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Madison Blue Spring, Madison County, April 2017

I should not have favorite springs, just like I don’t have favorite students, of course, but Madison Blue was one of my favorite springs.  I enjoyed all of the springs that I visited in their own ways, but Madison Blue had the perfect combination of breathtakingly blue water, an intimate feel (the vent and run were very small), and a lovely river at the end.

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The headspring of Madison Blue.  The water really was that blue.

limestone and clear water

The limestone wall around the spring.  This wall was natural.

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The short run of the spring into the Withlacoochee River.

withlacoochee downstream of spring

The plume of Madison Blue Spring into the Withlacoochee River.

Madison Blue Spring was cold, only 20.8C or 69F.  It was the farthest north that I ventured on this project and only Wakulla Spring was equally cold.  Given its small size (22×25 m, according to the Scott et al. 2004, Springs of Florida), the 96 cfs discharge of Madison Blue seemed high and the velocity of the water in the little run was quick.  Like the other Suwannee River springs, the average nitrate concentration was fairly high (1.65 mg/L) and the phosphate concentration was fairly low (0.04 mg/L) for 2016 (http://www.mysuwanneeriver.org/portal/springs.htm).  The dissolved oxygen was not particularly high (1-2 mg/L), but not the lowest that I measured in this study.  There was algae, certainly, but the water clarity was really good.

blue water under water

Underwater view of the headspring of Madison Blue.

There were a few fish at the headspring, mostly sunfish (Lepomis sp.) and the occasional mosquitofish (Gambusia holbrooki) or shiner (Notropis sp.), but the fish were really abundant in the tiny run.

sunfish in the run

Sunfish checking out that camera in the Madison Blue run.

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Shiners milling about in a backwater area in the short run of Madison Blue Spring.  And, of course, a curious sunfish.

Fish also aggregated near the plume of the spring.

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The transition point from spring water to Withlacoochee water.

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A startled spotted sucker (Minytrema melanops) fleeing the area where the spring meets the Withlacoochee.

In the end, the number of species observed and the diversity of the fish in the spring was relatively low (only 7 species), but the density of fish was comparable to springs on the Suwannee River.

After I finished collecting data, I paddled in the Withlacoochee a bit.  It was gorgeous.

withlacoochee

Suwannee River, Suwannee County, April 2017

I finished work early one day and decided to check out Suwannee River State Park.  After wandering around the park a bit, I got up my courage to go out on the river solo.  Up until that point, I did not have the guts to venture out onto the Suwannee by myself–the water just looked so big and my boat looked so small.

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The Suwannee River at Manatee Springs.

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The Suwannee River at Troy Spring.  It is interesting how much rockier it appears further north.

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The Suwannee River at Lafayette Blue Spring.  The river felt smaller there, but it was really windy that day.

For whatever reason, the Suwannee felt much more manageable upstream (and the weather was good), so I went exploring.  I was rewarded with beautiful scenery.

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The Suwannee River upstream of the boat ramp at Suwannee River State Park.  I love the roots over the limestone.

As I explored, I found three tiny springs that abut the river.

Lime spring

Lime Spring (it might also have been called “Little Gem”) in Suwannee River State Park.

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Ellaville Spring just south of Suwannee River State Park.  In the top photo, the spring is just barely visible on the bank (right side of photo).

For the third spring, I had to cut up the Withlacoochee (the north one) just a bit.

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The Withlacoochee River at its confluence with the Suwannee.

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Suwannacoochee Springs on the Withlacoochee, just above its confluence with the Suwannee.

 

Falmouth Spring, Suwannee County, April 2017

Lafayette Blue Spring was a little weird because of the limestone bridge that bisects its pool, but Falmouth Spring was truly weird.  Falmouth is strange enough that it has an entry on the Atlas Obscura website (http://www.atlasobscura.com/places/falmouth-springs), which describes itself as: “the definitive guide to the world’s wondrous and curious places”.  Falmouth Spring is not truly a spring; it feels like a giant crack in an otherwise normal forest with water flowing through it.  In reality, it is a more of an underground river with a short stretch that is exposed to the surface.  Its water, which was fairly brown when I visited, comes out of an underground vent, travels 450 feet, then disappears into a limestone wall.  The water whirls around as it funnels into the cave in the wall, producing a slightly creepy whirlpool effect.

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The source of the water (the “headspring”) of Falmouth Spring.  The pool was deep enough that I could not see the bottom, even with the camera, in the dark water.

