Minton, Gianna,van Bressem, M. F.,Willson, A.,Collins, T.,Al Harthi, S.,Sarrouf Willson, M.,Baldwin, R.,Leslie, M.,Robbins, J.,Van Waerebeek, K
Visual Health Assessment and evaluation of Anthropogenic threats to Arabian Sea Humpback Whales in Oman Technical Report
Document presented to the Scientific Committee of the International Whaling Commission no. 418, 2020.
Abstract | Links | BibTeX | Tags: Arabian Sea, Barnacle, Bycatch, disease, Fisheries, Humpback Whale, killer whale, lesions, megaptera novaeangliae, Oman, pathology, photo identification, predation, scarring, skin, tattoo
@techreport{,
title = {Visual Health Assessment and evaluation of Anthropogenic threats to Arabian Sea Humpback Whales in Oman},
author = {Minton, Gianna,van Bressem, M. F.,Willson, A.,Collins, T.,Al Harthi, S.,Sarrouf Willson, M.,Baldwin, R.,Leslie, M.,Robbins, J.,Van Waerebeek, K},
url = {https://arabianseawhalenetwork.org/wp-content/uploads/2020/06/sc_68b_cmp_16_rev1_visual-health-assessment-of-ashw-in-oman-1.pdf},
year = {2020},
date = {2020-01-01},
journal = {Paper presented to the meeting of the Scientific Committee of the International Whaling Commission},
number = {418},
pages = {25},
publisher = {IWC},
institution = {Document presented to the Scientific Committee of the International Whaling Commission},
abstract = {Arabian Sea humpback whales have been a subject of conservation concern in the IWC since 1997. Research conducted primarily off the coast of Oman has contributed to understanding the population’s distribution, abundance, and conservation status, whilst information on the population’s health and specific threats is more limited. This study examines all available images of Arabian Sea humpback whales obtained between 2000 and 2018 for evidence of disease, predation, epizoites and human-induced scarring or injury to individuals. Tattoo-like skin disease was detected in 43.4% of 83 adult whales, with a roughly equal distribution between males and females. The prevalence of the disease was significantly higher in 2012-2018 (51.7%) than in 2000-2011 (24.1%). The lesions persisted for two to 14 years in 10 whales and progressed in prevalence and percentage of body cover in six of them. Killer whale tooth rakes were detected in 12% (95% CI 4.5-18%) of individuals based on examination of photographs showing the ventral surface of tail flukes (n=77), but no cookie cutter shark wounds were detected on any body parts of any of the whales examined. Roughly two thirds (66.6%: 95% CI 52-80%) of individuals represented by good quality photos of the caudal peduncle region (n=42) bore scarring patterns considered likely to be associated with entanglement in fishing gear, with no significant differences in entanglement scarring rates between males and females. Four individuals bore injuries consistent with vessel strikes and at least two individuals showed severe injuries and deformations likely to have been caused by interactions with vessels and/or fishing gear. Five documented entanglement events from Oman and Pakistan involved large-mesh nylon gillnets, which are known to be used extensively throughout the Arabian Sea. In light of this population’s endangered status, these findings indicate an urgent need to continue monitoring Arabian Sea humpback whales, with an emphasis on methods that allow continued and expanded assessment of health, body condition, and anthropogenic interactions, aimed toward designing effective conservation strategies to mitigate known threats. },
keywords = {Arabian Sea, Barnacle, Bycatch, disease, Fisheries, Humpback Whale, killer whale, lesions, megaptera novaeangliae, Oman, pathology, photo identification, predation, scarring, skin, tattoo},
pubstate = {published},
tppubtype = {techreport}
}
Arabian Sea humpback whales have been a subject of conservation concern in the IWC since 1997. Research conducted primarily off the coast of Oman has contributed to understanding the population’s distribution, abundance, and conservation status, whilst information on the population’s health and specific threats is more limited. This study examines all available images of Arabian Sea humpback whales obtained between 2000 and 2018 for evidence of disease, predation, epizoites and human-induced scarring or injury to individuals. Tattoo-like skin disease was detected in 43.4% of 83 adult whales, with a roughly equal distribution between males and females. The prevalence of the disease was significantly higher in 2012-2018 (51.7%) than in 2000-2011 (24.1%). The lesions persisted for two to 14 years in 10 whales and progressed in prevalence and percentage of body cover in six of them. Killer whale tooth rakes were detected in 12% (95% CI 4.5-18%) of individuals based on examination of photographs showing the ventral surface of tail flukes (n=77), but no cookie cutter shark wounds were detected on any body parts of any of the whales examined. Roughly two thirds (66.6%: 95% CI 52-80%) of individuals represented by good quality photos of the caudal peduncle region (n=42) bore scarring patterns considered likely to be associated with entanglement in fishing gear, with no significant differences in entanglement scarring rates between males and females. Four individuals bore injuries consistent with vessel strikes and at least two individuals showed severe injuries and deformations likely to have been caused by interactions with vessels and/or fishing gear. Five documented entanglement events from Oman and Pakistan involved large-mesh nylon gillnets, which are known to be used extensively throughout the Arabian Sea. In light of this population’s endangered status, these findings indicate an urgent need to continue monitoring Arabian Sea humpback whales, with an emphasis on methods that allow continued and expanded assessment of health, body condition, and anthropogenic interactions, aimed toward designing effective conservation strategies to mitigate known threats.
