|Geange, Shane||Victoria University of Wellington||Principal Investigator, Contact|
|Shima, Jeffrey||Victoria University of Wellington||Co-Principal Investigator|
|Stier, Adrian||University of Washington (UW)||Co-Principal Investigator|
|Biddle, Mathew||Woods Hole Oceanographic Institution (WHOI BCO-DMO)||BCO-DMO Data Manager|
This dataset is from a manipulative experiment investigating the independent and combined effects of priority effects and habitat complexity on the strength of intraspecific competitive interactions among recently settled individuals of a coral reef fish (Thalassoma quinquevittatum: Labridae). This research was conducted in 2008 at the Gump Biological Research Station, Moorea, French Polynesia in the northern lagoon (17 30’ S, 149 50’ W).
This file describes the size distribution of Pocillopora colonies used in the experiment. For additional data, please see files listed in Related Datasets.
This dataset describes the size distribution of Pocillopora colonies used in the experiment.
We examined the effects of habitat complexity and timing of arrival in the context of the survival of focal Thalassoma quinquevittatum settlers. The study was conducted in the northern lagoon of Moorea between April and June 2008. We used an array of 30 isolated live-coral patch reefs separated by *10 m in water 2–4 m deep. Reefs were located within a sand-flat, separated from each other, and from nearby natural reefs, by a minimum of 15 m. We constructed reefs to minimize habitat variation by standardizing size, rugosity, and water depth. Each reef consisted of a base of live Porites lobata coral with an average area of 2.23 m2 (SD = 0.56), and a mean height of 0.59 m (SD = 0.10). We controlled habitat complexity by manipulating the availability of the branching coral Pocillopora verrucosa. This was achieved by drilling holes into the upper surface of patch reefs. Into these holes, we inserted stainless steel pins attached to P. verrucosa colonies with Z-Spar Splash Zone Compound (Kopcoat, Pittsburgh, PA, USA). Mean colony surface area was 0.2 m2 (SD = 0.07). We crossed the availability of P. verrucosa (two levels: two, or four colonies) with the presence of three tagged T. quinquevittatum competitors (three levels: absent, introduced simultaneously with (0 days), or 5 days earlier than the focal individuals). To each reef, we simulated settlement by introducing three tagged T. quinquevittatum focal individuals. Thus, our design had six treatments: (1) focal individuals without competitors, with two P. verrucosa colonies; (2) focal individuals and competitors introduced simultaneously, with two P. verrucosa colonies; (3) focal individuals with competitors introduced 5 days previously, with two P. verrucosa colonies; (4) focal individuals without competitors, with four P. verrucosa colonies; (5) focal individuals and competitors introduced simultaneously, with four P. verrucosa colonies; and (6) focal individuals with competitors introduced 5 days previously, with four P. verrucosa colonies. We ran the experiment in two temporal blocks (17–23 April and 1–7 May 2008), yielding ten replicates (five in each temporal block) for each of the six treatments. We surveyed reefs twice daily (approximately 0800 and 1600 hours) for 5 days after the introduction of focal individuals.
poc_area_m2 was calculated as the total surface area of a rectangle using over_top_length, over_top_width, and max_height.
|colony||unique identifier for each Pocillopora colony||unitless|
|over_top_length||distance in meters of the over the top length of the Pocillopora colony||meters (m)|
|over_top_width||distance in meters of the over the top width of the Pocillopora colony||meters (m)|
|max_height||distance in meters of the maximum height of the Pocillopora colony||meters (m)|
|poc_area_m2||surface area of the Pocillopora colony in square meters (calculated as the total surface area of a rectangle using over_top_length over_top_width and max_height.)||square meters (m2)|
Osenberg et al Moorea
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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).