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Richard F. Dame

Richard F. Dame. Acknowledgements. Robert Gardner, USC Fred Holland, NOAA US Forestry Service – Sewee Center.

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Richard F. Dame

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  1. Richard F. Dame

  2. Acknowledgements Robert Gardner, USC Fred Holland, NOAA US Forestry Service – Sewee Center

  3. From 4500 to 3000 B.P., oyster dominated estuarine ecosystems on the Southeastern Atlantic coasts of South Carolina, Georgia and Florida experienced a major change in state as evidenced by the presence and later abandonment of oyster shell rings. • In this presentation:(1) the prehistoric and modern oyster dominated systems will be examined and compared from a complex ecological systems perspective using literature data and simple reverse engineering techniques, • (2) the relative uncertainties of the findings will be estimated and • (3) lessons learned will be discussed.

  4. Some properties of complex ecological systems

  5. Intertidal reef during submergence Connections Hierarchical

  6. Ecological Phase Shifts From a management perspective, recognizing and predicting shifts between alternate regimes or states is probably among the most important aspects of ecological complexity. What are some of these shifts or potential shifts in Southeastern estuaries?

  7. Oyster Reef Phase or Regime Shift Mudflat Intertidal Oyster Reef Causes Over-harvesting Habitat Destruction Pollution Disease Rapid Climate Change (RCC)

  8. Benthic-Pelagic Shift Pelagic Subtidal Oyster Reef Causes Over-harvesting Eutrophication Pollution Disease Rapid Climate Change (RCC)

  9. Salt Marsh Shift Healthy Salt Marsh Marsh Converting to Mudflat Causes Drought Flow Modification RCC Fungi Snail Grazing

  10. Native American Indian Shell Ring after Trinkley (1997)

  11. Shell Rings • Shell rings are circular or semi-circular structures built mostly of oyster shells and are found along the coasts of South Carolina, Georgia and Florida. • They were built by native Americans between 4600 to 3000 years B.P. and stood up to 10 m above the surrounding landscape. • These constructs are the first indication of the end of the hunter-gathering period of Homo sapiens in North America. • The relatively short functional duration of these structures is an issue of intense debate.

  12. Natural Reef/Creek Shift to Shell Ring System Causes High Ecosystem Production Native American Indians

  13. Shell Ring System Shift to Natural Reef/Creek Causes Over-harvesting RCC Indians Disperse

  14. Location of Some Shell Rings on the South Carolina Coast

  15. Sewee Shell Ring • Size: 3.2 m high, 75 m diameter, 3900 m3 shell volume • Age: 4120 to 3675 +/- 70 years B.P. • Major Threat: erosion due to sea level rise • Comments: Earliest shell ring in SC; Only shell ring readily available for public viewing; site managed by US Forest Service, Francis Marion National Forest Russo and Heide (2003)

  16. Aerial Color IR of Sewee Area Sewee Shell Ring US 17 2nd or 3rd order tidal creek

  17. Sewee Shell Ring Wall

  18. Topographic Chart

  19. Fig Island 1 Shell Ring (Botany Bay Plantation, Edisto Island) • Size: 5.5 m high, 157 m diameter, 22,114 m3 shell volume • Age: 3861 to 3816 +/- 70 years B.P. • Major Threats: Previous shell mining; erosion due to sea level rise • Comments: Largest ring known; most studied in SC; managed by SCDNR Saunders and Russo (2002)

  20. Aerial IR of Fig Island Shell Rings 2nd and 3rd order tidal creeks

  21. Fig Island 1 aerial showing modern damage

  22. Fig Island 1 relative size

  23. Fig Island 1 Inside Out

  24. Topographic Chart

  25. Environmental Change And Shell Rings

  26. Climate Change Cool Warm Brooks Curve for South Carolina Coast RCC After Brooks et al. (1989)

  27. Low Prod. High Prod. Estuarine Ecosystems Salt Marshes Oyster Reefs Deltas Shift Shift Shift

  28. Coastal Native Americans Europeans Hunter Gathers Shell Ring Culture Shell Rings Abandoned Villages

  29. Were ecosystem services provided by oysters diminished by using oyster shells to build shell rings? • We can address this question by examining the density and size of the shells in the rings and in modern reefs. • Then allometric models can be used to estimate biomass and physiological rates. • It’s all a matter of size and scale.

