seagrass ecology estuarine seagrass ecosystems in north carolina and florida
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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 Commonname
Salinity range(ppt)
Zostera marina eelgrass 7 - 35
Halodule wrightii shoal grass 12-35
Thalassia testudinum turtle grass Tolerance: 3.5 - 60Optimum: 24-35
Syringodium filiforme manatee grass 24-35
Halophila spp. “Halophila” 35
Ruppia maritima widgeon grass 2 - 70
Major oligohaline aquatic macrophytes
Scientific name Common Name Salinity range (ppt)
Vallisneria americanum wildcelery or freshwatereelgrass
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 Location Productivity(gC/m
2/day)
Thalassia testudinum FloridaPuerto Rico
0.9 -162.5 - 4.5
Syringodium filiforme FloridaTexas
0.8 - 3.00.6 - 9.0
Halodule wrightii North Carolina 0.5-2.0
Zostera marina North CarolinaRhode Island
0.2-1.70.4-2.9
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
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