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  • 1
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    Dive metrics of sperm whales collected between 2017 and 2019 off the Azores, Portugal (2024)
    PANGAEA
    Details
    Publication Date: 2024-04-06
    Description: The development of sophisticated multi-sensor tags incorporating high-resolution movement sensors and hydrophones has enabled unprecedented views of the 3D fine-scale movement behaviour of cetaceans, especially for those species that use sound to forage. However, these tags are expensive, making them inaccessible to most researchers. Time-Depth Recorders (TDRs), which have been widely used to study diving and foraging behaviour of marine mammals, offer a more affordable alternative. Unfortunately, data collected by TDRs are bi-dimensional (time and depth only), so quantifying foraging effort from those data is challenging. Pérez-Jorge et al. (2023) developed a predictive model of prey capture attempts (PCAs) for sperm whales from low-resolution time-depth data. To develop this model, high-resolution movement and acoustic data from 12 sperm whales instrumented with digital acoustic recording tags (Dtags; Johnson et al., 2003; Oliveira et al., 2022) between 2017 and 2019 in the Azores archipelago, Portugal. This data was used to extract time-depth values at a sampling frequency of 1 second (typical sampling rate of low-resolution time-depth data) and detect buzzes, considered to represent PCAs. Based on the extracted time-depth values, a suite of dive metrics (ie., average depth, variance of depth) were obtained for different segment durations (30 seconds, 60 s, 180 s and 300 s). The present dataset includes the extracted dive metrics for the four segment durations selected on the final model of the study (Pérez-Jorge et al., 2023). Data provided for each record include the event number, individual identification, dive identification, date of sampling, latitude, longitude, dive phase, segment duration, number of buzzes, average of water depth per segment, variance of water depth per segment and variance of velocity.
    Keywords: Azores; Calculated; DATE/TIME; Digital acoustic recording tag according to Johnson and Tyack (2003); Dive, duration; Dive, number of buzzes; Dive, phase; Dive, velocity, vertical, variance; Dive/swim depth; Dive/swim depth, variance; Dive number; DTAG; Event label; Index; Latitude of event; Longitude of event; Mean values; Pmacrocephalus_2017_1; Pmacrocephalus_2017_9; Pmacrocephalus_2018_10; Pmacrocephalus_2018_11; Pmacrocephalus_2018_2; Pmacrocephalus_2018_3; Pmacrocephalus_2018_4; Pmacrocephalus_2019_12; Pmacrocephalus_2019_5; Pmacrocephalus_2019_6; Pmacrocephalus_2019_7; Pmacrocephalus_2019_8; Species, unique identification; Species, unique identification (Semantic URI); Species, unique identification (URI); Specimen identification; SUMMER; Sustainable Management of Mesopelagic Resources; VID; Visual identification
    Type: Dataset
    Format: text/tab-separated-values, 170890 data points
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    DATA PANGAEA
  • 2
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    Sex bias in biopsy samples collected from free-ranging dolphins (2010)
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in European Journal of Wildlife Research 56 (2010): 151-158, doi:10.1007/s10344-009-0299-7.
    Description: Biological samples of free-ranging dolphins are increasingly used to gain information on population structure and ecology. In small cetaceans, the gender of individuals usually cannot be determined at sea, and population sex ratio has to be inferred indirectly. We used molecular sexing to determine the gender of 340 biopsy samples of bottlenose dolphins, Tursiops truncatus, spotted dolphins, Stenella frontalis, and common dolphins, Delphinus delphis, collected around the Azores and Madeira. Sex ratio was globally skewed in favor of males, and differed between species and archipelagos. Skew was probably influenced by the selectivity of biopsy collectors and seasonal or year-round predominance of males in natural populations. Skew was also influenced by sampling duration and intensity. In the Azores, when several samples were successively collected within the same group, the proportion of female samples decreased as a function of sample order. This trend indicated a tendency for females to increasingly avoid the boat while samples were being collected. It showed that males and females reacted differently to the perturbation caused by the biopsy sampling process (i.e. sample collection and driving style).
