Oyster Reef Ecology: Habitat Value

Oyster Monitoring and Assessment:

Recruitment is the process of incorporating new oysters into a population.  In the summer months, adult oysters produce millions of microscopic larvae.  After a two to three week free-swimming larval cycle, young oysters permanently cement to hard surfaces, preferably other oyster shell. 

If there are not enough recruits to offset losses due to natural mortality and harvesting, a population will decline.  Such a population might be referred to as “recruitment-limited”.  SCDNR monitors oyster recruitment and early growth annually by deploying trays filled with oyster shell for 9-12 months and then counting and measuring all the live oysters. 

Life cycle of the oyster

This method has been in use since 1998, with trays deployed at 6 to 30 sites per year.  Average statewide recruitment is more than 4,000 oysters per square meter.  The 2004-5 recruitment year was the highest on record, with a statewide average of 6,650 oysters per square meter.  Oyster populations in South Carolina are not recruitment-limited.

Graph of Oyster recruitment in SC 1998-2004