The Suwannee River Continuum Project

Kind of part of the point of this project
is to understand the continuum of the river, all the way through the network. To understand all the things that rivers do
and all the the ways in which we as a society benefit from those things. What this project is about is being able to
study rivers in the way that they flow. My lab is an ecosystems hydrology lab so we
study the wetlands and streams and springs and aquifers and lakes. So the river system that we’re focusing
on here in the southeastern coastal plain is the Suwannee River, it’s one of the only
undammed rivers in North America, but it also is home to one of the highest densities of
artesian karst springs in the world. So one of the most exciting parts of this
project is that rather than taking a measurement once a month or once a week and subjecting
it to a suite of laboratory analyses, now there are a suite of sensors that are capable
of doing those measurements immediately while you are in the field that allow us to stitch
it all together and kind of tell the story of what’s called the river continuum, which
is to say from the headwaters all the way down to the sea. Right now we’re standing at the river rise,
this is where after about a five to eight mile underground journey, the Santa Fe River
is reemerging right there, there’s water coming out of the ground at an old sinkhole,
discharging and forming the Santa Fe River, which we’re about to paddle down. So it’s a nice place to start because the
water is coming out of the ground here, so really this is the rebirth of the water after
it’s been underground for a while. We’re gonna be over the next several days
traversing the entire Santa Fe River, one of its major tributaries, the Ichetucknee
River, also starting our descent all the way down to the Suwannee River and towards the
Gulf of Mexico. Now during drought conditions the lower river
is almost entirely spring fed. That’s right, this is really really like
almost historic low flow, so we’re pretty lucky to be able to sample at this time, and
we’ll hope to come back and get it when the river is flowing a little more vigorously. We started today at Rum Island which is where
we ended yesterday, and from Rum Island we’re gonna go down through the middle part of the
lower Santa Fe which is real springs country. We’re gonna hit a whole bunch of big, somewhat
regionally famous springs, Ginnie Springs, which is a world-renowned diving venue;
Gilchrist Blue Springs, which is a locally favorite recreation area; a bunch of other
springs, and the river’s gonna be picking up all sorts of water from the Floridian Aquifer
and we’re gonna start seeing again clearer and clearer and clearer but also picking up
a lot of nitrate from the landscape where there’s a lot of agriculture and septic
tanks and things like that. We’re gonna be tracking both the arrival
of that nitrate and also how the river is removing it. This is the part of the Suwannee that we call
“Springs Country.” There’s thousands of little springs, hundreds
of named springs along the Suwannee that are discharging water to the Suwannee along this
reach and we’re gonna go past this big tributary of the Santa Fe River and understand a little
bit about what happens in these big mixing zones where two rivers come together. Is the coming together of two rivers really
the sum of its parts or is there some interaction between waters of different types as they
come together? Alright, so Matt, what are we looking at here? It boggles my mind. So there’s some conduit that’s coming
up between this crack in the rock and it’s higher than the river, so basically we have
a spring right in the middle of the river, showing that the aquifer level is like a foot
higher than the river. There’s this huge boil right here, and it
happened to be coming through this crack in the rock that you can see down 25 feet down
to the bottom. This is karst in action, right? This is very complicated hydrology that’s
full of all these underground rivers, these pipes that connect the landscape together
in ways that are very very hard to see until you see the very end of the flow path, which
is coming up from the ground like this. This is like top 5 coolest things I’ve
ever seen. I’m going swimming in there. Yeah I want to go in there too. That is just wild. We’re studying the chemistry of the river,
so all the stuff that’s in the water. You guys know what’s in the water? What kinds of things? They said poop. They’re very interested in poop and pee,
being 5th graders. There’s poop in the water, and other things
too. That’s what he’s measuring, we’re going
to measure phosphorus in the water. Have you guys heard about nitrate? Nitrogen? We have a super cool thing, a big silver bullet
that measures nitrate every two seconds. Today’s run is going to be going about 14
miles down to the confluence with the Santa Fe’s biggest tributary, which is the Ichetucknee
River. As you can see the water’s very clear. Florida’s springs have some of the clearest
water in the world. Jacques Cousteau the famous oceanographer
when he came to Florida and went diving in Florida springs he joked that he had visibility
forever. Under normal flow conditions very different
chemistry than the water on the Santa Fe and the Suwannee is that very dark, acidic, tannic
water, versus this spring water that’s very clear, and alkaline, and very high in nutrients
because it’s fed directly from the upper Floridian aquifer which has become contaminated
with runoff from agricultural fertilizers that leach down into the aquifer. Where the Ichetucknee and the Santa Fe come
together we’re expecting to see some very interesting mixing dynamics created by that
different water chemistry. Coming together of two rivers really the sum
of its parts or is there some interaction between waters of different types as they
come together? It’s gonna be about a 25 mile day, we’re
gonna go all the way down the Suwannee to about 15 miles downstream of the confluence
near Manatee Springs. This right here is the confluence between
the Santa Fe River and the Suwannee River. Suwannee’s working its way down to the Gulf
over the next 50 or 60 miles. Pretty interesting place – the sturgeon are
jumping in the background, there’s obviously two different waters coming together if you
wade out into the river a little bit you can see the clear water of the Santa Fe flowing,
mostly spring water, mixing with the more tannic water of the Suwannee. It’s a beautiful spot and it’s sort of
halfway down the Suwannee River for our journey today, but we’re gonna continue the work
and float all the way down to the Gulf of Mexico. By looking at the way things change along
the entire flow of the Suwannee, we’re hoping to learn a little more about the way that
the Suwannee River is part and parcel of the landscape that it flows through and the kinds
of things that that river is doing for us. Then we’ll have a map of the chemistry of
the Suwannee River Valley, which I think will be really exciting scientifically, and meanwhile
we’re gonna have gotten to see this gorgeous river, gorgeous landscape, up close and personal.

2 thoughts on “The Suwannee River Continuum Project

  1. Excellent visual summary of your work Dr. Cohen. A great example of both research in action, and Extension work. A model for us all!

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