Van Bressem, Marie-Françoise,Minton, Gianna,Collins, Tim,Willson, Andrew,Baldwin, Robert,Van Waerebeek, Koen
Tattoo-like skin disease in the endangered subpopulation of the Humpback Whale, Journal Article
In: Zoology in the Middle East, no. 489, pp. 1-8, 2014, ISBN: 0939-7140.
Abstract | Links | BibTeX | Tags: Arabian Sea, health, Humpback Whale, lesions, megaptera novaeangliae, Oman, photo-ID, skin, tattoo, Threats
@article{,
title = {Tattoo-like skin disease in the endangered subpopulation of the Humpback Whale, },
author = {Van Bressem, Marie-Françoise,Minton, Gianna,Collins, Tim,Willson, Andrew,Baldwin, Robert,Van Waerebeek, Koen},
url = {http://dx.doi.org/10.1080/09397140.2014.994316},
issn = {0939-7140},
year = {2014},
date = {2014-01-01},
journal = {Zoology in the Middle East},
number = {489},
pages = {1-8},
publisher = {Taylor & Francis},
abstract = {The presence of tattoo-like skin disease is reported in an endangered, non-migratory subpopulation of Humpback Whales (Megaptera novaeangliae) from Oman. We examined 522 images taken during small-boat surveys in the Gulf of Masirah and in Dhofar in 2000-2006 and in 2010-2011. Tattoo-like lesions were detected in regular, good and outstanding images. They appeared as irregular or rounded, light grey marks often showing a whitish outline, and were located on the flanks, dorsum, dorsal fin and caudal peduncle. They could be relatively small to very large and cover up to an estimated 40% of the visible body surface. Over the whole study period disease prevalence reached 21.7% in 60 whales and 16.7% in 36 adults. In this category, prevalence was higher in males (26.7%, N=15) than in females (9.1%, N=11), but the difference was not significant. Lesions appeared larger in males than in the positive female and progressed in two males. Disease prevalence increased significantly from 2000 through 2011 (r2 =0.998). Advanced tattoo skin disease, with lesions extending over more than 10% of the visible body surface seemed to occur more frequently in 2010-2011 than in 2000-2006, but samples were small. This is the first confirmed report of tattoo-like disease in the Balaenopteridae family and the first time it is documented in the Arabian Sea. The disease high prevalence, its increase over time and its progression in some individuals are of concern.},
keywords = {Arabian Sea, health, Humpback Whale, lesions, megaptera novaeangliae, Oman, photo-ID, skin, tattoo, Threats},
pubstate = {published},
tppubtype = {article}
}
The presence of tattoo-like skin disease is reported in an endangered, non-migratory subpopulation of Humpback Whales (Megaptera novaeangliae) from Oman. We examined 522 images taken during small-boat surveys in the Gulf of Masirah and in Dhofar in 2000-2006 and in 2010-2011. Tattoo-like lesions were detected in regular, good and outstanding images. They appeared as irregular or rounded, light grey marks often showing a whitish outline, and were located on the flanks, dorsum, dorsal fin and caudal peduncle. They could be relatively small to very large and cover up to an estimated 40% of the visible body surface. Over the whole study period disease prevalence reached 21.7% in 60 whales and 16.7% in 36 adults. In this category, prevalence was higher in males (26.7%, N=15) than in females (9.1%, N=11), but the difference was not significant. Lesions appeared larger in males than in the positive female and progressed in two males. Disease prevalence increased significantly from 2000 through 2011 (r2 =0.998). Advanced tattoo skin disease, with lesions extending over more than 10% of the visible body surface seemed to occur more frequently in 2010-2011 than in 2000-2006, but samples were small. This is the first confirmed report of tattoo-like disease in the Balaenopteridae family and the first time it is documented in the Arabian Sea. The disease high prevalence, its increase over time and its progression in some individuals are of concern.