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     data   graph     files  public Grazing preferences by herbivorous fishes in The Bahamas in 2011    ?     I   M   background (external link) RSS Subscribe BCO-DMO bcodmo_dataset_700177

The Dataset's Variables and Attributes

Row Type Variable Name Attribute Name Data Type Value
attribute NC_GLOBAL access_formats String .htmlTable,.csv,.json,.mat,.nc,.tsv
attribute NC_GLOBAL acquisition_description String Methods from Kindinger and Albins (2016) \"Consumptive and non-consumptive
effects of an invasive marine predator on native coral-reef

To quantify NCEs of invasive lionfish on native herbivores, we observed the
grazing behavior of herbivorous fishes at each of the 10 experimental reefs
over 10 consecutive days in July 2011, observing paired reefs on adjacent
days. Each day, we collected 20 haphazardly selected pieces of algal-covered
coral rubble (0.43\u20130.94 m2 surface area) from a nonexperimental reef
containing an extensive area of dead Acropora cervicornis coral rubble
inhabited by a high density of three-spot damselfish (Stegastes planifrons).
This territorial fish maintains higher standing stocks of farmed palatable
seaweeds via interspecific aggression in response to intruding herbivores
(Ceccarelli et al. 2001 ).\u00a0

Each piece of algal substratum was carefully placed into a plastic bag filled
with seawater, photographed out of water onboard a boat, returned to its
plastic bag, and transported in a cooler of seawater to a nearby experimental
reef. At high-lionfish-density reefs, we randomly assigned paired substrata to
two similar, but separate microhabitats (e.g., next to a coral head, on a
ledge, etc.) that differed only in the presence (\\\ 0.25 m away) versus
absence ([ 3 m away) of lionfish at the time of observation. At low-lionfish-
density reefs, we placed algal substrata in paired microhabitats that were
similar to those used at high-lionfish-density reefs, except lionfish were
always absent during observation. All replicates were therefore placed in
types of microhabitats frequented by lionfish, regardless of actual lionfish
presence. Overall, we observed grazing of translocated algal-covered substrata
at three levels of lionfish presence: (1) low-lionfish-density reef with
lionfish absent from the observed microhabitat (n = 100); (2) high-lionfish-
density reef with lionfish absent from the microhabitat (n = 50); and (3)
high-lionfish-density reef with lionfish present in the microhabitat (n = 50);
hereafter referred to as low -absent , high -absent , and high -present
treatments, respectively. These treatments were designed to provide insight on
the spatial scale at which lionfish presence affects herbivorous fish behavior
by allowing simultaneous comparisons of grazing behavior between (1) low- and
high-lionfish-densities at the reef-scale while controlling for lionfish
presence at the within-reef scale (i.e., low-absent vs. high-absent
treatments) and (2) lionfish presence-absence at the within-reef scale while
controlling for lionfish density at the reef-scale (i.e., high-absent vs.
high-present treatments).\u00a0

At each experimental reef, we monitored four of the translocated algal
substrata\u2014one pair in the morning (0900\u20131200) and one pair in the
afternoon (1400\u20131600)\u2014for 60 min each using automated underwater
video cameras placed approximately 3 m away. Meanwhile, we observed the
remaining 16 algal substrata with SCUBA (8 replicates per diver) one at a time
for 20 min each, with observations divided evenly throughout the day (2 pairs
in the morning and 2 pairs in the afternoon per diver). All observations were
therefore performed during the day when the probability of lionfish predation
is greatly reduced (Green et al. 2011 ; Cure et al. 2012 ) and all lionfish
observed were inactive. We identified the species of each fish that visited
these substrata, visually estimated its TL to the nearest cm, and counted the
number of times it took a bite of algae. Each fish was considered to be a
unique individual once it entered the diver\u2019s field of view
(approximately 2 m surrounding the focal rock), and continuing until the time
it left the field of view and could no longer be visually tracked. At the end
of each observation period, the algal substratum was carefully returned to its
plastic bag full of fresh seawater and kept underwater until all 20 replicates
had been observed. We then rephotographed each replicate onboard the

