Anderson, Charles,Herrera, Miguel,Ilangakoon, Anoukchika,Koya, KM,Moazzam, M,Mustika, Putu L,Sutaria, Dipani N
Cetacean bycatch in Indian Ocean tuna gillnet fisheries Journal Article
In: Endangered Species Research, vol. 41, no. 292, pp. 39-53, 2020, ISSN: 1863-5407.
Abstract | Links | BibTeX | Tags: Bycatch, Estimates, Extrapolation, Gill net, gillnet, Indian Ocean, mortality, Observer programmes, Oman, Pakistan, Sri Lanka, Trends, tuna fishery
@article{,
title = {Cetacean bycatch in Indian Ocean tuna gillnet fisheries},
author = {Anderson, Charles,Herrera, Miguel,Ilangakoon, Anoukchika,Koya, KM,Moazzam, M,Mustika, Putu L,Sutaria, Dipani N},
url = {https://www.int-res.com/prepress/n01008.html},
doi = {https://doi.org/10.3354/esr01008},
issn = {1863-5407},
year = {2020},
date = {2020-01-01},
journal = {Endangered Species Research},
volume = {41},
number = {292},
pages = {39-53},
abstract = {Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combine published results from 10 bycatch sampling programmes (1981–2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100,000 individuals yr–1 during 2004–2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, nor of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean. },
keywords = {Bycatch, Estimates, Extrapolation, Gill net, gillnet, Indian Ocean, mortality, Observer programmes, Oman, Pakistan, Sri Lanka, Trends, tuna fishery},
pubstate = {published},
tppubtype = {article}
}
Pelagic gillnet (driftnet) fisheries account for some 34% of Indian Ocean tuna catches. We combine published results from 10 bycatch sampling programmes (1981–2016) in Australia, Sri Lanka, India and Pakistan to estimate bycatch rates for cetaceans across all Indian Ocean tuna gillnet fisheries. Estimated cetacean bycatch peaked at almost 100,000 individuals yr–1 during 2004–2006, but has declined by over 15% since then, despite an increase in tuna gillnet fishing effort. These fisheries caught an estimated cumulative total of 4.1 million small cetaceans between 1950 and 2018. These bycatch estimates take little or no account of cetaceans caught by gillnet but not landed, of delayed mortality or sub-lethal impacts on cetaceans (especially whales) that escape from gillnets, of mortality associated with ghost nets, of harpoon catches made from gillnetters, nor of mortality from other tuna fisheries. Total cetacean mortality from Indian Ocean tuna fisheries may therefore be substantially higher than estimated here. Declining cetacean bycatch rates suggest that such levels of mortality are not sustainable. Indeed, mean small cetacean abundance may currently be 13% of pre-fishery levels. None of these estimates are precise, but they do demonstrate the likely order of magnitude of the issue. Countries with the largest current gillnet catches of tuna, and thus the ones likely to have the largest cetacean bycatch are (in order): Iran, Indonesia, India, Sri Lanka, Pakistan, Oman, Yemen, UAE and Tanzania. These 9 countries together may account for roughly 96% of all cetacean bycatch from tuna gillnet fisheries across the Indian Ocean.
de Vos,Asha,Faux,Cassandra E.,Marthick,James,Dickinson,Joanne,Jarman,Simon N.
New Determination of Prey and Parasite Species for Northern Indian Ocean Blue Whales Journal Article
In: Frontiers in Marine Science, vol. 5, no. 84, 2018, ISBN: 2296-7745.
