[MARMAM] New publication: Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores

[Irma Cascão]

Dear Colleagues,

We are pleased to announce the publication of the following paper in 
Scientific Reports:

Irma Cascão, Marc O. Lammers, Rui Prieto, Ricardo S. Santos & Mónica A. 
Silva (2020) Temporal patterns in acoustic presence and foraging 
activity of oceanic dolphins at seamounts in the Azores. Scientific 
Reports. http://doi.org/10.1038/s41598-020-60441-4

Abstract
Several seamounts have been identified as hotspots of marine life in the 
Azores, acting as feeding stations for top predators, including 
cetaceans. Passive acoustic monitoring is an efficient tool to study 
temporal variations in the occurrence and behaviour of vocalizing 
cetacean species. We deployed bottom-moored Ecological Acoustic 
Recorders (EARs) to investigate the temporal patterns in acoustic 
presence and foraging activity of oceanic dolphins at two seamounts 
(Condor and Gigante) in the Azores. Data were collected in March-May 
2008 and April 2010-February 2011. Dolphins were present year round and 
nearly every day at both seamounts. Foraging signals (buzzes and bray 
calls) were recorded in >87% of the days dolphin were present. There was 
a strong diel pattern in dolphin acoustic occurrence and behaviour, with 
higher detections of foraging and echolocation vocalizations during the 
night and of social signals during daylight hours. Acoustic data 
demonstrate that small dolphins consistently use Condor and Gigante 
seamounts to forage at night. These results suggest that these seamounts 
likely are important feeding areas for dolphins. This study contributes 
to a better understanding of the feeding ecology of oceanic dolphins and 
provides new insights into the role of seamount habitats for top predators.

The paper is available at: www.nature.com/articles/s41598-020-60441-4. 
Or email me irma.cascao at gmail.com for a PDF.

You can also download two companion papers of this publication, which 
describe the effect of seamounts on the distribution and dynamics of 
micronekton scattering layers:

I. Cascão, R. Domokos, M.O. Lammers, V. Marques, R. Domínguez, R.S. 
Santos & M.A. Silva (2017) Persistent Enhancement of Micronekton 
Backscatter at the Summits of Seamounts in the Azores. Frontiers in 
Marine Science 4:25. https://doi.org/10.3389/fmars.2017.00025

I. Cascão, R. Domokos, M.O. Lammers, R.S. Santos & M.A. Silva (2019) 
Seamount effects on the diel vertical migration and spatial structure of 
micronekton. Progress in Oceanography 175, 1-13. 
https://doi.org/10.1016/j.pocean.2019.03.008

Best regards,
Irma Cascão


............................................................................................................................................................
Irma Cascão
PhD
MARE - Marine and Environmental Sciences Centre
IMAR - Institute of Marine Research
DOP - Department of Oceanography and Fisheries
University of the Azores
Rua Professor Dr. Frederico Machado 4
9901-862 Horta
Portugal
ResearchGate: https://www.researchgate.net/profile/Irma_Cascao2
Azores Whale Lab: http://whales.scienceontheweb.net