Coastal development impacts on biological Coastal development impacts on biological communities in the Chesapeake Baycommunities in the Chesapeake Bay

Examples from the Atlantic Slope ConsortiumExamples from the Atlantic Slope Consortium

R-82868401

Cast of many…

Smithsonian Environmental Research Center (SERC): Bill Deluca, Pete Marra, Don Weller, Tom Jordan, Tuck Hines, Chuck Gallegos, Ryan King, Matt Baker

Virginia Institute of Marine Science (VIMS): Donna Marie Bilkovic, Carl Hershner, Molly Roggero

Penn State University: Rob Brooks, Denice Wardrop

Atlantic Slope Consortium (ASC) = An Estuarine Indicator Research Atlantic Slope Consortium (ASC) = An Estuarine Indicator Research ProgramProgram

Goal: To develop a suiteof ecological and socioeconomic

indicators for assessingand managing the condition

ofthe vital resources in the

Mid-Atlantic region

Coastal development leads to disruption of ecosystem services…Coastal development leads to disruption of ecosystem services…

Coastal development and deforestation

reduce the filtration capacity of the riparian zone which impacts the

littoral zone

Loss of ecosystem Loss of ecosystem function and function and

structure due to structure due to coastal developmentcoastal development

Developed=Broken Links

Littoral

Shoreline

Biota

Littoral

Shoreline

Biota

Natural System

Water clarityDOTerrestrial inputsAquatic vegetation

Wetland lossForest lossNutrient input

BiodiversityFunctional groupsResilience

Broken Links lead to decreases in

biodiversity and functional groups

that reduce resilience, and the

ability of the communities to

respond to external drivers such as climatic events

• ““Estuarine Estuarine segments”: segments”:

Watersheds and Watersheds and subestuaries of a subestuaries of a larger estuarine larger estuarine

ecosystemecosystem

• Segment land-Segment land-use ranges from use ranges from

forested to forested to highly highly

agricultural or agricultural or developeddeveloped

ASC Goal: to identify linkages between patterns of ASC Goal: to identify linkages between patterns of land use and environmental indicators in estuarine land use and environmental indicators in estuarine

habitats.habitats.

Developed

Agricultural

Mixed-Developed

Mixed-Agricultural

Forested

IndicatorIndicator WatershedWatershed Local land useLocal land use

Stream nutrientsStream nutrients XX

Stream Stream macroinvertebratemacroinvertebrate

ss

XX XX

Estuarine water Estuarine water qualityquality

XX

Benthic IBIBenthic IBI XX XX

Fish IBIFish IBI XX XX

PhragmitesPhragmites abundanceabundance

XX XX

Blue crab Blue crab abundanceabundance

XX XX

PCB in White PCB in White perchperch

XX

Waterbird IBIWaterbird IBI XX XX

Wetland Bird IBIWetland Bird IBI XX

SAV abundanceSAV abundance XX

Potential environmental indicators of the health of Potential environmental indicators of the health of the Baythe Bay

Available subtidal habitat

Abundant Moderate Low

Fish

Com

mun

ity

Inde

x (F

CI)

0

1

2

3

4

5

6

7

Amount of Alterations to Shoreline

Minimal Moderate High

Fish

Com

mun

ity

Inde

x (F

CI)

0

1

2

3

4

5

6

7

Higher FCI scores were associated with increasing

abundance of subtidal habitat

FCI scores were lower at sites with highly altered shorelines versus natural

shorelines.Bilkovic et al. 2005

p<0.001; all different p=0.003; High vs. Minimal

Fish Communities and HabitatFish Communities and Habitat

r2 = 0.61, P < 0.001

% Developed Land in Watershed

0 20 40 60 80

Phragmites

abu

nd

ance

est

imat

e

0

1

2

3

4

5

6

7

DevelopedMixed-DevAgriculturalMixed-AgForested

r2 = 0.61, P < 0.001r2 = 0.61, P < 0.001

% Developed Land in Watershed

0 20 40 60 80

Phragmites

abu

nd

ance

est

imat

e

0

1

2

3

4

5

6

7

DevelopedMixed-DevAgriculturalMixed-AgForested

Whigham et al. 2005

Invasive Species and DevelopmentInvasive Species and Development

y = 10.3e0.067x

R2 = 0.77

1

10

100

1000

0 20 40 60 80

Percent Developed Land in Watershed

To

tal P

CB

s in

Wh

ite

Pe

rch

(n

g/g

)

