DOI: 10.5061/dryad.cfxpnvxmj
title: Habitat characteristics and priority effects shape fish and invertebrate assemblages inhabiting the coral <i>Pocillopora grandis</i> in Hawai'i

description: The structure of ecological communities is driven by an interplay of
 abiotic and biotic factors, yet the history of this interplay is less
 often considered. Priority effects, or how prior residents affect
 later-arriving individuals, can strongly affect local assemblage
 trajectory, potentially leading to indirect effects on ecosystem state or
 function. On Hawaiian reefs, pocilloporid corals provide the primary
 source of branching habitat for fishes and invertebrates, with Pocillopora
 grandis, the largest species, often hosting substantial, multispecies
 assemblages. Smaller Po. grandis colonies support assemblages dominated by
 an interference competitor, the Blue-eye Damselfish (Plectroglyphidodon
 johnstonianus), and/or a mesopredator, the Arc-eye Hawkfish (Paracirrhites
 arcatus), as well as mutualistic guard crabs of the genus Trapezia. Visual
 surveys showed that the assemblage size and abundance of other resident
 species, particularly the competitively inferior damselfish Dascyllus
 albisella and some guard crab species, increased greatly with colony size.
 During a six-month press removal of Pl. johnstonianus and Pa. arcatus on
 small Po. grandis colonies off the south shore of Oʻahu, Hawaiʻi, we
 tracked the colonization of fishes and invertebrates every two weeks in
 the presence and absence of these two strong interactors. By the end of
 the experiment, colonizing fish and invertebrate abundance were
 approximately 7- and 4-fold greater in the absence of the competitor and
 the predator, respectively. Likewise, fish and invertebrate species
 richness was approximately 6- and 1.7-fold greater, respectively. The
 damselfish D. albisella, of a genus known to benefit corals, was almost
 entirely prohibited by the strong interactors from colonizing these
 corals. However, trapezid guard crabs, while not directly manipulated
 during the experiment, were minimally affected. These results indicate
 that at smaller colony sizes, assemblages of fishes and invertebrates
 inhabiting Po. grandis in Hawaiʻi are likely inhibited by priority
 effects, potentially reducing mutualist interactions and affecting the
 host colony and local ecosystem function.
description: # Habitat characteristics and priority effects shape fish and invertebrate
 assemblages inhabiting the coral *Pocillopora grandis* in Hawai'i
 Dataset DOI:
 [10.5061/dryad.cfxpnvxmj](https://doi.org/10.5061/dryad.cfxpnvxmj) ##
 Description of the data and file structure Files contain data for the two
 parts of this study. Fish and invertebrate assemblages associated with
 *Pocillopora grandis* coral colonies in Hawaii were surveyed at three
 sites (Waikiki, Hanauma Bay, Kahe Point) to determine correlations between
 dominant fish and invertebrate species abundances with host colony and
 surrounding habitat characteristics. Host colony characteristics included
 colony volume (estimated from measurements of maximum diameter, orthogonal
 diameter, and height) and estimates of the percentage of living tissue.
 Surrounding habitat characteristics included the proportional cover of
 surrounding *Pocillopora meandrina* colonies, hardbottom, sand, and
 general structural complexity, as well as the relative height of
 surrounding 3D structure compared to the host colony (relief) and depth.
 These observational surveys (n = 492 surveys of 191 colonies) were
 conducted over 6 years for different studies that did not involve any
 manipulations.  Based on the results of this observational study
 component, a press removal experiment was designed to determine the
 effects of the prior arrival of the two most common fish species residing
 on *Pocillopora grandis* colonies, the Arc-eye Hawkfish (*Paracirrhites
 arcatus*) and the Blue-eye Damselfish (*Plectroglyphidodon
 johnstonianus*), on fish and invertebrate assemblage structure.
 Medium-sized *Pocillopora grandis* colonies (n=12; Waikiki site only) were
 paired and each pair were randomly divided into a removal colony and a
 control colony. One survey or associated fish and invertebrate assemblages
 was conducted on each colony prior to manipulations. At the beginning of
 the experiment, a pulse removal of all fish species (not including
 *Paracirrhites arcatus* and *Plectroglyphidodon johnstonianus*) was
 conducted on all twelve colonies. A six-month pulse removal of the two
 focal fish species was conducted on removal colonies (n = 6). Surveys of
 associated assemblages were conducted every 2 weeks, including colony and
 surrounding habitat characteristics. Measured colony characteristics
 included volume (see previous description of calculation), percentage of
 living colony tissue, and the average distance between five randomly
 selected pairs of branch tips (measure of inter-branch spacing). We also
 counted the number live *Pocillopora meandrina* colonies within the
 surrounding 100 square meters (10 x 10 m plot) as a measure of surrounding
 coral density. Statistical analyses included mixed effects models with all
 predictor variables (*Pocillopora grandis* colony volume, inter-branch
 spacing, and percent live tissue, as well as surrounding *P. meandrina*
 density) as fixed effects and colony ID, statistical block, date, and
 experimental day as random effects to account for repeated measures.
