Censuses of the native prey fish populations during lionfish surveys in Eleuthera, Bahamas from July to August in 2012 access_formats=.htmlTable,.csv,.json,.mat,.nc,.tsv acquisition_description=This was an observational field study conducted from June - August 2012 to determine whether lionfish behavior and movements change at different local lionfish and prey fish densities. \u00a0The study was conducted on sixteen reefs in Rock Sound, Elethera, The Bahamas.\u00a0 All reefs were at least 300 m from any reef on which lionfish removals had occurred, and were selected to encompass a range of natural lionfish densities and reef sizes. \u00a0

A pair of divers visited each reef at three times of day: within 2 hours of sunrise (\u2018dawn\u2019), greater than 3 hours from sunrise or sunset (\u2018midday\u2019), and within 2 hours of sunset (\u2018dusk\u2019).\u00a0 Upon arriving at a reef, observers counted the number of lionfish present by conducting lionfish-focused searches.\u00a0 For each lionfish, observers recorded the size (total length, visually estimated to the nearest cm), behavior, and location the moment it was sighted.\u00a0 Behaviors were categorized as resting (sitting on the substrate, not moving), hovering (in the water column oriented parallel to the bottom, but not moving), swimming (actively moving), or hunting (oriented head down with pectoral fins flared).\u00a0 Location was categorized as the microhabitat on which lionfish were observed (e.g. under a ledge, on top of the reef, in the surrounding seagrass) and later divided into two major categories: sheltering (hidden under structure) or exposed (on top of reef or in surrounding area).\u00a0 Then, 10-minute focal observations were conducted on two randomly-selected lionfish or a single lionfish when there was only one individual present per reef.\u00a0 During focal observations, a trained observer recorded the behavior of lionfish at 30-second intervals for 10 minutes using the same categories as above.\u00a0 The observers also noted any strikes at prey, successful kills, and obviously aggressive interactions (chases, posturing) between lionfish or between lionfish and other species.\u00a0 Throughout the entire visit to each reef, divers noted the time when any lionfish departed from or arrived at the reef and its behavior.\u00a0 A lionfish was defined as departing from the reef if it traveled at least 10 m from the reef.\u00a0 A lionfish was considered arriving at a reef if it swam in from the surrounding areas and had not been previously observed at that reef during that observation period.\u00a0 At the conclusion of the focal observations, the divers re-counted the number of lionfish present while conducting a survey of resident native fishes.\u00a0 Divers recorded the abundance and body size (TL) of all fish 1 - 15 cm TL, native mesopredators that are ecologically similar to lionfish (e.g. Cephalopholis cruentata [graysby grouper]), and top predators (e.g. Epinephelus striatus [Nassau grouper]) on and within 1 m of the reef. awards_0_award_nid=561016 awards_0_award_number=OCE-1233027 awards_0_data_url=http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=1233027 awards_0_funder_name=NSF Division of Ocean Sciences awards_0_funding_acronym=NSF OCE awards_0_funding_source_nid=355 awards_0_program_manager=David L. Garrison awards_0_program_manager_nid=50534 cdm_data_type=Other comment=Behavior and Movement - Native Fish Survey Lead PI: Mark Hixon Sub-Project Lead: Casey Benkwitt Version 10 August 2016 Species codes are first two letters of genus and species; See species key. Conventions=COARDS, CF-1.6, ACDD-1.3 data_source=extract_data_as_tsv version 2.3 19 Dec 2019 defaultDataQuery=&time<now doi=10.1575/1912/bco-dmo.653816.1 infoUrl=https://www.bco-dmo.org/dataset/653816 institution=BCO-DMO metadata_source=https://www.bco-dmo.org/api/dataset/653816 param_mapping={'653816': {}} parameter_source=https://www.bco-dmo.org/mapserver/dataset/653816/parameters people_0_affiliation=University of Hawaii people_0_person_name=Mark Hixon people_0_person_nid=51647 people_0_role=Principal Investigator people_0_role_type=originator people_1_affiliation=Oregon State University people_1_affiliation_acronym=OSU people_1_person_name=Cassandra E. Benkwitt people_1_person_nid=51706 people_1_role=Contact people_1_role_type=related people_2_affiliation=Woods Hole Oceanographic Institution people_2_affiliation_acronym=WHOI BCO-DMO people_2_person_name=Hannah Ake people_2_person_nid=650173 people_2_role=BCO-DMO Data Manager people_2_role_type=related project=BiodiversityLossEffects_lionfish projects_0_acronym=BiodiversityLossEffects_lionfish projects_0_description=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? projects_0_end_date=2016-07 projects_0_geolocation=Three Bahamian sites: 24.8318, -076.3299; 23.8562, -076.2250; 23.7727, -076.1071; Caribbean Netherlands: 12.1599, -068.2820 projects_0_name=Mechanisms and Consequences of Fish Biodiversity Loss on Atlantic Coral Reefs Caused by Invasive Pacific Lionfish projects_0_project_nid=561017 projects_0_project_website=http://hixon.science.oregonstate.edu/content/highlight-lionfish-invasion projects_0_start_date=2012-08 sourceUrl=(local files) standard_name_vocabulary=CF Standard Name Table v55 subsetVariables=year,length_max_45,length_max_50,length_max_100,length_max_150 version=1 xml_source=osprey2erddap.update_xml() v1.3

This field experiment was conducted on coral patch reefs to test for the effect of lionfish presence on native fish abundance both on main reefs where lionfish resided and in habitats surrounding the main reefs (satellite coral heads, open areas, and standardized habitat units [SHUs]). The experiment used 16 main reefs which were manipulated so that 8 reefs had few lionfish present (low lionfish treatment) and 8 had lionfish present at naturally-observed densities (high lionfish treatment). Complete censuses of the native prey fish populations on each reef and in the surrounding habitats were conducted weekly for 7 weeks during the summer recruitment season.

Related datasets:

• Effect of lionfish density on native reef fishes - DOI: 10.1575/1912/bco-dmo.655301.1
• Effect of lionfish in seagrass satellite coral head habitats - DOI: 10.1575/1912/bco-dmo.655380.1
• Effect of lionfish in seagrass open area habitats - DOI: 10.1575/1912/bco-dmo.655420.1
• Effect of lionfish in standardized habitat units in seagrass - DOI: 10.1575/1912/bco-dmo.655455.1

Species key for all individuals identified in this dataset - DOI: 10.1575/1912/bco-dmo.655195.2