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

Fairy basslet counts and density prior to manipulation experiments conducted at reefs near Eleuthera, Bahamas in 2012/ access_formats=.htmlTable,.csv,.json,.mat,.nc,.tsv,.esriCsv,.geoJson acquisition_description=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:\u00a0 low lionfish reefs (where divers regularly removed lionfish), and high lionfish reefs\u00a0 (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. awards_0_award_nid=55160 awards_0_award_number=OCE-0851162 awards_0_data_url=http://www.nsf.gov/awardsearch/showAward.do?AwardNumber=0851162 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=Fairy basslet baseline density (From sub-project "Lionfish alter density dependence in fairy basslet") Lead PI: Mark Hixon (OSU) Sub-Project Lead: Kurt Ingeman (OSU) Version: 24 April 2013 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.3922.1 Easternmost_Easting=-76.28745 geospatial_lat_max=24.81645 geospatial_lat_min=24.75715 geospatial_lat_units=degrees_north geospatial_lon_max=-76.28745 geospatial_lon_min=-76.3506 geospatial_lon_units=degrees_east infoUrl=https://www.bco-dmo.org/dataset/3922 institution=BCO-DMO metadata_source=https://www.bco-dmo.org/api/dataset/3922 Northernmost_Northing=24.81645 param_mapping={'3922': {'lat': 'master - latitude', 'lon': 'master - longitude'}} parameter_source=https://www.bco-dmo.org/mapserver/dataset/3922/parameters people_0_affiliation=Oregon State University people_0_affiliation_acronym=OSU people_0_person_name=Mark Hixon people_0_person_nid=51647 people_0_role=Lead Principal Investigator people_0_role_type=originator people_1_affiliation=Oregon State University people_1_affiliation_acronym=OSU people_1_person_name=Kurt Ingeman people_1_person_nid=51667 people_1_role=Scientist people_1_role_type=originator people_2_affiliation=Woods Hole Oceanographic Institution people_2_affiliation_acronym=WHOI BCO-DMO people_2_person_name=Shannon Rauch people_2_person_nid=51498 people_2_role=BCO-DMO Data Manager people_2_role_type=related project=Lionfish Invasion projects_0_acronym=Lionfish Invasion projects_0_description=Invasive species are increasingly introduced by human activities to new regions of the world where those species have never existed previously. In the absence of natural enemies (predators, competitors, and diseases) from their homeland, invasives may have strong negative effects on invaded ecosystems, especially systems with fewer species ("ecological release"), and may even drive native species extinct. However, if native natural enemies can somehow control the invaders ("ecological resistance"), then ecological disruption can be prevented or at least moderated. Most of the many invasive species in the sea have been seaweeds and invertebrates, and the few documented invasive marine fishes have not caused major problems. However, this situation has recently changed in a stunning and ominous way. In the early 1990s, lionfish (Pterois volitans) from the Pacific Ocean were accidentally or intentionally released from aquaria to the ocean in the vicinity of Florida. Camouflaged by shape and color, protected by venomous spines, consuming native coral-reef fishes voraciously, and reproducing rapidly, lionfish have subsequently undergone a population explosion. They now range from the mid-Atlantic coast of the US to the Caribbean, including the Bahamas. Native Atlantic fishes have never before encountered this spiny, stealthy, efficient predator and seldom take evasive action. In fact, the investigator has documented that a single lionfish is capable of reducing the abundance of small fish on a small coral patch reef by nearly 80% in just 5 weeks. There is great concern that invasive lionfish may severely reduce the abundance of native coral-reef fishes important as food for humans (e.g., grouper and snapper in their juvenile stages) as well as species that normally maintain the integrity of coral reefs (e.g., grazing parrotfishes that can prevent seaweeds from smothering corals). There are far more species of coral-reef fish in the Pacific than the Atlantic, so this invasion may represent a case of extreme ecological release with minor ecological resistance. Dr. Hixon and colleagues will study the mechanisms of ecological release in lionfish, as well as examine potential sources of ecological resistance in the heavily invaded Bahamas. Because very little is known about the ecology and behavior of lionfish in their native Pacific range, he will also conduct comparative studies in both oceans, which may provide clues regarding the extreme success of this invasion. In the Bahamas, the investigator will document the direct and indirect effects on native species of the ecological release of lionfish, both as a predator and as a competitor. These studies will be conducted at various scales of time and space, from short-term experiments on small patch reefs, to long-term experiments and observations on large reefs. Whereas direct effects involve mostly changes in the abundance of native species, indirect effects can be highly variable. For example, lionfish may actually indirectly benefit some native species by either consuming or outcompeting the competitors of those natives. The project will explore possible ecological resistance to the invasion by determining whether any native Bahamian species are effective natural enemies of lionfish, including predators, parasites, and competitors of both juvenile and adult lionfish. Comparative studies of natural enemies, as well as lionfish ecology and behavior, in both the Atlantic and the Pacific may provide clues regarding the explosive spread of lionfish in the Atlantic. Regarding broader impacts, this basic research will provide information valuable to coral-reef and fisheries managers fighting the lionfish invasion in the US, the Bahamas, and the greater Caribbean, especially if sources of native ecological resistance are identified. The study will fund the PhD research of U.S. graduate students, as well as involve assistance and participation by a broad variety of undergraduates and reef/fisheries managers, including women, minorities, native Bahamians, and native Pacific islanders. Participation in this project will promote education in marine ecology and conservation biology directly via Dr. Hixon's and graduate students' teaching and outreach activities, and indirectly via the experiences of undergraduate field assistants and various associates. projects_0_end_date=2012-11 projects_0_geolocation=Bahamas; Cayman Islands; Mariana Islands; Philippines projects_0_name=Ecological Release and Resistance at Sea: Invasion of Atlantic Coral Reefs by Pacific Lionfish projects_0_project_nid=2256 projects_0_project_website=http://hixon.science.oregonstate.edu/content/highlight-lionfish-invasion projects_0_start_date=2009-06 sourceUrl=(local files) Southernmost_Northing=24.75715 standard_name_vocabulary=CF Standard Name Table v55 version=1 Westernmost_Easting=-76.3506 xml_source=osprey2erddap.update_xml() v1.3