- Our first speaker is Kate Buckman.
She's a research scientist
in the Superfund Research Program at Dartmouth College
and is presenting Dragon Fly Larvae as Mercury Biosentinels:
From National Parks to National Forests.
Kate. - Great.
Thank you Nancy.
Hello everyone, nice to virtually see you.
I'm gonna share my screen here.
So I'm going to present an introductory talk basically
to our dragon fly mercury project program
that's currently being funded
through the Forest Ecosystem Monitoring Fund.
We just started the program this year,
so we don't have a lot of data
from the collections that happened this fall yet.
And so it's gonna be telling you what we have done
and what we're hoping to do in the future.
A little bit of background about this,
the lab that I work out of studies ecosystem contaminants,
and a big thing that we study is mercury.
And I'm sure that many of the people
that are in this audience know that
the forested landscapes in New England
are particularly success susceptible to mercury pollution.
We both receive a lot of mercury atmospheric deposition
in Northern New England,
and these forested landscapes can both enhance methylation
or the transformation of inorganic mercury
into the more bioavailable methylmercury form,
and also can enhance this bioaccumulation of methylmercury.
This has implications for both ecosystem and human health.
One of the unique things about methylmercury
is that it bio magnifies in the food chain,
and so you get higher concentrations of it
the higher you are in the food web.
And so by the time you get up here to high trophic levels,
exposure to methylmercury can cause a number of problems,
particularly neurological,
but also cardiac, reproductive.
There are many effects to high levels of mercury exposure
that we are concerned about
and are interested in understanding
why some areas are more susceptible
to mercury bioaccumulation than others.
Now the dragonfly mercury project
is actually a long-standing project.
It started over 10 years ago by our collaborator,
Dr. Sarah Nelson, who was then at the University Of Maine.
She's currently the director of research
at the Appalachian Mountain Club.
And it started as an educational program
in schools in Maine.
And this rapidly grew into what is now
the National Park Service Dragon Fly Mercury Project,
which I'm gonna talk about some of their data
a little bit more.
But it is a community science initiative
using park visitors to collect dragon fly larvae
to look at mercury bioaccumulation
and to use as a bio-monitoring tool
in national parks across the US.
Dragon fly larvae are good for this
because they're pretty common,
they are easy to collect and find,
they're in the middle of the food chain,
but they are predatory
and so they're really representative of these food webs
in these aquatic water bodies.
And they also exhibit site fidelity,
so they stay in one place
and they stay there for a long time,
and so they are very representative of what's going on
in terms of mercury transformations,
and bioaccumulation and fate
within the water bodies that you collect them from.
And the National Park Service Dragonfly Mercury Project
has been very successful.
It's one of the largest mercury data sets that we know of,
and it's been able to show variation
in these dragon fly larvae by eco region,
across families, by water body types,
but it's not well-represented in Northern New England.
You can see in this map here,
there are a couple of sites in New Hampshire and Vermont
and a couple in Maine,
but this New Hampshire, Vermont region
that we are interested in is not well represented
within the National Park Service Program.
Dartmouth has had a parallel track
of the Dragon Fly Mercury Project,
where we have continued to work in schools.
And we felt like this was an opportunity
to use this educational program
to both continue that and expand it
within the rural ecosystems in Vermont and New Hampshire,
and to give it a larger aspect of bio-monitoring.
And so we felt we had the opportunity
to add really important data points to Northern New England,
complimenting both the National Park Service dataset
and our Dartmouth school-based dataset.
And so we were really pleased to get funding from FEMC
in order to be able to do that.
And so this expansion started this year,
and I'm just gonna sort of walk you through
what we've done so far with it.
First was looking for sites.
We needed to go out and find sites,
particularly in the Green Mountain National Forest
and the White Mountain National Forest,
which were areas that we were interested in looking at
in order to compliment the National Park Service.
And so beginning in late August, early September this year,
we went out and visited a bunch of sites
along with our established sites through the school systems.
And so these are just a couple of pictures
of some of the areas that we've sampled.
This top area here is the Saxtons River,
and this is actually representative of what's turned out
to not be a particularly good sampling site.
I did say that the dragon fly larvae are ubiquitous
and they're easy to find,
but you can see this as a really rocky stream
and we did not have a good luck sampling here.
The lower one is Marshall Pond in Unity,
which is on conservation land in Unity,
and it is an excellent site.
It has a little bit of mucky bottom.
