Table of Contents

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

Reef morphological dimensions (physical characteristics) were measured specifically for the long term vermetid removal reefs (129-144 and 193-198) beginning in January of 2012. Physical characteristic surveys are meant to characterize the size dimensions of each reef. We ultimately hope to use these data to inform how vermetids influence reef size and shape and benthic composition.

Long Term Vermetid Removal (LTVR) Reef sites in this project are manipulated reefs characterized in the Long Term Reef Physical Characteristics dataset.

Reefs labeled "TOW" in this dataset, numbered 129-144, are a subset of a larger number of Long Term Reefs (LTR) that were monitored as part of the project "Cryptic density dependence: the effects of spatial, ontogenetic, and individual variation in reef fish" beginning in 2003. This long term study continues to monitor those reefs in addition to reefs 193-198 starting in 2012. Data for these reefs between the years 2003 and 2009 can be found on the project site http://www.bco-dmo.org/project/540423.

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

Other associated LTVR datasets:
LTVR - Fate of Reefs - Contains latitude and longitude of reefs used in this dataset 
LTVR - Fish Survey
LTVR - Percent Cover Point Contact
LTVR - Percent Visual Cover
LTVR - Pomacentrids
LTVR - Thalasssoma
LTVR - Vermetid Counts
LTVR - Vermetid Removal
LTVR - Vermetid Sizes in Quadrat

Sampling and Analytical Methodology:
Data were collected in 2012 for all reefs that are monitored. A diver swims up to one of the reefs. Using a transect tape, the diver determines the maximum length and perpendicular width. Three height measurements are taken: typical height, max height and water column depth. 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). The percent cover and direction of the nearest neighbor reefs were also measured during certain years. 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 "LTVR_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

Data version 2: 2017-12-20 replaces data version 1: 2016-05-23

BCO-DMO Data Manager Processing Notes for version 2017-12-20:
* Added a conventional header with dataset name, PI name, version date
* Modified parameter names to conform with BCO-DMO naming conventions
* added name "COMMENT" to un-named column with a comment in it.
* NA values changed to "nd" for "no data"
* NR values unchanged. NR indicates "not recorded" at certain times throughout the data set

Description from NSF abstract:
Ecological surprises are most likely to be manifest in diverse communities where many interactions remain uninvestigated. Coral reefs harbor much of the world's biodiversity, and recent studies by the investigators suggest that one overlooked, but potentially important, biological interaction involves vermetid gastropods. Vermetid gastropods are nonmobile, tube-building snails that feed via an extensive mucus net. Vermetids reduce coral growth by up to 80%, and coral survival by as much as 60%. Because effects vary among coral taxa, vermetids may substantially alter the structure of coral communities as well as the community of fishes and invertebrates that inhabit the coral reef.

The investigators will conduct a suite of experimental and observational studies that: 1) quantify the effects of four species of vermetids across coral species to assess if species effects and responses are concordant or idiosyncratic; 2) use meta-analysis to compare effects of vermetids relative to other coral stressors and determine the factors that influence variation in coral responses; 3) determine the role of coral commensals that inhabit the branching coral, Pocillopora, and evaluate how the development of the commensal assemblage modifies the deleterious effects of vermetids; 4) determine how vermetid mucus nets affect the local environment of corals and evaluate several hypotheses about proposed mechanisms; and 5) assess the long-term implications of vermetids on coral communities and the fishes and invertebrates that depend on the coral.

Note: The Principal Investigator, Dr. Craig W. Osenberg, was 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).