 Models were run with response variables for resident fish abundance and
 species richness, visiting fish abundance and species richness, *Dascyllus
 albisella* (competitor of *Plectroglyphidodon johnstonianus*) abundance,
 fish recruitment, invertebrate abundance and species richness, and guard
 crab abundance and species richness. Because the two focal fish species
 were continually removed from half of the colonies, recolonization of each
 species was also correlated with metrics of the colonizing fish assemblage
 structure on removal colonies (n = 6) to assess priority effects.  ###
 Files and variables #### File: Species.csv **Description:** Provides a key
 of all fish and invertebrate species identified in both the observational
 (environmental correlates) and experimental components of the study, and
 their unique species codes used in the data files.  ##### Variables *
 Species Code: the unique code for each species recorded in surveys *
 Species name: the species name associated with the code in the same row *
 Common name: the common name associated with the code in the same row ####
 File: Environmental_surveys.csv **Description:** Surveys conducted for the
 observational component of the study correlating associated fish and
 assemblage structure with host colony and surrounding habitat
 characteristics. A single survey is comprised of multiple rows in the
 dataset, as each row represents a different species within the assemblage
 (i.e., the number of species recorded in a survey is equal to the number
 of rows that survey takes up in the data set). ##### Variables * Year:
 year during which the survey occurred * Month: month during which the
 survey occurred * Day: day on which the survey occurred * Site: the site
 at which the *Pocillopora grandis* colony was surveyed (HAN: Hanauma Bay,
 KP: Kahe Point, WAI: Waikiki) * Time Step: the survey number for each
 coral (see description for POGR below). Because these data are
 consolidated from multiple data sets from different observational studies
 (i.e., no manipulations), Time Step numbers are unique within each data
 source (see description of Source below). The full breadth of surveys for
 a single colony across data sources can still be consolidated by survey
 date if desired * Source: These data are consolidated from multiple data
 sets from different observational studies (i.e.., no manipulations). This
 column indicates the four different studies (i.e., sources; Rec: a
 recruitment monitoring study, Misc: miscellaneous surveys that occurred as
 dive time allowed, Obs: a study correlating resident fish assemblage
 structure with host colony growth rates, Exp: surveys that occurred as
 part of the experimental component of this study prior to the beginning of
 any removals) * POGR: the identifying number for each *Pocillopora
 grandis* at each site. Numbers are unique to each site (i.e., 73 at
 Waikiki is not the same as 73 at Hanauma Bay) * Obs: initials of the
 person that conducted the survey * Type: indicates whether the recorded
 species in the row is a fish or invertebrate * Species: the recorded
 species (identified by species code) from a survey that is identified by
 metadata described above * Presence, &lt;0.5, 0.5, ...100, &gt;100: the
 estimated sizes (in cm) of individuals by species recorded in each survey.
 Presence was used to record species that were not sized (e.g., hermit
 crabs, echinoderms, etc.). All fish were sized by total length, crabs by
 carapace width, and shrimp by body length * Total: the total number of
 individuals recorded for the species in the associated row across all
 sizes * Notes: includes particular designations of the species recorded in
 that row (o/o: stands for "on & off" which designates that
 the fish recorded in that row did not spend the entirety of the survey
 time inhabiting the coral) * Notes2: includes extra notes about the
 species recorded in that row (descriptions of behavior, indications if the
 individuals were not identified to species, etc.) #### File:
 Environmental_corals.csv **Description:** measurements of the host
 *Pocillopora grandis* colony and surrounding habitat for each survey
 contained in Environmental_surveys.csv. Each row represents a single
 survey. Missing values are indicated by "NA" and represent
 variables that were not recorded for the survey represented in that row.
