fairly high at about 10 to 20 million tons per year, or 20 to 40 billion pounds per year.

So one of the main questions surrounding road salt usage is whether or not increased usage is always necessary.

Are we actually putting on our roadways as much road salt as is actually efficacious or are we over salting?

One good case study for over salting, in this case, is the case with the Winter Olympics of 1980 in upstate New York near Lake Placid.

During 1980, the New York Department of Transportation applied six times the typical amount of road salts onto the Adirondack roads.

And this continued thereafter.

They didn't curtail it after the Winter Games had ended.

Because of this increase in road salt usage, wells within this area, such as near Tupper Lake in the Adirondacks and near Lake Placid, are seeing elevated levels of sodium and chloride in their drinking wells in this region.

Indeed, they're seeing upwards of about 750 parts per million of sodium.

So under EPA guidelines, this is a heavy dose of sodium for those individuals who require low sodium diets.

So this is concentrations that are, that could potentially impact human health with potential outcomes such as hypertension, coronary heart disease, and congestive heart failure in the long term.

And this has led some organizations, such as The Fund for Lake George, which is in the Adirondacks, to coin road salt impacts as the acid rain of our time.

Moreover, there are indirect impacts of road salt usage.

That is, direct impacts can be things like hypertension, but there's also ways in which road salts and salinization in general can put our water resources at risk.

And such as the case with Flint, Michigan and their lead water crisis, which I'm sure many of us have, in some way, shape, or form, heard about in the past several years.

Researchers found that road salt was leading to the high levels of lead in the city's water.

And I'm going to show you a graph right now to display how road salt or salinization in general can lead to lead leaching from pipes.

So here on the y-axis we have leached amounts of lead in micrograms per liter.

So researchers put into lead pipes various levels of chloride from 10 to 1,000 milligrams per liter, and then calculated the amount of lead that leached from these pipes.

And shockingly, they found that 250 milligrams per liter of chloride led to very high levels of lead being leached from these pipes leading to evidence for indirect effects of salinization on human health by mobilizing lead from plumbing systems.

Moreover, this concentration of 250 milligrams per liter is actually found in 50% of wells in Southeastern New York.

So this is, has obvious implications for human health if these wells aren't remediated, or if the salinity issue isn't fixed.

And is this concentration of 250 is additionally well above the EPA chronic chloride threshold for aquatic life within our freshwater streams, lakes, and rivers.

So these are once again concentrations in well water not in lakes.

So quite a startling issue for this area of Southeastern New York both in terms of chloride levels but also the potential impacts of lead, which can cause damage to the brain and nervous system, learning and behavior problems, slowed growth and development, and hearing and speech problems.

So there are also economic costs that come along with this.

So once we have an issue and it needs to be taken care of, particularly for these areas in Southeastern New York, it costs money to fix or remediate these issues.

For instance, in upstate New York, 500 homes that had to have new wells dug out and have salt remediation undertaken, it cost about $13.2 million.

So, while there are benefits to road salt use in terms of economic, and social, and societal benefits, there are also quite a few negatives if we over salt, as is the case near Lake Placid and the Adirondacks.

Some additional economic costs are associated with things like corrosion, which I'm sure we're all aware of.

And if you're tuning in from the, from North America in the more Northern regions where we have to apply road salts, where you may be seeing corrosion on your vehicles, you may see infrastructure that has salt damage to it, and once again, home piping and plumbing, whether it's lead based or otherwise, still can have economic impacts.

And it's actually been estimated that there are about a cost of $1,320 per ton of road salt applied annually.

And this all comes together to form an estimate about $19.8 billion a year.

So this is just simply on what I've spoken about so far.

So not including social health costs necessarily or economic impacts on the environment.

Just more or less infrastructure.

So those are some of the good and the bad of road salt exposure.

So next, I'm going to be talking about the toxicological impacts of road salt usage with its impacts on wildlife and environmental health, particularly in aquatic environments.

So pictured here is a study that was undertaken by Dugan et al in 2017.

These researchers used public datasets for 371 freshwater lakes taken over three decades, and they found long-term chloride trends from this data for a variety of states and regions with a particular focus on New York, Minnesota, Wisconsin, and Rhode Island.

The researchers found that their estimate suggests that many lakes will surpass 100 milligrams of chloride by 2050, and some are set to surpass EPA chronic or acute, or yes, chronic chloride threshold of 235 chloride, milligrams of chloride per liter by this time.