There's some vegetation around the edges,
and we found a lot of dragon fly larvae there.
So you can see in the map on the left,
the purple dots are sites that we collected from
in September and October.
The blue circles are areas that we visited
with the intention to collect
but were not able to collect any larvae there
for a variety of reasons.
In one site, the water level was actually too high
from all of the rain earlier.
And then the yellow dot is a site that we visited
and I intended to go back and sample at and ran out of time,
and so we're actually gonna add that to our list of sites
that we'll be sampling in 2022 as well.
So what do we actually do when we sample?
This does continue to be a community science initiative.
And so we go out with volunteers or with schools
to do these collections,
and we utilize similar methods
to the National Parks Service Dragon Fly Mercury Project
as well.
And so we go out there,
we train our collectors in clean hands, dirty hands,
how to catch the dragon fly larvae,
how to recognize them,
and how to bag them up cleanly
so that we can use them for mercury analysis.
We also do some colorimetric water quality analysis
just to collect a little more data
and get our participants more engaged
in learning more about the environment
that they're working in as well.
So we do collections in the late summer through early fall,
and then the lead collector, which often is me,
but in cases of schools is also the teacher who's leading,
adds our data to an online community science platform
called Anecdata.org,
which is run through the MDI Biological Laboratory.
So if you're interested in the data
that we are collecting from this,
they will be available there once this year's data
have been added.
And I really enjoy the collection events.
I think they are a lot of fun
and it's a wonderful way to get the participants out there
and looking at some of our ecosystems
that they may not know are there
or know that there's cool things
like dragon fly larvae living in them as well.
So once we've completed the collections,
we do field identifications
with our our collection partners as well.
USGS National Parks Service and University of Maine
has this lovely publication that they have created,
field cards for identifying dragon fly nymphs to family,
and so we take that out with us
and our volunteers do their best
to figure out what we've caught.
Sometimes we get things that aren't dragon fly larvae,
and so we need to see what else is out there
and separate which ones we want to keep
and which ones we don't.
And so we go through the process of measuring them,
identifying them to family level,
and bagging them up cleanly
before the samples go back to Dartmouth for analysis.
At Dartmouth, we check all the identifications,
dry the samples,
and then analyze them for total mercury
by direct mercury analyzer.
This year samples,
which I had hoped to present some data to you,
but is not going to happen,
are still a work in progress,
thanks to some instrument issues
and some supply chain issues
in getting everything we needed
to get the instrument up and running.
So stay tuned for those data.
But we were able with our partners this year
to collect 130 larvae from 10 sites
in New Hampshire and Vermont.
All of those sites, we will be visiting again next summer,
as well as adding more sites in the Green Mountain
and White Mountain National Forests as well.
So what are we actually gonna do with this data
once we do get them?
And so last year,
Collin Eagle Smith and collaborators
published a really great paper
based on the National Park Service Dragon Fly Mercury data
that they had to date.
And one of the things that they did
that was really important,
and I actually highly recommend that you read this paper,
if you're interested in bio-monitoring,
particularly for mercury,
I thought it was a great paper.
And they were able to find relationships
between the dragon fly mercury concentrations
and the concentrations in fish.
And from these relationships
that they'd established from samples collected
all over the US,
they were able to create an integrated impairment index
which predicts from the dragon fly larvae concentrations,
where you would expect to see mercury impairments
within water bodies in terms of fish concentrations
and what would be an ecological health hazard
and a human health hazard
based on various impairment indices.
And so our intention is to do a similar process
for the samples that we are collecting
through this bio monitoring in New Hampshire and Vermont
through this project.
And so one of the things that you have to do with this,
following the same process,
is transform the family specific data
into what we call an Aeshnid equivalent mercury,
and so it's basically taking
whatever family dragonflies that you have collected
and using the relationships
established in the Eagle Smith et al paper
to transform it into an Aeshnid which is one family.
And what that concentration would be
had you collected an Aeshnid there.
And so we're going to use this model that they have created
within the data that we are collecting
in New Hampshire and Vermont as well.
And so just to give you an idea of what this may look like,
this is actually on the left,
data that we've collected with Pelham High School
for a number of years.
And there is both temporal and spatial variability
in these dragon fly data across the families
as well as across the sites.
And you can see the triangles within this graph are
one site within Beaverbrook,
which is actually a beaver pond in Beaverbrook
and the circles are a different site in Beaverbrook.
And so you can see there's spatial variability,
both within the same water body, essentially,
as well as across the state as well.
