https://doi.org/10.82144/52e5430d https://seamap.env.duke.edu/dataset/484 Jaime Bolanos Sea Vida Primary contact megapterax@yahoo.com OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

A328 LSRC building Durham NC 27708 US

seamap-contact@duke.edu https://seamap.env.duke.edu OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

A328 LSRC building Durham NC 27708 US

seamap-contact@duke.edu https://seamap.env.duke.edu distributor Jaime Bolanos Sea Vida Primary contact megapterax@yahoo.com owner 2025-07-31 eng Original provider: Jaime Bolaños-Jiménez Dataset credits: Jaime Bolaños-Jiménez Abstract: As part of an effort to assess the actual status of the Venezuelan cetaceans, Profauna (the Venezuela Fish and Wildlife Service) is conducting a two-year field research project on the State of Aragua, central coast of Venezuela. It is the first step to get baseline information to devise an action plan for the conservation and research of marine mammals. So far, one flight and 24 boat surveys have been made between October 1996 and June, 1997. During this period, 30 sightings were recorded over the continental shelf. Relative frequencies were as follows: 50% Atlantic spotted dolphins (<i>Stenella frontalis</i>), 17% bottlenose dolphins (<i>Tursiops truncatus</i>), 10% mixed aggregations of these two species, 17% unidentified dolphins and 6% unidentified (Balaenopterid) whales. Group size for <i>Tursiops truncatus</i> ranged from 1-15 individuals and from three to more than 300 for <i>S. frontalis</i>. Spotted dolphins showed a sociable behavior by bowriding, escorting and 'playing' around the boat from only a few minutes to more than one hour. Bottlenose dolphins, on the other hand, very seldom showed this behavior, being rather shy most of the time. While watching a school of more that 300 spotted dolphins underwater, 25 animals bowrode and escorted the boat; as the boat reduced speed while circling the area they dived to 45-60 feet, looping back to the stern of the boat and then bowrode again. This behavior was displayed several times and was always made by the same subgroup. In one of the rare occasions when 10 <i>Tursiops</i> were bowriding, another school of <i>S. frontalis</i> joined them and started bowriding too. Preliminary results suggest the presence of coastal populations of dolphins along the study area during most of the year and, possibly, daily easterly or westerly movements (parallel to the coastline). <i>Stenella frontalis</i> is the most abundant species both in absolute numbers and sighting frequency. Further research will provide information about seasonality of whales presence, as claimed by fishermen. These are preliminary results of Project DLAM 009, funded by <a href=http:/www.fundacite.arg.gov.ve>Fundacite Aragua</a>. Occurrence GBIF Dataset Type Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_type.xml Observation GBIF Dataset Subtype Vocabulary: http://rs.gbif.org/vocabulary/gbif/dataset_subtype.xml Marine Biology Visual sighting Vessels Sightings Cetacean conservation and management Venezuela N/A When <i>Stenella frontalis</i> and <i>Tursiops truncatus</i> were sighted together, they were contained in one record as 'sf+tt' and their group size included both species. In OBIS-SEAMAP, these records were classified as Delphinidae (TSN: 180415). All Delphinidae records are for 'st+tt' sightings.<br><br> In the original data, the group size can be a range (e.g., 30-40). In OBIS-SEAMAP, a mid-value is taken for those having range values. Currently, research on cetaceans is being conducted by the primary dataset contact and the non-governmental organization Sea Vida team. The access to this work requires permission. https://seamap.env.duke.edu/dataset/484 Oceans,State of Aragua,Atlantic spotted dolphin,Common bottlenose dolphin -67.767 -67.608 10.52 10.499 1996-10-08 1997-07-18 Scientific names are based on the Integrated Taxonomic Information System (ITIS). genus Balaenoptera Baleen whales order Cetacea Cetaceans family Delphinidae Dolphins species Stenella frontalis Atlantic spotted dolphin species Tursiops truncatus Common bottlenose dolphin This study was made with the purpose of generating baseline information of the cetaceans inhabiting the central coast of Venezuela. notPlanned Jaime Bolanos Sea Vida Primary contact megapterax@yahoo.com NA NA NA Jaime Bolanos owner NA zd_484 2025-07-31T14:18:02-04:00 dataset Bolanos, J. 2009. Current status of cetaceans in Aragua, Venezuela. Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/52e5430d. OBIS-SEAMAP Dataset Page UTF-8 Interactive map https://seamap.env.duke.edu/dataset/484 FGDC Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/484/fgdc EML Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/484/eml OBIS-SEAMAP zd_484 zd_484 Bolaños, J.J., A.M.Z. Campo and M.E. González-Fernández. 1998. Determinación del estado actual de los cetáceos de las costas del estado Aragua: Resultados de la etapa I. IT/MARNR/386, Serie Informes Técnicos, Ministerio del Ambiente, Caracas, Venezuela: 41.