Grazing behavior observed at each replicate algal substratum was comprised of
the following response variables: (1) visitation rate (number of fish/minute);
(2) percent visitation rate (percent fish/minute); (3) bite rate (number of
bites/minute); and (4) individual bite rate (number of bites per fish/minute).
The percent visitation rate and individual bite rate allowed us to account for
any potential differences in herbivorous fish densities between low- and high-
lionfish-density reefs. Percent visitation rates were calculated by dividing
the total number of fish observed grazing (per substratum) by the total number
of herbivorous fish counted at each reef during the reef fish surveys
conducted just prior (June 2011) to the grazing observations (July 2011). For
all the herbivorous fish that grazed on each experimental substrate, the
number of bites each fish took during individual grazing bouts was averaged to
measure the individual bite rate. We also used the before and after
photographs of each substrate to estimate the percent loss of algal cover from
observed grazing. We quantified percent cover from photographs using the image
processing program, ImageJ.\u00a0

We analyzed the response of all herbivorous fishes that grazed on the
experimental substrate by fish size class (small and large , with large
encompassing the response among fishes[ 10 cm TL, which remained consistent
regardless of further size binning into medium and large size classes).
Parrotfishes accounted for 69.2 % of the herbivorous fishes that we observed
grazing. Therefore, the behavioral response (same variables as above) of this
fish family was also analyzed by fish size class. The remaining fish families
(surgeonfishes, angelfishes, and damselfishes) were not further divided by
size class, because such extensive division of each response variable would
have resulted in highly zero-inflated data. The percent loss of algae from
substrata was not analyzed by fish size class nor by fish family, because
individual contributions of each fish to the overall algal loss could not be