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The Falmouth “run” as it leaves the “headspring”.  It was very shallow and fast flowing.  While I was working, an old man in swimming gear showed up and swam in this part of the run.  He swam hard without moving, the flow was that strong.

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The Falmouth run as it enters the second pool that is drained by the cave.  Yes, that is a tiny section of rapids–so rare in Florida!

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The limestone wall into which the water disappeared.  The darkest spot is the cave.

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A closer view of the limestone wall; the cave is the opening.  I felt as if my kayak was going to get sucked in if I got too close.  Images of a scene from Willy Wonka and the Chocolate Factory were whirling around my head–only with limestone and brown water.

Falmouth Spring looks even a little weirder from aerial view because it is actually fairly far from the Suwannee River.  I found it relatively easily on Google Earth as a break in the trees on the Falmouth Spring Conservation Area.

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Google Earth image of the landscape around Falmouth Spring.  The Suwannee runs through the band of green to the west.

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Closer aerial view of Falmouth Spring.  The dark area just below the marker is the “spring”.

The average discharge of Falmouth Spring is surprisingly high.  For 2014 and 2015, the average discharge was 131 cfs, which is almost as high as Volusia Blue Spring.  Of course, it also had a period in January 2015 when its discharge was -110 cfs; the spring is  known to reverse periodically.  The nutrient concentrations also were fairly high; the nitrate concentration was 1.02 mg/L for 2016-2017 and the phosphate concentration was likely about 0.06 mg/L (it was measured less recently), according to SRWMD (http://www.mysuwanneeriver.org/portal/springs.htm).  Not surprisingly, given the underground source of the water, the relatively high nutrient concentrations, the spring reversals, and the abundant dead algae in the upstream end, dissolved oxygen concentrations were quite low (0.36-1.18 mg/L).

dead algae on tree

Dead algae on a downed tree in the “headspring”.  If you look closely, there is a fish swimming away from the tree.  There were a lot of fish congregating around this tree, which fell across halfway across the “headspring”.

The run looked a bit healthier; it supported live algae as well as large plants (probably Potamogeton sp.).

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Live algae and plants over sand substrate in the Falmouth run.

I was surprised to find any fish in this spring other than mosquitofish (Gambusia holbrooki), given the lack of above ground connections, but I observed least killifish (Heterandria formosa), shiners (Notropis sp.), two species of sunfish (Lepomis sp.), and two longnose gar (Lepisosteus osseus) in addition to mosquitofish.  Did all of these fish travel underground to Falmouth???  I observed all of these fish in the “headspring” and in the run; I did not see any fish in the last pool.  Did any fish that ventured down there get sucked into the cave?????

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Two longnose gar in the “headspring” of Falmouth Spring.

Although I did not find any fish in the last pool, I found snails on the plants at the top of the pool (the bottom of the run).

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Plants at the bottom of the fast flowing run, just before the deep pool that leads to the cave.  The dark brown dots all over the plants are snails.

Definitely among the weirder places that I’ve been in my life.

Wes Skiles Peacock Springs, Suwannee County, April 2017

Peacock Springs was renamed in honor of the famous explorer and cave diver, Wes Skiles.  I understood the reason for the name change intellectually before visiting the spring, but it became much clearer why they chose that particular spring to rename after I visited it.  Some of the springs at the park are connected above ground (Peacock I, II, and III), and periodically these three springs are connected through the Peacock Slough to the Suwannee River.  On the day that I visited the park, that connection had dwindled to a trickle (it is a seasonal connection).  However, there are other sinks (holes that represent breaks in the limestone) that lead down to the massive cave system that underlies the park that is extremely popular with cave divers.  In fact, the park does not allow surface divers or swimmers.  I took all of my video from the bank.  To give the park visitors perspective, the trail that starts (or ends?) at Peacock I indicates, with signs, what part of the cave system is under your feet where you stand as you walk the trail.  Very cool.

park map closeup

Close up of the park map from the park’s unit management plan (http://www.dep.state.fl.us/lands/ARC/Meetings/2013/DEC/ITEM5_Peacock_Springs.pdf).  The pink lines represent the underground cave system with the above ground trail overlaid (the yellow dotted line).

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The Peacock spring run.  The photo was taken from just above Peacock I; the run narrows after this first spring, widens again at Peacock II and III, and narrows again after these springs.