And this is especially true for Minnesota, which receives quite a bit of road salt, particularly within the Twin Cities and has a lot of impervious surfaces.

So that is areas where road salts can flush off of pavement and end up into water bodies of which Minnesota has many.

So ultimately our lakes are becoming saltier.

What is the potential implication for freshwater species that will eventually be inhabiting these salinized environments?

So some research suggests that sodium chloride exposure and other commonly used roadway deicers, such as magnesium and calcium chloride, have the potential to delay growth and development of freshwater fishes, such as the salmon pictured here.

They can decrease population densities of zooplankton, and strikingly can even alter sex ratios of amphibians, such as the wood frog pictured here.

So these are some direct effects of road salt salinization on species, but direct impacts on one species can lead to indirect effects on others.

So what I'm going to be showing you here is a way in which road salt can directly impact zooplankton by decreasing their population density, and the potential ramifications of this decrease in population density of zooplankton on an entire lake ecosystem.

So I have modified this from Hintz and Relyea, 2018, which is a great paper if you wanna learn more about direct and indirect impacts of salinization.

So we're starting off here with our non-shaded area where road salt reduces the diversity and abundance of zooplankton.

So when zooplankton are reduced in abundance, what we ultimately see if that it reduces the food resources for fish.

So the fish that are relying on zooplankton as prey may not be in as good of health if they're lacking zooplankton for food, or they may have lowered recruitment.

So lower survival or population cycles overall.

And this, as we can see in the arrow going up, can have impacts for piscivores, or fish eating fish, if they then lack resources.

Because the fish that they would be consuming otherwise are lower in population density because of the zooplankton.

And ultimately, in terms of water quality health, zooplankton help to control phytoplankton balloons.

And this may be something that some of you are aware of or have maybe even seen out in your local lakes or ponds with regard to these algo balloons of blue green algae.

And this is something that has been a cause for concern in Dorchester Park up North of Binghamton in Whitney Point for quite a while.

And I don't believe any local dog deaths, but these cyanobacteria algae are a hepatotoxin, which means that these toxins can create toxicity in the liver for a species or for organisms that ingest them.

So salt is an issue not only for direct impacts but also the indirect impacts that can have on environmental health.

So tonight you were promised a talk about amphibians and road salts.

So why amphibians?

Why are these necessarily a species that's impacted?

So for one, they're relatively intolerant of saline conditions.

This is mainly due in part to their permeable skin and the fact that they have difficulty excreting excess ions from their body, and also difficulties undergoing osmoregulation in these saline environments.

So they have issues with ion concentrations within their bodies verses those that are in the environment when salinization's occurring.

And they're strikingly vulnerable across life stages.

So from embryonic stage to larvae to adults.

And moreover, while the previous example that I gave focused on lake ecosystems, a lot of amphibians such as the wood frog pictured here, inhabit really ephemeral or not seasonally standing bodies of water.

So these water bodies are relatively shallow, as we can see here in this photo.

So road salts that come into these ponds produce high concentrations.

And moreover, these ephemeral ponds dry up.

So as the summer progresses and temperatures heat up, the water level goes down while the salt ions stay within the system.

That is, all of the salt concentration is going to increase over time.

And this photo here is habitat that's pretty indicative of the wood frog pictured here.

So they're fairly relevant species to be studying the impacts of road salt on.

So some direct impacts of road salts have been undertaken in the Adirondack region by Nancy Character, Karraker, excuse me and James Gibbs of SUNY-ESF.

They conducted this skilled research up near Tupper Lake, which is one of the regions that I mentioned earlier in my talk.

Their field research showed or suggested that sodium chloride from road salt runoff can reduce the growth of spotted salamander larvae, up to a 33% reduction in growth, which has implications for the longevity of these populations, in amphibian population's body size is correlated to how many offspring individuals produce over their lifetime.

And they found that strikingly, that as intolerant as the larvae were, the spotted salamander embryos were even more intolerant with 945 milligrams of chloride per liter reducing its survival by 97% of these embryos.

However, with regard to my own research, road salts aren't all that amphibians contend with in the wild.

So ultimately around the globe a wide breath of taxa are undergoing issues concerning emerging infectious diseases from random viruses in turtles like in our lower right hand corner here to white-nose syndrome in bats and Lyme disease in mice populations.

