I. Data Set Descriptors A. Title: Steven C. Pennings. 2025. RTK survey of permanent monitoring plots at GCE sites 1-10 conducted between 2010 and 2022.. Georgia Coastal Ecosystems LTER Data Catalog (data set PLT-GCEM-2509; /data/PLT-GCEM-2509) B. Accession Number: PLT-GCEM-2509 C. Description 1. Originator(s): Name: Steven C. Pennings Address: Department of Biology and Biochemistry University of Houston Houston, Texas 77204-5513 Country: USA Email: scpennin@central.uh.edu 2. Abstract: Initial real time kinematic (RTK) GPS survey of ground elevations of the permanent monitoring plots at GCE sites 1-10 was conducted in June of 2010. Additional surveys of the active monitoring plots was conducted periodically through 2022. Plots that experienced terminal slump or could not be found for any reason were replaced with a new plot in the same general area with the plot code incremented by 10. For example if plot 3 was lost, it was replaced by 13, and then in turn by 23. This data set will be updated as future RTK measurement of the plots are made. 3. Study Type: Monitoring 4. Study Themes: Plant Ecology 5. LTER Core Areas: Primary Production 6. Georeferences: geographic coordinates as data columns 7. Submission Date: Sep 22, 2025 D. Keywords: elevation, GCE, GCE1, GCE10, GCE2, GCE3, GCE4, GCE5, GCE6, GCE7, GCE8, GCE9, Georgia, Georgia Coastal Ecosystems, global positioning system, LTER, plant communities, Primary Production, Sapelo Island, USA II. Research Origin Descriptors A. Overall Project Description 1. Project Title: Georgia Coastal Ecosystems LTER - IV 2. Principal Investigators: Name: Merryl Alber Address: Dept. of Marine Sciences University of Georgia Athens, Georgia 30602-3636 Country: USA Email: malber@uga.edu 3. Funding Period: Feb 01, 2019 to Jan 31, 2025 4. Objectives: The GCE-LTER project has four goals. 1) Track environmental and human drivers that can cause perturbations in our focal ecosystems. This will be accomplished this through continuing long-term measurements of climate, water chemistry, oceanic exchange, and human activities on the landscape. 2) Describe temporal and spatial variability in physical, chemical, geological and biological characteristics of the study system (coastal wetland complexes) and how they respond to external drivers. This will be accomplished through field monitoring in combination with remote sensing and modeling. 3) Characterize the ecological responses of intertidal marshes to disturbance. This will be accomplished by ongoing monitoring and experimental work to evaluate system responses to major perturbations in three key marsh habitats (changes in inundation and predator exclusion in Spartina-dominated salt marshes; increases in salinity in fresh marshes; changes in runoff in high marshes), by implementing standardized experimental disturbances along salinity and elevation gradients, and by tracking responses to natural disturbances. 4) Evaluate ecosystem properties at the landscape level (habitat distribution, net and gross primary production, C budgets) and assess the cumulative effects of disturbance on these properties. The project will also develop relationships between drivers and response variables, which can be used to predict the effects of future changes. This will be accomplished through a combination of data synthesis, remote sensing and modeling. 5. Abstract: The Georgia Coastal Ecosystems (GCE) Long Term Ecological Research (LTER) program, based at the University of Georgia Marine Institute on Sapelo Island, Georgia, was established in 2000 to study long-term change in coastal ecosystems. Estuaries (places where salt water from the ocean mixes with fresh water from the land) and their adjacent marshes provide food and refuge for fish, shellfish and birds; protect the shoreline from storms; help to keep the water clean; and store carbon. The GCE LTER researchers study marshes and estuaries to understand how these ecosystems function, to track how they change over time, and to predict how they might be affected by future changes in climate and human activities. They accomplish this by tracking the major factors that can cause long-term change in coastal areas (e.g. sea level, rainfall, upstream development), and measuring the effects of these factors on the study site. They also conduct focused studies to assess how key marsh habitats will respond to major changes expected in the future, including large-scale experiments to evaluate the effects of a) increases in the salinity of the water that floods freshwater marshes (mimicking drought and/or sea level rise), b) changes in water runoff from land into the upland marsh border (mimicking drought or upland development), and c) exclusion of larger organisms in the salt marsh (mimicking long-term declines in predators). During this award they will initiate additional studies to systematically evaluate how coastal wetlands respond to disturbances. Disturbances, or disruptions in the environment, are particularly important to understand in the context of long-term background changes such as increasing sea level, and GCE researchers are working to assess the cumulative effects of multiple disturbances on the landscape. The GCE education and outreach program works to share an understanding of coastal ecosystems with teachers and students, coastal managers, citizen scientist and the general public. 