    Description: Portuguese Foundation for Science and Technology (FCT) and the FEDER program for funding the CETAMARH (POCTI/BSE/38991/01) and the GOLFINICHO (POCI/BIA-BDE/61009/2004) projects, S.Q.'s post-doctoral grants (IMAR/FCT- PDOC-006/2001-MoleGen and SFRH/BPD/19680/2004), M.A.S.'s doctoral (SFRH/BD/8609/2002) and post-doctoral (SFRH/BPD/29841/2006) grants, S.M.'s investigation assistant grant (CETAMARHII/POCTI/BSE/38991/2001) and I.C.'s investigation assistant grants (IMAR/FCT/GOLFINICHO/001/2005 and IMAR/FCT/GOLFINICHO/004/2006). FCT for its pluri-annual funding to Research Unit #531 and the EU funded program Interreg IIIb for funding the MACETUS project (MAC/4.2/M10) as well as R.P. and S.M.’s grants (IMAR/INTERREGIIIb/MACETUS/MAC1/2).
    Keywords: Bottlenose dolphin ; Common dolphin ; Spotted dolphin ; Biological samples ; Sex ratio ; NE Atlantic
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
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  • 3
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    Underwater ambient noise in a baleen whale migratory habitat off the Azores (2017)
    Frontiers Media
    Details
    Publication Date: 2022-05-25
    Description: © The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Frontiers in Marine Science 4 (2017): 109, doi:10.3389/fmars.2017.00109.
    Description: Assessment of underwater noise is of particular interest given the increase in noise-generating human activities and the potential negative effects on marine mammals which depend on sound for many vital processes. The Azores archipelago is an important migratory and feeding habitat for blue (Balaenoptera musculus), fin (Balaenoptera physalus) and sei whales (Balaenoptera borealis) en route to summering grounds in northern Atlantic waters. High levels of low frequency noise in this area could displace whales or interfere with foraging behavior, impacting energy intake during a critical stage of their annual cycle. In this study, bottom-mounted Ecological Acoustic Recorders were deployed at three Azorean seamounts (Condor, Açores, and Gigante) to measure temporal variations in background noise levels and ship noise in the 18–1,000 Hz frequency band, used by baleen whales to emit and receive sounds. Monthly average noise levels ranged from 90.3 dB re 1 μPa (Açores seamount) to 103.1 dB re 1 μPa (Condor seamount) and local ship noise was present up to 13% of the recording time in Condor. At this location, average contribution of local boat noise to background noise levels is almost 10 dB higher than wind contribution, which might temporally affect detection ranges for baleen whale calls and difficult communication at long ranges. Given the low time percentatge with noise levels above 120 dB re 1 μPa found here (3.3% at Condor), we woud expect limited behavioral responses to ships from baleen whales. Sound pressure levels measured in the Azores are lower than those reported for the Mediterranean basin and the Strait of Gibraltar. However, the currently unknown effects of baleen whale vocalization masking and the increasing presence of boats at the monitored sites underline the need for continuous monitoring to understand any long-term impacts on whales.
    Description: Fundação para a Ciência e a Tecnologia (FCT) and Fundo Regional da Ciência e Tecnologia (FRCT), through research projects TRACE (PTDC/MAR/74071/2006), MAPCET (M2.1.2/F/012/2011), and FCT Exploratory project (IF/00943/2013/CP1199/CT0001), supported by funds from FEDER, the Competitiveness Factors Operational (COMPETE), QREN, POPH, European Social Fund, Portuguese Ministry for Science and Education, and Proconvergencia Açores/EU Program. We also acknowledge funds provided by FCT to MARE, through the strategic project UID/MAR/04292/2013, that also supported fees for this open access publication. MR is supported by a DRCT doctoral grant (M3.1.a/F/028/2015), IC was supported by a FCT doctoral grant (SFRH/BD/41192/2007) and MAS is supported by an FCT-Investigator contract (IF/00943/2013).
    Keywords: Underwater noise ; Ship noise ; Baleen whales ; MSFD ; Open ocean environment
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 4
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    Macro- and micro-geographic variation of short-beaked common dolphin’s whistles in the Mediterranean Sea and Atlantic Ocean (2014)
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 20113. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Ethology Ecology & Evolution 26 (2014): 392-404, doi:10.1080/03949370.2013.851122.
