QUANTIFYING MACROALGAE, SUBMERGED AQUATIC VEGETATION, AND FLOW IN FOUR FLORIDA SPRING-FED RIVERSLAURA BEDINGER1, DANIELLE ROGERS2, BARRY VANCE1 AND JORDAN MILLER2

1WATER & AIR RESEARCH, GAINESVILLE, FL, USA

2SWFWMD, BROOKSVILLE, FL USA

SUBMERGED AQUATIC VEGETATION (SAV)

• vascular plants and a moss• macrophytic algae (both filamentous and complex)

• Limiting Factors:• light • salinity• water velocity

• substrate type• nutrients (N and P)• biotic interactions

• Water & Air Research, Inc. sampled SAV and abiotic factors for SWFWMD

• Spring-fed rivers- all 1st

magnitude

• Homosassa, Chassahowitzka, and Weeki Wachee all flow into the Gulf of Mexico

• Rainbow flows into the Withlacoochee

Chassahowitzka – 25 transects

Homosassa – 26 transects

Rainbow River – 28 transects

Weeki Wachee – 21 transects

• established transects w/ sub-meter GPS

• 5 stations per transect• 0.5 x 0.5 m quadrats*

• cover• biomass• substrate type• tree canopy cover

• photo & video• GPS-paired full motion

• water velocity (Hach FH950)• water quality• Survey 123 for ArcGIS

Methods

Biomass by Taxon, All RiversNon-metric MDS on Station Data

Transform: Square rootResemblance: S17 Bray-Curtis similarity (+d)

RiverChassahowitzkaHomosassaRainbowWeeki Wachee

2D Stress: 0.17

ANOSIM RESULTS (PRIMER 7)

Comparison R Statistic p-valueChassahowitzka, Homosassa 0.173 0.0001Chassahowitzka, Rainbow 0.335 0.0001Chassahowitzka, Weeki Wachee 0.074 0.0001Homosassa, Rainbow 0.586 0.0001Homosassa, Weeki Wachee 0.203 0.0001Rainbow, Weeki Wachee 0.339 0.0001

00.

25 0.5

0.75 1

1.5 2

2.5 3

3.5 4

4.5 5

5.2 5 5.

5 66.

5 77.

25 7.5 8

8.5 9

9.5 10

Transect

0

0.1

0.2

0.3

0.4

0.5

0.6

Wat

er V

eloc

ity (m

/s)

WATER VELOCITY RESULTS

0.5

0.75 1

1.25 1.

5 22.

5 33.

153.

253 .

35 3.5 4

4.5 5

5 .5 6

6.5 7

7.5 8

8.5 9

9.5 10

10.5

Transect

0

0.1

0.2

0.3

0.4

0.5

0.6

Wat

er V

eloc

ity (m

/s)

HomosassaChassahowitzka

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Transect

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

Wat

er V

eloc

ity (m

/s)

WATER VELOCITY RESULTS

Rainbow River

0.5 1

1.5 2

2.5 3

3.5 4

4.5 5

5 .2 5 5.

5 6

6.5 7

7.5 8

8.5 9

9.5 10

Transect

0

0.1

0.2

0.3

0.4

0.5

0.6

Wat

er V

eloc

ity (m

/s)

Weeki Wachee

SAV FINDINGS (SUMMER 2019)• vascular plants: 13 taxa• moss: Fontinalis spp.• complex macrophytic green algae: Chara spp. (stonewort)• filamentous green algae• filamentous cyanobacteria• red seaweeds: Gracilaria, Compsopogon, Caloglossa

C. Harding, Water & AirC. Harding, Water & AirMarine Algae of Hawaii

VASCULAR SAV TAXA (SUMMER 2019)

Cabomba caroliniana Najas guadalupensis

Ceratophyllum demersum Potamogeton pusillusHydrilla verticillata Sagittaria kurzianaLudwigia repens Stuckenia pectinataMyriophyllum heterophyllum Utricularia sp.Myriophyllum spicatum Vallisneria americana

Chassahowitzka

total dry weight

upstream to downstream

August 2019

00.

25 0.5

0.75 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 66.

5 77.

25 7.5 8

8.5 9

9.5 10

Transect

-100

0

100

200

300

400

Tota

l DW

(g/m

2)

Chassahowitzka

vascular plants & moss

upstream to downstream

August 2019

00.

25 0.5

0.75 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 66.

5 77.

25 7.5 8

8.5 9

9.5 10

Transect

-100

0

100

200

300

400

Tota

l Pla

nt D

W (g

/m2)

Chassahowitzka

filamentous algae

upstream to downstream

August 2019

00.

25 0.5

0.75 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 66.