For amphibians, these individuals are contending with three broad categories of parasites, such as Ranaviruses, trematodes, and chytrid funguses.

Some of these parasites have been known to cause local extraction events.

And even in some cases, as with the chytrid fungus over here on the right, have caused extinction events or led to researchers having to bring populations into zoos for captive breeding programs because all of the individuals otherwise would have succumbed to this pathogen.

So, it's ultimately because of the ubiquity of road salt within our wetland ecosystems and the threats that amphibians in particular face, not only from road salt pollution, but also from parasitic infections, that for my PhD, I was really interested in asking questions about how roadway deicing salts may influence parasite susceptibility in amphibians.

And this is the first question that I'm going to tackle for this evening with regard to sodium chloride, magnesium, and calcium chloride, which are three of the most commonly used roadway deicing salts during the winter months.

So to answer this question, I utilized the wood frog, Rana sylvatica.

I used this individual as my model organism because it's one of the most widely distributed amphibian species here in North America.

And if we look at this rangement below, we can see that it's mostly inhabiting Northern latitudes where road salts are commonly applied.

And also, wood frog populations, for better or worse, commonly persist near roadways, which means that natural populations of wood frogs are likely to be exposed to road salts in their natural environment.

For my parasite, I utilized, or I utilized rather 'cause I'm going to be talking about this parasite a lot for the remainder of the evening, echinostomes.

So these are a parasite that utilizes a multi-host lifecycle with a free-living infectious stage.

And we can see the free-living infectious stage here on the left twirling about.

This parasite infects the kidneys of the amphibian host.

It swims freely throughout the water column, finds an amphibian, and crawls up the cloaca of the tadpole and eventually makes its way to the kidneys of the host.

And over here on the right we can see metacercarial cysts which result in edema for some individuals if they're heavily infected, edema, or bloating, as is the case with this tadpole on the lower right hand corner.

So, utilizing this wood frog and this free-living trematode, I'm once again asking whether or not commonly used road salts influence wood frog, echinostome interactions.

To do this I exposed wood frog tadpoles to a control solution and three concentrations of calcium, magnesium, and sodium chloride.

It's important to note here that I chose the concentration of 230 milligrams of chloride per liter because it relates to the chronic freshwater threshold under the EPA, and the value of 860 is related to the US EPA acute freshwater threshold for freshwater species.

So I exposed these individuals to these road salts at these various concentrations for seven days, and then I exposed them to our parasite to see whether or not they increased in their susceptibility to infection.

So pictured here, I'm going to pop up some data here shortly where on the y-axis we have the average number of cysts, or how heavily these individuals are infected.

And across the x-axis we have our control against our three types of salt at 500 milligrams of chloride per liter.

And what we ended up finding out is that exposure to sodium chloride, which is the most commonly applied roadway deicing salt, increased trematode infection in wood frogs by 63%.

So we also wanted to know what the effects of these three salts were on the parasite itself as this could impact the interaction between the two of them.

So with this we once again exposed these trematodes to the same concentrations in salts that we used for the amphibian infection, infection experiment.

So pictured here that I'm going to be popping up shortly is survival data.

So on the y-axis, we have average survival time in hours, and our three salt types along the x-axis.

So we expose the trematodes or echinostomes to these salts and checked every hour to see mortality.

And what we ended up finding out is that relative to either of the other salts or control water is that calcium chloride is fairly toxic to the cercarial life stage of echinostome parasites.

In fact, we saw that cercaria were dying as early as one hour following exposure.

So from this study, we learned that NaCl, or sodium chloride exposure at 500 milligrams increased the infection success of echinostome, echinostomes to wood frog hosts.

And additionally, that calcium chloride is toxic to trematodes, with exposure greatly reducing their lifespan in the time in which they're actually able to infect the wood frog host.

So I have to give a acknowledgement with this to Dr. Rick Relyea who allowed me into his laboratory, and we collaborated on this study.

So thank you to him for hosting me.

And also to my undergraduate mentee at the time, Kiersten Nelson, who assisted in greatly in this project.

So, road salt can influence the interaction between amphibians and echinostome parasites.

However, there are a great deal of other species that amphibians and their parasites exist alongside, namely predators.

So pictured here on the left is a predator of tadpoles.

This is the larval stage of Anax junius, or the green darner dragonfly.

And this is a really common predator of tadpoles.

And it actually leads to the reduction of movement in tadpoles because these are a sit and wait predator.

