Source level and vocalizing depth estimation of two blue whale subspecies in the western Indian Ocean from single sensor observations

2021 ◽  
Vol 149 (6) ◽  
pp. 4422-4436
Author(s):  
Léa Bouffaut ◽  
Martin Landrø ◽  
John R. Potter
Keyword(s):  
Indian Ocean ◽  
Western Indian Ocean ◽  
Depth Estimation ◽  
Blue Whale ◽  
Single Sensor ◽  
Source Level

Source level estimation of two blue whale subspecies in southwestern Indian Ocean

2010 ◽  
Vol 127 (6) ◽  
pp. 3800-3808 ◽  
Author(s):  
Flore Samaran ◽  
Christophe Guinet ◽  
Olivier Adam ◽  
Jean-François Motsch ◽  
Yves Cansi
Keyword(s):  
Indian Ocean ◽  
Blue Whale ◽  
Source Level ◽  
Southwestern Indian Ocean

scholarly journals A new blue whale song-type described for the Arabian Sea and Western Indian Ocean

2020 ◽  
Vol 43 ◽  
pp. 495-515
Author(s):  
S Cerchio ◽  
A Willson ◽  
EC Leroy ◽  
C Muirhead ◽  
S Al Harthi ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Arabian Sea ◽  
Western Indian Ocean ◽  
Small Population ◽  
Song Type ◽  
Blue Whale ◽  
Conservation Action ◽  
Status Assessment ◽  
The 1960S ◽  
Blue Whales

Blue whales Balaenoptera musculus in the Indian Ocean (IO) are currently thought to represent 2 or 3 subspecies (B. m. intermedia, B. m. brevicauda, B. m. indica), and believed to be structured into 4 populations, each with a diagnostic song-type. Here we describe a previously unreported song-type that implies the probable existence of a population that has been undetected or conflated with another population. The novel song-type was recorded off Oman in the northern IO/Arabian Sea, off the western Chagos Archipelago in the equatorial central IO, and off Madagascar in the southwestern IO. As this is the only blue whale song that has been identified in the western Arabian Sea, we label it the ‘Northwest Indian Ocean’ song-type to distinguish it from other regional song-types. Spatiotemporal variation suggested a distribution west of 70°E, with potential affinity for the northern IO/Arabian Sea, and only minor presence in the southwestern IO. Timing of presence off Oman suggested that intensive illegal Soviet whaling that took 1294 blue whales in the 1960s likely targeted this population, as opposed to the more widely distributed ‘Sri Lanka’ acoustic population as previously assumed. Based upon geographic distribution and potential aseasonal reproduction found in the Soviet catch data, we suggest that if there is a northern IO subspecies (B. m. indica), it is likely this population. Moreover, the potentially restricted range, intensive historic whaling, and the fact that the song-type has been previously undetected, suggests a small population that is in critical need of status assessment and conservation action.

Editorial Introduction

2020 ◽  
Vol 4 (1) ◽  
pp. 1
Author(s):  
Editors of the JIOWS
Keyword(s):  
Nineteenth Century ◽  
Indian Ocean ◽  
Western Indian Ocean ◽  
Late Nineteenth Century ◽  
Fourth Volume ◽  
History Of ◽  
The Indian Ocean ◽  
Complex Relationships ◽  
Indian Ocean World ◽  
Shed Light

The editors are proud to present the first issue of the fourth volume of the Journal of Indian Ocean World Studies. This issue contains three articles, by James Francis Warren (Murdoch University), Kelsey McFaul (University of California, Santa Cruz), and Marek Pawelczak (University of Warsaw), respectively. Warren’s and McFaul’s articles take different approaches to the growing body of work that discusses pirates in the Indian Ocean World, past and present. Warren’s article is historical, exploring the life and times of Julano Taupan in the nineteenth-century Philippines. He invites us to question the meaning of the word ‘pirate’ and the several ways in which Taupan’s life has been interpreted by different European colonists and by anti-colonial movements from the mid-nineteenth century to the present day. McFaul’s article, meanwhile, takes a literary approach to discuss the much more recent phenomenon of Somali Piracy, which reached its apex in the last decade. Its contribution is to analyse the works of authors based in the region, challenging paradigms that have mostly been developed from analysis of works written in the West. Finally, Pawelczak’s article is a legal history of British jurisdiction in mid-late nineteenth-century Zanzibar. It examines one of the facets that underpinned European influence in the western Indian Ocean World before the establishment of colonial rule. In sum, this issue uses two key threads to shed light on the complex relationships between European and other Western powers and the Indian Ocean World.

scholarly journals Factors influencing microbial mat composition, distribution and dinitrogen fixation in three western Indian Ocean coral reefs