5 77.

25 7.5 8

8.5 9

9.5 10

Transect

-50

0

50

100

150

200

250

300

350

400

filam

ento

us a

lgae

DW

(g/m

2)

Chassahowitzka

SWFWMD

upstream to downstream in study area

monthly data

2018 - 2020

Chassahowitzka

• most diverse• some marine influence• moderate level of vegetation• most vegetation in upper third of study

area

Homosassa

total dry weight

upstream to downstream

August 2019

Homosassa

vascular plants & moss

upstream to downstream

August 2019

0.5

0.75 1

1.25 1.

5 22.

5 33.

153.

253.

35 3.5 4

4.5 5

5.5 6

6.5 7

7.5 8

8.5 9

9.5 10

10.5

Transect

0

10

20

30

40

50

60

70

80

90

100

Tota

l Pla

nt D

W (g

/m2)

Homosassa

filamentous algae

upstream to downstream

August 2019

0.5

0.75 1

1.25 1.

5 22.

5 33.

153.

253.

35 3.5 4

4.5 5

5.5 6

6.5 7

7.5 8

8.5 9

9.5 10

10.5

Transect

-20

0

20

40

60

80

100

filam

ento

us a

lgae

DW

(g/m

2)

Homosassa

SWFWMD

upstream to downstream in study area

monthly data

2018 - 2020

0.5

0.75 1

1.25 1.

5 22.

5 33.

153.

253.

35 3.5 4

4.5 5

5.5 6

6.5 7

7.5 8

8.5 9

9.5 10

10.5

Transect

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0H

ydril

la v

ertic

illat

a D

W (g

/m2)

• least vegetated• 3rd in taxa richness• upstream third has the most biomass• marine influence

Homosassa

00.

25 0.5

0.75 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 66.

5 77.

25 7.5 8

8.5 9

9.5 10

Transect

-4

-2

0

2

4

6

Gra

cila

ria s

p. D

W (g

/m2)

Homosassa

Gracilaria sp.

occurred mid-way of study area

same pattern in the Chassahowitzka

2.5 pptHoyer et al. 2004

Rainbow River

total dry weight

upstream to downstream

August & September 2019

1 2 3 4 5 6 7 8 9 10 11 12 13 1 4 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Transect

-500

0

500

1000

1500

2000

Tota

l DW

(g/m

2)

Rainbow River

vascular plant and moss

upstream to downstream

August & September 2019

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Transect

-500

0

500

1000

1500

2000

Tota

l Pla

nt D

W (g

/m2)

Rainbow River

filamentous algae

upstream to downstream

August & September 2019

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Transect

-100

0

100

200

300

400

500

600

700

800

900

1000

1100

1200

1300

1400

1500

1600

1700

1800

1900

2000

filam

ento

us a

lgae

DW

(g/m

2)

Rainbow River

SWFWMD

upstream to downstream in study area

monthly data

2018 - 2020

Rainbow River

• Sagittaria kurziana drives differences

• shows opposite pattern to other rivers with more filamentous algae downstream than upstream

• more consistently vegetated

1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28

Transect

-500

0

500

1000

1500

Sagitta

ria kur

ziana

DW (g/

m2)

Weeki Wachee River

total dry weight

upstream to downstream

September 2019

0.5 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 6

6.5 7

7.5 8

8.5 9

9.5 10

Transect

-200

0

200

400

600

800

1000

Tota

l DW

(g/m

2)

Weeki Wachee River

vascular plants and moss

upstream to downstream

September 2019

0.5 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 6

6.5 7

7.5 8

8.5 9

9.5 10

Transect

-200

0

200

400

600

800

1000

Tota

l Pla

nt D

W (g

/m2)

Weeki Wachee River

filamentous algae

upstream to downstream

September 2019

0.5 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 6

6.5 7

7.5 8

8.5 9

9.5 10

Transect

0

100

200

300

400

500

600

700

800

900

1000

filam

ento

us a

lgae

DW

(g/m

2)

Weeki Wachee River

SWFWMD

upstream to downstream in study area

monthly data

2018 - 2020

0.5 1

1.5 2

2.5 3

3.5 4

4.5 5

5.25 5.

5 6

6.5 7

7.5 8

8.5 9

9.5 10

Transect

-200

0

200

400

600

800

1000Va

llisn

eria

am

eric

ana

DW

(g/m

2)

Weeki Wachee

• Vallisneria americanadominant in upper portion

• lowest taxa richness

• most vegetation in upper third

• no red algae

Weeki Wachee

AUDIENCE, THANK YOU!THANKS TO COLLEAGUES IN THE BIOLOGY GROUP AT WATER & AIR