So the more that a tadpole moves, the more likely they are to be ate by them, be ate by this larval dragonfly.

On the right hand side we have a damselfly larva, which is a common predator of our free-living echinostome parasite that we have wiggling about below it.

And in our own feeding assays, we found that these larval damselflies reduce parasite densities by up to 69%.

So to kind of hone in on why the reduction of movement is so important to amphibian, echinostome interactions, and why dragonfly nymphs reducing their movement is maybe of importance in this gif we have wood frog larvae, but also what you cannot see are these cercaria that are swimming around in the cup.

So when faced with parasitism by these individuals, wood frogs will try and shrug off the parasite as it crawls along their body, which results in some really uncanny flipping behaviors and really evasive bursts of speed.

So if dragonfly nymphs reduce tadpole movement, we may imagine that their presence could increase parasitism in wood frogs.

Conversely, the predator of parasites may decrease the infection intensity within the wood frogs.

So, this leads to the question of whether or not the presence of host and parasite predators will influence the effect of salt exposure on this dynamic between wood frogs and echinostomes.

So here on the graph, I'm going to be popping up data, which is once again on the y-axis, the average number of cysts or the number of infections within hosts.

And along the x-axis here, one at a time I'm going to be pulling up four different groups, either individuals that were not exposed to predators at all, individuals exposed to the parasite predator, the host predator, or a combination of the two.

And in blue we have our control treatment.

And in red we have individuals who were exposed to sodium chloride.

So in our no predator group, similar to the last study that I showed you, we found that salt exposure increased the susceptibility of wood frog hosts to these parasites.

Moving to the right, we expected our parasite predator to reduce the abundance of cysts or the infection intensity within hosts, and this is indeed what we see when we add our parasite predator to this host parasite interaction.

However, we still see an effect of salt type where sodium chloride is still increasing the infection intensity within hosts.

Within the host predator group we saw an overall increase between both of our salt exposure of zero PPT and one PPT, or part per thousand, on infection intensity.

So we see no difference between salt exposure groups, but we do see that the reduction of movement caused by the host predator is indeed causing an increase in infections.

And when we look at our parasite and host predator combination treatment here, we see an intermediate average number of cysts, or infection intensity within these individuals, which makes sense, an intermediate between our parasite predator and our host predator groups respectively.

So in conclusion, we found that predators of host and parasites can influence the outcome of salt exposure on these infection dynamics and alter infection outcomes.

So the next thing that I wanted to note towards my dissertation is might the same be true for ecological communities that contain multiple species of amphibian hosts?

That is, amphibians commonly co-occur within the same bodies of water as one another.

This also has implications for disease dynamics.

So pictured here is a really kind of, I don't wanna say popular, but much thought about hypothesis within disease ecology known as the dilution effect hypothesis.

This hypothesis posits that as host species richness, as shown here on our x-axis, increases the community infection load, or the severity of infections goes down due to some hosts being better at resisting infections.

They're less susceptible.

So their inclusion to the community should drive the parasite burden down.

Essentially under this hypothesis, host biodiversity or maintaining high levels of species richness serves as an ecosystem service towards mitigating or reducing parasite infection risk within host communities.

So this led me to the third and final question of the talk of, does the inclusion of multiple host species into ecological communities influence the effects of salt exposure on infection outcomes?

So to do this, I utilized three different host species.

The American toad, spring peeper, and wood frog, all which can be found here in Broome County locally.

And to answer this question I formed single-species and multi-species communities containing these species.

So on the left hand side here under single-species communities, we have our spring peeper host in pink, wood frogs in green, and American toads in blue.

And on the right hand side we have our multi-species communities where we have each species represented with one another.

And all the way on the right hand side we have our most diverse community, or the community that we expect to harbor the lowest number of infections of our spring peeper, once again in pink, wood frog in green, and American toad in blue.

We then expose these larval communities to sodium chloride or a control for 24 hours.

And we then took them out of the solution, put them into clean water, and then exposed them to our parasites once again.

So, here are the data for this study.

So along the y-axis, once again we have total infection, or infection intensity within our larval amphibian species, and along the x-axis here I have pulled up our single-species communities relative to our multi-species communities.

This is in our no salt added control group.

So once again, under the dilution effect, we expect to see a reduction in overall infection.

However, this is not what we see.

