|Hixon, Mark||Oregon State University (OSU)||Lead Principal Investigator|
|Ingeman, Kurt||Oregon State University (OSU)||Scientist|
|Rauch, Shannon||Woods Hole Oceanographic Institution (WHOI BCO-DMO)||BCO-DMO Data Manager|
This dataset contains counts of fairy basslet at reefs near Eleuthera, Bahamas prior to any manipulation of lionfish or basslet density.
To rigorously test whether and how lionfish have altered prey density-dependent dynamics, a manipulation was conducted of both basslet and lionfish densities in a cross-factored design, such that differences in patterns of mortality between treatments could be attributable to lionfish predation alone. Because density-dependent basslet mortality was attributed to predators aggregating preferentially near high prey concentrations, predatory behavior of both native and invasive predators was also examined in order to determine whether differences in any aggregative response could explain different patterns of prey mortality.
During the summer of 2012, a field experiment was conducted on 14 isolated patch reefs near the Cape Eleuthera Institute, Eleuthera, Bahamas. Reefs were paired into blocks by location, size, depth, and vertical relief so that reefs in each block demonstrated similar environmental characteristics. Reefs were then randomly assigned to one of two lionfish treatments: low lionfish reefs (where divers regularly removed lionfish), and high lionfish reefs (where lionfish were added to maintain differential lionfish densities. At each reef, the investigator selected two isolated populations of fairy basslet on small ledges sufficiently separated from each other and from other suitable basslet habitat to inhibit emigration or immigration. Populations were then randomly assigned to either receive artificially increased recruitment or remain unmanipulated. Following the establishment of treatments, the investigator returned to census each population after two days, four days and weekly thereafter, with a final census after four weeks. During each census, the investigator recorded the size of each basslet (adult and juvenile), the total population size, any predators within 2-m of the target basslet ledge, and whether those predators where actively hunting among the experimental basslet populations.
BCO-DMO Processing Notes:
- Added lat and lon for each site from the metadata provided.
- Converted lat and lon from degrees and decimal minutes to decimal degrees.
- Modified parameter names to conform with BCO-DMO naming conventions.
- Replaced 'Y' and 'N' with 'Yes' and 'No' where applicable.
- 28-Dec-2017: removed embargo from dataset.
|site||Name of reef site.||text|
|lat||Latitude of reef site.||decimal degrees|
|lon||Longitude of reef site.||decimal degrees|
|pair||Number of reef pair (each pair forms one experimental block).||integer|
|ledge_tag||Two-digit numeral corresponding to ear tag ledge marker.||dimensionless|
|lionfish_present||Indicates whether lionfish were added (Yes) or removed (No).||Yes or No|
|area||Area of ledge.||square meters|
|basslet_baseline_abund||Baseline abundance (count) of fairy basslet of all sizes.||integer|
|basslet_density||Baseline density of fairy basslet in fish/m^2.||fish per square meter|
|basslet_added||Indicates whether or not fairy basslet where added to ledge experimentally.||Yes or No|
|Start Date|| |
|End Date|| |
Reefs were surveyed near the Cape Eleuthera Institute, Eleuthera Bahamas during the summer of 2012 as part of the project "Ecological Release and Resistance at Sea: Invasion of Atlantic Coral Reefs by Pacific Lionfish" and "Mechanisms and Consequences of Fish Biodiversity Loss on Atlantic Coral Reefs Caused by Invasive Pacific Lionfish" (NSF OCE-0851162 & OCE-1233027).