    Description: Genetic studies have shown that there are small but significant differences between the short-beaked common dolphin populations in the Atlantic Ocean and those in the Mediterranean Sea. The short-beaked common dolphin is a highly vocal species with a wide sound production repertoire including whistles. Whistles are continuous, narrowband, frequency-modulated signals that can show geographic variation in dolphin species. This study tests whether the differences, highlighted by genetic studies, are recognisable in the acoustic features of short-beaked common dolphin’s whistles in the two adjacent areas of the Atlantic Ocean and the Mediterranean Sea. From a selected sample of good quality whistles (514 recorded in the Atlantic and 193 in the Mediterranean) 10 parameters of duration, frequency and frequency modulation were measured. Comparing data among basins, differences were found for duration and all frequency parameters except for minimum frequency. Modulation parameters showed the highest coefficient of variation. Through discriminant analysis we correctly assigned 75.7% of sounds to their basins. Furthermore, micro-geographic analysis revealed similarity between the sounds recorded around the Azores and the Canary archipelagos and between the Bay of Biscay and the Mediterranean Sea. Results are in agreement with the hypothesis proposed by previous genetic studies that two distinct populations are present, still supposing a gene flow between the basins. This study is the first to compare shortbeaked common dolphin’s whistles of the Atlantic Ocean and the Mediterranean areas.
    Description: Data collection and processing in the Azores was conducted under projects POCTI/BSE/38991/01, PTDC/MAR/74071/2006 and M2.1.2/F/012/2011, supported by FCT (Fundação para a Ciência e a Tecnologia) and DRCTC/SRCTE (Secretaria Regional de Ciência, Tecnologia e Equipamentos), FEDER funds, the Competitiveness Factors Operational (COMPETE), QREN European Social Fund and Proconvergencia Açores Program. We acknowledge funds provided by FCT to LARSyS Associated Laboratory & IMAR-University of the Azores/ the Thematic Area E of the Strategic Project (OE & Compete) and by the DRCTC – Government of the Azores pluriannual funding. M.A. Silva was supported by an FCT postdoctoral grant (SFRH/ BPD/29841/2006). I. Cascão and R. Prieto were supported by FCT doctoral grants (SFRH/BD/ 41192/2007 and SFRH/BD/32520/2006, respectively) and R. Prieto by a research grant from the Azores Regional Fund for Science and Technology (M3.1.5/F/115/2012). Data collection by SECAC (Society for the Study of Cetaceans in the Canary Archipelago) was funded by the U.E. LIFE programme – project LIFE INDEMARES (LIFE 07/NAT/E/000732)- and the Fundación Biodiversidad, under the Spanish Ministry of Environment, Rural and Marine Affairs (project ZEC-TURSIOPS).
    Description: 2014-11-05
    Keywords: Short-beaked common dolphin ; Intra-specific differences ; Geographic variation ; Mediterranean ; Atlantic ; Whistles
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
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  • 5
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    Spatial and temporal distribution of cetaceans in the mid-Atlantic waters around the Azores (2013)
    Details
    Publication Date: 2022-05-25
    Description: Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Taylor & Francis for personal use, not for redistribution. The definitive version was published in Marine Biology Research 10 (2014): 123-137, doi:10.1080/17451000.2013.793814.
    Description: Cetaceans living in offshore waters are under increasing pressure from anthropogenic activities. Yet, due to the lack of survey effort, relatively little is known about the demography or ecology of these populations. Spatial and temporal distribution of cetaceans in mid-Atlantic waters were investigated using a long term dataset collected from boat surveys and land-based observations around the Azores. From 1999 to 2009, 7307 cetacean schools were sighted during 271717 km of survey effort. In 4944 h of land-based observations, 2968 cetacean groups were detected. Twenty-four species were recorded: seven baleen whales, six beaked whales, eight dolphin species, Physeter macrocephalus, Kogia breviceps and K. sima. Overall, Delphinus delphis was the most frequently sighted species but its encounter rate decreased in June- November, coinciding with presence of Stenella frontalis in the region. Tursiops truncatus, P. macrocephalus and Grampus griseus were frequently encountered yearround, whereas large baleen whales showed a distinct peak in encounter rates in March-May. Mesoplodonts were fairly common and appear to be present throughout the year. These findings fill-in a significant gap in the knowledge of cetaceans occurring in a poorly studied region of the North Atlantic, providing much needed data to inform management initiatives.
