Climate Vulnerability Assessment for Threatened Bull Trout

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This webinar was conducted on March 10, 2015 as a part of the Climate Change Science and Management Webinar Series, co-hosted by the USGS National Climate Change and Wildlife Science Center and the USFWS National Conservation Training Center. Webinar Summary: Bull trout is the most cold-adapted fish in freshwaters of the Pacific Northwest. The species is listed as threatened under the U.S. Endangered Species Act, but climate change may place the species at further risk. Climate change may lead to a warming of streams in the summer and an increasing probability of floods in the winter. These changes are projected to lead to widespread loss of habitat for bull trout. This project, supported by the Northwest Climate Science Center, seeks to further elaborate how these climate-related threats influence bull trout across five western states (OR, WA, ID, MT, NV) that form the southern margin of the species’ range. Researchers used predictions of temperatures in streams across this extent to map coldwater streams or “patches” suitable for spawning and early rearing of bull trout. The study results indicated that larger patches of cold water were much more likely to support the species. The team also found that bull trout were more likely present in patches with extremely cold (<10C or 50F) temperatures in summer (August), fewer floods in winter, and low human impacts as measured by the Human Footprint index. In addition to elucidating the importance of local and climate-related threats, this work has identified dozens of places where bull trout may exist, but have not yet been detected, as well as other places where bull trout have been observed recently, but may be at high risk of local extinction. Climate projections based on these models have allowed researchers to identify where the species is most likely to persist in the future. This rangewide view of the species, in conjunction with local assessments of threats that cannot be evaluated at a broad extent, allows more effective prioritization for the conservation of bull trout in a changing climate.

Details

Date Taken:

Length: 00:43:51

Location Taken: Corvallis, OR, US

Transcript

Ashley Fortune Isham: Good afternoon from
the US Fish and Wildlife Services National

Conservation Training Center in Shepherdstown,
West Virginia.

My name is Ashley Fortune Isham.

I would like to welcome you to our webinar
series held in partnership with the U.S. Geological

Survey National Climate Change and Wildlife
Science Center in Reston, Virginia.

The NCCWSC Climate Change Science and Management
webinar series highlights their sponsored

science projects related to climate change
impacts and adaptation and aims to increase

awareness and inform participants like you
about potential and predicted climate change

impacts on fish and wildlife.

Today's webinar will focus on range wide climate
vulnerability assessments for the threatened

bull trout with Dr. Jason Dunham.

Please join me in welcoming Emily Fort from
the National Climate Change and Wildlife Science

Center, who will be introducing today's speaker.

Emily, welcome.

Emily Fort: Thanks, Ashley.

Thanks to everyone for joining us.

I'm here to introduce Jason Dunham.

He's an aquatic ecologist with the USGS Forest
and Rangeland Ecosystem Science Center in

Corvallis, Oregon, and has been working on
research related to bull trout for almost

20 years.

His work also spans a variety of other species
and ecosystems, ranging from native salmon

in Alaska, to non native salmon invasions
in Chile.

Jason received his PhD in Ecology Evolution
and Conservation Biology from the University

of Nevada at Reno.

Prior to his current position, Jason served
as a research fisheries biologist with the

US Forest Service Rocky Mountain Research
Station in Boise, Idaho.

Jason, please, we're looking forward to hearing
from you.

Dr. Jason Dunham: Hey, thanks Emily.

Can you hear me OK?

Emily: Yup, loud and clear.

Jason: Terrific.

Thanks everybody for dialing in today to hear
about this great work.

I really appreciate everyone's support for
the project.

I wanted to start with a thank you.

Thanks to the Fish and Wildlife Service here
in Oregon.

Their Science Applications Office, Steven
Zylstra provided some funding for this, as

well as the Climate Science Center, and the
Northwest Region of USGS.

I'm the lead on this project, but couldn't
have gotten it done without help from my team.

Dave Hockman Wert was our Spatial Analyst,
our GIS person.

Nate Chelgren, pictured there on the right
hand, he's our resident Bayesian in the lab,

quite handy.

