A Quick Note to Teachers:• The following is meant to serve as a basic

overview of Georgia salt marshes, impervious surfaces, and remote sensing. It is designed to precede the associated Remote Sensing Lab.

• Remote sensing research photos are proprietary. However, teachers can access and use some of these great images via the links provided in the Notes Section of this PowerPoint.

SALT MARSHPart I

What is an Estuary?

• Estuary: A partially enclosed coastal embayment where fresh water and seawater meet and mix.

What is a Salt Marsh?

• A salt marsh is one component of an estuary system

• Salt Marsh: Communities of emergent vegetation rooted in soils alternately inundated and drained by tidal action.

• One prominent example of this “emergent vegetation” is Spartina alterniflora.

Georgia’s CoastGeorgia’s Coast• Why are there so many salt marshes on

Georgia’s coast?

– Low elevation

– Large tidal range / The Georgia Bight

– Sediments

• Why are there so many salt marshes on Georgia’s coast?

– Low elevation

– Large tidal range / The Georgia Bight

– Sediments

Why are Salt Marshes Important?• Habitat– Nursery habitat for blue crab, sharks, shrimp, fish, etc.– Permanent home for Spartina, fiddler crabs, etc.

• Productivity– Bacteria breaks down wrack into

detritus– This decompositions produces hydrogen

sulfide (the rotten egg smell).

Why are Salt Marshes Important?(Continued)

• Water Quality– Water is filtered through grasses, roots, and soil– Filter feeders (like mussels and oysters) also filter

the water)

• Flood/Erosion Control– Marshes act like giant sponges on the coast,

absorbing water and releasing it slowly.

Why are Salt Marshes Important? (Continued)

• Recreation– Kayaking, fishing, crabbing, boating, birding

• Economy– Fishing industry– Jobs in education, conservation, recreation, etc.

IMPERVIOUS SURFACES & OTHER THREATS

Part II

Coastal Development

• As more people live near the coast, human impact on the marsh increases.– Marine debris– Runoff from parking lots– Rising sea levels

• Humans need a place to live, but salt marshes are an important habitat. How can we balance these needs?

Impervious Surfaces

• Impervious Surfaces: anything that prevents water from soaking into the ground

• Examples: parking lots, paved roads and paths, driveways, rooftops, etc.

Impervious Surfaces(continued)

• Impact on Marsh:– Ground cannot absorb/filter

surface water– Rate of runoff increases– Runoff often ends up in the

marsh

• Common Pollutants in Runoff:– Oil– Heavy Metals– Fertilizer– Human and animal waste

Possible Solutions• Semi-Permeable Trails

• Riparian Buffers

REMOTE SENSINGPart III

Remote Sensing• Remote Sensing: The science of identifying,

observing, and measuring an object without coming into direct contact with it.

• Have you ever used remote sensing?

Common Remote Sensing Strategies

• Aerial photos and satellite images

• Thermal

• Microwave

Why is Remote Sensing Useful in Scientific Research?

• Low impact on the study area

• Can detect and measure some phenomena that are difficult to see with the naked eye

GIS and Google Earth

• GIS: Geographic Information Systems