ORCID Profile
0000-0002-7171-3011
Current Organisations
Curtin University
,
Universidade Federal do Recôncavo da Bahia
,
Socioambiental Consultores Associados
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Publisher: FapUNIFESP (SciELO)
Date: 02-2014
Abstract: Oceanic waters are difficult to assess, and there are many gaps in knowledge regarding cetacean occurrence. To fill some of these gaps, this article provides important cetacean records obtained in the winter of 2010 during a dedicated expedition to collect visual and acoustic information in the Vitória-Trindade seamounts. We observed 19 groups of cetaceans along a 1300-km search trajectory, with six species being identified: the humpback whale (Megaptera novaeangliae, N = 9 groups), the fin whale (Balaenoptera physalus, N = 1), the Antarctic minke whale (Balaenoptera bonaerensis, N = 1), the rough-toothed dolphin (Steno bredanensis, N = 1), the bottlenose dolphin (Tursiops truncatus, N = 2), and the killer whale (Orcinus orca, N = 1). Most humpback whale groups (N = 7 78%) were observed in the Vitória-Trindade seamounts, especially the mounts close to the Abrolhos Bank. Only one lone humpback whale was observed near Trindade Island after a search effort encompassing more than 520 km. From a total of 28 acoustic stations, humpback whale songs were only detected near the seamounts close to the Abrolhos Bank, where most groups of this species were visually detected (including a competitive group and groups with calves). The presence of humpback whales at the Trindade Island and surroundings is most likely occasional, with few sightings and low density. Finally, we observed a significant number of humpback whales along the seamounts close to the Abrolhos Bank, which may function as a breeding habitat for this species. We also added important records regarding the occurrence of cetaceans in these mounts and in the Western South Atlantic, including the endangered fin whale.
Publisher: Cambridge University Press (CUP)
Date: 03-10-2018
DOI: 10.1017/S0025315416001338
Abstract: This study investigated the emission of subaquatic noise from recreational tourism motorboats, schooners and a sea-bottom mounted water pump. Analyses demonstrated alterations in several whistle (IF: t = 2.42, P = 0.015 FF: t = −2.22, P = 0.025) and calls patterns (MIF: t = −3.13, P = 0.001 MAF: t = −3.49, P = 0.0005 FD: t = −2.21, P = 0.027 D: t = 2.89, P = 0.004), caused primarily by motorboats. Duration of clicks was also modified (D: t = −3.85, P = 0.0001), mainly by the water pump. The frequency range of all noises (0.43–35.8 kHz) overlaps that used by dolphins (1–48 kHz), causing sound emissions changes, with a considerable increase in number of whistles and a reduction in clicks trains. These changes may be a strategy developed by these dolphins to overcome the noise band. Mitigation measures, such as boating regulations and environmental education for the local community, boaters and tourists are needed to conserve the species. The Guiana dolphin population is apparently already suffering, evidenced by diminished residence time and reduced number of in iduals entering the inlet during the presence of pleasure craft.
Publisher: Cambridge University Press (CUP)
Date: 30-08-2012
DOI: 10.1017/S0025315412001154
Abstract: Although it is largely assumed that shark predation and predation risk are unimportant to large cetaceans, whales can make up large portions of the diets of some shark species. We investigated interactions between sharks and cetaceans in the Abrolhos Bank (16°40′ to 19°40′S), off the eastern coast of Brazil, including scavenging and predation attempts on living humpback whales ( Megaptera novaeangliae ). In order to determine the frequency of shark bites on cetaceans, both living and postmortem, we used carcasses discovered along the coast of Abrolhos Bank between 2001 and 2010 and photographs of living cetaceans during systematic and opportunistic visual surveys from 2004 to 2009. We analysed a total of 221 cetacean carcasses, of which 150 (67.8%) were humpback whales. Large sharks had fed on 22.3% (35 of 150) of humpback whales carcasses, and 20.8% (10 of 48) of carcasses of other species. Only three living humpback whales ( %) had bite scars from large sharks, suggesting that they at least occasionally target living humpbacks. Cookiecutter shark bite marks also were observed on both dead and living cetaceans, with numerous living humpbacks showing multiple bites. The abundance of humpback whale carcasses available over the Abrolhos Bank, mainly during the humpback breeding season, may be an important component of shark diets seasonally. Further work is needed to better understand the frequency of shark attacks on mysticetes, potential costs of sublethal injuries, and importance of whales to shark diets.
