Dataset: lionfish effects on grazing
Deployment: LSI_Reef_Surveys_09-12

Experiment comparing herbivorous fish grazing at reefs with manipulated lionfish densities.

Lead Principal Investigator:

Mark Hixon (Oregon State University, OSU)

Scientist:

Tye L. Kindinger (Oregon State University, OSU)

BCO-DMO Data Manager:

Shannon Rauch (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

Ecological Release and Resistance at Sea: Invasion of Atlantic Coral Reefs by Pacific Lionfish (Lionfish Invasion)

Current State:

Final no updates expected

Version:

16 Aug 2013

Version Date:

2013-08-16

Data URL:

https://www.bco-dmo.org/dataset-deployment/456071/data

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Description

A field experiment was conducted at Lee Stocking Islands, Bahamas from 07/22/2011 to 07/31/2011 to study the grazing activity of herbivorous fishes at reefs with manipulated lionfish (Pterois volitans) densities (low and high).

Methods & Sampling

Dataset acquisition description

The grazing rates of herbivorous fishes (bites/time) and the resulting algal loss rates (change in percent cover/time) were measured on paired-by-treatment, algal-covered substrata. At reefs with high lionfish densities, treatments consisted of the presence vs. absence of lionfish in local habitats where algal-covered substrata were distributed. Reefs with low lionfish densities included only the lionfish-absent treatment. Divers counted the number of bites on each replicate sample of algal-covered substratum for each herbivore observed during each of 16 replicate 20-min observation periods per reef. Herbivore behavior was sampled by 4 replicate 60-min automated video observations per reef. Each grazing herbivore was identified to the species-level and its total body length was estimated visually. Changes in percent algal cover were measured from before-after photographs of each replicate substratum using ImageJ.

Data Processing Description

Dataset Processing Description

BCO-DMO Processing Notes:
- Modified parameter names to conform with BCO-DMO naming conventions.
- Added lat and lon values, and other descriptive information, for each site from the metadata.
- Replaced abbreivated reef name with full reef name from metadata.
- Transposed/re-arranged family names into a column (rather than separate columns).
- 09-Jan-2018: removed embargo on dataset.

More information about this dataset deployment

Funding

Award Number	Funding Source
OCE-0851162	NSF Division of Ocean Sciences

Instruments

None available yet

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
date	Date when data were collected.	mm/dd/YYYY	date
site	Name of experimental reef site.	text	site
lat	Latitude of experimental reef site.	decimal degrees	lat
lon	Longitude of experimental reef site.	decimal degrees	lon
area	Approximate area of hard substrate at each reef location.	square meters	no_bcodmo_term
depth_min	Approximate minimum depth at reef location.	meters	depth_min
depth_max	Approximate maximum depth at reef location.	meters	depth_max
reef_pair_code	Reef pair code. Reefs with same code were paired based on similarities in reef area; type; depth and location. One reef in each pair was assigned to one of the two lionfish treatments.	code	no_bcodmo_term
nearest	Approximate distance to nearest natural reef.	meters	no_bcodmo_term
tidal_chan	Approximate distance to nearest tidal channel.	meters	no_bcodmo_term
ex_sound	Approximate distance to nearest edge of Exuma Sound.	meters	no_bcodmo_term
substrate_type	Short description of predominant substrate type.	text	no_bcodmo_term
site_treatment	Experimental treatment type. LOW = low lionfish density; HIGH = high lionfish density.	text	no_bcodmo_term
replicate	Replicate number of algal-covered substrate observed.	integer	replicate
treatment	Relative lionfish presence treatment (where grazing on replicate substrata were observed): CTRL = within low-lionfish density reef where lionfish are absent; LABS = within high-lionfish density reef where lionfish are absent; LPRS = within high-lionfish density reef where lionfish are present	text	no_bcodmo_term
ledge_pair	Ledges where replicate substrata were placed in order to observe grazing were paired by similar microhabitat within reefs (10 pairs per reef).	code	no_bcodmo_term
ledge_treatment	Lionfish presence-absence at time of observation.	text	no_bcodmo_term
filmed	Whether replicate was filmed with an underwater camera or observed by a SCUBA diver. Y = yes; N = no.	Y or N	no_bcodmo_term
obs_time	Amount of time replicate was observed.	minutes	time_elapsed
algal_pcnt_init	Initial algal percent cover of each replicate substrate prior to observation.	percentage	no_bcodmo_term
algal_pcnt_final	Final algal percent cover of each replicate substrate following observation.	percentage	no_bcodmo_term
algal_loss	Total loss in algal percent cover of each replicate substrate (difference between initial and final percent cover).	percentage	no_bcodmo_term
fish_count_tot	Total number of fish (of all families) observed grazing on introduced substrate per replicate.	integer	count
bites_tot	Total number of bites (from all families) observed on introduced substrate.	integer	no_bcodmo_term
prey_tot	Total number of fish (from all families)	integer	count
prey_bites_tot	Total number of bites from fish (from all families)	integer	no_bcodmo_term
adult_tot	Total number of fish (from all families) >10 cm TL observed grazing on introduced substrate per replicate.	integer	count
adult_bites_tot	Total number of bites from fish (from all families) >10 cm TL observed on introduced substrate.	integer	no_bcodmo_term
graze_rate	Total number of bites per observation time.	integer	no_bcodmo_term
family	Family name.	text	family
family_common	Common name of family.	text	family
count	Total number of fish of the family observed on introduced substrate. (Equal to prey_num + adult_num)	integer	count
number_of_bites	Total number of bites observed on introduced substrate per family of fishes. (Equal to prey_bites + adult_bites)	integer	no_bcodmo_term
prey_num	Number of prey fish (	integer	count
prey_bites	Number of bites observed by prey fish (	integer	no_bcodmo_term
adult_num	Number of adult fish (>10 cm TL) of the family observed on introduced substrate.	integer	count
adult_bites	Number of bites observed by adult fish (>10 cm TL) of the family on introduced substrate.	integer	no_bcodmo_term

Database

Contribute Data

Dataset: lionfish effects on grazing
Deployment: LSI_Reef_Surveys_09-12

Dataset acquisition description

Dataset Processing Description

Database

Contribute Data

Dataset: lionfish effects on grazingDeployment: LSI_Reef_Surveys_09-12

Dataset acquisition description

Dataset Processing Description

Dataset: lionfish effects on grazing
Deployment: LSI_Reef_Surveys_09-12