Grasses 101

What are Underwater Grasses?Rooted, flowering

vascular plantsGrow completely

submerged in shallow water of Bay and tributaries

A.K.A.: SAV, seaweed, seagrasses

Factors Affecting Underwater Grass Growth

Ecological Functions of Underwater Grasses

Decomposition of underwater grasses form the base of the detrital food chain in the Bay.

Importance of Underwater Grasses to Crabs

Juvenile Crab Density

1

30

0

510

15

20

2530

35

areas withunderwater

grasses

areas withoutunderwater

grasses

crab

s pe

r sq.

met

er

Submergered Aquatic EducationBefore 1900’s

more than 600,000 acres

By 1984 only 38,000 acres remained

Too many :SedimentsNutrients

Decline of Underwater GrassesThermal StressTropical Storm Agnes

Degraded Water Quality

Wet SpringInvasives

9/12/2011

Bay-wide Underwater Grass Area

Restoration StrategiesAccomplished by:

• Improving Water Quality (reducing

sediment and nutrient inputs/TMDL/LID)

• Protecting Existing Beds (dredging issues, mute swans, water quality)

• Restoring grass beds (suitable water quality)

What can you do?EducateAdvocateSchoolyard

Habitat/LID

What should students know?Identification?One of the Bay’s 4

Natural FiltersRole within the

ecosystemEcological ValueThreatsPersonal ConnectionAs a context for

teaching…