    Description: This work was supported by FEDER funds, through the Competitiveness Factors Operational Programme – COMPETE, by national funds, through FCT – Foundation for Science and Technology, under projects CETAMARH (POCTI/BSE/38991/01) and TRACE (PTDC/MAR/74071/2006), and by regional funds, through DRCT/SRCTE, under project MAPCET (M2.1.2/F/012/2011). We thank the Azorean Regional Government for funding POPA, the Shipowners Proprietors and the Association of the Tuna Canning Industries for their support to the programme. MAS was supported by an FCT postdoctoral grant (SFRH/BPD/29841/2006), and IC and RP were supported by doctoral grants SFRH/BD/41192/2007 and SFRH/BD/32520/2006. IMAR-DOP/UAç is the R&D Unit #531 and part of the Associated Laboratory #9 (ISR) funded through the pluri-annual and programmatic funding schemes of FCT-MCTES and DRCTAzores.
    Keywords: Cetaceans ; Spatial and temporal distribution ; Mid-Atlantic waters ; Sighting surveys
    Repository Name: Woods Hole Open Access Server
    Type: Preprint
    Format: application/pdf
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  • 6
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    Dolphin whistles can be useful tools in identifying units of conservation (2021)
    BMC
    Details
    Publication Date: 2022-05-27
    Description: © The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Papale, E. B., Azzolin, M. A., Cascao, I., Gannier, A., Lammers, M. O., Martin, V. M., Oswald, J. N., Perez-Gil, M., Prieto, R., Silva, M. A., Torri, M., & Giacoma, C. Dolphin whistles can be useful tools in identifying units of conservation. Bmc Zoology, 6(1), (2021): 22, https://doi.org/10.1186/s40850-021-00085-7.
    Description: Prioritizing groupings of organisms or ‘units’ below the species level is a critical issue for conservation purposes. Several techniques encompassing different time-frames, from genetics to ecological markers, have been considered to evaluate existing biological diversity at a sufficient temporal resolution to define conservation units. Given that acoustic signals are expressions of phenotypic diversity, their analysis may provide crucial information on current differentiation patterns within species. Here, we tested whether differences previously delineated within dolphin species based on i) geographic isolation, ii) genetics regardless isolation, and iii) habitat, regardless isolation and genetics, can be detected through acoustic monitoring. Recordings collected from 104 acoustic encounters of Stenella coeruleoalba, Delphinus delphis and Tursiops truncatus in the Azores, Canary Islands, the Alboran Sea and the Western Mediterranean basin between 1996 and 2012 were analyzed. The acoustic structure of communication signals was evaluated by analyzing parameters of whistles in relation to the known genetic and habitat-driven population structure.
    Description: Data collection and processing in the Azores was funded by Fundação para a Ciência e a Tecnologia (FCT) and Fundo Regional da Ciência e Tecnologia (FRCT), through research projects TRACE-PTDC/MAR/74071/2006 and MAPCET-M2.1.2/F/012/2011 (FEDER, the Competitiveness Factors Operational (COMPETE), QREN European Social Fund, and Pro convergencia Açores/EU Program). We also thank FCT for supporting MARE (UID/MAR/04292/2019) and OKEANOS (UIB/05634/2020), as well as for the research grants awarded to PR (SFRH/BPD/108007/2015) and CI (Project Awareness - PTDC/BIA-BMA/30514/2017). SMA is supported through project SUMMER (H2020-EU.3.2.3.1, GA 817806). Data collection by SECAC was funded by the EU LIFE programme—project LIFE INDEMARES (LIFE 07/NAT/E/000732)— and the Fundación Biodiversidad under the Spanish Ministry of Environment, Rural and Marine Affairs (project ZEC-TURSIOPS). EP was supported by a LLP/Erasmus grant 2010–2011 for collecting data in the Canary Islands.
    Keywords: Communication signals ; Acoustic divergence ; Geographic variability ; Phenotypic diversity ; Cetaceans
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 7
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    Baleen whale acoustic presence and behaviour at a Mid-Atlantic migratory habitat, the Azores Archipelago (2020)
    Nature Research
    Details
    Publication Date: 2022-05-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Romagosa, M., Baumgartner, M., Cascão, I., Lammers, M. O., Marques, T. A., Santos, R. S., & Silva, M. A. Baleen whale acoustic presence and behaviour at a Mid-Atlantic migratory habitat, the Azores Archipelago. Scientific Reports, 10(1), (2020): 4766, doi: 10.1038/s41598-020-61849-8.