Publisher: Elsevier BV
Date: 09-2012
Publisher: Wiley
Date: 06-03-2007
Publisher: Oxford University Press (OUP)
Date: 20-03-2008
Abstract: Rossi-Santos, M. R., Neto, E. S., Baracho, C. G., Cipolotti, S. R., Marcovaldi, E., and Engel, M. H. 2008. Occurrence and distribution of humpback whales (Megaptera novaeangliae) on the north coast of the State of Bahia, Brazil, 2000–2006. – ICES Journal of Marine Science, 65: 667–673. The Abrolhos Bank off Brazil is considered the main breeding ground for the humpback whale (Megaptera novaeangliae) in the Southwest Atlantic. However, owing to an increase in the occurrence of the species along the north coast of the State of Bahia, it has been suggested that the species is reoccupying that region, which was probably utilized by the whales before commercial whaling. Information is presented on the occurrence and distribution of humpback whales along the north coast of the State of Bahia, with a comparative overview, for the period 2000–2006. Daily research cruises were conducted from July to October, departing from Praia do Forte (13°40′S 38°10′W) and lasting ∼9 h. Data on s ling and sighting effort, and geographical position and composition of groups of humpback whales, were collected on standardized field sheets. In all, 230 surveys were performed, covering some 9740 nautical miles in 1645 h of s ling effort, during which 1626 humpback whales were sighted, including 118 calves. Humpback whales were sighted throughout the study area. Solitary in iduals and pairs were the most frequent group composition, 26% and 37% of the observed groups (n = 723), respectively. Depth of water varied from 15 to 1657 m (mean = 62.4 s.d. = 99). The sightings values were grouped into depth classes to ascertain the highest frequencies (∼30%) for the two classes, i.e. between 35.1 and 55 m of water. There was an increase in the encounter rates of humpback whales on the north coast of the State of Bahia between 2000 and 2006, identifying a difference in SPUE [sightings per unit (h) of effort] among years (Kruskal–Wallis H = 30.155, d.f. = 6, p 0.05). The results support the hypothesis that humpback whales are reoccupying former breeding areas along the Brazilian coast.
Publisher: Wiley
Date: 09-05-2010
Publisher: Coastal Education and Research Foundation
Date: 2015
Publisher: The Company of Biologists
Date: 02-2004
DOI: 10.1242/JEB.00770
Abstract: Recent studies of vocal mechanics in songbirds have identified a functional role for the beak in sound production. The vocal tract (trachea and beak)filters harmonic overtones from sounds produced by the syrinx, and birds can fine-tune vocal tract resonance properties through changes in beak gape. In this study, we examine patterns of beak gape during song production in seven species of Darwin's finches of the Galápagos Islands. Our principal goals were to characterize the relationship between beak gape and vocal frequency during song production and to explore the possible influence therein of ersity in beak morphology and body size. Birds were audio and video recorded (at 30 frames s–1) as they sang in the field, and 164 song sequences were analyzed. We found that song frequency regressed significantly and positively on beak gape for 38 of 56 in iduals and for all seven species examined. This finding provides broad support for a resonance model of vocal tract function in Darwin's finches. Comparison among species revealed significant variation in regression y-intercept values. Body size correlated negatively with y-intercept values, although not at a statistically significant level. We failed to detect variation in regression slopes among finch species, although the regression slopes of Darwin's finch and two North American sparrow species were found to differ. Analysis within one species (Geospiza fortis) revealed significant inter-in idual variation in regression parameters these parameters did not correlate with song frequency features or plumage scores. Our results suggest that patterns of beak use during song production were conserved during the Darwin's finch adaptive radiation, despite the evolution of substantial variation in beak morphology and body size.
