Sperm whales off Peru during IMARPE surveys (1995-2002)

Ignacio García-Godos

doi:10.15468/txahj5

Sperm whales off Peru during IMARPE surveys (1995-2002)

Citation

García-Godos, I. 2007. Sperm whales off Peru during IMARPE surveys (1995-2002). Data downloaded from OBIS-SEAMAP (http://seamap.env.duke.edu/dataset/386) on yyyy-mm-dd. https://doi.org/10.15468/txahj5 accessed via GBIF.org on 2024-12-12.

Description

Original provider: Instituto del Mar del Perú (IMARPE) Dataset credits: Instituto del Mar del Perú (IMARPE) Abstract: Thirty-eight sightings of sperm whales (Physeter macrocephalus) 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 Dosidicus gigas suggest some grade of interaction, although the question about the role of D. gigas 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. Purpose: To show the general pattern of distribution of sperm whales off Peru, a previously important whaling ground.

Purpose

To show the general pattern of distribution of sperm whales off Peru, a previously important whaling ground.

Sampling Description

Study Extent

NA

Sampling

NA

Method steps

NA

Additional info

marine, harvested by iOBIS

Taxonomic Coverages

Scientific names are based on the Integrated Taxonomic Information System (ITIS).

Physeter macrocephalus
common name: Sperm Whale rank: species

Geographic Coverages

Oceans

Bibliographic Citations

Contacts

Ignacio García-Godos
originator
position: Primary contact
Instituto del Mar del Perú
email: agarcia@imarpe.gob.pe

OBIS-SEAMAP
metadata author
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

OBIS-SEAMAP
distributor
Marine Geospatial Ecology Lab, Duke University
A328 LSRC building
Durham
27708
NC
US
email: seamap-contact@duke.edu
homepage: http://seamap.env.duke.edu

Ignacio García-Godos
owner
position: Primary contact
Instituto del Mar del Perú
email: agarcia@imarpe.gob.pe

Ignacio García-Godos
administrative point of contact
position: Primary contact
Instituto del Mar del Perú
email: agarcia@imarpe.gob.pe