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Peacock I (with stairs) looking down toward Peacock II and III.

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The Peacock II vent.

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The mostly dry run below Peacock III.

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This sign shows the cave system and a photo of one of the caves under the trail.

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“The Pothole” described in the sign above.  This tiny watery hole is one of the sinks that are linked to the cave system below.

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A close up of “The Pothole”.

There are many sinks on the property; The Pothole was just one of the closest to the spring.  At the entrance of the park, a much larger sink, Orange Grove, provides divers with another access point to the cave system (The Pothole is too small!).

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The limestone wall of the Orange Grove sink.  Looking at the wall gives a better picture of the porous stone that breaks to form a sink.

diver hole in the duckweed

The Orange Grove sink was covered in duckweed; the surface only cleared when divers were coming up and their bubbles pushed the duckweed to the side.

The park sits in a pocket of managed pine forest, which makes the drive into the park especially lovely.  However, the larger landscape matrix incorporates a lot of agriculture and the system is not without nutrient enrichment.  I have not yet found concrete numbers, but the unit management plan for the park indicated that nutrient enrichment was a problem http://www.dep.state.fl.us/parks/planning/parkplans/PeacockSpringsStatePark.pdf).  I suspect the extensive duckweed coverage is a result of nutrient enrichment.

peacock aerial

Google Earth image of the landscape around Peacock Springs.

Despite the periodic connections to the Suwannee River, I measured only slightly lower species richness (total number of species) and densities of fish and comparable diversity (a measure of how evenly fish are distributed among the species) than for some of the springs that are more persistently connected to the river.  Most of these fish were small, like mosquitofish (Gambusia holbrooki) and bluefin killifish (Lucania parva), but there also were a lot of sunfish (Lepomis sp.) and some quite nice largemouth bass (Micropterus salmoides).  Not surprisingly, some of the most mobile species, like mullet (Mugil cephalus), were absent from the spring.

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Largemouth bass on the edge of Peacock II.

bluefin and shiners

A bluefin killifish (with the orange tail) in the foreground with large golden shiners (Notemigonus crysoleucas), bass, and sunfish in the background.

Interestingly, I also observed fish in three of the sinks on the property.  There is literally no overland connection between these sinks and the spring, so it would appear that these fish would have to travel through the cave system to get to them?

first sink

Mosquitofish in the small sink closest to Peacock I.  I was not surprised that the fish in this sink were all mosquitofish–the most vagile and tolerant fish in Florida.

pothole underwater

A largemouth bass in “The Pothole” sink.  I was surprised when I saw this fish and other fairly large species (sunfish, Lepomis sp., and a chubsucker, Erimyzon sucetta) in this conduit to the cave system.

sunfish and divers in orange grove

A view of sunfish and divers, peeking over the stair, in Orange Grove sink.  The sunfish got a lot more active when the bubbles started coming up from the divers.  I liked the contrast of the blue where the divers’ bubbles removed the duckweed and the green where the duckweed coverage was intact.  The divers are visible in the background.

I used the color photos above because the color gives a better sense of place.  However, I liked the way some of the black and white photos turned out.  In the spots where the water was covered in duckweed, I think that the duckweed was reminiscent of snow.

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Peacock Spring run looking down from Peacock I.

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Peacock Spring run looking back up towards Peacock I.  The stairs are just barely visible in the background.

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Peacock Spring run.

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Cypress knees in duckweed, just below Peacock III.

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Riparian forest and duckweed on the pool just below Peacock III.

 

Lafayette Blue Spring, Lafayette County, April 2017

Each of the springs of Florida seems to have its own character and Lafayette Blue Spring seems even more exceptional than most.  It is one of a host of short-run springs on the Suwannee River, but it is further north than the springs that I had visited previously (Manatee, Fanning, Troy, Otter, Hart).  Two characteristics make it different than the other springs: it has a natural limestone bridge that divides the spring on the surface into two pools and discharge that is so variable that the average for 2015 was negative (-13 cfs, the range was -179 to 138 cfs, http://www.mysuwanneeriver.org/portal/springs.htm).  Not knowing the discharge at the time of my visit, what struck me first was the limestone bridge, which looked as if it had been smoothed out to accommodate visitors.

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Lafayette Blue Spring from the boardwalk overlook.  The natural limestone bridge is about halfway down the short run.

lafayette blue bridge

The limestone bridge of Lafayette Blue.  I was surprised by how wide and flat it was.  Water travels under the bridge from the pool on the right to the pool on the left.