Mike Heck, who deals with everything else
that falls through the cracks.

He's our leather man tool in the lab.

Throughout the study we've had help from Dan
Isaak as many of you know, he and Seth Wenger

have been working on the NorWeST Temperature
Prediction Project, which is a very key piece

of this assessment as well.

I just want to give all these guys a shout
out, and couldn't have got it done without

them.

Here's an outline for what I'm going to go
through today.

I'm going to try to keep it somewhat short.

No one ever complained when a seminar ended
early.

Hopefully there will be plenty of time for
questions.

I'm just going to go through a little bit
of bull trout 101 to begin with in case folks

are not already familiar with this species.

Then I'll give you a brief description of
what the rangewide vulnerability assessment

is, and we'll describe some results that we
have to date, and then let you know what we're

going to be doing in the future.

Bull trout is one of three chars of the Pacific
Rim.

Chars are fishes of the genus Salvelinus.

I know folks who are dialing in from out east.

Some experts there studying brook trout, which
is an important native species out there.

Lake trout may be another familiar one.

But here, around the Pacific Rim, we've got
bull trout in North America, western North

America, and Dolly Varden to the north.

Dolly Varden wrap all the way around into
Asia, getting into Northern Japan, where they

overlap with the white spotted char.

This will give you a sense of what these critters
look like.

These are Dolly Varden on the left, from Japan,
on the right, from Alaska.

The fish on the right probably just got back
from the ocean.

On the lower left hand side of your slide
is a whitespotted char.

This is a picture I took of a fish in Hokkaido.

Surprisingly, white-spotted char is the closest
cousin to bull trout here, in North America.

Dolly Varden is more closely related to Arctic
char.

Finally, there's a shot of a bull trout from
here, in Oregon, in the Metolius River, taken

by Jeremy Monroe.

These are the kinds of places these fish live,
headwater streams, and, as you can tell, a

broad diversity of headwater stream habitats.

The upper left hand panel is a shot of a bull
trout stream immediately following the eruption

of Mount Saint Helens in the early 1980s.

You can also have bull trout...Pictured in
the upper right hand slide, this is a coastal

stream with a very flashy flow regime that
can persist in there, as well as in more traditional

cold headwater streams or spring creeks, such
as the one pictured on the lower right hand

slide.

They're everywhere in different types of streams,
but one thing all chars have in common is

they like it cold.

They are the most cold water Salmonidae, salmon
and trout, in the world.

Once you get above maximum temperatures of
about 15 degrees Celsius, these fish really

start to suffer physiologically, and definitely
the case for bull trout as you can see in

this graph here.

This is relating probability of presence of
bull trout to temperature.

It really starts to drop once you get to about
15 degrees Celsius.

Water temperature is important in the part
of this world.

It's the number one source of water quality
impairment under the 303D list.

In the region, we've got over 30,000 miles
of streams listed for temperature impairment

across Oregon, Washington, and Idaho.

This map of Oregon shows you some of those
streams outlined in the red color.

Here's a graph showing you how important water
temperature is relative to other water quality

parameters in this part of the world.

It is driving the bus here.

It is important for bull trout, but it's also
important for water quality in general.

A few stats on bull trout.

We didn't even know that bull trout was a
species until 1978.

It was synonymous with Dolly Varden until
it was formally described.

Then, it was petitioned for ESA listing in
1992.

It was listed in different parts of its range
as a threatened species in the US between

1998 and 1999.

There is critical habitat designated for bull
trout.

This was done in 2010 by the service.

That includes almost 20,000 miles of streams,
almost 800 miles of marine shoreline and almost

500,000 acres of lakes and reservoirs.

It affects quite a bit of the landscape here
in the Pacific Northwest.

I'll move on to talk about what the vulnerability
assessment is, basically four steps.

Step one is to map suitable habitat or what
I call "patches" for bull trout across the

species range here in the lower 48.

Step two is to attribute these patches and
migratory habitats with information on local

and climate related threats.