Publisher: Cambridge University Press (CUP)
Date: 21-07-2009
DOI: 10.1017/S0025315409000897
Abstract: The large majority of cetacean interspecific studies report only on dolphin interactions, while studies on interactions between odontocete and mysticete are less common. The present work aims to report on sightings of cetacean interactions, during the breeding season of humpback whales (Megaptera novaeangliae) , along 370 km of the Bahia State, north-eastern Brazil, addressing aspects of cetacean distribution and behaviour. During 7 seasons (2000–2006), a total of 230 research cruises were performed, in which 38 events of interactions among humpback whales and other cetaceans (Tursiops truncatus, Steno bredanensis, Peponocephala electra and Balaenoptera acutorostrata) were observed, plus another 5 encounters without the whale's presence, including T. truncatus, S. bredanensis, P. electra, Stenella clymene and Stenella attenuata . Our results confirm the occurrence of multiple cetacean species in the Bahia State, being the first study in the world to report on a large range of interactions involving another 4 cetacean species, grouped with up to 3 mixed species per sighting, with humpback whales in their annual breeding ground.
Publisher: Cambridge University Press (CUP)
Date: 02-2007
DOI: 10.1017/S0025315407055683
Abstract: Between April 2002 and April 2005, 210 estuarine dolphin groups were sighted, with 58 animals in idually identified. Fifteen dolphins were photo-identified just once, while only two animals were sighted in 15 different months. Some in iduals showed long-term residence (more than 3 y). Residence rates showed heterogeneity in the dolphin's permanence of the estuary, with 60% of the in iduals with low numbers ( ) and only 7% showing high values for residence (maximum=45.9). Continued resightings of some dolphins support the regular use of the study area by the animals, despite some in iduals that, after a long time without resightings were registered again. In idual range analysis showed that dolphins shared the same common area, the Caravelas River Estuary. A marked fluctuation in the number of photo-identified dolphins was observed in the study area, revealed by the high number of in iduals with just a few resightings. The majority of the dolphins (60%) present a yearly residence pattern, as observed in other areas, suggesting that a few in iduals show high fidelity for the area, while many other dolphins move constantly between different areas for unknown reasons.
Publisher: Springer Science and Business Media LLC
Date: 25-07-2007
Publisher: Cambridge University Press (CUP)
Date: 20-01-2012
DOI: 10.1017/S0025315411002074
Abstract: Humpback whales ( Megaptera novaeangliae ) migrate between their feeding grounds, located in high latitudes, and their breeding grounds, located in low latitudes, exhibiting certain levels of site fidelity to their migratory destinations. The residence time, also known as occupancy rate, can be defined as the minimum number of days that those in iduals remained in the same area. In this paper, site fidelity and residence time of humpback whales that breed off the northern coast of Bahia, Brazil were investigated. Data were collected between 2000 and 2009 on-board research cruises and whale watching vessels. This paper also studies possible differences between males and females with respect to site fidelity off the Brazilian coast, using data collected since 1989. A total of 841 whales were photo-identified. The vast majority of the whales (96%, N = 809) were seen only once in the studied area, while 4% (32 in iduals) were seen twice. Most of the resights occurred within the same season (72%, N = 23), while 9 resights (28%) occurred in different years. None of the in iduals were seen more than twice. The average site fidelity rate was 1% and the occupancy rate varied from one up to 21 days (mean = 5.3 SD = 5.4, N = 23).
Publisher: Cambridge University Press (CUP)
Date: 17-03-2008
DOI: 10.1017/S0025315408000404
Abstract: The aim of this work is to describe the repertoire of calls utilized by the spinner dolphins ( Stenella longirostris ) in the southern Atlantic Ocean. We measured four acoustic parameters of the fundamental frequency of each call: (i) duration (ii) frequency litude (iii) minimum frequency and (iv) maximum frequency. We also classified calls by their shape contour by visual inspection of the spectrograms. The obtained values for call duration were 0.046 to 2.08 seconds (mean 0.433, standard deviation (SD) 0.433), litude of 0.13 to 2.01 kHz (mean of 0.36, SD 0.29), minimum frequency of 0.22 to 1.80 (mean 0.55, SD 0.29), maximum frequency of 0.46 to 7.50 (mean 1.00, SD 0.89). We classified 73 calls by spectral contour, identifying six basic types of discernible calls, showing heterogeneity among the call types, with C1, C2 and C3 calls presenting higher frequencies, 21, 30 and 23%, respectively. We found that the calls of S. longirostris in the Fernando de Noronha Archipelago are more erse and complex than previously recognized for spinner dolphins and further studies worldwide can reinforce the broad use of this sound for the species repertoire.