1 meal/mo

0.5 meal/mo

no consumptionrecommended*

Developed

Agricultural

Mixed-Developed

Mixed-Agricultural

Forested

y = 10.3e0.067x

R2 = 0.77

1

10

100

1000

0 20 40 60 80

Percent Developed Land in Watershed

To

tal P

CB

s in

Wh

ite

Pe

rch

(n

g/g

)

1 meal/mo

0.5 meal/mo

no consumptionrecommended*

Developed

Agricultural

Mixed-Developed

Mixed-Agricultural

Forested

Developed

Agricultural

Mixed-Developed

Mixed-Agricultural

Forested

Total PCBs in white perch in relation to percent developed land in the watershed. USEPA (1999) guidelines for cancer

health endpoints.

King et al. 2004

White Perch and PCBsWhite Perch and PCBs

Juvenile blue crabs (< 3 in) were most abundant at sites with extensive shoreline wetlands, forested watersheds, and sub-estuaries with average salinity > 16 ppt.

King et al. 2005

Juvenile Blue Crabs and HabitatJuvenile Blue Crabs and Habitat

Developed riparian land use (%)0 20 40 60 80 100

Cu

mu

lati

ve p

rob

abil

ity

of c

han

ge p

oin

t

0

20

40

60

80

100B

IBI

in t

he

Nea

rsh

ore

0

1

2

3

4

5

6

Negative macrobenthic community responses occurred when developed shorelines were 10% or higher.

Cumulative Probability Curve

Changepoint AnalysisChangepoint Analysis——Assessing Ecological ThresholdsAssessing Ecological Thresholds

Bilkovic et al. 2006

King et al. 2005

Cu

mu

lati

ve P

rob

ab

ility

of

A

Th

resh

old

Str

eam

macr

oin

vert

eb

rate

dis

sim

ilari

ty

score

s

Increasingly positive scores=more diverse,

pollution-sensitive taxa

Increasingly Negative score = taxa associated with impaired streams

Development appeared to have its greatest

effect on stream macroinvertebrates when close to the

sampling station, where it contributes to

riparian degradation and reduced woody-

debris input.

21-32% Dev. threshold

1-22% Local Dev. threshold

Stream Macroinvertebrates and DevelopmentStream Macroinvertebrates and Development

Mar

sh B

ird

Co

mm

un

ity

Inte

gri

ty

Low

High

Percent Development within 500m of a Wetland

0 25 50

100

0

50

Cu

mu

lati

ve P

rob

abili

ty o

f a

Th

resh

old

Occ

urr

ing

Mar

sh B

ird

Co

mm

un

ity

Inte

gri

ty

Low

High

Percent Development within 500m of a Wetland

0 25 50

100

0

50

Cu

mu

lati

ve P

rob

abili

ty o

f a

Th

resh

old

Occ

urr

ing

When 15% of the land within 500 m of a marsh was developed there was a significant decline in Marsh Bird

Community Integrity.

Marsh Bird Integrity and DevelopmentMarsh Bird Integrity and Development

DeLuca et al. 2004

Sources (SERC; VIMS): Dennis Whigham, Donna Marie Bilkovic, Ryan King, Bill Deluca, Peter Marra,

Matt Baker, Don Weller, (Figure from Dennis Whigham) Threshold analyses: Qian et al. 2003 (Ecol. Mod.); King and Richardson 2003 (Env. Man.)

1 5 10

15

20 25 30

35

40

45

50

55

60

65

70

76

80

85

90

95

10

0

0

0.2

0.4

0.6

0.8

1

Pro

ba

bil

ity

of

Ch

an

ge

% Development

Invert IBI

Phrag abundance

Water bird index

Wetland bird index

Benthic IBI

Ecological Thresholds of CommunitiesEcological Thresholds of Communities

YES--Our research indicated that structural and functional changes in biological communities

occurred in relation to alterations in subtidal habitat, shoreline condition, and/or land use.

Do Biota Respond to Variations in Nearshore Condition?

► Both the amount of development and its proximity to the estuary or wetland contributes to degradation of aquatic resources.

►In general, > 20% development (at local and/or watershed levels) was related to shifts in biological communities (indicators), revealing possible ecological thresholds

►Forest buffers were also noted to reduce sediment and nutrient loads along stream corridors or around wetlands

►In many instances, local development had stronger links with the aquatic resource than watershed development

FINAL ASC REPORT ONLINE: http://www.asc.psu.edu/public/pubs/_Final%20Report_AtlanticSlopeConsortium.pdf

SUMMARYSUMMARY