We did collect preliminary data in 2020
from four sites in the White Mountain National Forest,
and when we look at these sites,
comparing them to the Aeshnid equivalents
and the integrated impairment index
established in Eagle Smith et al,
we see that most of these sites
fall within the moderate impairment as far as mercury goes.
And we sort of expect to see similar things
across all of our sites
that we will be sampling next year,
and the ones that we haven't analyzed yet this year.
I think I'm running out of time,
and so I'm gonna go just to the,
this one and say that we have a lot of help
collecting these dragon fly larvae,
and we really appreciate all this help,
both from our school partners and our community partners
who just came out and volunteered to go sample with us
and many thanks to all of them.
Thanks to the USDA Forest Service
and the National Park Service for facilitating this work
and helping get permits to do some of the work
and particularly to the FEMC Ecosystem Monitoring Fund
and our other funders who are helping fund this work
this year and next year.
And if you are interested in going out
helping collect in 2022,
please don't hesitate to get in touch with me.
We would love to see you.
So I'm happy to answer any questions that you have.
It was very brief,
and so if you want to talk about this
at any point in the future
and want more information as well,
please don't hesitate to get in touch.
Thank you so much.
- [Nancy] People can either, if you have questions,
you can post them in the chat and I'll read them to Kate,
or if you want to just unmute yourself,
you can do so and ask your question directly.
I'll ask a question.
Did you find that you had,
like, did you feel like you said you went to some sites
and you weren't able to collect data,
did you feel that you still had a good representative sample
in Vermont?
Or if you do this work again,
will you be adding more sites
to make sure that you're covering what you want?
- We actually are definitely adding more sites.
So the funding through FEMC is for multiple years
and it just started this fall,
and so we're collecting next summer and next fall as well
and we'll be adding a bunch more sites directly in.
I'm hoping, particularly that big chunk of forest
in Northern Vermont that's not well-represented.
So we will definitely be going to other sites.
I guess, stay tuned next year,
hopefully I'll have the data to show you
that we weren't able to show this year.
- [Man] Hi, I'm sorry, I came in a little late I missed.
Did you collect mud samples to look at mercury
in the substrate?
- No we're not looking at it in the substrate,
it's just in the dragon fly larvae.
All right, just a note in the chat
about would we accept collections
from an elementary school class?
Yeah, if you're a teacher
and you are interested in participating
and helping with collections,
definitely get in touch with me
and we can figure out how that will work.
We do have both high school and elementary school students
that work with us.
Thanks for asking.
You also don't have to be a student.
If you just want to go out, that's fine too.
- [Man] Seeing as I'm here,
the reason I ask about substrate
is we've seen elevated levels of mercury
in the organic NDA horizon
in some of the soil tests that we've done in Connecticut.
And I didn't know if the mercury in these systems
is mostly legacy mercury from past.
So if you expect it to be persistent over time
or to slowly be covered up,
so the dragon fly larva don't interact with it.
- Yeah, so it's an interesting question,
and that actually sort of does depend on the system.
But one thing that we know about Northern New England
is that it does receive a lot of
atmospheric deposition of mercury,
and so as long as that's happening,
there's always gonna be new inputs to these water bodies
to be methylated and be taken up
into the biota that live in them.
But there are definitely areas
where there is legacy contamination,
and if there's high deposition that has the potential
or high sediment deposition
that does have the potential to be buried over.
But I think that is one of the interesting things
about the potential of dragon fly larvae
for bio-monitoring,
and what we've seen in the National Park Service Project
is that there is a lot of variability,
so we can hopefully start to tease out
some of those questions over time as well.
- [Nancy] There is one more question in the chat,
I don't know if you can answer that quickly,
but Georgia Marie is asking,
are there other water quality indicators
that you would prioritize collection if you could?
- So we do do those colorimetric assays as well,
and we collect a nitrate ammonia, pH, temperature.
There's one more, dissolved oxygen as well,
that are sort of general water quality indicators
that are interesting to do.
We are particularly interested just in the mercury,
but we do have this other data to go along with it,
which to be honest,
I haven't delved into looking at
a lot of the relationships there yet,
but we do have those data for the collections as well.
Thanks for your question.
- [Nancy] I think we are out of time I think at this point.
We're supposed to leave a little break in between the talks
so that people can get to the next one,
but thank you Kate and everyone who attended,
we'll be starting the next talk at 1:25 in this track.
- Great, thank you everyone.