Seagrass, algal blooms & thth IRL IRLthe IRL · 50 ~50 ” mg g annual ... Chione sp. (venus clam) 16.3–27.7 °C ... – IRL Symposium 2013IRL Symposium 2013

Seagrass,Seagrass,Seagrass,Seagrass,algal blooms &algal blooms &

th IRLth IRLthe IRLthe IRL

C JacobyC Jacoby

Is the IRL important?Is the IRL important?•• Comprises 3 Comprises 3 waterbodieswaterbodies

St t h 156 ilSt t h 156 ilNew Smyrna Beach

•• Stretches 156 milesStretches 156 miles•• Spans 5 countiesSpans 5 counties

Banana RiverBanana River

Mosquito LagoonMosquito Lagoon

•• National Estuary ProgramNational Estuary Program•• Generates $3.7BGenerates $3.7B

Banana RiverBanana River

Indian RiverIndian River

–– $1.3B recreation$1.3B recreation–– $0.9B real estate values$0.9B real estate values

Indian RiverIndian River

•• Supports 15,000 jobsSupports 15,000 jobs•• Supports > 4 000 speciesSupports > 4 000 species West Palm BeachSupports > 4,000 speciesSupports > 4,000 species

Is seagrass important?Is seagrass important?

•• Ecological rolesEcological rolesgg–– habitat (> 80% of valued fish use)habitat (> 80% of valued fish use)–– food (e.g., manatees)food (e.g., manatees)( g )( g )–– improves water qualityimproves water quality

oo absorb nutrientsabsorb nutrientsoo reduce sediment reduce sediment resuspensionresuspension

Is seagrass important?Is seagrass important?•• Management roleManagement role

l i i d d t t i t l dl i i d d t t i t l d–– lagoon impaired due to nutrient loadslagoon impaired due to nutrient loads–– TMDL & BMAP establishedTMDL & BMAP established

l t i tl t i t l tl t–– lower nutrients lower nutrients clearer waterclearer water–– clearer water clearer water greater light penetrationgreater light penetration

d & i t t li htd & i t t li ht–– seagrass needs & integrates lightseagrass needs & integrates light–– deep edge of meadow = metric of successdeep edge of meadow = metric of success

What does the TMDL mean?What does the TMDL mean?

N th IRLNorthern IRL

Banana Ri er Lagoon

WaterbodyReductionTN TP

River LagoonN-IRL 22% 44%BRL 40% 62%

Central IRL

C-IRL 51% 47%

Central IRL

What does impairment mean What does impairment mean to seagrass?to seagrass?

Seagrass assessment1986 – 1989

How has seagrass been How has seagrass been doing?doing?

2.5

acre

s)

Melbourne

(hec

tare

= 2

rass

cov

er

Vero Beach

Sea

gr

How has seagrass been doing?How has seagrass been doing?

2 500

3,000Port St. John

1,000

1,500

2,000

2,500

Port St. John

2.5

acre

s)

0

500

Eau Gallie (hec

tare

=

600

800

1,000

1,200Eau Gallie

rass

cov

er

0

200

400

600

Sea

g

What led to improvement?What led to improvement?

2.5

acre

s)(h

ecta

res

= ra

ss c

over

(S

eagr

Drought &Vero WWTP discharge

‘04 hurricanessurge & flushing

Mini-drought

Drought &IRFWCD di h

TS Fayflushing

surge & flushing IRFWCD discharge

What led to improvement?What led to improvement?

60

70

Vero Beach – S. Central IRL

~62”30‐yr mean* = 56.6” Inter-decadal

drop of ~12” in moving average ch

es)

20

30

40

50

60~50”

m g gannual rainfall

~20% reduction in watershed e

rain

fall

(in

0

10

20 watershed nutrient loadings

Aver

age

What changed?What changed?

2010 2011 2012

Two phytoplankton (microalgal) blooms

Dec 24Oct 3

2010

Apr 1 July 3

2011

Sep14 Oct 23 Dec 8 Mar 18

2012

Superbloom in the north –record magnitude & duration

2° bloom in CIRL –long duration

What changed?What changed?