GOPR1458.JPGA close-up of the limestone that makes up the bridge.  Limestone is a very soft rock that erodes relatively easily in even very slightly acidic water.

The website “Florida’s Springs” describes Lafayette Blue in this way: “Lafayette Blue Springs is one of the 33 first-magnitude springs in Florida and discharges at a very variable rate, ranging from approximately 13 million to 168 million gallons per day. When the Suwannee River floods the spring vent, which happens fairly frequently, it can become a siphon”  (http://www.floridasprings.org/visit/map/lafayette%20blue%20springs/).  This siphon phenomenon occurs because the aquifer is shallow and unconfined in this portion of Florida (http://www.dep.state.fl.us/parks/planning/parkplans/LaFayetteBlueSpringsStatePark.pdf).  An aquifer is considered confined if it has a layer of relatively impenetrable clay above it.  This clay layer keeps this water separate from the surface water, so without the clay layer, the aquifer water in the vicinity of Lafayette Blue Spring may be more vulnerable to intrusion from the river.  An unconfined aquifer also would be more vulnerable to pollution from surface water.  It appears that the reversal of the Lafayette Blue Spring is a dry season phenomenon, but there were more negative values in 2015 than in any previous year.  I am not sure of the discharge on the day that I was there, but it definitely appeared discharging (rather than siphoning) due to the flow downstream.  At the mouth of the spring where it gets quite shallow, the water velocity was actually somewhat strong, and I had to paddle hard to keep myself from floating out into the river.  Usually, I like to go out into the river, but on that particular day, it was very windy and there were whitecaps out in the Suwannee, so I decided to keep my little boat in the protected valley of the spring.

Video of water rushing out of Lafayette Blue Spring.

Like the other springs that I visited on the Suwannee River, Lafayette Blue had high nitrate concentrations (2.88 mg/L) and moderate phosphate concentrations (0.05 mg/L).  Perhaps as a result of both the nutrient concentrations and the recent rain, the water clarity was not super high and my fish videos were not great.  Lafayette Blue is in a similar type of area, in terms of landuse, as the other Suwannee Springs and its nitrate and phosphate concentrations were comparable to these other springs, but its oxygen concentrations were the lowest of any spring that I have visited to date.  The highest dissolved oxygen concentration that I measured in the spring was 1.12 mg/L on the bank of the first pool in the algae.  Oddly, the oxygen was even lower in the second pool (0.66-0.83 mg/L).  By comparison, the dissolved oxygen  in Rainbow Springs ranged from 6.25 mg/L to 8.11 mg/L in January (during the slow growing season for plants and algae) and the measurements in Salt Springs ranged 3.16 mg/L to 9.98 mg/L in April.  Lafayette Blue Spring oxygen concentrations were an order of magnitude lower than these springs and the oxygen stress showed in the fish behavior.

lafayette aerial

Google Earth image of the landscape around Lafayette Blue Spring.  Like the other Suwannee Springs, Lafayette Blue sits in a landscape matrix of green corridor along the river surrounded by agricultural fields.  A large green space sits to the west of the spring, but I don’t know the size or shape of the springshed, nor do I know the pattern of flow in that springshed, other than its more superficial connection to surface water than in areas with a confined aquifer.

fish at surface

Juvenile sunfish (Lepomis sp.) breathing at the air-water interface of the first pool of Lafayette Blue Spring.  Small fish like mosquitofish (Gambusia holbrooki) often perform this behavior in low oxygen conditions, but I had not seen sunfish breathing at the surface this way.  Mosquitofish are better suited anatomically for this behavior because the top of their heads are flat.

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Female mosquitofish–photo by Missy Gibbs.

sunfish in second pool

Not all of the fish appeared so stressed.  This juvenile sunfish was clearly not gulping air at the surface.  The bubbles on the algae are supersaturated oxygen.  The water cannot absorb the oxygen as fast as the algae are producing it.  The string and float help me find my camera; I usually try to keep them out of the videos…

Overall, the density of fish at Lafayette Blue Spring was comparable to other springs that I visited, even with my probable low estimate due to the poor water clarity.  However, the diversity of fish was lower than any other spring that I have visited.  My diversity estimate is probably artificially low because of the water clarity issue, but I think that the diversity honestly was really low in this spring.  Low diversity would not be surprising given the low oxygen concentrations; many fish would not be able to persist at concentrations that low.