  30. SIZE • Size is one of the most significant characteristics of individual organisms. • Size is important because along with temperature it governs many physiological rates. • Bivalve size is measured linearly as height and as biomass or body weight . • The two measures are related allometrically and provide a method to estimate biomass on archaeological samples. • An example for intertidal oysters is: Wt = -2.38 H2.21

  31. Allometric Model for Oyster Clearance Rate CR = 0.120 Wt0.75

  32. Location Environment Category Height (mm) Ashley River Polluted Average 89 Sewee Pristine Average 98 Sewee Pristine Largest 120 Sewee Shell Mound Average 166 Sewee Shell Mound Largest 200 Santee Delta Pristine Largest 210 Sizes of Crassostrea virginica in SC Lunz (1938); Dame (unpublished)

  33. 69,538/ m3 (69,538/ m3) Density 2200/ m2 Biomass 345 gdb/ m2 56,848 gdb/m3 (56,848 gdb/m3) Total pop. Density 1.65 x 106 1.54 x 109 (2.71 x 108) Total pop. Biomass 2.59 x 105 1.26 x 109 (2.21 x 108) Avg. Biomass/ind 0.20 gdb 0.82 gdb (0.82 gdb) Clearance Rate/Ind 0.04 m3/d 0.10 m3/d (0.10 m3/d) Total Clearance Rate 6.60 x 104 m3/d 1.21 x 108 m3/d ( 2.71 x 107 m3/d) Characteristic NI Live Reef Fig Island 1 Sewee Area 750 m2 17,427 m2 4416 m2 Volume (shell) NA 22,114 m3 3,900 m3 Sample Size 0.25 m2 0.025 m3 (0.025 m3 ) Species Crassostrea virginica Crassostrea virginica Crassostrea virginica Age Live 3820 +/- 70 B.P. 4120 +/- 70 B.P.

  34. Is it possible that the removal of oysters from the tidal creeks caused a phase shift? • Direct Effects of Overfishing: fewer and smaller oysters available to main oyster consumer, Native American Indians, and oysters were the main item in their diet. • Effects may be amplified by RCC, particularly declining sea level and increased exposure with cooling conditions. • Modern phase shifts almost always involve multiple forces. • With declining food availability, Native Americans had to choose between staying and starving or returning to the hunter-gatherer mode.

  35. Native American Indians built the Fig Island 1 shell ring using over a billion oyster shells from the surrounding creeks, thus establishing a new more complex state. Implies over-fishing as an anthropomorphic stress on the ecosystem. Prehistoric and modern oysters may or may not be similar in size. Contradictory evidence from different sites suggests that size is the result of fishing intensity and food availability, i.e., habitat specific. Oysters from polluted environments are smaller than those from pristine locations. The loss of oyster clearance capacity due to shell ring building may have had an impact on the tidal creek system. Reduced clearance capacity due to over-harvesting does seem to occur in modern systems. +/+ +/- +/+ +/- Evidence Uncertainty

  36. Sea level decline and rapid climate cooling were coincidental with the abandonment of shell rings. The error of up to (+/-) 150 years and the scarcity of replication in radiocarbon analysis increases uncertainty. The Native Americans abandoned the shell rings and never reestablished their use, i.e., changed state of the ecosystem. Some archaeological evidence suggests a lack of quantity and quality of food for the Indians. By 3000 B.P. (+/-) 150 yr, all shell rings were abandoned. Oysters still flourish in the creeks surrounding Fig Island 1 and Sewee. Archaeological and modern evidence from Sapelo Island, GA suggests that today’s oyster reefs are at least as productive as those of the shell ring era. +/- +/- +/- +/+ Evidence Uncertainty

  37. Conclusions • Like today, the prehistoric system probably collapsed or shifted to another state due to a combination of anthropogenic and climatic stresses. • The oysters returned to at least the same levels of production as in pristine areas today and that production is similar to that of the pre-shell ring era. • The Native American shell ring culture was abandoned and eventually replaced by a culture that did not focus on oysters as their major food and feasting source, as well as building material.