 ##### Variables * Year: year during which the survey occurred *
 Month: month during which the survey occurred * Day: day on which the
 survey occurred * Site: the site at which the *Pocillopora grandis* colony
 was surveyed (HAN: Hanauma Bay, KP: Kahe Point, WAI: Waikiki) *
 TimeStep: the survey number for each coral (see description for POGR
 below). Because these data are consolidated from multiple data sets from
 different observational studies (i.e., no manipulations), Time Step
 numbers are unique within each data source (see description of Source
 below). The full breadth of surveys for a single colony can still be
 consolidated survey date if desired * Source: These data are consolidated
 from multiple data sets from different observational studies (i.e.., no
 manipulations). This column indicates the four different studies (i.e.,
 sources; Rec: a recruitment monitoring study, Misc: miscellaneous surveys
 that occurred as dive time allowed, Obs: a study correlating resident fish
 assemblage structure with host colony growth rates, Exp: surveys that
 occurred as part of the experimental component of this study prior to the
 beginning of any removals) * POGR: the identifying number for each
 *Pocillopora grandis* at each site. Numbers are unique to each site (i.e.,
 73 at Waikiki is not the same as 73 at Hanauma Bay) * Depth(ft): the depth
 at which the coral occurs (feet) * %Alive: the estimated percentage of
 living tissue on the coral colony * Density: the approximate percentage
 (to the nearest 10%) of the surrounding 10m radius of habitat occupied by
 3D structure of any kind * Relief: a relative characterization of the
 surrounding 3D habitat (1: majority of habitat is shorter than the colony
 being surveyed, 2: majority of habitat is similar in height to the colony
 being surveyed, 3: majority of habitat is taller than the colony being
 surveyed) * POME: the approximate percentage (to the nearest 10%) of the
 surrounding 10m radius of habitat occupied by colonies of *Pocillopora
 meandrina* * POLO: the approximate percentage (to the nearest 10%) of the
 surrounding 10m radius of habitat occupied by colonies of *Porites lobata*
 * POCO: the approximate percentage (to the nearest 10%) of the surrounding
 10m radius of habitat occupied by colonies of *Porites compressa* *
 Hard: the approximate percentage (to the nearest 10%) of the surrounding
 10m radius of habitat occupied by hard substrate lacking living coral *
 Rubble: the approximate percentage (to the nearest 10%) of the surrounding
 10m radius of habitat occupied by rubble * Sand: the approximate
 percentage (to the nearest 10%) of the surrounding 10m radius of habitat
 occupied by sand * MaxD: from a top-down view, the maximum diameter of the
 coral colony to the nearest cm * OrtD: from a top-down view, the
 orthogonal diameter of the coral colony to the nearest cm * Height: the
 height of the coral colony to the nearest cm * Volumecm: a proxy for
 colony volume calculated by the equation for an elliptical cylinder using
 MaxD, OrtD, and Height in cubic cm * Volumem: a proxy for colony volume
 calculated by the equation for an elliptical cylinder using MaxD, OrtD,
 and Height in cubic m * InterAVG: the average measurement between five
 randomly selected branch tips as an estimate of inter-branch space (cm)
 #### File: Experiment_corals.csv **Description:** measurements of the host
 *Pocillopora grandis* colony and surrounding habitat for each survey
 contained in Experiment_surveys.csv. Each row represents a single survey.
 Missing values are indicated by "NA" and represent variables
 that were not recorded for the survey represented in that row. #####
 Variables * Year: year during which the survey occurred * Month: month
 during which the survey occurred * Day: day on which the survey occurred *
 Block: the statistical block (n = 6) for each *Pocillopora grandis* colony
 survey, with each block consisting of one removal colony and one control
 colony paired together * POGR: the identifying number for each
 *Pocillopora grandis* * TimeStep: the survey number for each host coral
 (-1: pre-manipulation survey, 1-15: surveys conducted during the press
 removal, 16-17: surveys conducted after the conclusion of the press
 removal and natural recolonization of the two focal species was allowed to
 resume) * Treat: the treatment that the *Pocillopora grandis* colony is
 part of (Removal or Control) * Depth(ft): the depth at which the coral
 occurs (feet) * %Alive: the estimated percentage of living tissue on the
 coral colony * %Light: the estimated percentage of tissue on the coral
 colony that appeared substantially lighter than the rest of the colony *
 %Bleach: the estimated percentage of tissue on the coral colony that
 appeared bleached * POMEs: the number of pocilloporid corals (almost
 exclusively *Pocillopora meandrina*) found in the surrounding 100 square
 meter plot (10x10m with *Pocillopora grandis* colony in the middle) as a
 measure of surrounding coral density * Density: the approximate percentage
 (to the nearest 10%) of the surrounding 10m radius of habitat occupied by
 3D structure of any kind * Relief: a relative characterization of the
 surrounding 3D habitat (1: majority of habitat is shorter than the colony
 being surveyed, 2: majority of habitat is similar in height to the colony
 being surveyed, 3: majority of habitat is taller than the colony being
 surveyed) * POME: the approximate percentage (to the nearest 10%) of the
 surrounding 10m radius of habitat occupied by colonies of *Pocillopora
 meandrina* * POLO: the approximate percentage (to the nearest 10%) of the
 surrounding 10m radius of habitat occupied by colonies of *Porites lobata*