Despite the low oxygen and poor water clarity, my visit to Lafayette Blue Spring was lovely.  I stayed in one of the cabins on the property (which are very nice!) and I was able to experience the spring at dawn and dusk.  I had not realized the full extent of how peaceful a spring can be until I went down there at dawn and dusk.  I was told that the spring can get quite crowded in the summer and the reinforced wall on the side of the second pool was like an echo of summer crowds.  In a way, it made my time there all the more peaceful.

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A retaining wall on the bank of the second pool keeps the many summer visitors from causing the bank to cave in.

The Suwannee River at dusk and dawn was amazing, too.

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The Suwannee River upstream of Lafayette Blue Spring just before dusk.  I was playing with the color filters on the camera.

suwannee river at dawn

The Suwannee River downstream of the spring at dawn.  The float line represents the edge of the swimming area for the spring.

Volusia Blue Spring, Volusia County, March 2017

Volusia Blue Spring is like home.  I have dodged happy, tube-wielding swimmers in summer and overly-friendly manatees in winter.  I have seen the sunlight stealing into the boil over the trees along its edge in the early morning and the long rays of the setting sun streaming up the run from the direction of the river at dusk.  I have seen the spring steaming in winter; winter is actually my favorite time in the spring.  I have watched rain hitting the water from under the surface; rain drops look like diamonds hitting the water.  I have looked up through the iced tea-colored St Johns River water as it slips over the spring water in the fall when the river is full from the fall rains and the river water is warmer than the spring water.  Probably anyone who has worked on Florida springs has had similar experiences. I have seen impossibly small newborn least killifish (Heterandria formosa) and surprisingly large longnose gar (Lepisosteus osseus).  I have seen more blue tilapia (Oreochromis aureus) and exotic catfish (Pterygoplicthys disjunctivus) than I ever wanted to see.  After visiting all of these other springs, I realized how much I value Volusia Blue.

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My happy selfie at the boil of Volusia Blue Spring.

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Volusia Blue Spring run, looking up from the St. Johns River early in the morning.

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The Volusia Blue Spring headspring with a large tree that fell into the run a few years ago.  The vent itself is just past the tree.

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Another shot of the headspring with a little blue heron (that I probably started) flying over to the bank on the left side of the photo.

Volusia Blue Spring is the largest spring on the St. Johns River with a historical average discharge of 157 cfs (its discharge is a little below that now).  Like many of the springs of Florida, it supports a lot of tourism, but the only permanent human elements that intrude on the spring are a set of stairs near the headspring and a big metal swim dock a little more than halfway down the run.  It is managed for swimmers and picnickers in the summer, for manatees in the winter, and for divers year round.

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The vent.  I took this photo years ago, but it shows the long, thin vent.  The big springs on the Suwannee, Manatee, Fanning, and Troy, have more circular vents.  In the summer, there are many more swimmers than shown in this photo.

divers' bubbles

Bubbles from divers in the cave streaming around the tree in the vent at Volusia Blue Spring.  As the divers move through the cave, the bubbles will sometimes seem to come from nowhere, from the sand on the side of the headspring, because the cave travels horizontally so divers can be under foot even when you’re not over the vent.  In this photo, the divers were coming up so there were a lot of bubbles coming out of the vent itself.

Video of the vent with divers’ bubbles.  I thought that that they were prettier in motion than in the still.

Like most of the St. Johns River springs (and probably springs all over Florida), municipal and agricultural water use threatens the maintenance of the discharge for the spring.  It seems like the balance of those two uses differ in the St. Johns River and the Suwannee River springs; I think that the St. Johns springs are more threatened by municipal water use and the Suwannee springs are more threatened by agricultural water use, given the landscapes around the springs.  To protect the discharge in the St. Johns River springs, the SJRWMD (St. Johns River Water Management District) has set a minimum flow level for Volusia Blue Spring that matches its historical mean (the other St. Johns springs minimum flows have been proposed for up to 15% reduction of their historic means) to maintain critical habitat for the Florida manatee (Trichechus manatus).  And manatees flock to the spring in ever greater numbers; this past year the short and wide spring run (~30 m x 650 m) hosted 533 manatees with 50 calves (http://www.savethemanatee.org/cam_manatee_reports.html).  Unfortunately, the other springs on St. Johns River do not have the protection of a large, noticeable, popular threatened species.