We see relatively the same infection load between individual, between communities, whether it's individual single-species within a community or if they're multi-species host communities.

So next, we wanted to get out whether or not these sort of changes in host species composition with regard to single-species communities and multi-species communities changes when we change the environment.

So here we have our individuals that have been exposed to road salt.

And what I'm going to be pulling up here in a moment are the infection data for multi-species communities.

And what we can see is that relative to our spring peeper here in pink, when we add species to the spring peeper community under salinized conditions, we see that their infection load drops quite substantially, particularly when we add wood frogs to these communities.

So that is, if we have salinized wetlands, and we have single-species spring peeper communities, it would be beneficial from this data to include more species into these wetlands.

We see a similar pattern for our wood frog here in green when we add American toads to these communities.

We see a decrease in infection as we do indeed see evidence for the dilution effect hypothesis, but only under salinized conditions.

So some overall conclusions.

So in total, exposure to NaCl, which is the most commonly applied road salt, can increase parasite infections in larval amphibians.

However, when we start to think about the complex community dynamics that likely take place on a lot of salinized wetlands, infection outcomes really depend on ecological community contacts and can be quite variable.

And there's likely more facets of the ecological community that we're missing here that were not studied in my experiment.

So there's quite a bit that we still have to learn with regard to infection outcomes between wood frogs, spring peepers, American toads, and their trematode parasites.

So, that ends it for our toxicological impacts on wildlife and environmental health.

Next, I wanna talk about some ways in which you can help to monitor road salt impacts, and also maybe see some of the cool animals, or hopefully you think they're cool, that I've shown you this evening.

So, with this, I wanna highlight how effective citizen science can be, particularly within the Adirondack region.

There has been over 50 lakes sampled with some being sampled for over 10 years for road salt contamination.

And a lot of this work has been used to sort of give precedent for changes to be enacted at the state and local level with regard to road salt pollution.

That is, really, in order to detect that there's a problem in the first place, we have to monitoring for it.

It's needed to recognize issues if they're already in place or maybe even to curtail a potential issue in the future.

And one of the great things that happened last year is a bill to curtail road salt in the Adirondack region.

So with that being said, we have an opportunity coming up for all of you to get involved, if you're tuning in locally to WSKG, through Binghamton University, is BioBlitz.

So this is a opportunity for sampling that's going to be occurring on BU's campus and properties.

We're looking for things like plants, animals, fungi.

Maybe you'll even get to see some of the animals that I've talked about this evening.

And also, measuring water quality.

So things like conductivity, which is an indicator of road salt pollution.

So I believe that someone can pop this into the chat 'cause here I've listed a mailing list, and this is through Binghamton University's Center for Integrated Watershed Studies.

So, check it out.

I've been a part of BioBlitzs before, and they're a lot of fun.

So, ultimately, thank you all for coming, and a huge shout out to a ton of folks who have helped me over the years with this laboratory work that I've detailed to y'all.

Namely Devin DiGiacopo, Dr. Vanessa Weurthner, Grascen Shidemantle, Dr. Jessica Hua, and a whole slew of undergrads, committee members, and collaborators.

And with that, I'm going to turn on my plant light again and take some questions.

- All right, thank you, Nick, for that presentation.

There are many questions in the chat, and I will go ahead and run through as many as we can.

So the first question that we have here is from Heather.

Do you think that the results would differ if tadpoles were given the option to hide, similarly to how they would in natural environments?

- So there is some evidence that suggest that structural barriers can play a role in transmission of these parasites.

So, I believe that could be a possibility.

Things like leaf litter have been shown to reduce transmission, for instance.

So you could imagine that a tadpole sitting on the bottom of a pond could very well have less transmission of these parasites, which can affect them, than a tadpole in the middle of the water column.

However, I'm unsure as to whether or not they would actually seek out that cover response to parasite transmission, like an actual parasite avoidance mechanism.

That sounds like a really interesting question that one could test in the laboratory.

That is a great question.

Thank you.

- Sounds like we have the next experiment in the lab.

(Nick laughs) Next up, when you are testing substances on frogs, how do you know what their levels might already be, or are they bred in the lab?

- Yeah, so for all of my individuals, I collect them within, hopefully, the goal is 12 hours of being on the wetland.

Because what you're saying is actually exactly what I'm trying to mitigate, is we want naive individuals who have never been exposed to a contaminant within that generation.

We know that there is cross contamination that can occur.

