Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Tidal Creek Ecosystems: Sentinel Habitats for Assessing and Predicting

the Consequences of Coastal Development and Climate Change

Denise Sanger1,2, Anne Blair1

1 Center of Excellence in Oceans and Human Health

at Hollings Marine Laboratory and

2 S.C. Sea Grant Consortium

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

•  Provide a synthesis of the impacts of coastal development on coastal ecosystems and the humans that live in them.

•  Provide a case study highlighting a current modeling effort – ultimately predicting the impacts of changes in climate and the level of urbanization. •  Changes in precipitation and soil saturation

Objectives of Presentation

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Tidal Creeks Sampled

Over 55 Tidal Creeks Representing Forested, Suburban, and Urban Land Uses

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Creek Continuum

Creek Lengths

1A – 850 m

1B – 850 m

2A – 6400 m

2B – 4600 m

3 – 5800 m A

A B

B

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

0

4

8

12

16

0 10 20 30 40 50 60 70 80

Popu

lation

Den

sity

(ind

hec-

1 )

Impervious Cover (%)

Intertidal Subtidal

R² = 0.82*

R² = 0.90*

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Forested Watershed

Groundwater recharge

Evapotranspiration Rainfall

Subsurface flow

Stormwater Runoff

Developed Watershed Rainfall Evapotranspiration

Stormwater Runoff

Subsurface flow

Groundwater recharge

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Modeled Runoff Volume More rainfall is converted to stormwater runoff in developed watersheds

27%

50%

67%

0

25

50

75

100

Forested Suburban Urban

Run

off

Vol

ume

(mm

)..

WatershedPresent scenario – 24-hr 4.5-in storm event, average runoff conditions

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Projecting Impact of Climate Change

0

25

50

75

100

Forested Suburban Urban

Run

off

Vol

ume

(mm

)..

Watershed

78%

42%

65%

Present scenario – 24-hr 4.5-in storm event, average runoff conditions Climate scenario– 12-hr 5.2-in storm event, semi-saturated runoff conditions

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Water Pathogens vs Impervious Cover Interitdal Subtidal

0

2

4

6

ENT

(log

CFU 1

00 m

l-1)

R2 = 0.33*

R2 = 0.03

0

1

2

3

F+ (log

PFU 1

00 m

l-1)

R2 = 0.40*

R2 = 0.26*

0

1

2

3

4

0 10 20 30 40 50 60 70 80

F- (log

PFU 1

00 m

l-1)

Impervious Cover (%)

R2 = 0.27*

R2 = 0.31*

0

2

4

6

0 10 20 30 40 50 60 70 80

FC (log

CFU 1

00 m

l-1)

Impervious Cover (%)

R2 = 0.24*

R2 = 0.64*

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Charleston Flood Prone Areas

Post and Courier

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

http://www.scseagrant.org/pdf_files/tidal_creeks_booklet.pdf

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Leveraging a NOAA/UNH Science Collaborative Project – PI Erik Smith

Model the loading of Enterococci (indicator bacteria) from surface water discharges along the Grand Strand and relate the findings to the SCDHEC Beach Monitoring Program.

Withers Swash, Myrtle Beach Dogwood Swash, Surfside Beach

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

White Point

Singleton

13th

Ave. S

Floral Surfside

Myrtle

Dogwood 16th Ave N.

Ocean Lakes Beaver Dam Creek

Midway

Withers

Deep Head

Cane Patch

Bear Branch

Grand Strand Swashes

Watersheds are undergoing QA/QC

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Loading •  Event Load = Concentration * Volume

– Measure concentration in runoff and instream •  2 swashes – 6 runoff and 2 instream • Historical data – in runoff and instream

– Model volume •  Current land use •  Potential to add climate and development change scenarios

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory 0

1

2

3

0 10 20 30 40 50 60 70

Run

off

(m3 /s

/km

2 )..

Time (h)

Urban

Forested

Suburban

Prediction Schematic Im

per.

cov

er (%

)

0

20

40

60

80

Basins

(a) Watershed Attributes

(b) Hydrographic Characteristics

(c) Bacterial Indicators

0

1

2

3

4

5

0 20 40 60 80 Impervious cover (%)

ENT

(log

(x+1

) (d) Prediction of Load

(c) Bacterial Indicators

0

1012

Basins

Load

(col

onie

s)

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Relating Runoff to Beach Monitoring

Schematic of relating land sources to beach monitoring

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

192K 248K357K

465K

0

200

400

600

1 10 30 50

Run

off

Vol

ume

(m3 )

..

Thousands

Watershed Impervious Cover Percent

538K

634K

420K351K

Projecting impact of climate change Modeled climate scenario for current and built development levels shows increases in runoff far exceeding precipitation increase

Village Creek watershed – 630 ha Undeveloped - forested

Present scenario – 24-hr 4.5-in storm event, average runoff conditions Climate scenario– 12-hr 5.2-in storm event, semi-saturated runoff conditions

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Interactions/Partnerships

•  North Inlet-Winyah Bay NERR – USC •  Local Municipalities Planning and

Stormwater •  SCDHEC – EQC (WQ, Beach Monitoring,

Watershed Planning) •  SCDHEC – OCRM •  SCDNR

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Needs for Addressing Problem

•  Good climate scenarios –  Precipitation patterns –  Sea level rise and potential impacts on soil saturation

•  Assumption that the concentration will stay the same which don’t know

•  Time to commit to collaboration

Center of Excellence for Oceans and Human Health at the Hollings Marine Laboratory

Questions