Download Seagrass Ecology

Seagrass Ecology
Estuarine seagrass ecosystems in
North Carolina and Florida
Seagrasses
• Angiosperms (flowering plants) that live
life entirely underwater
• Primary productivity is among the highest
measured (500 - 4000 g C/m2/year)
• Important feeding and refuge habitat for
fishery species (shrimp, scallops, fishes)
• Seagrasses act as sediment stablizers help to
filter water
Major polyhaline seagrass
species
Scientific name
Zostera marina
Common
name
eelgrass
Salinity range
(ppt)
7 - 35
Halodule wrightii
shoal grass
12-35
Thalassia testudinum
turtle grass
Tolerance: 3.5 - 60
Optimum: 24-35
Syringodium filiforme
manatee grass
Halophila spp.
“Halophila”
Ruppia maritima
widgeon grass
24-35
35
2 - 70
Major oligohaline aquatic
macrophytes
Scientific name
Common Name
Salinity range (ppt)
Vallisneria americanum
wildcelery or freshwater
eelgrass
0-9
Potamogeton pectinatus
Sago pondweed
0-9
Potamogeton perfoliatus
redhead grass
0-9
Zanichellia palustris
horned pondweed
0 -25
Myriophyllum spicatum
Eurasian watermilfoil
0 -10
Najas guadalupensis
bushy pondweed
1- 15
Seagrass productivity
Species
Thalassia testudinum
Syringodium filiforme
Halodule wrightii
Zostera marina
Location
Productivity
2
(gC/m /day)
Florida
0.9 -16
Puerto Rico
2.5 - 4.5
Florida
0.8 - 3.0
Texas
0.6 - 9.0
North Carolina
0.5-2.0
North Carolina
Rhode Island
0.2-1.7
0.4-2.9
Habitat Complexity
• Habitat complexity is high in seagrass/SAV
• Predators are inhibited by complexity
because the prey have many places to hide
• Densities of many invertebrates (infaunal
and epifaunal) and small fishes are greater
in SAV than in nearby unvegetated areas
• Seagrass provides a refuge from predation
Types of animals in seagrass
• Infauna: bury in sediment.
– Polychaete worms, amphipods, clams, benefit from root and
rhizome mat which protects from predators
– deeper-living animals survive better than shallow-living
(Mercenaria > Chione)
• Epifauna: Live on surface of blades and sediment
– Meiofauna (harpacticoid copepods), macrofauna (amphipods.
isopods), tube-dwelling sessile polychaetes, gastropods, decapods
– Shoot and leaf complexity provides refuge
• Mobile fauna: Live in water over canopy
– fishes swim above canopy, dive into it when predator