These juvenile manatees nursing on their mother made it to the “cutest twin animals” page for the Daily Rattle (http://www.dailyrattle.com/cutest-twin-animals-15-images/).  Too bad that they’re not twins!  The one on the right is clearly older; manatees stay with mothers for one to two years, so the one on the right was probably last year’s calf.  It does not appear that that individual has been in the run for very long; the exotic armored catfish (Pterygoplichthys disjunctivus) usually clean them off by grazing on their backs pretty quickly and that one clearly has algae on its back.

Although the discharge target for the minimum flow was set for its historic mean, the spring is not there yet; the last year for which I had a complete data set (Sept 2014 – Sept 2015), the discharge was ~142 cfs.  According to the MFL (minimum flow and level) program, the target was not supposed to be achieved until 2024.  Hopefully, we will get there.  The nutrient concentrations of Volusia Blue Spring also differ from the Suwannee River springs, which tend to be extraordinarily high for nitrate, but moderate for phosphate.  Volusia Blue, on the other hand, has moderate (although increasing) nitrate concentrations (~0.8 mg/L) and slightly high phosphate concentrations (~0.075 mg/L) than the Suwannee springs, according to SJRWMD (http://www.sjrwmd.com/springs/blue-volusia.html).  The difference may be due to the landuse around Volusia Blue, which tends to be municipal rather than agricultural.

blue spring aerial

Google Earth image of the landscape around Volusia Blue Spring.  Although there are large green spaces along the St. Johns River to the west and in the lower lying areas to the east, the springshed is comprised of the lower half of DeLand, Orange City, and most of Deltona rather than these green spaces.  The springshed sits on the “DeLand Ridge”, which is high ground and great for building, hence the location of our towns.

Algae can grow pretty thick in Volusia Blue at times, but I have now seen many springs on the Suwannee that support much larger algal populations–even in winter.  Last winter, I tried to get some algae for a student project in Volusia Blue and I was unable to find much of anything.  No doubt the 500+ manatees affected the algal population size, if only by sitting on it, but still.  The exotic armored catfish (P. disjunctivus) and blue tilapia (O. aureus), both of which can be much more abundant than manatees, also likely reduce algal population sizes, as do people. In the spring, I can always tell when they open the swimming area after manatee season because there is a strip of sand down the middle of the run from people’s feet dislodging the blanket of algae where they walk most often.

The stripe

The edge of the stripe that forms as people walk on the bottom of the spring.  It forms each year after the park opens the spring to swimmers.

I always thought that it was funny when I heard people say that there weren’t any fish in Blue Spring (you overhear all kinds of things while sampling) because there are millions of fish if you look.  There are gradients in fish abundances along the length of the run, from the headspring to the St. Johns river, following the oxygen gradient.  At the headspring, the oxygen is incredibly low; the dissolved oxygen in the water coming out of the vent is 0.1 mg/L, which is essentially nothing.  As a result, most of the fish at the headspring are the small mosquitofish (Gambusia holbrooki) and sailfin mollies (Poecilia latipinna) that can breathe at the air-water interface where the water is more oxygenated.  During our surveys, we often observed some scattered sunfish (Lepomis sp.) in some bushes on the bank of the headspring where some algae accumulates, but not really anywhere else.  However, in the videos I discovered fish that were in more open areas, but working really hard to breathe.

Video of sunfish breathing at the headspring.  When they were not breathing at the surface, it appeared that they were working really hard, holding their opercula (the flaps over their gills) out farther than normal and moving them faster.  I’m not sure when I’ve seen fish work so hard to breathe.  Mosquitofish and sailfin mollies are breathing at the surface in the background.

A little further down the run near the diver entry, the oxygen concentration is typically a bit higher (it was 1.15-1.32 mg/L when I visited in the morning) and the small fish diversity typically increases to include more killifish (Lucania spp., Fundulus spp.), shiners (Notropis spp., Notemigonus crysoleucas), and sunfish (Lepomis spp.).  Occasional largemouth bass (Micropterus salmoides) pass through.  However, I discovered a large number of juvenile sunfish breathing at the surface.  Up until then, I did not even realize that that was a sunfish behavior.

sunfish surface breathing

Sunfish (bluegills, Lepomis macrochirus, and redear, Lepomis microlophus) downstream of the headspring of Volusia Blue Spring.  These sunfish appeared to be interested in the camera, but those in the background are breathing at the surface.

largemouth at site 2

The same location with a largemouth bass cruising through an aggregation of sunfish and seminole killifish (Fundulis seminolis– not apparent in this still, but in the footage right before the bass comes in).