I'll talk about what those are in a few minutes.

With these pieces in hand, we can model persistence
of bull trout in these patches and give you

a sense of where they're likely to be present,
where they're not likely to be present across

that vast range that I just described to you
here in the Pacific Northwest.

Finally, I'll talk about how we're starting
to apply these results to conservation efforts

here.

Step one, map suitable habitat patches.

When I say patch, patch could mean anything
in a landscape, anything that's more homogenous

internally relative to other pieces of the
landscape.

Here, I'm talking about cold water, because
we know that chars like it cold.

Typically, you're going to find this cold
water in the highest elevation portions of

stream networks.

These are the places that are cold enough
to support spawning and rearing for bull trout

on a year round basis.

You can see that in this slide here, this
cartoon of a network, that black outlined

piece of the landscape is that cold enough,
year round piece or patch for bull trout.

Bull trout do range widely outside of patches.

They get into places that may be unsuitable
thermally on a seasonal basis, but they do

make use of them when they're cold enough.

That's something that we tried to roll into
the assessment as well.

Why patches?

This table, a little bit complicated for a
presentation, but this gives you a sense of

how patches fit into... the scale that we're
talking about.

We're not talking about sites or little places
in the streams.

We're talking about headwater networks.

Those patches in turn can be comprised of
patch networks, so relationships among patches.

You can scale those up further to sub basins
or to regions.

In the middle column of this table, I have
a brief description of how this relates to

the scaling that is used in the bull trout
recovery plan.

On the right hand side, some potential indicators.

In our case, we're looking at patch size,
how patches are connected, how conditions

are playing out within a patch.

The patch scale is a bit different from what
we've done in the past on bull trout.

You can see on the left hand side of the slide
is a figure taken from a paper by Seth Wenger

et al, published in 2011.

In this case, we looked at presence of bull
trout in sites.

You can see those little dots distributed
across the landscape that we studied in this

particular publication.

A lot of those little points or dots or sites
are nested within a single patch.

We know that they're not independent.

We know that we need to deal with that.

That's why I'm taking a patch based approach.

If you look on the right hand side, this is
the HUC based view of landscape.

This is what the service used in 2008 for
their core area assessment.

These are fourth code HUCs.

Nested within each of these HUCs are dozens
of patches.

This scale's a little bit too big, I would
argue.

Sites are a little bit too small.

I think patches are basically just right in
terms of being defined based on the species

requirements and scaled or tailored, if you
will, to the species.

We're creating patches from a spatial temperature
layer that is created by the NorWeST project.

This is led by Dan Isaak.

Essentially they have cobbled together thousands
of observations of stream temperatures across

the domain that you see on the left hand side
of the slide.

They've been able to model and map maximum
and mean temperatures for the month of August

at one kilometer intervals throughout the
stream networks across the entire extent.

It's a really huge effort, extremely valuable
for us.

With those temperature predictions in hand,
we can classify portions of the landscape

that are suitable or not suitable for bull
trout and see how those are patchily distributed.

On the right hand side of this slide, I've
got the details of how we delineated patches.

You can ask me about that later if you want,
later in the presentation.

On the left hand side, what you see here are
red stream lines.

Those are places that are too hot for bull
trout.

The dark blue lines are places that are cold
enough.

Those are patches, networks that are cold
enough for bull trout and known to be currently

occupied.

The light blue are places where it could be
cold enough to support bull trout, but we've

not observed them to occur there.

Three different types of streams in our world.

The second step in this process, once we have
those little pieces, those puzzle pieces,

those patches, is to attribute them with different
characteristics.

The first thing that I thought about was to
consider connectivity.

That is, connectivity between or among patches
within these networks, so looking at distances

between patches as well as their connectivity
to migratory destinations used for feeding,

refuge or overwintering.

Two types of connectivity, connectivity among
patches and connectivity to lakes and reservoirs.

Those are incorporated into the model.

We looked at human influences in terms of
non native trout presence.

We had good information on the presence of
non native lake trout.

Lake trout is a char.