  38. Addendum • Height to dry body weight spreadsheet model • Clearance rate spreadsheet model • Bibliography

  39. Brooks et al. 1989. Sea-level change, estuarine development and temporal variability during the Woodland Period . In: Goodyear and Hansen, Studies in South Carolina Archaeology Brown, JH, Gillooly, JF, Allen, AP, Savage, VM, West, GB. 2004. Towards a metabolic theory of ecology. Ecology 85:1771-1785. Carbotte, SM, Bell, RE, Ryan, WBF, McHugh, C, Slagle, A, Nitsche, F, and Rubenstone, J. 2004. Environmental change and oyster colonization within the Hudson River estuary linked to Holocene climate. Geo-Mar Letters 24:212-224. Claassen, C. 1998. Shells. Cambridge University Press, Cambridge. 266 pages. Crook, MR. 1992. Oyster sources and their prehistoric use on the Georgia coast. Journal of Archaeological Science 19:483-396. Crook, MR. 2007. Prehistoric pile dwellers within an emergent ecosystem: An archaeological case of hunters and gatherers at the mouth of the Savannah River during the mid-Holocene. Human Ecology 33:223-237. Dame RF. 1972a. Comparison of various allometric relationships in intertidal and subtidal American oysters. Fishery Bulletin 70:1121-1126. Dame, RF. 2005. Oyster reefs as complex systems. In: The Comparative Roles of Suspension-Feeders in Ecosystems, RF Dame S Olenin (Eds), Kluwer Academic Publishers, Dordrecht. Dame, RF. and 10 other authors. 2000. Estuaries of the South Atlantic coast of North America: Their geographical signatures. Estuaries 23:793-819. Dame, RF, Childers, D, and Koepfler, E. 1992. A geohydrologic continuum theory for the spatial and temporal evolution of marsh-estuarine ecosystems. Netherlands Journal of Sea Research 30:63-72. DePratter, CB, and Howard, JD. 1981. Evidence for a sea level lowstand between 4500 and 2400 B.P. on the southeast coast of the United States. Journal of Sedimentary Petrology 51:1287-1295. Gardner, LR, and Porter, DE. 2001. Stratigraphy and geologic history of a southeastern salt marsh basin, North Inlet, South Carolina, USA. Wetlands Ecology and Management 9:371-385. Grattan, J. 2006. Aspects of Armageddon: An exploration of the role of volcanic eruptions in human history and civilization. Quaternary International 151:10-18. Jackson, JBC, & 18 others. 2001. Historical overfishing and the recent collapse of coastal ecosystems. Science 293:629-638. Keith, WJ, and Gracie, RC. 1972. History of the South Carolina Oyster. SC Wildlife Resources Department. Educational Rept. No. 1, 20 pages. Lunz, GR. 1938. Comparison between pre-colonial and present-day oysters. Science 87: 367. Manning, S. 1999(with update). A Test of Time: the volcano of Thera (Santorini). Oxbow, Oxford. Mannino, MA, and Thomas, KD. 2002. Depletion of a resource? The impact of prehistoric human foraging on intertidal mollusc communities and its significance for human settlement, mobility and dispersal. World Archaeology 33(3):452-474.

  40. Mayewski, PA. and 15 others. 2004. Holocene climate variability. Quaternary Research 62:243-255. Newell, R. 1988. Ecological changes in Chesapeake Bay: are they the result of overharvesting the American oyster, Crassostrea virginica? In: Understanding the estuary: advances in Chesapeake Bay research, Lynch MP Krome EC (Eds), Chesapeake Bay Research Consortium, Solomon’s Maryland. pp 536-546. Reitz, EJ, and Wing, ES. 2008. Zooarchaeology, 2nd Edition. Cambridge University Press, Cambridge. 533 pages. Russo, M. 1991. A method for the measurement of season and duration of oyster collection: Two case studies from the prehistoric South-East U.S. coast. Journal of Archaeological Science 18:137-158. Russo, M. 2002. Faunal analysis at Fig Island. In: Saunders, R. (Ed.) 2002. The Fig Island ring complex: Coastal adaptation and the question of ring function in the Late Archaic. Report to the South Carolina Department of Archives and History, Columbia, SC. Pages 141-153/ Russo, M. 2004. Notes on South Carolina and Florida shell rings. NPS. Russo, M, and Heide, G. 2001. Shell rings of the southeast. Antiquity 75:491-492. Sadler, JP and Grattan, JP. 1999. Volcanoes as agents for past environmental change. Global and Planetary Change 21:181-196. Sanger, D, and Sanger, MJ. 1986. Boom or bust on the river: The story of the Damariscotta oyster shell heaps. Archaeology of Eastern North America 14:65-78. Saunders, R. (Ed.) 2002. The Fig Island ring complex: Coastal adaptation and the question of ring function in the Late Archaic. Report to the South Carolina Department of Archives and History, Columbia, SC. Scott, DB, Gayes, PT and Collins, ES. 1995. Mid-Holocene precedent for a future rise in sea-level along the Atlantic coast of North America. Journal of Coastal Research 11:6150-622. Surge, DM, Lohmann, KC, and Goodfriend, GA. 2003. Restructuring estuarine conditions: oyster shells as recorders of environmental change. Estuarine, Coastal and Shelf Science 57:737-756. Trinkley, M. 1985. Form and function in South Carolina’s early Woodland shell rings. In: Dickens, R, and Ward, T. (Eds.), Structure and Process in Southeastern Archaeology. University of Alabama Press, Tuscaloosa. Pages 102-118. Wood, R. 2000. Reef Evolution. Oxford University Press, Oxford. 414 pages.

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