6. Funding Source: NSF OCE 1832178 B. Sub-project Description 1. Site Description a. Geographic Location: GCE1 -- Eulonia, Georgia, USA GCE2 -- Four Mile Island, Georgia, USA GCE3 -- North Sapelo, Sapelo Island, Georgia, USA GCE4 -- Meridian, Georgia, USA GCE5 -- Folly River, Georgia, USA GCE6 -- Dean Creek, Sapelo Island, Georgia, USA GCE7 -- Carrs Island, Georgia, USA GCE8 -- Alligator Creek, Georgia, USA GCE9 -- Rockdedundy Island, Georgia, USA GCE10 -- Hunt Camp, Sapelo Island, Georgia, USA Coordinates: GCE1 -- NW: 081 25 42.53 W, 31 32 48.30 N NE: 081 24 38.64 W, 31 32 48.30 N SE: 081 24 38.64 W, 31 32 02.27 N SW: 081 25 42.53 W, 31 32 02.27 N GCE2 -- NW: 081 19 08.26 W, 31 33 09.19 N NE: 081 17 34.24 W, 31 33 09.19 N SE: 081 17 34.24 W, 31 32 00.97 N SW: 081 19 08.26 W, 31 32 00.97 N GCE3 -- NW: 081 13 59.70 W, 31 32 48.72 N NE: 081 11 44.38 W, 31 32 48.72 N SE: 081 11 44.38 W, 31 30 54.68 N SW: 081 13 59.70 W, 31 30 54.68 N GCE4 -- NW: 081 22 14.71 W, 31 27 48.72 N NE: 081 21 26.12 W, 31 27 48.72 N SE: 081 21 26.12 W, 31 26 54.31 N SW: 081 22 14.71 W, 31 26 54.31 N GCE5 -- NW: 081 21 15.89 W, 31 26 33.14 N NE: 081 19 37.92 W, 31 26 33.14 N SE: 081 19 37.92 W, 31 25 03.50 N SW: 081 21 15.89 W, 31 25 03.50 N GCE6 -- NW: 081 17 58.28 W, 31 23 38.66 N NE: 081 15 51.76 W, 31 23 38.66 N SE: 081 15 51.76 W, 31 22 15.61 N SW: 081 17 58.28 W, 31 22 15.61 N GCE7 -- NW: 081 29 36.59 W, 31 20 55.59 N NE: 081 28 33.24 W, 31 20 55.59 N SE: 081 28 33.24 W, 31 20 03.71 N SW: 081 29 36.59 W, 31 20 03.71 N GCE8 -- NW: 081 25 34.58 W, 31 19 04.11 N NE: 081 24 38.28 W, 31 19 04.11 N SE: 081 24 38.28 W, 31 18 14.63 N SW: 081 25 34.58 W, 31 18 14.63 N GCE9 -- NW: 081 20 48.23 W, 31 21 29.31 N NE: 081 19 35.38 W, 31 21 29.31 N SE: 081 19 35.38 W, 31 20 21.02 N SW: 081 20 48.23 W, 31 20 21.02 N GCE10 -- NW: 081 17 43.82 W, 31 29 49.29 N NE: 081 15 32.07 W, 31 29 49.29 N SE: 081 15 32.07 W, 31 27 44.35 N SW: 081 17 43.82 W, 31 27 44.35 N b. Physiographic Region: GCE1 -- Lower coastal plain GCE2 -- Barrier island GCE3 -- Barrier island GCE4 -- Lower coastal plain GCE5 -- Barrier island GCE6 -- Barrier island GCE7 -- Lower coastal plain GCE8 -- Lower coastal plain GCE9 -- Barrier island GCE10 -- Barrier island c. Landform Components: GCE1 -- Intertidal salt marsh bordering maritime forest GCE2 -- Intertidal salt marsh GCE3 -- Intertidal salt marsh, mud flat, and maritime forest GCE4 -- Intertidal salt marsh bordering maritime forest GCE5 -- Intertidal salt marsh GCE6 -- Intertidal salt marsh, sand beach, maritime forest GCE7 -- Freshwater tidal marsh, devegetated fields GCE8 -- Brackish tidal marsh GCE9 -- Intertidal salt marsh GCE10 -- Intertidal salt marsh bordering maritime forest d. Hydrographic Characteristics: GCE1 -- Site contains the upper reaches of the Sapelo River, and is subject to 2-3m semi-diurnal tides GCE2 -- Site contains the Sapelo River and associated tidal creeks, and is subject to 2-3m semi-diurnal tides GCE3 -- Site includes Sapelo Sound and portions of Blackbeard Creek, and is subject to 2-3m semi-diurnal tides GCE4 -- Site includes Hudson Creek and is subject to 2-3m semi-diurnal tides GCE5 -- Site contains the Folly River and borders Doboy Sound, and is subject to 2-3m semi-diurnal tides GCE6 -- Site contains Dean Creek and borders Doboy Sound, and is subject to 2-3m semi-diurnal tides GCE7 -- Site contains Hammersmith Creek and borders the South Champney River, and is subject to 2-3m semi-diurnal tides GCE8 -- Site contains the Altamaha River, and is subject to 2-3m semi-diurnal tides GCE9 -- Site contains Crooked Creek and borders the Little Mud River, and is subject to 2-3m semi-diurnal tides GCE10 -- Site borders the Mud River and contains tidal creeks and the upper reach of the Duplin River, and is subject to 2-3m semi-diurnal tides e. Topographic Attributes: GCE1 -- Flat, with elevations ranging from 0-3m above mean low tide GCE2 -- Flat, with elevations ranging from 0-3m above mean low tide GCE3 -- Flat, with elevations ranging from 0-3m above mean low tide GCE4 -- Flat, with elevations ranging from 0-3m above mean low tide GCE5 -- Flat, with elevations ranging from 0-3m above mean low tide GCE6 -- Flat, with elevations ranging from 0-3m above mean low tide GCE7 -- Flat, with elevations ranging from 0-3m above mean low tide GCE8 -- Flat, with elevations ranging from 0-3m above mean low tide GCE9 -- Flat, with elevations ranging from 0-3m above mean low tide GCE10 -- Flat, with elevations ranging from 0-3m above mean low tide f. Geology, Lithology and Soils: GCE1 -- unspecified GCE2 -- unspecified GCE3 -- unspecified GCE4 -- unspecified GCE5 -- unspecified GCE6 -- unspecified GCE7 -- unspecified GCE8 -- unspecified GCE9 -- unspecified GCE10 -- unspecified g. Vegetation Communities: GCE1 -- Vegetation is 3/4 Juncus and 1/4 Spartina alterniflora, and upland area is heavily forested. GCE2 -- Spartina alterniflora all tall or medium. GCE3 -- Short and tall Spartina alterniflora, very small amounts of Juncus. GCE4 -- Vegetation is 1/4 Juncus, 3/4 medium and tall Spartina alterniflora. GCE5 -- Dominated by short and medium Spartina alterniflora, with areas of taller S. alterniflora near several small creeks. GCE6 -- Vegetation is mostly short and tall Spartina alterniflora, with small amounts of Juncus and Borrichia. GCE7 -- dominated by Zizaniopsis GCE8 -- Fringe of tall Spartina alterniflora and S. cynosuroides at creek banks. High marsh has narrow band of medium height S. alterniflora backed by vast expanses of Juncus. GCE9 -- Low marsh is tall Spartina alterniflora, high marsh has a small amount of medium Spartina alterniflora and lots of Juncus. Some hammocks with upland vegetation. GCE10 -- Vegetation mostly tall and medium Spartina alterniflora, with some Juncus present. Upland heavily forested. h. History of Land Use and Disturbance: GCE1 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 16, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4, C5, C6, C7, C8. The following creekbank plots are on creekbank areas that are collapsing: C5, C6, C8. No disturbance by animal activity was observed and no plots were replaced. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C5, C6, C7 and C8. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 25, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C7, C8. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C5, C6. The following plots are on creekbank areas that are collapsing: C18. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 16, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2, C16. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 22, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C3, C15. The following plots were disturbed by wrack or wildlife activity: C17, C18, C25. The following plots are on creekbank areas that are collapsing: C18. No plots were replaced. Oct 27, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C25, C26. The following plots were disturbed by wrack: C17, C18, C36. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 16, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7. No plots were disturbed or lost, and none were replaced. Oct 19, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C4, C17, C18, C36. The following plots are on creekbank areas that are collapsing: C4, C12, C18, C36. No plots were disturbed by wildlife and none were lost and replaced. Oct 25, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C36 (now C46), C17 (now C27), C18 (now C28). Oct 13, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed due to creekbank: C27, C36. No plots were disturbed by wrack or wildlife activity, and none were replaced. Oct 16, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C27. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C25 (replaced by C35), C26 (replaced by C36). Oct 17, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was noted; however, plots C35, C36 and C28 were renumbered as C45, C46 and C38, but in the same location for unspecified reasons. Oct 20, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C4, C46, C27, C38. The following plots are on creekbank areas that are collapsing (slumping): C4, C45, C27, C38. No plots were disturbed by wildlife. GCE2 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. Plot C6 was disturbed by wrack and Plots C3 and C4 were disturbed by creekbank slumping. Not plots were lost and none were replaced. Oct 18, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4, C5, C6. The following creekbank plots are on creekbank areas that are collapsing: C2, C6. The following plots were lost due to creekbank erosion or catastrophic wrack disturbance: C1 (replaced with C11). No disturbance by animal activity was observed. Oct 19, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C2. No disturbance by wrack or wildlife activity was observed, and no plots were replaced. Oct 22, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C4, C6, C8. No disturbance by wildlife activity was observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C2, C4. No disturbance by wrack or wildlife activity was observed, no plots were lost due to creekbank erosion, and no plots were replaced. Oct 17, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C12, C4, C6. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2. The following plots were lost for unknown reasons: C8. No plots were disturbed by wildlife, and no plots were replaced. Oct 23, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C4, C12, C13, C18. The following plots were disturbed by wrack or wildlife activity: C6, C7, C11, C22, C23. The following plots are on creekbank areas that are collapsing: C18. No plots were replaced. Oct 28, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C22, C28. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 15, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. Oct 19, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C5, C7, C11, C38. The following plots were lost due to creekbank erosion or catastrophic wrack disturbance: C14, C23 (replaced with C24 and C33, resp.). No plots were disturbed by wrack or wildlife. Oct 25, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C11 (now C21), C38 (now C48) Oct 13, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by creek bank erosion adjacent to the plot: C17, C24, C42. The following plot was disturbed by wrack: M4. No plots were lost or replaced. Oct 16, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C21 (replaced with C31), C5 (replaced with C15), C17 (replaced with 27). Oct 16, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance or catastrophic wildlife activity: C31, C27 (replaced with C41, C37, resp). Oct 22, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C6. The following plots are on creekbank areas that are collapsing (slumping): C41, C42, C33, C24, C15, C48. No plots were disturbed by wildlife and none were lost and replaced. GCE3 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 20, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4, C5, C6, C7, C8. The following plots were disturbed by wildlife (some have no shoots): M2, M5, M6, M7, M8 (snails). The following creekbank plots are on creekbank areas that are collapsing: C8. No plots were replaced. Oct 19, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C3, C4. The following plots were disturbed by wildlife (some have no shoots): M5, M6. The following creekbank plots are on creekbank areas that are collapsing: C8. The following plots were disturbed by marsh dieback: M7. No plots were lost due to creekbank erosion or catastrophic wrack inundation, and not plots were replaced. Oct 24, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C2, C3, C4, C5, C6, C7. The following plots were disturbed by wildlife (some have no shoots): M5, M7. No plots were lost due to creekbank erosion or catastrophic wrack inundation, and not plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance by wrack or wildlife activity was observed, no plots were lost due to creekbank erosion, and no plots were replaced. Oct 15, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C2, C3, C4, C5, C6 (plot C3 has no shoots). The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C6. No plots were disturbed by wildlife, and no plots were replaced. Oct 24, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C1, C2, C3, C4. No plots were lost and none were replaced. Oct 26, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C1, C2, C3. The following plots were distrurbed by wildlife (some may have no shoots): M5. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 17, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. Oct 20, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. Oct 27, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed and none were replaced. Oct 14, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed and none were replaced, but the following plots were observed to be too far from the creek bank and may be repositioned in the future: C7, C8. A new creek bank tributary is also forming near C5. Oct 18, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C4. The following plots were disturbed by wildlife: M6. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C5 (replaced with C15), C17 (replaced with 27). Oct 18, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C17. Not plots were lost and none were replaced. Oct 25, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C11. The following plots are on creekbank areas that are collapsing (slumping): C11, C12, C14, C28. The following plots were lost due to terminal slumping of the creekbank: C15, C17 (replaced with C25, C27). No plots were disturbed by wildlife and none were lost and replaced. GCE4 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 18, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4. The following plots were disturbed by wildlife (some have no shoots): M6, M8 (snails). No plots were disturbed by creekbank erosion or replaced. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C5, C8. No disturbance by wrack or wildlife activity were observed, and no plots were replaced. Oct 25, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C4. The following creekbank plots are on creekbank areas that are collapsing: C6. No plots were distrurbed by wildlife and no plots were lost or replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C6. No disturbance by wrack or wildlife activity was observed, no plots were lost due to creekbank erosion, and no plots were replaced. Oct 16, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C2, C3, C16. No plots were lost or disturbed by wildlife, and none were replaced. Oct 22, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C5, C7, C16. The following plots were disturbed by wrack or wildlife activity: C15, C26, M1, M3. No plots were replaced. Oct 27, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): M3 (no shoots). The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 16, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife: M3 (snails). No plots were disturbed by wrack or were on creekbank areas that are collapsing, and no plots were replaced. Oct 21, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance or catastrophic wildlife activity: C26 (replaced with C36). No plots were disturbed by wrack or wildlife or are on creekbank areas that are collapsing. Oct 25, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C3, C15. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C36 (now C46). Oct 13, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed and none were replaced, but C25 was slightly reposition due to nearby creekbank erosion. Oct 16, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed and none were replaced, but C25 was slightly reposition due to nearby creekbank erosion. Oct 17, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was noted, and not plots were replaced. Oct 20, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing (slumping): C3, C4, C5, C6. The following plots were lost due to terminal slumping of the creekbank: C1 (replaced with C11). No plots were disturbed by wildlife. GCE5 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 15, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C6, C7. No disturbance by wrack inundation or animal activity was observed, and no plots were replaced. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C7. No disturbance by wrack or wildlife activity were observed, and no plots were replaced. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C5. No plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7, C8. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 17, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C2. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C6. No plots were disturbed by wildlife and none were replaced. Oct 21, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C2, C4, C5, M2. No plots were lost and none were replaced. Oct 28, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C3, C5. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 15, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C3. No plots were disturbed by wildlife and no plots were lost and replaced. Oct 19, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C5. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C3 (replaced with C13). No plots were disturbed by wrack or wildlife. Oct 25, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7, C8. The following plots are on sections of creek bank that are collapsing: C5. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C3 (now C13). Oct 13, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plot was disturbed by nearby creekbank erosion: C13. The following plots were disturbed by wrack: C4, C5. Also, two missing markers were replaced at M5. Oct 15, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C13 (replaced with C23). Note that C8 was relabeled as C18 for unspecified reasons. Oct 16, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C5. The following plots were lost due to creekbank slumping: C23 (replaced with C33). Oct 21, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C2, C5. The following plots are on creekbank areas that are collapsing (slumping): C2, C5, C16, C7. No plots were disturbed by wildlife or lost and replaced. GCE6 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to catastrophic disturbance and replaced with new plots as indicated: zone 1, plot 3 (not replaced). Oct 19, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C1. The following plots were disturbed by wildlife (some have no shoots): M6, M7, M8 (snails). The following creekbank plots are on creekbank areas that are collapsing: C4, C5. No plots were replaced. Oct 17, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife (some have no shoots): M8. The following creekbank plots are on creekbank areas that are collapsing: C5. The following plots were lost due to creekbank erosion or catastrophic wrack inundation and were replaced: C2, C4 (replaced with C12, C14). Oct 22, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C12, C23, C5, C6, C8. The following plots were disturbed by wildlife (some have no shoots): M8. No plots were lost due to creekbank erosion, and none were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C5, C12. The following plots were disturbed by wildlife: M8. No plots were lost due to creekbank erosion, and none were replaced. Oct 15, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C23, C6, C7 (C1, C23 have no plants). The following plots were disturbed by wildlife (some have no shoots): M8. The following creekbank plots are on creekbank areas that are collapsing: C12, C14, C5. No plots were lost and none were replaced. Oct 23, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C5, C14, C22. The following plots were disturbed by wrack or wildlife activity: C15, C16, C23, M8. No plots were replaced. Oct 26, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C24. The following plots were disturbed by wrack: C23. The following plots were distrurbed by wildlife (some may have no shoots): M8 (no shoots). The following plots are on creekbank areas that are collapsing: C22, C23. No plots were replaced. Oct 16, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C22, C23. No other plots were disturbed by wildlife or wrack, and none were replaced. Oct 20, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C6. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C32 (replaced with C42). No plots were disturbed by wildlife or are on creekbank areas that are collapsing. Oct 25, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are located on sections of creek bank that are collapsing: C6, C33. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C15 (now C25). Oct 15, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C6, C8, C33, C34. No plots were disturbed by creekbank erosion or wildlife, but no living plants were observed in C34 and M5 is now in an apparent die-back zone. Oct 16, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C15 (replaced with C25), C16 (replaced with C26), C8 (replaced with 18). Oct 18, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was noted, and no plots were lost; however, plots C33, C34 and C26 were relabeled as C43, C44 and C36, resp. for unspecified reasons. Oct 15, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: M2. The following plots are on creekbank areas that are collapsing (slumping): C42, C36. The following plots were lost due to terminal slumping of the creekbank: C43, C44, C25 (replaced with C53, C54, C35). No plots were disturbed by wildlife. GCE7 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 17, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 17, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No evidence of plot disturbance was observed, and no plots were replaced. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No evidence of plot disturbance was observed, and no plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 14, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C7. No plots were disturbed by wrack or wildlife, and none were replaced. Oct 20, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were lost or disturbed by wrack or wildlife, and none were replaced. Oct 25, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 14, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. Oct 18, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. Oct 24, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C2 (now C12). Oct 12, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed by creekbank erosion, wrack or wildlife, and none were replaced. Oct 14, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C7. No plots were lost and none were replaced. Oct 20, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was noted, and no plots were replaced. Oct 23, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing (slumping): C3, C7. No plots were disturbed by wrack or wildlife and none were lost and replaced. GCE8 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to catastrophic disturbance and replaced with new plots as indicated: zone 1 plots 5, 6, 7, 8 (added new plots 15, 16, 17, 18). New plots were not in exactly the same locations as lost plots, and so have new numbers. Oct 17, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C4. The following plots were disturbed by wildlife (some have no shoots): M2, M3, M4, M7 (pigs). No disturbance due to creekbank collapse was observed, and no plots were replaced. Oct 17, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife (some have no shoots): M2, M4. The following creekbank plots are on creekbank areas that are collapsing: C2. No disturbance by wrack was observed, but plot M8 was merging with the path and was relocated as M18. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife (some have no shoots): M2. The following creekbank plots are on creekbank areas that are collapsing: C2. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: M3. No plots were replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing: C2, C16. The following plots were disturbed by wildlife: M1, M4. No plots were lost due to creekbank erosion, and none were replaced. Oct 14, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C1, C4, C15, C16, C17, C18. The following plots had no live shoots due to seasonal senescence: M2. No plots were disturbed by wrack or wildlife, and none were replaced. Oct 20, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost for unknown reasons: C2, C11. The following plots were disturbed by wrack or wildlife activity: M1, M2, M7, M13. No plots were replaced. Oct 25, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C26, M4. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 14, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife: M1, M2 (pigs). No plots were disturbed by wrack or were on creekbank areas that are collapsing, and no plots were lost or replaced. Oct 18, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C26. The following plots were disturbed by wildlife (some may have no shoots): M1, M2, M13 (pigs). The following creekbank plots are on creekbank areas that are collapsing: C12, C14. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C27, C28 (replaced with C37, C38 resp.). Oct 24, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on sections of creek bank that are collapsing: C25. The following plots were disturbed by wildlife and may have no shoots: M2, M13, M18. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: M1 (now M11). Oct 12, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife: M1, M2, M6, M7, M18. The following plot was lost due to creekbank erosion: C21 (replaced by C31). Also, no living plants were observed in plots M1, M2. Oct 14, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wildlife (some may have no shoots): M1, M2, M13 (pigs). The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C25 (replaced with C35). Oct 21, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was recorded, but plots C35, M1, M2 and M13 were renumbered as C45, M11, M12 and M23 for unspecified reasons. Oct 23, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C3. The following plots are on creekbank areas that are collapsing (slumping): C14. No plots were disturbed by wildlife and none were lost and replaced. GCE9 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes. Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to catastrophic disturbance and replaced with new plots as indicated: zone 1, plot 4 (added new plot 14). New plots were not in exactly the same locations as lost plots, and so have new numbers. Oct 17, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C5, C6, C8. The following creekbank plots are on creekbank areas that are collapsing: C1, C6. The following plots were lost due to creekbank erosion or catastrophic wrack disturbance: C3 (replaced with C13). No disturbance by wildlife activity was observed. Oct 18, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C1, C2, C6, C13. The following creekbank plots are on creekbank areas that are collapsing: C1, C2, C6. The following plots were lost due to creekbank erosion or catastrophic wrack inundation and were replaced: C5, C7, C8 (replaced with C15, C17, C18). No disturbance by wildlife activity was observed. Oct 23, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C13, C14, C6. No disturbance by wildlife activity was observed, and no plots were lost or replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C2, C18. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 14, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C14. No plots were disturbed by wildlife or lost, and none were replaced. Oct 21, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C1, C2, C13. No plots were lost and none were replaced. Oct 25, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: C2. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: C1, C13, C16. No plots were replaced. Oct 15, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C1, C13. The following plots were disturbed by wrack: C16. No plots were otherwise disturbed by wildlife or are on creekbank areas that are collapsing and none were replaced. Oct 21, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C16. The following plots are on creekbank areas that are collapsing: C16, C23. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: C2, C11, C14 (replaced with C12, C21 and C24, resp.). No plots were disturbed by wildlife. Oct 24, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C24. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity and were replaced: C16 (now C26), C23 (now C32). Oct 12, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed by creekbank erosion, wrack or wildlife, and none were replaced. Oct 15, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following creekbank plots are on creekbank areas that are collapsing: C18. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife: C21 (replaced with C31), C33 (replaced with C43). Oct 15, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was observed, and no plots were replaced. Oct 21, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No disturbance was observed, and no plots were replaced. GCE10 -- Oct 01, 2000: Permanent plots were established in two nominal marsh zones based on marsh structure -- creek zone and high marsh -- and eight plots were randomly located in each zone and marked with stakes Oct 01, 2001: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No significant disturbance was observed, and no plots were replaced. Oct 20, 2002: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C1, C2, C3, C4, C5, C6, C8. The following plots were disturbed by wildlife (some have no shoots): M5 (snails). No disturbance by creekbank erosion or collapse was observed, and no plots were replaced. Oct 19, 2003: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack (some have no shoots): C3, M1. The following plots were disturbed by wildlife (some have no shoots): M5. The following creekbank plots are on creekbank areas that are collapsing: C2. No plots were replaced. Oct 22, 2004: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C7. No disturbance by wildlife was observed, and no plots were lost or replaced. Oct 21, 2005: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were distrurbed by wildlife, none were lost due to creekbank erosion, and none were replaced. Oct 15, 2006: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. Note that a new zone (zone 3) was added at site GCE10 in 2005. This is a juncus zone in the high marsh. Oct 24, 2007: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack or wildlife activity: C1, C2, C3, C4, C8, M1, M2. The following plots are on creekbank areas that are collapsing: C13. No plots were lost and none were replaced. Oct 26, 2008: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were lost due to creekbank erosion, catastrophic wrack disturbance, or catastrophic wildlife activity: none. The following plots were disturbed by wrack: none. The following plots were distrurbed by wildlife (some may have no shoots): none. The following plots are on creekbank areas that are collapsing: none. No plots were replaced. Oct 17, 2009: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C3. No plots were disturbed by wildlife, and none are on creekbank areas that are collapsing or were replaced. Oct 20, 2010: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed or lost, and none were replaced. Oct 26, 2011: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed and none were replaced. Oct 14, 2012: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C6, C7. The following plots were repositioned due to nearby creekbank erosion: C12, C13. No plots were lost and none were replaced. Oct 13, 2013: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. No plots were disturbed, and none were lost and replaced. Oct 18, 2014: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots were disturbed by wrack: C1, C12, C13, C5. No plots were lost and none were replaced. Oct 24, 2015: Plots were examined for signs of disturbance by wrack inundation, animal activity, and creek bank erosion. The following plots are on creekbank areas that are collapsing (slumping): C1. No plots were disturbed by wrack or wildlife and none were lost and replaced. i. Climate: Climate summary for Sapelo Island, Georgia, based on NWS data from 1980-2010: Daily-aggregated Values: Mean (sample standard deviation) mean air temperature: 20.09°C (7.28°C) minimum air temperature: 15.02°C (7.96°C) maximum air temperature: 24.82°C (6.98°C) total precipitation: 3.26mm (10.3mm) Yearly-aggregated Daily Values: Mean (sample standard deviation) total precipitation (1980-2010): 1124mm (266mm) 2. Experimental or Sampling Design a. Design Characteristics: We established permanent vegetation monitoring plots in creekbank and midmarsh at GCE sites 1-10 in 2000. A dedicated Juncus zone was later added at sites 10 and 9. b. Permanent Plots: Active plots were measured at each survey. Some plots were lost and replaced with a new plot in the same general area with the plot code incremented by 10. For example if plot 3 was lost, it was replaced by 13, and then in turn by 23. c. Data Collection Duration and Frequency: Initial real time kinematic (RTK) GPS survey of ground elevations of the permanent monitoring plots at GCE sites 1-10 was conducted in June of 2010. In the 2010 survey, the location was measured at the mid-point of the plot edge furthest from the creek. A second survey of the active monitoring plots was conducted during July and August, 2022. Beginning of Observations: Jun 01, 2010 End of Observations: Sep 01, 2022 3. Research Methods a. Field and Laboratory Methods: Method 1: 2010 - 2015 RTK Survey -- At each sampling location the RTK Rover foot was placed flush with the marsh surface and care was taken to leave the sediment and vegetation undisturbed. The measurements were taken at the mid-point of the plot edge furthest from the creek. For each sampling location, the RTK was set to record 5 sec readings, with a logging interval of 1 sec. Other RTK settings included: 10 degree elevation mask, PDOP mask of 6, minimum vertical precision of 0.015 m and a minimum horizontal precision of 0.020 m. All RTK observations were automatically stored in the handheld Trimble Survey Controller and uploaded to the LTER GIS computer using the Trimble Geomatics Office Software. Method 2: 2021 - 2022 RTK Survey -- At each sampling location the RTK Rover foot was placed flush with the marsh surface and care was taken to leave the sediment and vegetation undisturbed. The measurements were taken at the mid-point of the plot edge on the upstream side of the creek. All RTK observations were automatically stored in the handheld Trimble Survey Controller and uploaded to the LTER GIS computer using the Trimble Geomatics Office Software. b. Protocols: Method 1: none Method 2: none c. Instrumentation: Method 1: RTK GPS Manufacturer: Trimble (Model: R6) Parameter: Elevation (Accuracy: 20mm + 1 ppm RMS, Readability: 1mm, ) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Latitude (Accuracy: 10 mm + 1 ppm RMS, Readability: 1mm, Range: 0-90 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Longitude (Accuracy: 10 mm + 1 ppm RMS, Readability: 1mm, Range: 0-180 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Method 2: RTK GPS Manufacturer: Trimble (Model: R12i) Parameter: Elevation (Accuracy: 15mm + 0.5ppm RMS, Readability: 1mm, ) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Latitude (Accuracy: 8mm + 0.5ppm RMS, Readability: 1mm, Range: 0-90 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. Parameter: Longitude (Accuracy: 8mm + 0.5ppm RMS, Readability: 1mm, Range: 0-90 degrees) Protocol: Base receiver is placed on a permanent cement base installed near each field site, connected to GLONASS satellite services via mobile 3G Internet connection, and allowed to establish a stable benchmark positional fix. A portable wireless rover unit is then used to collect and log horizontal position and vertical elevation data for sites being surveyed. d. Taxonomy and Systematics: Method 1: not applicable Method 2: not applicable e. Speclies List: f. Permit History: Method 1: not applicable Method 2: not applicable 4. Project Personnel a. Personnel: 1: Steven C. Pennings 2: Christine M. Hladik 3: Jonah Michael Rigdon b. Affiliations: 1: University of Houston, Houston, Texas 2: Georgia Southern University, Statesboro, Georgia 3: University of Georgia Marine Institute III. Data Set Status and Accessibility A. Status 1. Latest Update: 08-Oct-2025 2. Latest Archive Date: 08-Oct-2025 3. Latest Metadata Update: 08-Oct-2025 4. Data Verification Status: Reviewed by IM B. Accessibility 1. Storage Location and Medium: Stored at GCE-LTER Data Management Office Dept. of Marine Sciences Univ. of Georgia Athens, GA 30602-3636 USA on media: electronic data download (WWW) or compact disk 2. Contact Person: Name: Adam Sapp Address: Department of Marine Sciences University of Georgia Athens, Georgia 30602 Country: USA Email: asapp@uga.edu 3. Copyright Restrictions: not copyrighted 4. Restrictions: This information is licensed under a Creative Commons Attribution 4.0 International License (see: https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) has an ethical obligation to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. a. Release Date: Affiliates: Sep 22, 2025, Public: Sep 22, 2027 b. Citation: Data provided by the Georgia Coastal Ecosystems Long Term Ecological Research Project, supported by funds from NSF OCE 1832178 (data set PLT-GCEM-2509) c. Disclaimer: The user assumes all responsibility for errors in judgement based on interpretation of data and analyses presented in this data set. 5. Costs: free electronic data download via WWW, distribution on CD may be subject to nominal processing and handling fee IV. Data Structural Descriptors A. Data Set File 1. File Name: PLT-GCEM-2509_1_0.CSV 2. Size: 343 records 3. File Format: ASCII text (comma-separated value format) 3a. Delimiters: single comma 4. Header Information: 5 lines of ASCII text 5. Alphanumeric Attributes: 6. Quality Control Flag Codes: Q = questionable value, I = invalid value, E = estimated value 7. Authentication Procedures: 8. Calculations: 9. Processing History: Software version: GCE Data Toolbox Version 3.9.10 (23-May-2022) Data structure version: GCE Data Structure 1.1 (29-Mar-2001) Original data file processed: PlotCoods.txt (343 records) Data processing history: 08-Oct-2025: new GCE Data Structure 1.1 created ('newstruct') 08-Oct-2025: 343 rows imported from ASCII data file 'PlotCoods.txt' ('imp_ascii') 08-Oct-2025: 13 metadata fields in file header parsed ('parse_header') 08-Oct-2025: data structure validated ('gce_valid') 08-Oct-2025: automatically assigned study date metadata descriptors based on the range of date values in date/time columns (add_studydates) 08-Oct-2025: sorted by column Date_Measured(ascending) ('sortdata') 08-Oct-2025: sorted by columns Date_Measured(ascending), Site(ascending), Zone(ascending) ('sortdata') 08-Oct-2025: updated 1 metadata fields in the Dataset section(s) ('addmeta') 08-Oct-2025: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 08-Oct-2025: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement section(s) ('addmeta') 08-Oct-2025: copied/reordered columns Location, Site, Site_name, Zone, Plot, Description, UTM_Zone, UTM_Northing, UTM_Easting, UTM_Datum, Longitude, Latitude, Elevation, Elevation_Datum, Date_Measured and Duplicate ('copycols') 08-Oct-2025: updated 1 metadata fields in the Dataset section(s) ('addmeta') 08-Oct-2025: imported Dataset, Project, Site, Study, Status, Supplement metadata descriptors from the GCE Metabase ('imp_gcemetadata') 08-Oct-2025: updated 57 metadata fields in the Dataset, Project, Site, Status, Study, Supplement section(s) ('addmeta') 08-Oct-2025: Units of column Elevation_Datum changed from 'non' to 'none ('ui_editor') 08-Oct-2025: updated 6 metadata fields in the Data section(s) ('addmeta') 08-Oct-2025: updated 15 metadata fields in the Status, Data sections to reflect attribute metadata ('updatecols') 08-Oct-2025: parsed and formatted metadata ('listmeta') B. Variable Information 1. Variable Name: column 1. Location column 2. Site column 3. Site_name column 4. Zone column 5. Plot column 6. Description column 7. UTM_Zone column 8. UTM_Northing column 9. UTM_Easting column 10. UTM_Datum column 11. Longitude column 12. Latitude column 13. Elevation column 14. Elevation_Datum column 15. Date_Measured column 16. Duplicate 2. Variable Definition: column 1. Geographic location code in the GCE Metadata Database for the sampling plot column 2. GCE LTER sampling site number column 3. GCE LTER sampling site name column 4. Nominal marsh zone column 5. Permanent plot number column 6. Location description column 7. UTM zone column 8. UTM northing column 9. UTM easting column 10. UTM datum column 11. Longitude in decimal degrees column 12. Latitude in decimal degrees column 13. Plot elevation in meters column 14. Elevation datum column 15. Date of location measurement column 16. Duplicate measurement of previously measured plot (0 = no, 1 = yes) 3. Units of Measurement: column 1. none column 2. none column 3. none column 4. none column 5. none column 6. none column 7. none column 8. m column 9. m column 10. none column 11. degrees column 12. degrees column 13. m column 14. none column 15. YYYY-MM-DD column 16. none 4. Data Type a. Storage Type: column 1. string column 2. integer column 3. string column 4. integer column 5. integer column 6. string column 7. string column 8. floating-point column 9. floating-point column 10. string column 11. floating-point column 12. floating-point column 13. floating-point column 14. string column 15. string column 16. integer b. Variable Codes: Site: 1 = GCE1 (Eulonia), 2 = GCE2 (Four Mile Island), 3 = GCE3 (North Sapelo), 4 = GCE4 (Meridian), 5 = GCE5 (Folly River), 6 = GCE6 (Dean Creek), 7 = GCE7 (Carrs Island), 8 = GCE8 (Alligator Creek), 9 = GCE9 (Rockdedundy Island), 10 = GCE10 (Hunt Camp) Zone: 1 = creek bank zone, 2 = mid-marsh zone, 3 = additional Juncus zone in high marsh c. Numeric Range: column 1. (none) column 2. 1 to 10 column 3. (none) column 4. 1 to 3 column 5. 1 to 68 column 6. (none) column 7. (none) column 8. 3463759.157 to 3489472.248 column 9. 454458.573 to 478274.271 column 10. (none) column 11. -81.4787 to -81.2288 column 12. 31.3075 to 31.5395 column 13. -0.752 to 1.07 column 14. (none) column 15. (none) column 16. 0 to 1 d. Missing Value Code: 5. Data Format a. Column Type: column 1. text column 2. numerical column 3. text column 4. numerical column 5. numerical column 6. text column 7. text column 8. numerical column 9. numerical column 10. text column 11. numerical column 12. numerical column 13. numerical column 14. text column 15. text column 16. numerical b. Number of Columns: 16 c. Decimal Places: column 1. 0 column 2. 0 column 3. 0 column 4. 0 column 5. 0 column 6. 0 column 7. 0 column 8. 3 column 9. 3 column 10. 0 column 11. 6 column 12. 6 column 13. 3 column 14. 0 column 15. 0 column 16. 0 6. Logical Variable Type: column 1. free text (none) column 2. nominal (discrete) column 3. free text (none) column 4. coded value (discrete) column 5. nominal (discrete) column 6. free text (none) column 7. free text (none) column 8. geographic coordinate (continuous) column 9. geographic coordinate (continuous) column 10. free text (none) column 11. geographic coordinate (continuous) column 12. geographic coordinate (continuous) column 13. geographic coordinate (continuous) column 14. free text (none) column 15. datetime (none) column 16. logical (discrete) 7. Flagging Criteria: column 1. none column 2. none column 3. none column 4. none column 5. none column 6. none column 7. none column 8. none column 9. none column 10. none column 11. none column 12. none column 13. none column 14. none column 15. none column 16. none C. Data Anomalies: V. Supplemental Descriptors A. Data Acquisition 1. Data Forms: 2. Form Location: 3. Data Entry Validation: B. Quality Assurance/Quality Control Procedures: C. Supplemental Materials: D. Computer Programs: E. Archival Practices: F. Publications: not specified G. History of Data Set Usage 1. Data Request History: not specified 2. Data Set Update History: none 3. Review History: none 4. Questions and Comments from Users: none