Publisher: Wiley
Date: 07-2002
Publisher: Acoustical Society of America
Date: 2016
DOI: 10.1121/2.0000271
Publisher: Cambridge University Press (CUP)
Date: 04-03-2011
Publisher: Brill
Date: 2006
Publisher: Informa UK Limited
Date: 04-01-2022
Publisher: FapUNIFESP (SciELO)
Date: 06-2007
DOI: 10.1590/S0101-81752007000200001
Abstract: The behavioral patterns of the estuarine dolphin, Sotalia guianensis (P. J. van Bénéden, 1864), were compared between two populations along the Brazilian coast: Caravelas (Bahia), along the eastern coast, and Norte Bay (Santa Catarina), along the southern coast. Applying the focal-group s ling in both areas, information such as the geographic position (UTM) of groups and predominant behavioral patterns were obtained. Geographic positions were used to calculate the total distance traveled by estuarine dolphin groups on each observation day. Since the distance traveled varies with time, the daily mean speed of the dolphin’s group was used as an index of movement intensity. Two comparable and easily recognizable behavioral patterns were considered: travelling and foraging. Overall movement intensity and behavioral pattern frequency were similar between both areas. However, a seasonal variation was observed in both parameters in Norte Bay, while in Caravelas these parameters were homogeneous throughout the year. Variation in the behavior of the estuarine dolphin was consistent with variations in environmental factors, such as water temperature.
Publisher: Springer International Publishing
Date: 2016
Publisher: Wiley
Date: 03-2011
Publisher: Springer International Publishing
Date: 11-08-2017
Publisher: Acoustical Society of America (ASA)
Date: 10-2015
DOI: 10.1121/1.4931900
Abstract: Acoustic parameters for the spinner dolphins' bioacoustic sounds have previously been described. However, the dolphins in the Southwest Atlantic Ocean were only recently studied near the Fernando de Noronha Archipelago. Therefore, to contribute to additional knowledge of this cosmopolitan species, this study compares previous results with a Brazilian recording. Despite statistically significant differences, the mean value comparison indicated that Hawaiian and Southwest Atlantic Ocean spinners emit similar whistles. The fact that geographical isolation does not lead the dissemblance nor the similarity of the acoustic variations in this species raises the possibility of other factors influencing those emissions. Here those differences and similarities are discussed, thereby contributing to an understanding of how distinct populations and/or species communicate through different ocean basins.
Publisher: Springer International Publishing
Date: 11-08-2017
Publisher: Springer International Publishing
Date: 11-08-2018
Publisher: Public Library of Science (PLoS)
Date: 15-09-2022
DOI: 10.1371/JOURNAL.PONE.0255868
Abstract: The Antarctic minke whale ( Balaenoptera bonaerensis ) (AMW) is one of the smallest species among baleen whales, occurring in the southern hemisphere from Antarctica to near the equator, and performing seasonal migrations from polar to tropical waters. Information about (AMW) occurrence in the winter breeding grounds is scarce, mostly coming from old records from whaling stations before the 1960’s international moratorium, such as Costinha Station in Northeastern Brazil (6° S / 34° W) and some sightings from few dedicated visual surveys. Acoustic methods can provide important data on the occurrence and distribution of migratory species. This work describes the occurrence of the Antarctic minke whale through acoustic detections of their “Bioduck” vocalisations in the Santos Basin, South-Southeastern Brazil (22° and 28° S / 42° and 48° W). Data was recorded between November 12 and December 19, 2015. AMW calls were detected for 12 days. We detected and classified 9 different Bio-duck calls in Brazilian coastal waters, evidencing a highly erse acoustic behavior for the minke whale breeding ground. This is the first attempt to describe the acoustic ersity of AMW vocalizations in lower latitudes, contributing important information for future conservation efforts and management of AMW populations and their habitat. Therefore, our study presents the foremost acoustic evidence of the Antarctic minke whale in Brazilian coastal waters.
Publisher: Springer International Publishing
Date: 11-08-2018
No related grants have been discovered for Marcos Rossi-Santos.