Caged Crassostrea ariakensisDeployment in Chesapeake Bay: Growth, Disease and MortalityKennedy T. Paynter, Jacob Goodwin, Marcy ChenUniversity of Maryland, College ParkDonald MerittUniversity of Maryland Center of Environmental ScienceStan AllenVirginia Institute of Marine Science

Previous ObservationsCalvo et al., C. ariakensis grew much faster than C. virginicaC.a. experienced much lower mortality due to diseaseGrabowski et al.,C.a. grew faster than C.v. in intermediate to high salinities but did not grow well in low salinities.However both studies, Compared diploid C.v. to triploid C.a.Did not compare specific parasite free (SPF) C.a. to SPF C.v.

Experimental DesignMd sites - Severn, Patuxent, Choptank RiversVa site - York RiverDeployed April 20041300 individuals of each species -Both triploid400 in each of two ADPI bags - sample250 in each of ADPI reef trays - left alone

Monitored monthly since deploymentSize, mortality, P. marinus prevalence

Site LocationsSevern RiverPatuxent RiverChoptank RiverYork River

6 psu

9 psu

11 psu

17 psu

C. ariakensisC. virginicaApproximately 200 of each species

Perkinsus marinusIn addition to growth, the difference in disease susceptibility between native and non-native oysters is important in considering an introduction

Mortality since deployment

LOCATIONC. ariakensisC. virginicaSevern 26 20Choptank 36 45Patuxent 24 6York 11 21Mean 24 23

Summary

C. ariakensis grew much faster in higher salinities but only slightly faster in lower salinity waters in Maryland.

C. ariakensis acquired lower dermo prevalence.

Mortality in both species was low and similar, however, dermo infections remained light during this portion of the study and heavy disease-related mortalities appear likely in C.v. in the near future.

York River Spat Settlement in 2004

0.4 spat/oyster2.3 spat/oysterC. virginicaC. ariakensisSpat settlement on C. virginica (A) and C. ariakensis (B). Spat were found in significantly higher numbers in C. ariakensis (ANOVA; P

Additional Observations

There were differences in Polydora sp. infestations (See poster A6. Ward)

Hypoxia tolerance varied between C. ariakensis and C. virginica (See poster A4. Harlan)

AcknowledgementsFunding from Maryland Sea Grant, NOAA, and Maryland Department of Natural Resources.Technical assistance from, Mark Sherman Steve Allen,, Tim Koles, Nancy Ward, Terra Lederhouse, Nicole Harlan, Paul Miller, Kennedy and Rick Paynter.

Spat SettlementYork River was the only site with spatfall in 2004

Spat were found in significantly higher numbers in C. ariakensis (ANOVA: P

Mortality Table Comparisons

LocationC. AriakensisC. virginicaSevern 74 80Choptank 64 55Patuxent 76 94York 89 79Avg. 76 77