It's not a native species through much of
the bull trout's range, although they do coexist

naturally in the Saskatchewan basin on the
east side of the Rockies.

Surprisingly, we didn't have good enough information
on the presence of non native brown trout

or non native brook trout pictured here in
the slide.

These two species are listed as threats to
bull trout, but one thing we learned through

this assessment is we don't know enough about
these non native species to include them in

the model yet.

For human influences, sort of a generic indicator
of human influences, we used the human footprint.

You can see a clip there from the publication.

This was published in "Ecological Applications"
a few years ago.

This is a generic indicator of human influences
across the landscape.

It incorporates a lot of different factors.

In terms of climate influences in these patches,
this is something of particular interest for

us, we looked at patch size.

That was our first variable of interest.

It's how big is that chunk of cold water in
the landscape.

Does that have something to do with the presence
of bull trout?

Within that patch, we also asked how much
really cold water you have.

For us, really cold water is a water temperature
of 10 degrees or less for an August mean temperature.

That's very cold water.

That could be important for egg incubation
of bull trout or perhaps maybe a refuge from

disease or some other factor.

The second thing we focused on was winter
floods.

We know that winter flooding is going to increase
as snow goes away in the West.

It turns into precipitation in the winter.

We know that this sort of high flow event
could scour bull trout redds or nests or displace

juveniles.

We looked at the percent of patch length with
w95, that is a winter high flood event, less

than two of those.

If it had a low flood frequency, we predicted
bull trout to be more likely to be present.

We also had information on wildfire, the monitoring
trends, in burn severity datasets.

There's a really good one for this, the MTBS.

We looked at the percent of a patch in terms
of its area with a severe wildfire in the

last 20 years.

That's another very climate responsive variable
as most of you probably know.

Here's a horrendogram showing you how things
are related to each other in my mental model

of how these variables all conspire to influence
the presence of bull trout in patches across

the landscape.

The yellow circles are the variables that
we have information for in this analysis.

Essentially what we did after attributing
the patches, after delineating and attributing

them, was to conduct a big logistic regression
to look at how the presence of bull trout,

zeros and ones, presence or absence, is related
to all of these variables.

In a nutshell, these are the variables that
turned out to be more important, only four

of them.

Flow regime, as we hypothesized.

Thermal regime, which we expected as well.

Stream length in a patch, that's our measure
of patch size.

It turned out to be a major driver, as well
as the human footprint.

Surprisingly, things like patch connectivity
or migratory connectivity didn't turn out

to be important.

Neither did presence of non native fish.

Remember, that was only lake trout that we
were able to look at.

Let's talk about these variables that turned
out to be significant in the analysis.

I have some slides at the end of the presentation
if you have questions about things that turned

out to be not significant.

I'm ready to discuss those if you want.

In terms of temperature, we found that it
was doubly important.

Not only do bull trout need large cold patches
of stream networks in the landscape that's

less than 13 degrees Celsius, they also need
very cold water within those patches.

There's two pieces, cold enough and very cold.

Like I said before, that very cold water might
have something to do with spawning and rearing

requirements, egg incubation for the species.

Most chars need really cold temperatures for
egg incubation.

Essentially this is a form of what I would
call thermal habitat complementation.

You need different thermal characteristics
for different parts of the life cycle.

Patch size we know is important, because it's
likely to lead to larger population size or

just a larger area that is less vulnerable
to a single large disturbance, like a debris

flow or other effects from big disturbances
like wildfires or floods.

In terms of climate, the question here, of
course, is how much will this cold water warm.

The answer to this is all over the board.

Generally, from what we know right now, is
that interestingly, cold waters are actually

warming less than warm waters or warm streams.

That's good news.

The bad news is that cold water is going to
go away with climate change.

We're just not sure how much.

In terms of the W95 variable, this is the
winter flooding variable.

It turned out to be a really good predictor
of the presence of bull trout.

Like I said before, this sort of flood we
think is more likely related to displacement

of juveniles in the winter.

Bull trouts spawn in the fall.