What happened to seagrass?What happened to seagrass?

5

88

9

5

88

9

5

88

92009 to 2011 to2010 to-100 -100 200 0-100 200200 00

Percentage gain (green), loss (red) & sustained loss (black)

9

11

13

14

17

19

9

11

13

14

17

19

9

11

13

14

17

19

2009 to2010

2011 to2012

2010 to2011

89

21

22

23

25

28

89

21

22

23

25

28

89

21

22

23

25

28

30

32

34

74

37

39

30

32

34

74

37

39

30

32

34

74

37

39

41

43

45

47

49

51

41

43

45

47

49

51

41

43

45

47

49

51

75

55

75

55

75

55

What happened to seagrass?What happened to seagrass?

•• SeagrassesSeagrasses shadedshadedSeagrassesSeagrasses shadedshaded•• SeagrassesSeagrasses lostlost

lagoonlagoon wide ~ 32 000 acreswide ~ 32 000 acres–– lagoonlagoon--wide ~ 32,000 acreswide ~ 32,000 acres–– BRL ~ 21,000 acresBRL ~ 21,000 acres

NIRL ~ 5 000 acresNIRL ~ 5 000 acres–– NIRL ~ 5,000 acresNIRL ~ 5,000 acres–– CIRL ~ 6,000 acresCIRL ~ 6,000 acres

Why did this happen?Why did this happen?Eutrophication

progressionschemescheme

IncreasedIncreasednutrient deliverynutrient delivery

Enhanced growthEnhanced growthEnhanced growthEnhanced growthphytoplankton &phytoplankton &

macroalgaemacroalgae

Increased shading &Increased shading &benthic respirationbenthic respiration

Seagrass lossSeagrass lossSeagrass lossSeagrass lossAdapted from C.M. Duarte (1995)

Why did this happen?Why did this happen?Following C-1 Canalconstruction

Historical watersheds(Pre-1920s)

B f 572 000

Melbourne‐TillmanWater Control District

Before 572,000 acresAfter 1.4 million acresMore than double!

St. Johns River Basin

Indian River Lagoon Basin

Why did this happen?Why did this happen?1920s          1940s           1970s         1990s

DevelopmentDevelopmentAgricultureNaturalWaterOther

Why did this happen?Why did this happen?

Why did this happen?Why did this happen?600000

Total zooplankton

400000

500000

95%

CL

300000

bers

m-3

±

200000

Mea

n nu

mb

0

100000M

2004 2005 2006 2007 2009 2010 2011

Why did Why did thsths happen?happen?6

V1 V2 V3 V4 V5 V6

4

5

SE

Chione sp. (venus clam)16.3–27.7 °C32 6 37 2

3

4

num

ber ± 32.6–37.2

1

2

Mea

n

0

1

2008 2009 2010 2011 2012Year

Why did this happen?Why did this happen?

25V1 V2 V3 V4 V5 V6

Anomalocardia a beriana20

SE

Anomalocardia auberiana(pointed venus)

10

15

num

ber ±

S

5

10

Mea

n

02008 2009 2010 2011 20122008 2009 2010 2011 2012

Year

What will happen next?What will happen next?

What will happen next?What will happen next?

What will happen next?What will happen next?

•• Seagrass recovery?Seagrass recovery?g yg y•• Repeat of bloom conditions?Repeat of bloom conditions?•• Improve understandingImprove understandingImprove understandingImprove understanding

–– IRL 2011 Scientific ConsortiumIRL 2011 Scientific Consortium–– IRL Symposium 2013IRL Symposium 2013IRL Symposium 2013IRL Symposium 2013–– this symposiumthis symposium

•• “Assist” recovery“Assist” recovery•• Assist recoveryAssist recovery•• Prevent occurrencePrevent occurrence

Thank youThank you

Questions?Questions?