Table of Contents

• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Parameters
• Instruments
• Deployments
• Project Information
• Funding

Reef morphological dimensions (physical characteristics) were measured for each of 192 reefs in 2003, 2004 (reefs marked be letters only in this year), 2007, and 2009, 2012 and 2014. Beginning in 2012, reefs 129-144 and the added reefs 193-198 were manipulated for a project studying the effects of vermetid removals; information pertaining to this manipulation can be found in the project “Spatial patterns of coral-vermetid interactions: short-term effects and long-term consequences.” All data collected on reefs 129-144 and 193-198 beginning in 2012 can also be found under that project. In 2003, percent cover of nearest neighbor reefs were also estimated. Physical characteristic surveys are meant to characterize the size dimensions of each reef. We ultimately hope to use these data to inform how reef size and shape influence benthic composition and Thalassoma populations.

Location: Moorea, French Polynesia (17.48 degrees S, 149.82 degrees W)

Sampling and Analytical Methodology:

Data were collected for reefs 1-192, in 2003, 2004, 2007, 2009, 2012, and 2014. In 2004, letter-marked reefs were monitored. A diver swims up to one of the reefs. If the reef has two distinct sections they are labeled A and B randomly. Using a transect tape, the diver determines the maximum length and perpendicular width. Three height measurements are taken. After 2003, measurements were made by dropping a weighted transect tape from the water surface to an average high point on the reef (typical height), to the highest point on a reef (max height), and to the seafloor (H20 max height). In 2003, a diver measured from the sea floor to an average high point on the reef (typical height) and a high point on the reef (max height) with transect tape. In 2003, H20MHeight was the distance from the maximum height to the surface, measurements were made with a transect tape. 2003 data were converted to be congruent with 2004 onward. The percent cover and direction of the nearest neighbor reefs were also measured. These “Nearest Neighbor (NN)” estimates are conducted by visually estimating the percent area within 2 meters of the edge of the sampled reef that is comprised of hard/other substrate (in other words, it is the percent hard/other substrate cover surrounding the sampled reef within a 2 meter radius).

Materials: transect tape

Data Processing:
“NNAVGEST” was calculated as the average of each observer’s estimate (NNJEST, NNCWOEST, NNJSWETS, NNTAEST). When only one observer who was not originally listed in a column heading ((i.e., JS, CWO, JSW, TA) made observations, data was recorded directly into the NNAVGEST column.

NA- Not applicable (never recorded) to this data set
NR- Not recorded at certain times throughout the data set

BCO-DMO Processing Notes
- Generated from original file "LTR_PhysicalCharacteristics.csv" contributed by Rebecca Atkins
- Parameter names edited to conform to BCO-DMO naming convention found at Choosing Parameter Name
- Any blank rows removed

Description from NSF award abstract:
Ecologists have long been interested in the factors that drive spatial and temporal variability in population density and structure. In marine reef systems, attention has focused on the role of settlement-the transition of pelagic larvae to a benthic stage-and on density-dependent processes affecting recently settled juveniles. Recent data suggest that co-variance in settlement and subsequent density-dependent survival can obscure the patterns of density dependence at larger scales, a phenomenon called cryptic density dependence. This research will explore the mechanisms that underlie the spatial covariance of settlement and site quality - a process that has received little attention in the standard paradigm. These mechanistic studies of cryptic density dependence will facilitate the development of new frameworks for fish population dynamics that incorporate larval ecology, habitat quality, density dependence, life history, and the patterns and implications of spatial covariance among these factors. More generally, the work provides a specific empirical context, and a general theoretical treatment, of cryptic heterogeneity (hidden individual variation in demographic rates).

Note: Drs. Craig W. Osenberg and Ben Bolker were at the University of Florida at the time the NSF award was granted. Dr. Osenberg moved to the University of Georgia during the summer of 2014 (current contact information). Dr. Bolker moved to McMaster University in 2010 (current contact information).