Abstract | Links | BibTeX | Tags: Acanthocephala, Arabian Sea, balaenoptera musculus, behaviour, blue whales, DNA metabarcoding,Sri Lanka,Blue whales,feeding,Northern Indian Ocean,faeces,Sergestid,Euphausiidae,Acanthocephala,shrimp,krill,behaviour, euphasids, Faeces, fecal analysis, feeding, Krill, Northern Indian Ocean, parasites, prey, Sergestid shrimp, shrimp, Sri Lanka
@article{,
title = {New Determination of Prey and Parasite Species for Northern Indian Ocean Blue Whales},
author = {de Vos,Asha,Faux,Cassandra E.,Marthick,James,Dickinson,Joanne,Jarman,Simon N.},
url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00104},
issn = {2296-7745},
year = {2018},
date = {2018-01-01},
journal = {Frontiers in Marine Science},
volume = {5},
number = {84},
abstract = {Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behaviour of blue whales using dietary DNA metabarcoding of faecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87 % of prey DNA amplicons extracted from faecal samples from this population were sergestid shrimp, demonstrating that blue whales can locate and feed on dense swarms of other types of prey when they occur. Within the Indian Ocean sergestids are present within the top 300 m, which correlates with the deep scattering layer observed by hydroacoustics. Studies suggest that this requirement to dive deeper in search of prey likely explains the prevalence of fluke up diving within this population of blue whales relative to other parts of the globe. Furthermore, this study revealed the presence of acanthocephalan endoparasites within the stomach and intestines of the Northern Indian Ocean blue whales. This represents the first record of Acanthocephala in blue whales in the Northern Indian Ocean and highlights the need for further studies on both the ecto- and endoparasitic flora and monitoring of health of these cetaceans for their management and conservation.},
keywords = {Acanthocephala, Arabian Sea, balaenoptera musculus, behaviour, blue whales, DNA metabarcoding,Sri Lanka,Blue whales,feeding,Northern Indian Ocean,faeces,Sergestid,Euphausiidae,Acanthocephala,shrimp,krill,behaviour, euphasids, Faeces, fecal analysis, feeding, Krill, Northern Indian Ocean, parasites, prey, Sergestid shrimp, shrimp, Sri Lanka},
pubstate = {published},
tppubtype = {article}
}
Blue whales are little studied, face significant anthropogenic threats and within the Northern Indian Ocean, have a restricted range, making them an archetype for conservation needs of megafauna around the world. We studied feeding behaviour of blue whales using dietary DNA metabarcoding of faecal samples. While globally blue whale populations feed predominantly on Euphausiidae, 87 % of prey DNA amplicons extracted from faecal samples from this population were sergestid shrimp, demonstrating that blue whales can locate and feed on dense swarms of other types of prey when they occur. Within the Indian Ocean sergestids are present within the top 300 m, which correlates with the deep scattering layer observed by hydroacoustics. Studies suggest that this requirement to dive deeper in search of prey likely explains the prevalence of fluke up diving within this population of blue whales relative to other parts of the globe. Furthermore, this study revealed the presence of acanthocephalan endoparasites within the stomach and intestines of the Northern Indian Ocean blue whales. This represents the first record of Acanthocephala in blue whales in the Northern Indian Ocean and highlights the need for further studies on both the ecto- and endoparasitic flora and monitoring of health of these cetaceans for their management and conservation.
de Vos, Asha
First record of Omura’s whale, Balaenoptera omurai, in Sri Lankan waters Journal Article
In: Marine Biodiversity Records, vol. 10, no. 82, pp. 18, 2017, ISBN: 1755-2672.