We fitted LMMs using a similar procedure as the one described above to account
for the nested design of the fish grazing surveys when comparing grazing
behavior of herbivorous fish among lionfish treatments. Random effects
consisted of paired microhabitats nested within paired reefs. In addition to
lionfish treatment (lowabsent, high-absent, and high-present), all full models
included the initial algal percent cover (algae ) of each replicate
substratumas a fixed factor in order to account for any influence this
parameter could have on grazing behavior, as well as an algae 9 lionfish
interaction. With the exception of the model of percent loss in algal cover,
we log-transformed all rate response variables and allowed variances to differ
among reefs with weighted terms to meet all assumptions of normality,
homogeneity, and independence. When lionfish treatment was significant in the
model based on LRTs, we performed multiple comparisons of the response at
every combination of lionfish treatments using Tukey\u2019s Honestly
Significant Difference (HSD) method. All statistical analyses of both reef
fish surveys and fish grazing observations were conducted using the
statistical software R (R Core Team 2014 ) with the associated packages, nlme
(Pinheiro et al. 2014 ) and multcomp (Hothorn et al. 2008 ).
attribute NC_GLOBAL awards_0_award_nid String 561016
attribute NC_GLOBAL awards_0_award_number String OCE-1233027
attribute NC_GLOBAL awards_0_data_url String http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1233027 (external link)
attribute NC_GLOBAL awards_0_funder_name String NSF Division of Ocean Sciences
attribute NC_GLOBAL awards_0_funding_acronym String NSF OCE
attribute NC_GLOBAL awards_0_funding_source_nid String 355
attribute NC_GLOBAL awards_0_program_manager String David L. Garrison
attribute NC_GLOBAL awards_0_program_manager_nid String 50534
attribute NC_GLOBAL cdm_data_type String Other
attribute NC_GLOBAL comment String Grazing Assays
M. Hixon and T. Kindinger
Version 16 May 2017
attribute NC_GLOBAL Conventions String COARDS, CF-1.6, ACDD-1.3
attribute NC_GLOBAL creator_email String info at bco-dmo.org
attribute NC_GLOBAL creator_name String BCO-DMO
attribute NC_GLOBAL creator_type String institution
attribute NC_GLOBAL creator_url String https://www.bco-dmo.org/ (external link)
attribute NC_GLOBAL data_source String extract_data_as_tsv version 2.3 19 Dec 2019
attribute NC_GLOBAL date_created String 2017-05-17T23:30:45Z
attribute NC_GLOBAL date_modified String 2019-03-28T19:07:11Z
attribute NC_GLOBAL defaultDataQuery String &time<now
attribute NC_GLOBAL doi String 10.1575/1912/bco-dmo.700177.1
attribute NC_GLOBAL infoUrl String https://www.bco-dmo.org/dataset/700177 (external link)
attribute NC_GLOBAL institution String BCO-DMO
attribute NC_GLOBAL keywords String algae, algae_initial, algae_pcntCoverChange, bco, bco-dmo, biological, bite, bite_number, change, chemical, cover, data, dataset, date, dmo, erddap, family, fish, fish_size, initial, management, micro, micro_treatment, number, observation, observation_time, oceanography, office, pair, pcnt, preliminary, replicate, replicate_number, replicate_pair, site, site_treatment, size, species, time, treatment
attribute NC_GLOBAL license String https://www.bco-dmo.org/dataset/700177/license (external link)
attribute NC_GLOBAL metadata_source String https://www.bco-dmo.org/api/dataset/700177 (external link)
attribute NC_GLOBAL param_mapping String {'700177': {}}
attribute NC_GLOBAL parameter_source String https://www.bco-dmo.org/mapserver/dataset/700177/parameters (external link)
attribute NC_GLOBAL people_0_affiliation String University of Hawaii
attribute NC_GLOBAL people_0_person_name String Mark Hixon
attribute NC_GLOBAL people_0_person_nid String 51647
attribute NC_GLOBAL people_0_role String Principal Investigator
attribute NC_GLOBAL people_0_role_type String originator
attribute NC_GLOBAL people_1_affiliation String Oregon State University
attribute NC_GLOBAL people_1_affiliation_acronym String OSU
attribute NC_GLOBAL people_1_person_name String Tye L. Kindinger
attribute NC_GLOBAL people_1_person_nid String 51707
attribute NC_GLOBAL people_1_role String Contact
attribute NC_GLOBAL people_1_role_type String related
attribute NC_GLOBAL people_2_affiliation String Woods Hole Oceanographic Institution
attribute NC_GLOBAL people_2_affiliation_acronym String WHOI BCO-DMO
attribute NC_GLOBAL people_2_person_name String Hannah Ake
attribute NC_GLOBAL people_2_person_nid String 650173
attribute NC_GLOBAL people_2_role String BCO-DMO Data Manager
attribute NC_GLOBAL people_2_role_type String related
attribute NC_GLOBAL project String BiodiversityLossEffects_lionfish
attribute NC_GLOBAL projects_0_acronym String BiodiversityLossEffects_lionfish
attribute NC_GLOBAL projects_0_description String The Pacific red lionfish (Pterois volitans), a popular aquarium fish, was introduced to the Atlantic Ocean in the vicinity of Florida in the late 20th century. Voraciously consuming small native coral-reef fishes, including the juveniles of fisheries and ecologically important species, the invader has undergone a population explosion that now ranges from the U.S. southeastern seaboard to the Gulf of Mexico and across the greater Caribbean region. The PI's past research determined that invasive lionfish (1) have escaped their natural enemies in the Pacific (lionfish are much less abundant in their native range); (2) are not yet controlled by Atlantic predators, competitors, or parasites; (3) have strong negative effects on populations of native Atlantic fishes; and (4) locally reduce the diversity (number of species) of native fishes. The lionfish invasion has been recognized as one of the major conservation threats worldwide.
The Bahamas support the highest abundances of invasive lionfish globally. This system thus provides an unprecedented opportunity to understand the direct and indirect effects of a major invader on a diverse community, as well as the underlying causative mechanisms. The PI will focus on five related questions: (1) How does long-term predation by lionfish alter the structure of native reef-fish communities? (2) How does lionfish predation destabilize native prey population dynamics, possibly causing local extinctions? (3) Is there a lionfish-herbivore-seaweed trophic cascade on invaded reefs? (4) How do lionfish modify cleaning mutualisms on invaded reefs? (5) Are lionfish reaching densities where natural population limits are evident?
