[Intro Music begins]
[Steven Sobieszczyk] Each year USGS scientists systematically
assess the ecological health and water-quality conditions in
streams and rivers across the United States. This research
plays a vital role in land management and natural
resource decisions around the country. Contrary to
popular belief, these extensive data collection efforts
completed by researchers in the USGS National
Water-Quality Assessment Program involve much
more than just water quality.
[Kurt Carpenter] Back when the NAWQA program
first started, the National Water-Quality Assessment
Program, they recognized the need to incorporate biology
into the sampling. We look at the algae that’s in the different
streams and rivers and the bugs that eat the algae and then
also the fish that rely upon the bugs as a food source.
We also look at the habitat and the water quality
to see how all these different groups of organisms
respond to things like nutrients, pesticides,
temperature, and other stressors.
[Ian Waite] What we’ve done is we’ve developed
these methods that seem to work well across the nation.
We have standard methods and standard protocols
and so that way when we do the sampling here…
and the same methods are used back in the east
coast or the Midwest or whatever, that we’ve
sampled everything in the same way. So we can
compare and combine the data sets and
actually assess things nationally or regionally.
[Kurt Carpenter] The program, in general, is
looking at watersheds across the nation in
pretty large river basins. And that has provided
hundreds and hundreds of sampling locations
in areas of urbanization, agricultural land uses,
but also in settings like this…forested ecosystems
that haven’t been as impacted by anthropogenic activities.
[Ian Waite] One of the things that’s really
important in what we call “biologic assessments”
of streams, so how do we…can we understand the
conditions of streams and make a comparison
between one stream and the next is…you have to
know what is your reference, or minimally
impacted condition. If you don’t know what your
benchmark is, you can’t then say when are things
impacted or impaired or how or when are things
changing. With climate change? Or with land
use changes? You need to know your benchmark.
[Ian Waite] All the different ecological data, the
algae, the macroinvertebrates, the fish, they give
us different indications of what’s happening. One of
the things we’re realizing is that it’s important to
study more than one type of biological organism in
the stream. Because each one can give you a slightly
different signal. The other thing that it really gives
us an indication of…is land use affects. Or when
we look at the affects of agricultural land use on
streams that we see that the biological is a really
good response indicator of impacts due to water
quality, or habitat changes, or sedimentation, or things like that.
[Kurt Carpenter] When we start to see impacts
from things like water pollution on the biota,
we see that in a variety of indicator species, a
lot of the time we’ll see the diversity decline.
Instead of having a food web where nutrients
and light energy combine to produce a real
productive stream that we tend to see as having
a healthy trout population, or at least in these
mountainous streams in the west. What you
find is that you don’t see very many trout
and the benthic vertebrate population is greatly
simplified, you don’t see a lot of mayflies
and stoneflies or other types of food for the fish.
That can ultimately be traced back to water pollution.
[Ian Waite] Water quality is important to sample
but one of the problems is it is expensive and
it is only a one-time sample. It only grabs the
water and gives you an assessment of what is
happening at that one time. Where the biology,
they live there all year long. So what you find
when you’re sampling is they’ve been living
and have been exposed to all the conditions
that have happened all year long. And that’s
why biology is a really good indicator of the whole system.
[Kurt Carpenter] A lot of the management and
policy decisions that are set are driven by
bio-criteria. And so we look at the health of
biologic communities, really the full assemblage
of fish, bugs, and the algae to get a full assessment
of what the biota look like. But then we also
collect samples and analyze water samples for
nutrients and pesticides. Through the monitoring
that we do and these interdisciplinary studies,
and multidisciplinary approaches, we use all kinds
of different modeling, and multivariate statistics
and tease all this stuff apart, but ultimately we hope
that the information we generate can be used by
management agencies that dictate things like
nutrient levels that are permitted in streams and
controlling runoff and erosion and all those sort
of processes. And really, without this kind of
information where do you really begin.
[Steven Sobieszczyk] To find out more about NAWQA
sampling efforts in your area or to learn more about how
the USGS monitors the ecological health of rivers in the
United States, please visit the USGS online. Historical
data from Oregon, as well as the rest of the country can
be found at our National Water Information
System or at our biodata websites.
This has been a video production of the Oregon
Science Podcast, U.S. Geological Survey, Department of the Interior.
[Outro Music ends]