Further still down the run in the refuge, the sunfish get larger and longnose gar become abundant.  The gar can be so large that they can be almost as long as Missy Gibbs is tall (she’s not short), which is how I evaluate how big they are while snorkeling with her.  Mullet (Mugil cephalus) and blue tilapia cruise up and down the run.  In the winter, small tarpon (Megalops atlanticus) invade the run.  Whereas the gar literally just hang there while we swim past, the tarpon are very skittish and freak out when we approach (and then sometime follow us, which is a little creepy).  Alas, there were no tarpon on the day that I visited the spring with cameras.

Video of gar and armored catfish in the refuge below the swimming area.  The armored catfish usually stick close to the bottom, but this one appeared to be following the gar.  The spring is much deeper in the refuge, so the footage appears blue.

The most dramatic event of the trip, after I had downloaded the footage, was the discovery of a cichlid that was not reputed to be in the St. Johns River drainage basin.  Given that I found this black acara (Cichlasoma bimaculatum) in 14 minutes of footage, there are likely to be many others.

black acara

A black acara near the small spring that enters the run about 1/3 of the distance from the headspring to the St. Johns River.

acara map

The distribution of the black acara in March 2017 (it goes farther north now, alas).

In addition to potential reductions in discharge, increases in nutrient concentrations, and invasions of exotic species, Volusia Blue Spring has an erosion problem.  This problem, at least at the headspring, is largely human-made.

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This bank was not nearly as steep when Missy Gibbs and I started working here in 2000.  The park had to move the overlook in the background further back in the early 2000s because the previous one was going to fall into the spring.  Kids climb the bank and jump off.  Enough said.

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That palm tree was not that far out into the headspring years ago (if I remember correctly, it was on the bank!).  The tree that protrudes across headspring in the background fell in due to erosion.  Kids like to sit on it now.  The eroded bank is visible behind the tree.  That bank, like the bank under the overlook, has been falling in for years.  Sigh.

Hornsby Spring, Alachua County, March 2017

Hornsby Spring (near High Springs on the Santa Fe) was one of the most unusual springs that I visited, although I am afraid that I might have missed the best part (more on that later).  The spring was not originally on my list of springs to visit, but the Director of Camp Kalaqua, which surrounds the spring, graciously allowed me access to the spring on short notice.

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The headspring of Hornsby Spring.  The large jumping pillow is on the right side of the vent.

I decided to visit it after one of my colleagues told me that I should see it because of its unusual history.  Even now, I do not know the full story of the spring, but Craig Pittman, the springs’ advocate and outspoken Tampa Bay Times reporter, mentioned Hornsby Spring at the outset of his 2012 article on vanishing springs (http://www.tampabay.com/news/environment/water/floridas-vanishing-springs/1262988).  According to the article, people flocked to the spring in the 1950s to dive down into its 80 foot-deep boil.  However, in the 2000s the flow declined until it stopped flowing, the water level dropped until the boil was only 50 feet deep, and the camp built a water park to give the campers an alternative swimming spot.  As I drove through the well-kept and extensive camp, I was expecting no flow, no fish, no snails.  Once I got there, however, there was flow, albeit low.  I downloaded SRWMD data on historical flow for Hornsby to get a better picture of its flow history:

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The discharge history of Hornsby Spring.  The discharge has been highly variable even as far back as the 1970s, but the spring stopped flowing for extended periods in 2001, 2002, and 2012.

The entire vent area of the spring was blanketed with algae, much of it dead and decaying so that it came apart in my hands.  I did not notice a boil, which would be obvious at a discharge of 250 cfs for that size of a vent (250 cfs is higher than any of the springs that I visited with the exception of Rainbow Springs).  Although the nitrate concentration was only 0.51 mg/L the last time that it was measured by SRWMD (http://www.mysuwanneeriver.org/portal/springs.htm) in January 2017, which fairly low, the phosphate concentration was 0.07 mg/L, which is a pretty high.  The high phosphate may be the culprit in the algal accumulation.

 

The Hornsby headspring.  It was overcast that day and the combination of no direct sunlight and algal coverage made the vent inscrutable from above.  It is a bit clearer on the underwater footage.  This spring also looked like a good candidate for a sea monster coming out of the depths.