2012 ◽  
Vol 47 (1) ◽  
pp. 51-66 ◽  
Author(s):  
Loïc Charpy ◽  
Katarzyna A. Palinska ◽  
Raeid M. M. Abed ◽  
Marie José Langlade ◽  
Stjepko Golubic
Keyword(s):  
Indian Ocean ◽  
Coral Reefs ◽  
Western Indian Ocean ◽  
Dinitrogen Fixation ◽  
Microbial Mat ◽  
Composition Distribution ◽  
Factors Influencing

scholarly journals Movement ecology of black marlin Istiompax indica in the Western Indian Ocean

2021 ◽  
Author(s):  
Christoph A. Rohner ◽  
Roy Bealey ◽  
Bernerd M. Fulanda ◽  
Jason D. Everett ◽  
Anthony J. Richardson ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Movement Ecology ◽  
Western Indian Ocean

scholarly journals Post-bleaching mortality of a remote coral reef community in Seychelles, Western Indian Ocean

2019 ◽  
Vol 18 (1) ◽  
pp. 11
Author(s):  
Elena Gadoutsis ◽  
Clare A.K. Daly ◽  
Julie P. Hawkins ◽  
Ryan Daly
Keyword(s):  
Coral Reef ◽  
Indian Ocean ◽  
Western Indian Ocean ◽  
Coral Reef Community ◽  
Reef Community

scholarly journals Variability in the Mozambique Channel Trough and Impacts on Southeast African Rainfall

2020 ◽  
Vol 33 (2) ◽  
pp. 749-765 ◽  
Author(s):  
Rondrotiana Barimalala ◽  
Ross C. Blamey ◽  
Fabien Desbiolles ◽  
Chris J. C. Reason
Keyword(s):  
Indian Ocean ◽  
Austral Summer ◽  
Western Indian Ocean ◽  
Strong Relationship ◽  
Ocean Basin ◽  
Moist Convection ◽  
South Indian Ocean ◽  
Mozambique Channel ◽  
Mascarene High ◽  
South Indian

AbstractThe Mozambique Channel trough (MCT) is a cyclonic region prominent in austral summer in the central and southern Mozambique Channel. It first becomes evident in December with a peak in strength in February when the Mozambique Channel is warmest and the Mascarene high (MH) is located farthest southeast in the Indian Ocean basin. The strength and the timing of the mean MCT are linked to that of the cross-equatorial northeasterly monsoon in the tropical western Indian Ocean, which curves as northwesterlies toward northern Madagascar. The interannual variability in the MCT is associated with moist convection over the Mozambique Channel and is modulated by the location of the warm sea surface temperatures in the south Indian Ocean. Variability of the MCT shows a strong relationship with the equatorial westerlies north of Madagascar and the latitudinal extension of the MH. Summers with strong MCT activity are characterized by a prominent cyclonic circulation over the Mozambique Channel, extending to the midlatitudes. These are favorable for the development of tropical–extratropical cloud bands over the southwestern Indian Ocean and trigger an increase in rainfall over the ocean but a decrease over the southern African mainland. Most years with a weak MCT are associated with strong positive south Indian Ocean subtropical dipole events, during which the subcontinent tends to receive more rainfall whereas Madagascar and northern Mozambique are anomalously dry.

“Research in the Western Indian Ocean Region” Conference’: Preliminary Report and Recommendations

1966 ◽  
Vol 9 (01) ◽  
pp. 33-37
Author(s):  
Aidan Southall
Keyword(s):  
Indian Ocean ◽  
Cultural Anthropology ◽  
Western Indian Ocean ◽  
Social Background ◽  
Columbia University ◽  
Indian Ocean Region ◽  
Research Committee ◽  
Northwestern University ◽  
Ocean Region ◽  
Syracuse University

The conference was sponsored by the African Research Committee and was held at the Minnowbrook Conference Center of Syracuse University from October 30 to November 2, 1965. The disciplines represented were social and cultural anthropology, musicology, sociology, social psychology, political science, and history. Participants included Philip Allen (Department of State); Frederick Burke (Syracuse University); Remi Clignet (Northwestern University); L. Gray Cowan (Columbia University); Norma McCloud (Tulane University); John Middleton (Northwestern University); Allen Rawick (Library of Congress); Aidan Southall, Chairman (Syracuse University); and Peter Wilson (Yale University). The conference concentrated its efforts on seeking and sharing a common understanding of the social background of the diverse ocean and island region that includes Madagascar, the Comoros, Mauritius, Réunion, and the Seychelles and on exploring precisely the extent to which linked interdisciplinary and comparative studies would be fruitful. The conference came to a strong and unanimous conclusion that the Western Indian Ocean Region offers the challenging possiblity of a real breakthrough in a number of dissimilar but closely interlocking research interests. The main recommendations of the conference are as follows: 1. That a rather informal clearinghouse should be established which would institute and maintain contact between social scientists interested in the region and keep them up to date on all relevant plans and work in progress. 2. That a careful and detailed application should be drawn up to obtain funds for carrying out a series of well-balanced and integrated studies, attracting graduate students and training them for further work, securing library resources, and forming appropriate ties with interested scholars and academic institutions overseas.

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