Oyster Reef Ecology: Habitat Value

Oyster reefs are home to many estuarine and marine organisms. Those which remain on the reefs at low tide are referred to as "resident" species while those which only use the reefs at high tide are referred to as “transients”. As part of our oyster reef development study we sampled constructed oyster reefs quarterly to census residents and form a picture of how early developing oyster reefs are colonized.

Each quarter we also sampled nearby natural reefs in order to compare their resident populations. Samples were rinsed on a 1 mm mesh and all incidental organisms were collected for later identification.

Experimental oyster reef constructed of trays filled with shell

As oysters recruited to the constructed reef and began to form a more complex three dimensional habitat, the resident community also became more complex and started to resemble the populations on the natural reefs.

In terms of biomass, mussels, predominantly the ribbed mussel Geukensia demissa and the scorched mussel Brachiodontus exustus, are the second most abundant taxon after the oysters themselves.

The constructed reefs were also used to study transient species.  These include smaller individuals seeking refuge among the oysters and larger ones which find ample prey in the complex oyster reef community. Transient species were censused seasonally by surrounding each reef with a 24 m2 lift net. The net was raised on a high tide when transients are using the reef. When the tide retreated the visitors were trapped and collected.

Liftnet in position at high tide Liftnet surrounding constructed reef after tide retreats

Transient species which use oyster reefs include recreational and commercial species of fish. The table below lists some of the more frequent users of our reefs.

Transient Species on South Carolina Oyster Reefs


Common Name Scientific Name
Spottailed bass Sciaenops ocellatus
Gray snapper Lutjanus griseus
Southern flounder Paralichthys lethosti1!ma
Summer flounder Paralichthys dentatus
Spot Leiostomus xanthurus
Sheepshead Archosargus probatocephalus
Darter goby Gobionellus boleosoma
Naked goby Gobiosoma bosc
Striped blenny Chasmodes bosquianus
Striped mullet Mugil cephalus
White mullet Mugil curema
Oyster toadfish Opsanus tau
Bay anchovy Anchoa mitchilli
Strioed anchovy Anchoa hepsetus
Mummichog Fundulus heteroclitus
Atlantic silverside Menidia menidia
Inland silverside Menidia beryllina
Spotfin mojarra Eucinostomus argenteus
Pinfish Lagodon rhomboides
Silver perch Bairdiella chrysoura
Pigfish Orthopristis chrysoptera
Soeckled worm eel Myrophis punctatus
Chain pipefish Syngnathus louisianae


Common Name Scientific Name
Daggerblade grass shrimp Palaemonetes pugio
Marsh grass shrimp Palaemonetes vulgaris
Brown shrimp Penaeus aztec us
White shrimp Penaeus setiferus
Blue crab Callinectes sapidus
Lesser blue crab Callinectes similis

Because of their dimensional complexity and the lack of seagrass beds in South Carolina, we expected oyster reefs to rank with salt marsh and seagrasses as important fish habitats. To demonstrate this, we used lift nets to sample for transients over mudflats and saltmarshes.

Oyster reefs attract a diversity and abundance of transient species similar to that found in saltmarsh. While mudflats generally support fewer species, they are not the barren wilderness we anticipated.