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Salt Marsh Communities
•Found in protected estuarine habitats
• Created by grasses, which stabilize soft sediment substrate
Salt Marshes – Physical Characteristics
•Intertidal habitats
• Lower elevations of salt marsh are usually submerged daily for several hours, while upper border of salt marsh is only submerged once or twice a month.
Salt Marsh-Zonation
• Few species can be good at everything. Salt marsh grasses are usually either good competitors or able to tolerate the physiologically stressful conditions of the low salt marsh.
• Grasses and flowering plants that are good stress tolerators like Spartina alterniflora dominate the low marsh.
Salt Marsh - Distribution
Worldwide
-low seacoasts
-inside barrier bars and beaches
-in estuaries
-on deltas
Salt Marshes Plants & Animals
• Important nursery grounds for many commercially important fishes
• Important feeding and breeding habitat for waterfowl
Plant roots hold the sediment in and are a place for animals to hide.
Uses • Natural filter system Natural barrier against coastal flooding
• Nursery ground for economically important species
• Beautiful!
Human Abuses
• Construction/Development (habitat loss)
• Ditching for mosquito “control”
• Overharvesting of resources
Dominant Animals
• Birds
• Fish
• Invertebrates– Crustaceans– Mollusks
Geukensia demissa
Agelaius phoeniceus
Limulus polyphemus
Salt Marsh Plants
• Halophytes - plants that tolerate salty water -Some push salt through pores
-Some push salt to the end of the plant and drop the end off - Salicornia
Spartina patens
Spartina alterniflora
Phragmites australis – that all too common, common reed
Salt Marsh at Low Tide
Salt Marsh at High Tide
To Learn More About Salt Marshes
Local salt marshes:
www.chipr.sunysb.edu/eserc/longis/flaxpond.html
Regional salt marshes:
http://www.edc.uri.edu/restoration/html/gallery/plants/reed.htm
http://serc.carleton.edu/introgeo/roleplaying/examples/tide.html
http://www.nationalgeographic.com/xpeditions/lessons/08/g35/oceans35.html
http://www.dnr.sc.gov/marine/pub/seascience/dynamic.html
Mud (Tidal) Flats
Mud (Tidal) Flats – Physical Characteristics
• Some areas of estuary wetlands are relatively devoid of plant matter. These Soft sediment habitats are the Tidal (Mud) Flats.
• They occur along outer edges of the salt marshes where low current flow allows fine sediment to drop out of suspension
Who lives in Mud (Tidal) Flats?• Home to a diverse
community of invertebrates:
Snails, Clams & Segmented worms-all move through the bottom, mixing deeper, oxygen-starved sediments with surface sediments (bioturbation).
Mud flats provide habitat/feeding ground for many invertebrates –
and their predators
Digging Clams
Human Uses
• Similar to salt marsh
- important nursery ground for young fish
- barrier from storm damage to land/coastal flooding
- beautiful
Threats to Mud (Tidal) Flats• Change in current
velocity• Development of
surrounding marshes• Dredging• Global warming
Seagrass Distribution-Shallow sub-tidal habitats created
by marine grasses-Found in estuaries and lagoons in
both temperate and tropical systems throughout the world
Values of Seagrasses
-Modify environment by reducing current velocity, which can in turn affect sedimentation rates & soil grain size
-Help slow down storms moving inland-Increase habitat complexity, reducing
predation intensity-FOOD, SHELTER, NURSERY !!
Values of Seagrasses continued
Increased number of individuals and species in seagrass
bed, compared to
bare or sandy areas outside the
bed.Our local seagrass is
Eelgrass
Who Lives There?Values of Seagrasses continued
-Fish, crabs, shrimp, and scallops are much more common inside sea grass beds than outside them. Some species, such as clams and scallops, also grow faster within a sea grass bed.
Threats To Seagrasses• Boat propeller damage
• Global warming, sea level rise
• Water quality & clarity decreases from runoff (making photosynthesis difficult)
• Brown Tide
To learn more about Seagrasses:http://www.sms.si.edu/IRLspec/Seagrass_Habitat.htm
http://www.ncl.ac.uk/tcmweb/tcm/sglinks.htm
Rocky Intertidal Communities
Physical Characteristics:Dependent on
tides-periodically covered by water
or exposed to elements
Rocky – cobble to boulder sized
sediment
Value of Rocky Intertidal
Structure, habitat for economically & environmentally important species
Threats to the Rocky Intertidal
• Global Climate Change & Sea Level Rise
• Waste disposal/sewage disposal
• Overcollecting, trampling by humans
http://www.youtube.com/watch?v=25F7xMVNt-w
Barnacles Feeding
Rocky Intertidal Flora & Fauna
Helpful Links to Communities
Salt Marsh & Rocky Shores:http://www.uri.edu/cels/bio/rishores/
home.htmBarnacles!
http://www.youtube.com/watch?v=M2ow4sB-RQs&feature=related