So things like, you may be exposed to road salt but also pesticides.

And the outcome of those duel exposures can change results dramatically with regard to toxicology end points like survival, behavior even, and growth.

So we do pull these eggs out of the environment, this year, very fresh, less than 12 hours.

- Great.

Thank you, Nick.

Third question.

Do other cold states use much less road salt than we do?

Any good alternatives being tested?

- Yeah, so in terms of road salt usage between states, I am not quite sure.

What I can tell you is that our neighbors up North in Canada have less, or have a more strict guideline for environmental protections for sodium chloride.

Our acute chronic threshold for chloride id 230 milligrams.

There's is 160.

So just up North there are different regulations that I can tell you for sure, which will impact how much road salt is actually applied to be under that law.

With regard to alternatives, there are quite a few folks, actually, Dr. Rick Relyea, who I mentioned before, who are testing out road salt alternatives such as beet juice.

So beet juice, one of the things that it does when you add it to road salt.

If you've ever been behind a road deicing truck that's spitting out that salt, is the salt bounces quite a bit.

If you add water, particularly a sticky substance like sugary beet juice, it becomes sticky.

So that means that you're not going to have road salt bouncing off the roads, and it also lowers the melting point of the ice itself.

So it helps to facilitate the melting without adding as much road salt to the roads.

And sand is a good abrasive as well.

My home state of Indiana uses sand quite often.

Although, I haven't seen too much here.

- All right, moving on.

From Kelsey, is there a known reason why calcium chloride has the greatest effect on trematodes?

- Yes.

So, there has been quite a few studies with schistosome parasites, which are a trematode of humans.

So these are a really, really devastating tropical or neotropical disease currently, especially for countries who do not have access to waste water treatment plants or some of like the modern infrastructures that we may take for granted.

So ultimately if you go into a water body in these areas and they're untreated, you can end up with these fluke worms penetrating your skin and ending up in your body.

So one of the ways that this is treated is with praziquantel.

And one of the mechanisms of praziquantel that it does to these worms is it actually paralyzes them.

And one of the ways in which it does this is through calcium.

So calcium can affect the skeleton, for lack of a better word, of trematodes.

So one potentially cool thing in the future to look at is not only survival but also how it alters the behavior of these parasites.

Is it slowing them down?

Which could also curtail their transmission to host species.

- Great.

The next question here I think is referring to the, how salt gets into the environment.

The question is, I didn't realize salt was using crop irrigation.

Do you know why?

- So in crop irrigation, this is just, this is just naturally occurring salts that are within the water table.

So the issue becomes when you have all this water that's being put onto the cropland, that water's taken up by the plants, but the salts stay on the soil.

So when you're pumping a lot of water, potentially hundreds of thousands of gallons a day, and you have that over time, the soil can become heavily salinized, and then you can have a runoff event from a major storm.

So this is one of those things that's possible, and it does certainly happen, but isn't a major cause of secondary salinization.

- Great.

The next one has to do with private wells.

So who is responsible for paying for private wells to be fixed, in other words, cleaned or rebuilt, when things like this happen?

- So if you are one of those 50 homeowners in upstate New York, it is you.

So unfortunately that headline about the upset citizens, one of the reasons why they're upset isn't only that the state has salinized their drinking water, but they're also making them foot the bill, at least at the time of that article's publication for the remediation of those wells.

- Yeah, that's quite unfortunate.

Next question, what about food safety regarding fish?

So if you are fishing in these contaminated environments, who might be responsible for addressing food safety issues?

- So for food safety, so to the best of my knowledge, I don't know if sodium chloride in the environment is a major concern for like sport fishing, let's say.

Not nearly as much so as PFOS, for instance, which can bioaccumulate in fish tissues to high levels.

They're having issues in Lake Michigan with that currently and have whole teams dedicated to bio monitoring a fish tissue where biologist go out and fish as part of their job, and take these organisms back into the lab for PFOS.

Or say mercury, or lead.

So I don't believe that there's necessarily, at least to the best of my knowledge, any human health implications for salinization from these ions being in fish.

- Interesting.

We have a question from Clare.

She asked, what is the reason for exposing amphibian single-species and multi-species communities to a salt solution for 24 hours, and then removing them, and exposing them to echinostomes in freshwater environments?

- Okay, yes.

I realized once I said it that would be maybe a question.

Good question.

