https://doi.org/10.82144/e303ee62 https://seamap.env.duke.edu/dataset/386 https://www.gbif.org/dataset/655150a1-87a4-4e07-b51b-536d52187fb3 https://obis.org/dataset/c4abaa14-c71a-4a4c-a3a2-e39f0136aa6e Ignacio García-Godos Instituto del Mar del Perú Primary contact agarcia@imarpe.gob.pe OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

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seamap-contact@duke.edu https://seamap.env.duke.edu distributor Ignacio García-Godos Instituto del Mar del Perú Primary contact agarcia@imarpe.gob.pe owner 2025-07-31 eng Original provider: Instituto del Mar del Perú (IMARPE) Dataset credits: Instituto del Mar del Perú (IMARPE) Abstract: Thirty-eight sightings of sperm whales (<i>Physeter macrocephalus</i>) were recorded off Peru (3 degrees S - 18 degrees S) during 21 surveys conducted aboard platforms of opportunity between 1995 and 2002, with a search effort of 33,406.6 nautical miles of observation. Two main areas of concentration were detected: northern Peru (19 sightings) and southern Peru (16 sightings), but seasonality could not be confirmed. Almost 58% of sightings occurred during the same or consecutive days. Group size ranged from 1 to 18 individuals, with a mean of 3.5 individuals (SD = 3.9). The modal group size was one, with single whales accounting for 36.8% of sightings. Groups of three or more individuals accounted for 39.5%. An important increase of sightings occurred between 2001 and 2002, accounting 68% of the records, suggesting migratory movements towards Peruvian waters from other regions of the eastern Pacific Ocean. Positive correlations between indices of relative abundance and the anomaly of sea surface temperature were found, although warm events as El Niño appear to increase the uncertainty in sighting rates, reducing correlation values. Positive relationship between indices of relative abundance and fishery's CPUE of <i>Dosidicus gigas</i> suggest some grade of interaction, although the question about the role of <i>D. gigas</i> in the diet of sperm whales in the area must be solved for further conclusions. It is priority to perform specific surveys for population estimation, as well as non-lethal research about feeding and the effect of the fishery competition over sperm whales. 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 N/A This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC) 4.0 License. https://seamap.env.duke.edu/dataset/386 Oceans -84.0623333 -71.4536 -3.7388333 -18.0476667 1995-12-19 2002-11-09 Scientific names are based on the Integrated Taxonomic Information System (ITIS). species Physeter macrocephalus Sperm whale To show the general pattern of distribution of sperm whales off Peru, a previously important whaling ground. notPlanned Ignacio García-Godos Instituto del Mar del Perú Primary contact agarcia@imarpe.gob.pe NA NA NA Ignacio García-Godos owner NA zd_386 2025-07-31T14:14:01-04:00 dataset García-Godos, I. 2007. Sperm whales off Peru during IMARPE surveys (1995-2002). Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/e303ee62. OBIS-SEAMAP Dataset Page UTF-8 Interactive map https://seamap.env.duke.edu/dataset/386 FGDC Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/386/fgdc EML Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/386/eml OBIS-SEAMAP zd_386 zd_386 García-Godos, I. 2006. A note on the occurrence of sperm whales (Physeter macrocephallus) off Peru, 1995-2002. Journal of Cetacean Research and Management: 8(1):113-119.