Large-scale movements of common bottlenose dolphins in the Atlantic: dolphins with an international courtyard

Ana Dinis; Carlota Molina; Marta Tobeña; Annalisa Sambolino; Karin Hartman; Marc Fernandez; Sara Magalhães; Rui Peres Dos Santos; Fabian Ritter; Vidal Martín; Natacha Aguilar de Soto; Filipe Alves

doi:10.7717/peerj.11069

Large-scale movements of common bottlenose dolphins in the Atlantic: dolphins with an international courtyard

PeerJ. 2021 Mar 25:9:e11069. doi: 10.7717/peerj.11069. eCollection 2021.

Authors

Ana Dinis^{1

2}, Carlota Molina^{2

3}, Marta Tobeña⁴, Annalisa Sambolino^{1

2}, Karin Hartman⁵, Marc Fernandez^{1

6}, Sara Magalhães⁷, Rui Peres Dos Santos⁸, Fabian Ritter⁹, Vidal Martín¹⁰, Natacha Aguilar de Soto¹¹, Filipe Alves^{1

2}

Affiliations

¹ Mare-Marine and Environmental Sciences Centre, Agência Regional para o Desenvolvimento da Investigac˛ão Tecnologia e Inovac˛ão (ARDITI), Funchal, Madeira, Portugal.
² OOM - Oceanic Observatory of Madeira, Funchal, Madeira, Portugal.
³ Department of Animal Biology, Ecology and Environmental Sciences, University of Barcelona, Barcelona, Catalonia, Spain.
⁴ Centro I&D Okeanos, University of Azores, Horta, Azores, Portugal.
⁵ Risso's Dolphin Research Center, Nova Atlantis Foundation, Pico, Azores, Portugal.
⁶ cE3c - Centre for Ecology, Evolution and Environmental Changes/Azorean Biodiversity Group, University of Azores, Ponta Delgada, Azores, Portugal.
⁷ Mar Ilimitado, Sagres, Portugal.
⁸ Futurismo, Pico, Azores, Portugal.
⁹ M.E.E.R. e.V, Berlin, Germany.
¹⁰ SECAC Society for the Study of Cetaceans in the Canary Archipelago, Lanzarote, Canary Island, Spain.
¹¹ BIOECOMAC, Department of Animal Biology, University of La Laguna, Tenerife, Canary Island, Spain.

Abstract

Wide-ranging connectivity patterns of common bottlenose dolphins (Tursiops truncatus) are generally poorly known worldwide and more so within the oceanic archipelagos of Macaronesia in the North East (NE) Atlantic. This study aimed to identify long-range movements between the archipelagos of Macaronesia that lie between 500 and 1,500 km apart, and between Madeira archipelago and the Portuguese continental shelf, through the compilation and comparison of bottlenose dolphin's photo-identification catalogues from different regions: one from Madeira (n = 363 individuals), two from different areas in the Azores (n = 495 and 176), and four from different islands of the Canary Islands (n = 182, 110, 142 and 281), summing up 1791 photographs. An additional comparison was made between the Madeira catalogue and one catalogue from Sagres, on the southwest tip of the Iberian Peninsula (n = 359). Results showed 26 individual matches, mostly between Madeira and the Canary Islands (n = 23), and between Azores and Madeira (n = 3). No matches were found between the Canary Islands and the Azores, nor between Madeira and Sagres. There were no individuals identified in all three archipelagos. The minimum time recorded between sightings in two different archipelagos (≈ 460 km apart) was 62 days. Association patterns revealed that the individuals moving between archipelagos were connected to resident, migrant and transient individuals in Madeira. The higher number of individuals that were re-sighted between Madeira and the Canary Islands can be explained by the relative proximity of these two archipelagos. This study shows the first inter-archipelago movements of bottlenose dolphins in the Macaronesia region, emphasizing the high mobility of this species and supporting the high gene flow described for oceanic dolphins inhabiting the North Atlantic. The dynamics of these long-range movements strongly denotes the need to review marine protected areas established for this species in each archipelago, calling for joint resolutions from three autonomous regions belonging to two EU countries.

Keywords: Connectivity; Home range; Photo-identification; Residency patterns; Tursiops truncatus.

Grants and funding

Partnership Program (US) and project “Cetáceos, Oceanografía y Biodiversidad de las Aguas Profundas de La Palma y El Hierro” funded by “Ministerio de Ciencia e Innovación” of the Spanish Government, grant number CETOBAPH-CGL2009-1311218 supported the work in the Canary Island. In Madeira, this study was supported by the Oceanic Observatory of Madeira through the project M1420-01-0142-FEDER-000001 and by the Portuguese Foundation for Science and Technology through the strategic project UID/MAR/04292/2020. Ana Dinis and Filipe Alves have grants funded by ARDITI—Madeira’s Regional Agency for the Development of Research, Technology and Innovation, throughout the project M1420-09- 5369- FSE- 000002, and Annalisa Sambolino is supported by the Portuguese Foundation for Science and Technology through the PhD grant number SFRH/BD/1416092018. In Azores, the MONICET platform is supported by project MEEMO (ACORES-01-0145-FEDER-000079) and Marta Tobena is supported by a PhD grant (M31a/F/0722015). There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.