So the reason why we did that is to isolate the effects of salt exposure on the amphibians themselves.

That way we didn't confound our study with potential effects on the parasite.

As I showed you in that first study, road salt reduced the survival time of the parasite.

I didn't show you an additional data set where at a level of 860, all of those values for infection dropped off and became similar to the control.

So one thing that we think may have happened in that study is that there were sublethal affects of the salts on the parasite.

So reducing their ability to infect the tadpole.

So in this case, we wanted to measure parasite susceptibility.

And so, in short, we wanted to measure parasite susceptibility.

And if that's your goal, you have to isolate the effects on the host itself without confounding effects of the salt on the parasite.

If that clears that up.

That's a good question.

- And astute listener for sure.

The ninth question we have here is from Luke, and he's wondering, have there been any studies correlating the impacts of salt on sulfur concentrations in water or vise versa?

- Oh, Luke.

I do not know unfortunately.

- Yeah, I don't think there's much on that, Luke.

That's an interesting question.

I think most of what we know is in soil.

Again, maybe another interesting question to ask in the lab in the future.

The next question is from Angela.

Has any research been done to better understand why certain species of frogs impact other frog species vulnerability to infection by parasites?

- So in the data that I brought up it was infection within the total host community.

So what that dataset suggested to us is that the inclusion of those species reduced the chances that a parasite would contact another host species that had increased in its relative susceptibility due to road salt exposure.

So that is, the spring peepers became relatively more susceptible to the parasite when we exposed them to salt.

So when we added other species in, it reduced the opportunity for the parasite to make contact with the spring peeper, and they ended up making contact with a less suitable host.

But there's also an aspect to the study in that in this host parasite system, a lot of it is mediated by behavior like I showed you with the wood frogs and the deli tubs.

So one interesting thing that we could do in the future is to see if these different species influence the relative behavior of other species.

For instance, the spring peepers, when we expose them to these parasites, they sit on the bottom of the tub.

They do not move like the wood frogs do, and for as much as the wood frogs move, the American toads, just for lack of a better word, go crazy.

They start flipping around and doing circles.

So whether or not the American toad moving really quick throughout the water column influences the spring peeper's behavior and maybe makes them move more and avoid parasites is an interesting question and one I don't have an answer to.

- Great.

Well, thank you, Nick.

That actually brings us to the end of most of the audience questions.

And so, before I move on to introduce the next Science Pub, one final question for you.

What do you plan to study next?

- Yeah, so I'm, not to totally switch my focus around, but I'm very interested in microplastic pollution.

So it's really an understudy field.

As of right now, the bulk of research has primarily been focused on where are microplastics and how many microplastics are out there in the environment.

And what we've ultimately come to find is that microplastics are almost everywhere.

They're in our drinking bottles.

They're in our Aquafina bottles.

They're in the Arctic in ice.

So moving forward, toxicological research is really needed to determine what the negative or potential health implications for microplastic exposure are, especially for freshwater species such as amphibians.

'Cause this just simply hasn't been looked at yet.

So that is the next horizon of my career is microplastics research and delving into that world, which is exciting.

- And we're really excited to see that research come through.

Stay tuned.

Nick is going to be a fantastic, if not already, an amazing scientist.

He's gonna have his own lab one day and will wow us with all the discoveries.

Thank you again, Nick.

Wanted to just leave you all with some information about our next Science Pub, which will be June 15th at seven p.m.

The topic will be Antarctica to the Adirondacks, the ice lady's amazing journey.

So the guest speaker for the next Science Pub is Michelle Cross.

So please come and hear how Michelle Cross turned her love of science into a lifelong adventure.

After a seven-week research exposition into Antarctica, the special education teacher was selected to work with NASA scientists studying ice and snow in the Adirondacks.

So the information is posted in the chat.

Please register for your spot today for that presentation.

And with that, I wanted to thank Nick Buss again for your time and expertise.

It was a fantastic talk.

Thank you, Kristine, Julia, and Nancy for the opportunity to have this incredible program here in Broome County that has attracted so many amazing people.

So with that, thank you all, and we hope to see you next time at Science Pub.

Again, thank you Allysa also for directing and producing this event.

And also WSKG Public Media.

If you enjoyed yourself tonight, be sure to like the Facebook page for future events and science updates.

We are at Science Pub BING, and you can find us on WSKG's website.

Hope you all have a fantastic night.

Thank you again.

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