Their juveniles emerge sometime in the winter.

They're very small, less than 30 millimeters
in size, not real good swimmers.

Winter flood is not a very welcome event.

Like I said before, we know that winter floods
are going to become more important as we lose

snow and ice across the range of the species.

The human footprint also turned out to be
an excellent predictor of the absence of bull

trout.

The bigger human footprint index, the less
likely to see bull trout in a patch.

This was the best we could do.

It's a catch-all indictor of human influences.

It doesn't point to any specific factor that
we might think of as being important for bull

trout.

It doesn't tell us anything about stocking
of non native trout, angling pressure.

It doesn't deal with small barriers, things
like stream/road crossings, culverts, water

diversions, levees, those sorts of things.

Anything that wasn't in the Army Corps of
Engineers dams database, we weren't able to

incorporate into this analysis.

There are various other sorts of local factors
that you could list that we don't have good

wall to wall data on.

That's one thing that really came home to
us in trying to do this work.

You really need data on these little things
that can make a big difference for fish on

the landscape.

We don't have those spatial databases.

That's the story for patches.

What about patch networks?

How do the effects of these variables I just
talked about, how do they vary among the different

sorts of units that we split bull trout into?

What we did here was included a random effect.

We allowed the coefficients for those different
variables to vary across core areas or other

units.

Core areas turned out to be the most informative
for us, these polygons here in this slide

show you the currently designated core areas
for bull trout across the species range in

the lower 48.

We allowed the effects of temperature.

We allowed the effects of stream flow and
the effects of the human footprint to vary

across all of these core areas.

Here are the results.

The values of the coefficient are on the Y
axis, the vertical axis of this graph.

Then, you can see different recovery areas
listed on the X axis.

Within each of those recovery areas, each
dot is a core area.

Recovery areas are larger extents within which
you have core areas nested.

Each dot is a core area.

You can see in the upper left hand graph,
that's for patch size, that length of the

network, length of cold water, you can see
the coefficient is all over the board for

that.

There is no such thing as a universal, magic
patch size for bull trout.

It really depends on the core area that you
look at.

That was a very important take home from this
analysis.

Until we get some of the other coefficients,
they don't seem to vary as much.

There is some variation that could be important.

Interestingly, the very cold variable, that's
the V_cold, is highly invariant among the

core areas.

The red dots indicate core areas where we
had a significant effect of that particular

variable.

The unfilled blue outlined dots are places
where it was not statistically significant,

so some interesting variation there as well.

Move on to the final step, applications of
predictions from this model.

What you're looking at here is the extent
of the range that we've been able to cover

to date.

This was the point at which the NorWeST effort
had completed modeling and mapping stream

temperatures when we wrapped up this work
last fall.

We're continuing to finish the whole range
now that we have all of the temperatures available.

We're going to zoom into these four different
boxes, these portions of the range that represent

some interesting variation across the range
of bull trout in the US.

Here's a zoom in to those four locations.

What you're looking at here in terms of the
stream lines are what we call "prediction

anomalies."

In red are patches where bull trout are thought
to be present, but the model predicted them

to be absent.

In yellow are places where bull trout are
not known to occur, but the model predicts

bull trout to be present.

Take a look at panel A. That's in the upper
left hand corner of this slide.

This is the lower Pend Oreille basin.

Lake Pend Oreille is that sort of snaky lake
there on the lower right hand side of that

panel A.
If you get down into the lower Pend Oreille

basin, you'll see three red streams.

Those are patches where bull trout have been
observed.

People thought bull trout should be present,
but the model thinks they should be absent.

It turns out that people have looked for bull
trout in these places for the last 5 or 10

years and haven't found them.

The model could have told us that.

The orange or yellow network in the lower
part of the Pend Oreille basin, that is unoccupied

because there is a dam there that is not in
the Army Corps of Engineers database.

The model picked up on that.

It's like, "Hey, how come bull trout aren't
here?"

Currently, folks are talking about a bull
trout reintroduction in that particular patch.