 * POCO: the approximate percentage (to the nearest 10%) of the surrounding
 10m radius of habitat occupied by colonies of *Porites compressa* *
 Hard: the approximate percentage (to the nearest 10%) of the surrounding
 10m radius of habitat occupied by hard substrate lacking living coral *
 Rubble: the approximate percentage (to the nearest 10%) of the surrounding
 10m radius of habitat occupied by rubble * Sand: the approximate
 percentage (to the nearest 10%) of the surrounding 10m radius of habitat
 occupied by sand * MaxD: from a top-down view, the maximum diameter of the
 coral colony to the nearest cm * OrtD: from a top-down view, the
 orthogonal diameter of the coral colony to the nearest cm * Height: the
 height of the coral colony to the nearest cm * Volcm: a proxy for colony
 volume calculated by the equation for an elliptical cylinder using MaxD,
 OrtD, and Height in cubic cm * Volm: a proxy for colony volume calculated
 by the equation for an elliptical cylinder using MaxD, OrtD, and Height in
 cubic m * InterAVG: the average measurement between five randomly selected
 branch tips as an estimate of inter-branch space (cm) #### File:
 Experiment_recolonizations.csv **Description:** An accounting of the
 number of *Paracirrhites arcatus* and *Plectroglyphidodon johnstonianus*,
 the two fish species that were removed in the six-month long press removal
 experiment, that recolonized *Pocillopora grandis* colonies during the
 experiment.  ##### Variables * Block: the statistical block (n = 6) for
 each *Pocillopora grandis* colony survey, with each block consisting of
 one removal colony and one control colony paired together * POGR: the
 identifying number for each *Pocillopora grandis* colony * Period:
 indicates that these were recolonizations that occurred during the
 experiment (not after the press removal concluded and recolonization was
 allowed to occur naturally) * Species: the species that recolonized and
 was subsequently removed as part of the press removal (PAAR:
 *Paracirrhites arcatus*, PLJO: *Plectroglyphidodon johnstonianus*) *
 Removals: the number of recolonizations for each species that occurred on
 each colony for the entirety of the six-month press removal experiment.
 Each individual that recolonized a coral was subsequently removed ####
 File: Experiment_recruit_sizes.csv **Description:** The maximum size
 considered as a new recruit for all species recorded in surveys during the
 experiment for which recruitment (as opposed to adult immigration)
 occurred.  ##### Variables * Fish_species: the code of the species for
 which that row applies * Max_new_recruit_size_cm: the maximum size in cm
 (total length for fishes, carapace width for crabs) that the species was
 considered a new recruit * Max_recent_recruit_size_cm: the maximum size in
 cm (total length for fishes, carapace width for crabs) that the species
 was considered a juvenile #### File: Experiment_surveys.csv
 **Description:** Surveys conducted for the press removal experiment. A
 single survey is comprised of multiple rows in the dataset, as each row
 represents a different species within the assemblage (i.e., the number of
 species recorded in a survey is equal to the number of rows that survey
 takes up in the data set). ##### Variables * Year: year during which the
 survey occurred * Month: month during which the survey occurred * Day: day
 on which the survey occurred * TimeStep: the survey number for each host
 coral (-1: pre-manipulation survey, 1-15: surveys conducted during the
 press removal, 16-17: surveys conducted after the conclusion of the press
 removal and natural recolonization of the two focal species was allowed to
 resume) * ExpDay: the experimental day that the survey in question took
 place on, with initial removals occurring on Day 1 * Block: the
 statistical block (n = 6) for each *Pocillopora grandis* colony survey,
 with each block consisting of one removal colony and one control colony
 paired together * POGR: the identifying number for each *Pocillopora
 grandis* * Treat: the treatment that the *Pocillopora grandis* colony is
 part of (Removal or Control) * Obs: initials of the person that conducted
 the survey * Type: indicates whether the recorded species in the row is a
 fish or invertebrate * Species: the recorded species (identified by
 species code) from a survey that is identified by metadata described above
 * Presence, &lt;0.5, 0.5, ...100, &gt;100: the estimated sizes (in cm) of
 individuals by species recorded in each survey. Presence was used to
 record species that were not sized (e.g., hermit crabs, echinoderms,
 etc.). All fish were sized by total length, crabs by carapace width, and
 shrimp by body length * Total: the total number of individuals recorded
 for the species in the associated row across all sizes * Notes1: includes
 particular designations of the species recorded in that row (o/o: stands
 for "on & off" which designates that the fish recorded in
 that row did not spend the entirety of the survey time inhabiting the
 coral; underneath: designates fish and invertebrates that occurred
 underneath the colony and not on the colony itself; chased: indicates if
 the fish identified in the row were chased off of the coral by another
 species during the survey) * Notes2: includes extra notes about the
 species recorded in that row (descriptions of behavior, indications if the
 individuals were not identified to species, etc.) ## Code/software All
 files are in the .csv format and can be uploaded, viewed, and analyzed
 within the software *R*.  ## Access information Other publicly accessible
 locations of the data: * N/A Data was derived from the following sources:
 * N/A