    Description: The identification of important areas during the annual life cycle of migratory animals, such as baleen whales, is vital for their conservation. In boreal springtime, fin and blue whales feed in the Azores on their way to northern latitudes while sei whales migrate through the archipelago with only occasional feeding. Little is known about their autumn or winter presence or their acoustic behaviour in temperate migratory habitats. This study used a 5-year acoustic data set collected by autonomous recorders in the Azores that were processed and analysed using an automated call detection and classification system. Fin and blue whales were acoustically present in the archipelago from autumn to spring with marked seasonal differences in the use of different call types. Diel patterns of calling activity were only found for fin whales with more calls during the day than night. Sei whales showed a bimodal distribution of acoustic presence in spring and autumn, corresponding to their expected migration patterns. Diel differences in sei whale calling varied with season and location. This work highlights the importance of the Azores as a migratory and wintering habitat for three species of baleen whales and provides novel information on their acoustic behaviour in a mid-Atlantic region.
    Description: This work was supported by Fundação para a Ciência e Tecnologia (FCT), Azores 2020 Operational Programme and Fundo Regional da Ciência e Tecnologia (FRCT) through research projects TRACE (PTDC/MAR/74071/2006), MAPCET (M2.1.2/F/012/2011) and AWARENESS (PTDC/BIA-BMA/30514/201), co-funded by FEDER, COMPETE, QREN, POPH, ERDF, ESF, the Lisbon Regional Operational Programme, and the Portuguese Ministry for Science and Education. Funding for publication fees was provided by Project AWARENESS (PTDC/BIA-BMA/30514/201). Okeanos R&D Centre is supported by FCT, through the strategic fund (UIDB/05634/2020). MR was supported by a DRCT doctoral grant (M3.1.a/F/028/2015) and MAS by an FCT-Investigator contract (IF/00943/2013). TAM thanks partial support by CEAUL (funded by FCT - Fundação para a Ciência e a Tecnologia, Portugal, through the project UID/MAT/00006/2013). We are grateful to Rui Prieto, Sérgio Gómez, Norberto Serpa, skilled skippers and crew that participated in the preparation and deployment of EARs at DOP/IMAR and to Ken Sexton and Michael Richlen for their roles in manufacturing the EARs. We are also grateful to Dr. Helena Silva for her feedback on statistical analysis.
    Repository Name: Woods Hole Open Access Server
    Type: Article
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  • 8
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    Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores (2020)
    Nature Research
    Details
    Publication Date: 2022-05-26
    Description: © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cascao, I., Lammers, M. O., Prieto, R., Santos, R. S., & Silva, M. A. Temporal patterns in acoustic presence and foraging activity of oceanic dolphins at seamounts in the Azores. Scientific Reports, 10(1), (2020): 3610, doi:10.1038/s41598-020-60441-4.
    Description: 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.
    Description: This research was supported by the Fundação para a Ciência e a Tecnologia (FCT), Azores 2020 Operational Programme and the Fundo Regional da Ciência e Tecnologia (FRCT), through research projects TRACE (PTDC/MAR/74071/2006), MAPCET (M2.1.2/F/012/2011), FCT-Exploratory (IF/00943/2013/CP1199/CT0001), WATCH IT (Acores-01-0145-FEDER-000057) and MISTIC SEAS II (GA11.0661/2017/750679/SUB/ENV.C2), co-funded by FEDER, COMPETE, QREN, POPH, European Social Fund (ESF), the Portuguese Ministry for Science and Education, and EU-DG/ENV. The Azores 2020 Operational Programme is funded by the community structural funds ERDF and ESF. Funds were also provided by FCT to MARE, through the strategic project UID/MAR/04292/2013. MAS was supported through a FCT Investigator contract funded by POPH, QREN, ESF and the Portuguese Ministry for Science and Education (IF/00943/2013). IC was supported by a FCT doctoral grant (SFRH/BD/41192/2007) and RP by a FCT postdoctoral grant (SFRH/BPD/108007/2015). We thank the field and crew teams for assisting with the many deployments and recoveries of the EARs. Special thanks to Norberto Serpa for helping with mooring design, Ken Sexton and Michael Richlen for their roles in manufacturing the EARs, Sergio Gomes for building the battery packs, and Lisa Munger for adapting Triton for EAR data analysis.
    Repository Name: Woods Hole Open Access Server
    Type: Article
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