https://doi.org/10.82144/9589c68c https://seamap.env.duke.edu/dataset/726 https://www.gbif.org/dataset/c2c49376-3b67-416f-a1c8-60690afaff4a https://obis.org/dataset/b1c9cbdc-a72e-4fee-80a0-0ce9f9d03336 Cristina Brito Escola de Mar Primary contact cristina.brito@escolademar.pt OBIS-SEAMAP Marine Geospatial Ecology Lab, Duke University

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seamap-contact@duke.edu https://seamap.env.duke.edu distributor Cristina Brito Escola de Mar Primary contact cristina.brito@escolademar.pt owner ACCOBAMS and WDCS The Agreement on the Conservation of Cetaceans of the Black Sea, Mediterranean Sea and contiguous Atlantic Area (ACCOBAMS) and Whale and Dolphin Conservation Society (WDCS) http://www.accobams.org/ originator 2025-07-31 eng Original provider: Escola de Mar Dataset credits: Escola de Mar Abstract: Throughout the years some researchers have dedicated their efforts to the study of cetaceans’ occurrence off Mainland Portugal. However, it is still missing a systemic scientific methodology for studying the presence of coastal dolphins and whales. This work intends to be a first approach on the occurrence of cetaceans off the west central coast of Portugal. Our objective was to contribute towards the compilation of relevant “forgotten science” such as whaling data and observations of opportunity, together with two years of boat-based surveys. We found 1,313 occurrences of great whales captured off Setúbal and Sesimbra (1925-1927 and 1944-1951) and a total of 45 cetaceans in non-directed captures between 1976 and 1978. We accounted 45 dolphins and whales in sea-sightings as a result of observations of opportunity, from 2002 to 2008. In 2007 and 2008 a total of 63 boat-based visual surveys were conducted from three different geographic locations, Nazaré, Peniche and Sesimbra, and as a result 45 independent sightings of cetaceans were recorded. The most frequent small dolphin off the Portuguese mainland coast is the common dolphin (<i>Delphinus delphis</i>) as shown by the three distinct approaches used in this study. Regarding whales the most common species is the fin whale (<i>Balaenoptera physalus</i>) as shown by whaling records. Overall, the small delphinid community along the central coast of Portugal is similar to the one that can be found along the Iberia shore. This dataset contains only the boat-based sightings. 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 N/A Records did not have time recorded and were filled with 00:00:00. Records that did not have group size recorded were filled with 1. When an estimated range of animals was sighted, the median value (rounded down) was used as the observed count. Time and group size details are recorded in the [Notes] column. Three opportunistic sightings of <i>Delphinus delphis</i> recorded for August 2007 were excluded because the day information was not available. One erroneous record of <i>Delphinus delphis</i> sightings on land was also excluded. This work is licensed under a Creative Commons Attribution Non Commercial (CC-BY-NC) 4.0 License. https://seamap.env.duke.edu/dataset/726 Oceans -9.4786 -8.811317 41.515383 38.348767 2007-01-08 2008-12-23 Scientific names are based on the Integrated Taxonomic Information System (ITIS). species Balaenoptera acutorostrata Common minke whale family Delphinidae Dolphins species Delphinus delphis Short-beaked common dolphin species Stenella coeruleoalba Striped dolphin species Tursiops truncatus Common bottlenose dolphin This work intends to be a preliminary approach on the occurrence of cetaceans off the west central coast of Portugal. Our objective was to contribute towards the compilation of relevant “forgotten science”, namely 20th century whaling and dolphin capture data and opportunistic observers’ reports on whales and dolphins, in order to reduce the lack of knowledge in central mainland Portugal. This information together with boat-based surveys for obtaining new biological data is a starting point for a new methodological approach. notPlanned Cristina Brito Escola de Mar Primary contact cristina.brito@escolademar.pt NA NA NA Cristina Brito owner NA zd_726 2025-07-31T15:32:56-04:00 dataset Brito, C. 2011. Cetacean occurrence off the west central Portugal coast from boat-based surveys 2007-2008. Version 1.0.0. Dataset published in OBIS-SEAMAP. https://doi.org/10.82144/9589c68c. OBIS-SEAMAP Dataset Page UTF-8 Interactive map https://seamap.env.duke.edu/dataset/726 FGDC Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/726/fgdc EML Metadata UTF-8 XML https://seamap.env.duke.edu/dataset/726/eml OBIS-SEAMAP zd_726 zd_726 Brito, C., N. Vieira, E. Sá and I. Carvalho. 2009. Cetaceans’ occurrence off the west central Portugal coast: A compilation of data from whaling, observations of opportunity and boat-based surveys. Journal of Marine Animals and Their Ecology: 2(1): 4 pp.