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Dead algae on the edge of the headspring. When I tried to pick some up, it came apart in my hand.

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An algal mat just below the headspring.  This algae also looked dead, but I did not try to pick it up.

However, once I left the headspring, the run was shallow and the water velocity was appreciable.  When a volume of water is forced through a smaller cross-sectional area (like moving from a deep headspring to a shallow run), the velocity of the water increases.  And, although there was a lot of algae downstream as well, a significant proportion (much more than I expected) of the spring run substrate was covered with native plants waving in the flow instead of algae.  Oddly, this spring is one of the only springs at which I have seen this plant (possibly Potamogeton) and it was all over the place.

 

Plants in the Hornsby Spring run.

Perhaps my introduction would suggest that I did not enjoy my trip to Hornsby and, in truth, I did not really expect to enjoy it.  However, the spring run has a stark beauty.  I tend to gravitate to narrow runs with a lot of tree cover and Hornsby Spring has both of those characteristics.  The spring is lined with cypress trees and it is lovely.

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The Hornsby run.  I was not expecting the beauty of this run.

Ah, but why did I call it stark beauty?  The photo above just looks beautiful.  However, a closer look at the trees reveals that the bases of the cypress trees were somewhat disfigured and many were leaning awkwardly.  There also were a surprising number of downed trees, not as evident in this particular photo.

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The knobby base of a cypress tree with its leaning partners.  Many trees along the banks were leaning or had fallen over (more than other, similar springs?).

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A close up of the irregular surface of the base of a cypress tree.

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The roots of this tree were rotted and I could see through it.

I floated downstream in this somewhat ghostly-feeling run (due to all the leaning and downed trees) until I reached this fallen tree house.  Strangely, I was thinking of childrens’ stories as I floated.  The knobby and rotted cypress trees made me think of a forest of elves from the Lord of the Rings.  This fallen tree house made me think of Robinson Crusoe or some weird Peter Pan.

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A fallen tree house about half or 1/3 of the way down the run.

Alas, just on the other side of this tree house, which was on a little island that divided the flow in the run, there was a float line (the type used to designate swimming areas).  Exotic water hyacinth had built up along this line and I could not get my kayak through it, try as I might.  I considered portaging around the blockage because a) I wanted to get to the Santa Fe and b) I am just that compulsive, but when I climbed out and walked around the blockage on land, it was peppered with cypress knees and I decided that it would be a miserable portage.  Oddly, most of the cypress knees that I stepped on by accident bent under my feet, further contributing to my feeling that I was in a ghost forest.  Instead, I thought that I could go out to the Santa Fe and paddle upstream to the blockage so that, in that way, I could see the whole run.

When I turned around to do my tripod filming, I discovered that, indeed, there were fish.  There were a lot of largemouth bass (Micropterus salmoides) and sunfish (Lepomis sp.) around debris from the tree house at the blockage.  On the other bank, there were loads of mosquitofish (Gambusia holbrooki), sailfin mollies (Poecilia reticulata), and bluefin killifish (Lucania goodei).

 

Bass and sunfish around debris from the collapsed tree house.

 

Small fish on the bank opposite the collapsed tree house.  The float line clogged with water hyacinth obstructed the surface flow producing eddies in the trapped water.

And, while waiting for my camera, I also discovered that there were loads of tiny snails in the run.

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Hydrobiid snails dotting the algae in Hornsby Spring run.

In the end, I captured 14 species of fish on video, which is comparable to many other springs that have a healthier history, and 29 individuals per video segment.  This number also is comparable to many of the other spring runs that I have visited.  I was really surprised (pleasantly).

Once I finished my filming, at least as far as I was able to go with the obstruction, I went back to the camp office and spoke with the very helpful security guard.  In the course of a conversation about whether there was a boat ramp that would let me access the spring from the river without a day-long paddle, he told me that Hornsby Spring has a whirlpool just downstream of where I was stopped by the water hyacinth.  The prospect of a whirlpool really cemented my desire to see the rest of the run, so I drove down the road and put in on the Santa Fe River.  I paddled upstream for an hour, both into the current and into the wind, but alas, the most that I found were two impassable beds.  I suspected that one of the two non-flowing outflows was Hornsby Spring.  Perhaps all of the discharge went down the whirlpool…  Sigh.  At least it only took my half an hour to get back.

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Perhaps the outflow location of Hornsby Spring on the Santa Fe River.  I so wanted to find that whirlpool…