attribute NC_GLOBAL projects_0_end_date String 2016-07
attribute NC_GLOBAL projects_0_geolocation String Three Bahamian sites: 24.8318, -076.3299; 23.8562, -076.2250; 23.7727, -076.1071; Caribbean Netherlands: 12.1599, -068.2820
attribute NC_GLOBAL projects_0_name String Mechanisms and Consequences of Fish Biodiversity Loss on Atlantic Coral Reefs Caused by Invasive Pacific Lionfish
attribute NC_GLOBAL projects_0_project_nid String 561017
attribute NC_GLOBAL projects_0_project_website String http://hixon.science.oregonstate.edu/content/highlight-lionfish-invasion (external link)
attribute NC_GLOBAL projects_0_start_date String 2012-08
attribute NC_GLOBAL publisher_name String Biological and Chemical Oceanographic Data Management Office (BCO-DMO)
attribute NC_GLOBAL publisher_type String institution
attribute NC_GLOBAL sourceUrl String (local files)
attribute NC_GLOBAL standard_name_vocabulary String CF Standard Name Table v55
attribute NC_GLOBAL summary String Grazing preferences by herbivorous fishes in The Bahamas in 2011
attribute NC_GLOBAL title String Grazing preferences by herbivorous fishes in The Bahamas in 2011
attribute NC_GLOBAL version String 1
attribute NC_GLOBAL xml_source String osprey2erddap.update_xml() v1.3
variable date   String  
attribute date bcodmo_name String date
attribute date description String Date of observation; YYYY/MM/DD
attribute date long_name String Date
attribute date nerc_identifier String https://vocab.nerc.ac.uk/collection/P01/current/ADATAA01/ (external link)
attribute date source_name String date
attribute date time_precision String 1970-01-01
attribute date units String unitless
variable site   String  
attribute site bcodmo_name String site
attribute site description String Name of study site (reef)
attribute site long_name String Site
attribute site units String unitless
variable site_treatment   String  
attribute site_treatment bcodmo_name String treatment
attribute site_treatment description String Lionfish treatment of site (reef): Low-lionfish-density reef or High-lionfish-density reef
attribute site_treatment long_name String Site Treatment
attribute site_treatment units String unitless
variable replicate_number   byte  
attribute replicate_number _FillValue byte 127
attribute replicate_number actual_range byte 1, 20
attribute replicate_number bcodmo_name String sample
attribute replicate_number colorBarMaximum double 100.0
attribute replicate_number colorBarMinimum double 0.0
attribute replicate_number description String Replicate number; replicates = algal-covered substrata placed in study site
attribute replicate_number long_name String Replicate Number
attribute replicate_number nerc_identifier String https://vocab.nerc.ac.uk/collection/P02/current/ACYC/ (external link)
attribute replicate_number units String unitless
variable replicate_pair   String  
attribute replicate_pair bcodmo_name String sample
attribute replicate_pair description String Replicate pairs
attribute replicate_pair long_name String Replicate Pair
attribute replicate_pair nerc_identifier String https://vocab.nerc.ac.uk/collection/P02/current/ACYC/ (external link)
attribute replicate_pair units String unitless
variable observation_time   byte  
attribute observation_time _FillValue byte 127
attribute observation_time actual_range byte 20, 60
attribute observation_time bcodmo_name String time_elapsed
attribute observation_time description String Length of observation
attribute observation_time long_name String Observation Time
attribute observation_time nerc_identifier String https://vocab.nerc.ac.uk/collection/P01/current/ELTMZZZZ/ (external link)
attribute observation_time units String minutes
variable micro_treatment   String  
attribute micro_treatment bcodmo_name String treatment
attribute micro_treatment description String Lionfish treatment of microhabitat where substrate was placed/observed: lionfish were absent or present during observation
attribute micro_treatment long_name String Micro Treatment
attribute micro_treatment units String unitless
variable algae_initial   float  
attribute algae_initial _FillValue float NaN
attribute algae_initial actual_range float 34.8745, 170.427
attribute algae_initial bcodmo_name String unknown
attribute algae_initial description String Initial amount of algae covering substrate
attribute algae_initial long_name String Algae Initial
attribute algae_initial units String centimeters squared
variable algae_pcntCoverChange   float  
attribute algae_pcntCoverChange _FillValue float NaN
attribute algae_pcntCoverChange actual_range float 9.0E-4, 0.4637
attribute algae_pcntCoverChange bcodmo_name String cover_pcent
attribute algae_pcntCoverChange description String Change in percent cover of algae quantified from before vs. after photos of substrate
attribute algae_pcntCoverChange long_name String Algae Pcnt Cover Change
attribute algae_pcntCoverChange units String percent
variable family   String  
attribute family bcodmo_name String family
attribute family description String Family of fish
attribute family long_name String Family
attribute family units String unitless
variable species   String  
attribute species bcodmo_name String species
attribute species description String Species of fish: species codes are first two letters of genus and species (see species key)
attribute species long_name String Species
attribute species units String unitless
variable fish_size   byte  
attribute fish_size _FillValue byte 127
attribute fish_size actual_range byte 2, 45
attribute fish_size bcodmo_name String fish_len
attribute fish_size description String Total body length of fish
attribute fish_size long_name String Fish Size
attribute fish_size units String centimeters
variable bite_number   short  
attribute bite_number _FillValue short 32767
attribute bite_number actual_range short 1, 242
attribute bite_number bcodmo_name String count
attribute bite_number colorBarMaximum double 100.0
attribute bite_number colorBarMinimum double 0.0
attribute bite_number description String Number of bites fish took of algae from substrata during observation
attribute bite_number long_name String Bite Number
attribute bite_number units String count

The information in the table above is also available in other file formats (.csv, .htmlTable, .itx, .json, .jsonlCSV1, .jsonlCSV, .jsonlKVP, .mat, .nc, .nccsv, .tsv, .xhtml) via a RESTful web service.

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