The model would tell us that might not be
a bad idea.

Looking across other portions of the range
you can see a number of places where you have

these small networks outlined in red, where
bull trout have been observed.

The model says they should be absent.

Those are generally the smaller patches across
the landscape.

There's a few exceptions here and there.

A lot of these places where the model thought
bull trout should be are upstream of barriers

that we couldn't track in our database to
fit the model.

Even though those aren't in the model itself,
the model is showing us that those are big

patches of cold water that could be suitable
had those barriers not been there, just based

on looking at these prediction anomalies.

Notably, in the lower panel, panel D, the
model is predicting that bull trout should

be present downstream of Anderson Ranch Dam.

This is in central Idaho.

Anderson Ranch Reservoir is a huge reservoir.

It has a hypolimnetic discharge, very cold
water coming out the bottom.

Based on the NorWeST predictions, it's a cold
stream now.

The model thinks bull trout should be there.

In fact, bull trout have started moving into
that reach of stream since it's cooled down.

Nobody's documented them spawning there yet,
but we haven't looked that hard.

It's worth noting that we have those predictions
available for literally thousands of patches

across the range of bull trout.

There're a lot of places we've not looked
for this fish.

That alone is a huge help in terms of us strategizing,
in terms of monitoring and evaluation of those

species across its huge range.

We can't sample everywhere all the time, so
having those a priori predictions is a huge

help.

They can help us focus our efforts and save
money in the long run.

In terms of the next steps, we're going to
work to finish the species range.

This is a map of the thermal scape of the
bull trout's range, a little bit bigger than

the actual extent of bull trout, but the bull
trout's range is nested within this.

It's all done.

We're busy creating new patches, attributing
those patches.

We'll be fitting final models to cover the
entire species range some time later this

spring.

The whole thing will be done in the lower
48.

The next step, following that, will be to
project what might happen to bull trout patches

in the future.

We're going to take a look at a very optimistic
climate and emissions scenario and a pessimistic

climate and emissions scenario.

We're going to pull that out of the NorWeST
database and see what that looks like for

bull trout.

We've done this before for the species, but
the models that we've used before are based

on associations between bull trout and air
temperatures.

I'm not sure of a good way to say this, but
we've been projecting hot air to look at climate

effects.

That's all we had before the NorWeST effort
was available.

When you project air temperatures, things
don't look so good for bull trout.

My prediction is that in looking at water
temperatures, we're going to get a considerably

more optimistic story.

Overall, bull trout are going to lose a lot
of habitat in any sort of warming scenario,

but it's not going to look as bad as it does
for air temperature.

The other thing we're considering doing in
these climate scenarios is given a climate

scenario, how much can we change that human
footprint to make a difference?

How much can we do to minimize human influences
in a very generic way, as indexed by the human

footprint, to see if we can adapt, in the
climate sense, to climate change.

Like I mentioned before, another important
next step for us is to do what we can to try

to learn about those little things that we
weren't able to incorporate into this assessment.

I mentioned presence of non natives, at least
brown trout or brook trout.

We don't know that.

Small barriers, there are thousands of them.

Diversions, the same thing.

We need to get better information on these
little things to really know what's going

on.

To help with this, we've put together a number
of what I call patch attribution tools.

This is one that we put together using Google
Earth.

This allows managers to attribute these patches
with their expert opinion or their actual

real data on the presence of bull trout or
these non native fish, like brown trout and

brook trout.

We're working right now with the state of
Oregon.

They are adopting these tools.

They're working with their district managers
to get us this data so we can come up with

an improved assessment at least of the effects
of those non native trout on bull trout.

Trying to move that forward.

As this comes to a close, we'd like to find
ways to use these results in local vulnerability

assessments, local conservation assessments.

Here's one example that's just out in the
"Canadian Journal of Fisheries and Aquatic

Sciences."

Here we looked at climate vulnerability of
bull trout in the Wenatchee River basin in

the context of managing wildfire.

I won't get into this in too much detail.

