1. North Cape Scallop Restoration Project
Lessons learned from the restoration efforts in Rhode Island’s south county salt ponds
Boze Hancock1, James Turek2, Najih Lazar3, and John Catena4
1Coordinator, North Cape Shellfish Restoration Program, Narragansett, RI
2NOAA Restoration Center, Narragansett, RI
3RIDEM Division of Fish and Wildlife, Jamestown, RI
4NOAA Restoration Center, Gloucester, MA

2. Grounding of the North Cape, January 1996
828,000 Gallons of No. 2 Fuel Oil Released to Block Island Sound

3. ‘North Cape’ Restoration
Damages settlement in 2000
Shellfish Restoration one of several programs to compensate for 150 million lost bivalves
Shellfish Restoration program began in Coordinator (Karin Tammi, ; Boze Hancock,2004 – present) Assistant & 4 to 6 staff and students annually
Project completion expected 2007

4. North Cape Shellfish Restoration Program
Aim
To restore lost biomass and ecological functions by establishing and enhancing sustainable shellfish populations.
Target species
Bay scallop Argopecten irradians, restoration
Eastern oyster Crassostrea virginica, restoration
Quahog Mercenaria mercenaria, enhancement

5. South County salt ponds

6. Scallop restoration 2 phases; Direct seeding Caged spawner sanctuary
Phase 1, Direct seeding 2002 & 2003
Large scale seeding of 25 – 35 mm hatchery produced stock, fall of 1st growing season Provide broodstock for next breeding season
Capture of spat for subsequent re-stocking of other ponds using ‘spat bags’
Dive surveys to monitor survival

7. North Cape Scallop Restoration Project
Direct seeding of broodstock
Release sites, based on habitat assessments

8. Scallop direct seeding
2002 Point Judith Pond ,000
2003 Potter Pond ,300 Greenhill Pond ,980 Ninigret Pond ,090 Quonochontaug Pond ,029,840
Total ,766,200

9. Ninigret Pond; Release areas and indicating strata used for random transect surveys of scallop abundance

10. North Cape Scallop Restoration Project
Direct seeding of broodstock - release sites
Results, Abundance
Ninigret Pond ~ 10,000
Quonochontaug Pond < 1,000
Green Hill Pond ~
Potter Pond ~
Pt. Judith Pond

11. Phase 2 – Spawner sanctuary from 2004 3 components
Broodstock cages Maximize reproductive output by protecting broodstock Ninigret Pond 2004 to 2005, Quonochontaug Pond Hatchery produced broodstock 10,000 to 20,000
Settlement of larvae monitored using ‘spat bag arrays’ 4 array locations per pond Six bags / line, Retrieved every 4 weeks, 2 week overlap
Annual diver surveys to estimate abundance, (Survival of spat to maturity),

12. for protection from predators
Spawner sanctuary
Mature broodstock
Maintained in cages
for protection from predators

13. Schematic
Spat Bag array
Field example

14. Ninigret Pond 2004 to 2006 Spawner cages 10,000 broodstock 04 & 05
Spat bag arrays
Same structure each year
4 sites, 6 bags, 8 collections
Settlement index
Σ mean spat per bag
Free Scallops
Dive surveys
2004, 88 transects (6 strata)
2005, 36 transects (3 strata- west basin)
2006, 80 transects (6 strata)

15. ? 2004, # Broodstock ~ 20,000 10,000 free (SE 5,500) 10,000 caged
Settlement Index 32
2005, # Broodstock ~ 142,000
132,000 free (SE 55,000)
10,000 caged
Settlement Index
137
2006, # Broodstock ~ 210,000
210,000 free (SE 102,000)
0 caged
Settlement Index
35 + ? ?

16. Summary – Ninigret Pond
-04 and -05 results very encouraging
-06 results more difficult to interpret Broodstock only in western basin Settlement only in central basin (larval transport / asymmetric survival)
Environmental conditions extreme in 06 Wettest year on record Low salinity (16 to 27 ppt), stable stratification, evidence of anoxia Massive kill of scallops in central & northern basins

17. Quonochontaug Pond Similar design to Ninigret Pond Spawner sanctuary Settlement surveys Monitoring broodstock abundance
2006, # Broodstock ~ 20,000
~ 400 free
20,000 caged ?

18. Conclusions
Due to high predation rates, direct seeding of scallops was not a productive restoration method
Caged spawner sanctuary with relatively few broodstock has been cost effective. Produced appreciable spatfalls and population increases
Water quality. High flushing rates may reduce likelihood of anoxic events
Benefit from a long term project commitment