A genetic assessment of Bay Scallop restoration in Bogue Sound, North Carolina Sherman, M. 1, D. Schmidt 2, A.E. Wilbur 1 1 Department of Biology and Marine Biology, Center for Marine Science, University of North Carolina Wilmington, Wilmington, NC Goose Creek Rd. Newport, NC 28570

Background Methods Results Conclusions State of the scallop fishery in North Carolina –Declining fishery likely due to several factors Red tide in 1987 –Recruitment failure Predation –Cownose rays Hurricanes –low scallop abundance has prompted the investigation of restoration practices NC Scallops Landings ( )

Background Methods Results Conclusions Types of restoration strategies –Preserve and protect Releases population from pressures –Rebuild habitat Useful for substrate limited organisms –Supplementation Transplantation Hatchery production –Traditional hatchery practices »Spawn, grow to size, and release –Larval releases »May be inexpensive and efficient

Background Methods Results Conclusions Larval releases in Florida- Pine Island Sound (Arnold 2008) –In 2003, 1,500,000 larvae released from hatchery stock from 12 Anclote broodstock scallops –In 2005, found an increase in abundance by a factor of 18 indicative of enhancement Retrospective genetic analysis –Microsatellite analysis (9 loci) (Hemond 2006) Genotypes of broodstock not determined Broodstock source population (Anclote, FL) Pine Island scallops from before (2001) and after (2005) the 2003 larval release –Could not confidently assign a source population Lack of differentiation between sources limits assignment success Jay Leverone releasing larvae in Pine Island Sound Frequentist method (Praetkau et al. 1995) Based on probabilistic framework Log L (Pine Island source) Log L (Anclote source) Pine Island Sound Assignment Test

Broodstock scallops are genetically characterized Broodstock scallops are spawned Larvae are grown to the pediveliger stage Larvae are released into the wild Spat and adult assessment scallops collected and genetically characterized Genetic signatures of broodstock and assessment scallops are compared to identify potential hatchery offspring Background Methods Results Conclusions

Fall A total of 85 wild scallops were collected for broodstock - Separated into five sets of broodstock

Background Methods Results Future Implications Before release spat traps were deployed surrounding the release site –6 traps placed feet from release site to be collected one month after deployment

Background Methods Results Conclusions Scallops were then introduced to the release site o Healthy subtidal seagrass bed o Low tide o Limit vertical profile

Background Methods Results Conclusions Larval Release Summary BroodstockLocation Age at larval release (days) Number of Broodstock Number of larvae Total larvae per site RedTaylor Bay ,000 GreenTaylor Bay1117 1,000,000 PurpleTaylor Bay ,0001,404,000 OrangePiney Island ,000 YellowPiney Island ,0001,087,000 Total 852,491,000 Releases took place in September and October 2007

Background Methods Results Future Implications June Scallops collected by snorkeling inside and outside of the deployment area o Muscle tissue was extracted for genetic analysis Taylor Bay Piney Island

Background Methods Results Conclusions Genetic assessment to date: Mitochondrial DNA –Sequencing of a 930bp region- 113/142 showed unique haplotypes 07 Wild scallops (N=57) 48 haplotypes (46 uniques) 07 Broodstock TB (N=53) 44 haplotypes (43 uniques) 07 Broodstock PI (N=32) 26 haplotypes (24 uniques) v v v Overlap between broodstock and wild population before releases

Background Methods Results Conclusions Genetic assessment to date Mitochondrial DNA –In /57 (19.3%) wild scallops exhibited broodstock haplotypes –In /265 (24%) assessment scallops exhibited broodstock haplotypes v Mostly Haplotype 1 where overlap between broodstock and wild population greatest 08-Assessment PI 08-Assessment TB 07-Broodstock PI 07-Broodstock TB 07- Wild Scallops

Background Methods Results Conclusions Microsatellite Analysis –5 loci to date Allele frequency plots suggest wild population and broodstock not differentiated AI115 AI327 m26 AI131 g Piney Island 07- Taylor Bay 07- Wild Scallops

Background Methods Results Conclusions Assignment test of potential source populations –25/57 wild correctly assigned to wild –18/85 broodstock scallops correctly assigned to hatchery –Less than ½ of broodstock and wild scallops assigned correctly

Background Methods Results Conclusions Assignment of assessment scallops Taylor Bay –41 mtDNA matches 22 assigned to broodstock released at Taylor Bay 2 assigned to broodstock released at Piney Island 17 assigned to wild population Piney Island –14 mtDNA matches 4 assigned to broodstock released at Piney Island 10 assigned to broodstock released in Taylor Bay

Background Methods Results Conclusions Conclusions –Potential enhancement looks promising, but significant impact not detected with microsatellites to date 22/157 (~14%) properly assigned scallops in Taylor Bay 4/108 (~4%) properly assigned scallops in Piney Island Increased loci will likely increase the power to detect hatchery scallops Suggestions for future assessments –Broader perspective Larval transport away from release site Broader geographic sampling –Density survey Larval releases may work- how well? Are there more scallops?

Acknowledgements NC Sea Grant Fisheries Resource Grant 06-EP-07 UNCW DNA Analysis Core Facility Bill Arnold (FFWRI), Skip Kemp (CCC), Tina Moore (NCDMF), Don Morlock