Here you can see how we have drawn the patches
in the Wenatchee River basin and looked at

their vulnerability as a function of future
wildfire regimes.

All those little tiny polygons within the
passes are giving us a picture of how habitat

conditions are going to change based on wildfire.

What we learned in this particular paper,
in a really small nutshell, is that if we

manage for wildfire, that can be a very effective
way of buffering bull trout from the effects

of climate change under moderate scenarios
for climate change.

If things change very strongly, and climates
really warm substantially, there's not much

we can do to protect the species, but definitely,
managing fire, which is not a small task,

is something that could be effective.

Managing for connectivity, we found out in
this particular analysis, is considerably

less effective than managing for fire.

Very interesting to use results like this
to contrast the effectiveness of different

management strategies, both of which are very
expensive.

Good to know in advance before you do this.

Hopefully I'm wrapping up a little bit early
here.

I just wanted to point you to the website
where all this information is.

All our data is posted there, available for
you to use as you like.

We've got several publications, including
a more detailed report based on the vulnerability

assessment that you can access there.

Thanks for listening, and I would be very
happy to take any questions, or have a discussion

about this.

Ashley: David Hines, you can ask your question.

David Hines: Jason, you said all your data
was available on that website.

I just went there.

Which link do I click on to find the bull
trout data?

Jason: ScienceBase.

David: OK.

Sciencebase.gov.

OK.

Thank you.

Jason: Yeah.

Thanks, Dave.

You can contact my Dave, too, if you want.

You know where to find him.

David: Yep.

I also sent you an email, too.

Talk to you later.

Jason: OK.

Cool.

Ashley: OK.

From Lew Gorman we have a question.

It says, "Since this species range has a large
portion along the Canadian border, has Canada

generated similar data?"

Jason: No.

That's a good question.

The first picture of a bull trout I showed,
I took that up in British Columbia this year

and gave a presentation on this up there,
and invited them to join us.

They're thinking about it.

It would be awesome to have data from Canada.

It's much easier said than done, and there's
definitely a north/south gradient in available

data.

Bull trout get all the way up into the Northwest
Territories, and that might be a good spot

to start studying them.

Ashley: From Don, "So, you have the assessment.

What are the management implications?"

Jason: We can take a look at those threats
and how those vary from place to place.

That's very important in terms of thinking
about the species' status.

One of the reasons that threatened endangered
species are listed is based purely on the

threats.

We can also take a look at that in the context
of some of the local factors.

I mentioned wildfire, managing connectivity,
how does that play with climate change to

influence our view of priorities for managing
bull trout.

Another use is sampling.

The predictions from the model give us an
a priori expectation of where bull trout should

be across the landscape, even without dipping
a toe in the water.

That improves our ability to strategically
target our sampling to find this fish.

There are hundreds of places where bull trout
could be that we've not looked.

Those are just a few examples of some of the
management applications.

Ashley: And Don asks, "Less clearcutting?"

Jason: I'm a science guy.

Ashley: [laughs] We did have another question
come in from Brittany.

It says, "What is the US doing currently to
protect remaining patches, and what do you

suggest Canada can do better, or should do
better?"

Jason: Well, I don't really have a big message
for Canada.

[laughs] Interacting with the Canadian biologists,
they're excellent.

I work with them a lot, and it would be nice
if we could do a better job of coordinating

on getting a common piece of information so
it's not a rangewide vulnerability assessment

for bull trout in the US, it's a rangewide
vulnerability assessment across the whole

species' range.

To me, that's really where I would like to
go.

We have so much uncertainty, so many questions,
so many concerns about what climate is going

to do to the species in the lower 48.

Canada is definitely going to be a stronghold,
and we know the least about it the further

you get north.

That would be the most important thing to
do, I think.

Ashley: Thank you.

We have a question from Sondra Collins.

While you're typing in, I'm going to call
on...I saw another hand up here.

Chad, you can ask your question now.

Chad: Can you hear me?

Ashley: Yes.

Chad: Hi, Jason.

Jason: Hey, what's up?

Chad: Not much.

