How long does oyster shell last on an oyster reef? Photo courtesy of David Bushek, Haskin Shellfish Research Laboratory John N. Kraeuter, Eric N. Powell and Kathryn A. Ashton-Alcox Haskin Shellfish Research Laboratory, Rutgers University

Photo courtesy of David Bushek, Haskin Shellfish Research Laboratory

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Recent Box Counts from the monitoring program. Depict the of relatively low constant rate of new boxes following major input from 2002, and lack of recruitment. It is data such as this that allows estimating loss rate of boxes into cultch.

dS/dt = (b(t) - L)S b(t)b(t)S LS

Taphonomic attack on shell in the Delaware Bay Cliona - yellow boring sponge Cliona + redbeard sponge Cliona + calcareous tube worms Urosalpinx - oyster drill Drilled oyster spat Cliona + worm burrows Blue Crab - Callinectes sapidus

Number of Spat Number of Oysters

Cultch (L m -2 )

Doubling times and half-lives of shell on New Jersey oyster beds for the time period of 1998 to 2005 Years i

Addition and loss rates of shell on New Jersey oyster beds for the time period of

Summary The recent 6 consecutive years of low recruitment has allowed us to estimate the loss rate of oyster shell on beds in Delaware Bay. Shell loss rates were unexpectedly high – half the shell added to a bed in Delaware Bay is lost over the next 2-10 years. Minimal shell doubling times under the assumption of no shell loss (maximum accretion) vary from less than an decade to more than twenty years. The rarity of documentation of shell accumulation (vertical or lateral expansion of reefs) suggests that most shell does not remain recognizably intact for long. On the scale of oyster generation times, shell doubling times are not rapid. Projects need to consider the shell budget when presenting various restoration options.