A couple of the predictor variables were surprising,
too, that they didn't come out as important.

Do you think with maybe a little better data
or more information that some of those would

start to pop up as being more important?

Jason: Yeah, certainly so.

Probably the biggest surprise to me, Chad,
was the lake trout not having an effect on

presence of bull trout.

There's a few reasons for that.

One is that we're looking at presence over
the last 20 years, so maybe that invasion

has happened so recently that we're not picking
up those recent extinctions, or that lake

trout are really depressing abundance of bull
trout, but not causing them to go completely

extinct, at least yet.

We definitely have cases of that in Oregon,
where they're able to coexist at the expense

of bull trout
The other thing to keep in mind is that bull

trout and lake trout coexist naturally in
the Saskatchewan Basin.

They've been there for millennia.

I think it would be good to try to figure
out how those two get along.

With other variables, like the fire variable,
I don't know if that goes far enough back

in time to really pick up some of the major
events that have happened in some of those

basins that could explain variability in presence
of bull trout.

It may not be a long enough time series for
fire, either.

A couple of examples of why things didn't
come up that seem a little bit surprising.

The connectivity variable, I think definitely
better data on lakes and reservoirs.

I was really amazed at how little we know
about our standing water bodies in trying

to get the data we needed.

We don't know how deep they are, we don't
know anything about their water quality.

Some we do, but across the board, we don't.

We don't have a national lakes database that's
good enough to be incorporated in an assessment.

Just a couple of examples of things that I
thought should have been important, but weren't.

Chad: OK.

Thanks.

Jason: Sure.

Ashley: Seth Willey asks, "You predicted declines
due to warming, but not as extreme as in air.

In light of this, I'm wondering if you could
weigh in on long term prospects for recovery,

potential viability to be returned, or not?"

Jason: Super good question.

Remember, at the beginning of the talk I mentioned
we have 30,000 miles of streams that are already

listed as impaired for warm temperatures under
the Clean Water Act.

We've already done a lot to water temperatures
to warm them up.

You talk about climate effects on stream temperatures,
you may be getting into two to four degrees

warming.

There are many examples where we have over
10 degrees of warming due to channel alteration,

loss of riparian vegetation that provides
shade to the stream, loss of water in the

channel.

A lot of streams are dry.

I think there's a lot that we can do to get
these systems back in shape, just based on

the legacy impacts alone.

I do think that the vulnerability assessment
provides this broader context and gives you

a better picture of where those sorts of local
restoration efforts are more likely to be

effective in the centuries-long time scale.

There may be some places that, no matter what
you do, you're just going to run out of cold

water, but there are definitely other places
on the landscape that you can see, in this

assessment, where you can make a lot of ground
up by those local management effects.

Ashley: Sondra was able to go through the
chat, and ask, "What will be the team sampling

schedule?

When?

Where?

And is there a timeline available for the
next five water years?"

Jason: No, we don't have any money to do sampling.

If we get some money for dry suits and gas
in the gas tank, or filters for environmental

DNA, we'll be out there and do it, but right
now there aren't any plans on my part.

Ashley: Then, Don also asks, "Is the research
being utilized by management?"

Jason: Absolutely.

As soon as we get it out, it gets used.

Folks have been using it in Montana.

That's where we started, Region One of the
Forest Service Area.

Scott Spaulding has used it in some of their
bull trout conservation planning efforts.

Other folks have been grabbing the patches
and using them in other core areas.

As soon as it comes out, it gets used.

Ashley: All right.

That's all I'm seeing.

Again, Jason, thank you very much.

It was very interesting.

Jason: Yeah, great discussion.

Thank you so much.

Ashley: Great.

Our next NCCWSC's webinar is going to be on
Thursday, April 16th at 5:00 PM Eastern.

Yes, that will be recorded and posted to the
NCCWSC's webinar page if you can't make it.

We hope to see you then.

Please stay tuned for another announcement,
or watch for an announcement over your email.

Thank you again, Jason.

Have a great day.

Jason: You bet.