Abstract | Links | BibTeX | Tags: Arabian Sea, balaenoptera omurai, Distribution, Northern Indian Ocean, Omura's Whale, Sri Lanka
@article{,
title = {First record of Omura’s whale, Balaenoptera omurai, in Sri Lankan waters},
author = {de Vos, Asha},
url = {http://dx.doi.org/10.1186/s41200-017-0121-2},
issn = {1755-2672},
year = {2017},
date = {2017-01-01},
journal = {Marine Biodiversity Records},
volume = {10},
number = {82},
pages = {18},
abstract = {An unusually coloured, small baleen whale was documented off the southern coast of Sri Lanka in February 2017 during routine field surveys. Based on five distinct morphological characteristics including jaw asymmetry, presence of a prominent central rostral ridge, blaze on right side, asymmetrical chevron on left and right sides and a strongly falcate dorsal fin the individual was positively identified as an Omura’s whale (Balaenoptera omurai). This discovery represents the first confirmed sighting of Omura’s whale in Sri Lankan and therefore central Northern Indian Ocean waters.},
keywords = {Arabian Sea, balaenoptera omurai, Distribution, Northern Indian Ocean, Omura's Whale, Sri Lanka},
pubstate = {published},
tppubtype = {article}
}
An unusually coloured, small baleen whale was documented off the southern coast of Sri Lanka in February 2017 during routine field surveys. Based on five distinct morphological characteristics including jaw asymmetry, presence of a prominent central rostral ridge, blaze on right side, asymmetrical chevron on left and right sides and a strongly falcate dorsal fin the individual was positively identified as an Omura’s whale (Balaenoptera omurai). This discovery represents the first confirmed sighting of Omura’s whale in Sri Lankan and therefore central Northern Indian Ocean waters.
Nanayakkara, Ranil P.,Jefferson, Thomas A.,Abayaratne, Sandaruwan
First records of the Indo-Pacific Finless Porpoise Journal Article
In: Journal of Threatened Taxa, vol. 9, no. 181, pp. 11081-11084, 2017.
Abstract | Links | BibTeX | Tags: Arabian Sea, Finless Porpoise, Neophocaena phocaenoides, Sri Lanka, stranding
@article{,
title = {First records of the Indo-Pacific Finless Porpoise },
author = {Nanayakkara, Ranil P.,Jefferson, Thomas A.,Abayaratne, Sandaruwan},
url = {https://threatenedtaxa.org/index.php/JoTT/article/view/1811},
year = {2017},
date = {2017-01-01},
journal = {Journal of Threatened Taxa},
volume = {9},
number = {181},
pages = {11081-11084},
abstract = {Thirty species of marine mammals have been recorded from Sri Lanka. Amongst them the Indo-Pacific Finless Porpoise Neophocaena phocaenoides is the only representative of the family Phocoenidae. The only previous record from Sri Lanka was a specimen caught on the Wadge Bank by a Smithsonian Carangid Survey team in 1970. Wadge Bank is west of the island and is, in fact, in Indian territorial waters. Here we present the first legitimate records of the Finless Porpoise from Sri Lanka, based on one stranding and three live sightings. Furthermore, the occurrence of threatened species such as the Indo-Pacific Finless Porpoise in the waters of the Palk Bay and the Gulf of Mannar indicates that a cross boundary research initiative between Indian and Sri Lankan scientists, simultaneously focusing on the conservation of the species, is essential. We believe, through such an initiative, a more holistic approach could be adopted when studying and conserving the species, which could then be expanded to encapsulate many other marine species and ecosystems. },
keywords = {Arabian Sea, Finless Porpoise, Neophocaena phocaenoides, Sri Lanka, stranding},
pubstate = {published},
tppubtype = {article}
}
Thirty species of marine mammals have been recorded from Sri Lanka. Amongst them the Indo-Pacific Finless Porpoise Neophocaena phocaenoides is the only representative of the family Phocoenidae. The only previous record from Sri Lanka was a specimen caught on the Wadge Bank by a Smithsonian Carangid Survey team in 1970. Wadge Bank is west of the island and is, in fact, in Indian territorial waters. Here we present the first legitimate records of the Finless Porpoise from Sri Lanka, based on one stranding and three live sightings. Furthermore, the occurrence of threatened species such as the Indo-Pacific Finless Porpoise in the waters of the Palk Bay and the Gulf of Mannar indicates that a cross boundary research initiative between Indian and Sri Lankan scientists, simultaneously focusing on the conservation of the species, is essential. We believe, through such an initiative, a more holistic approach could be adopted when studying and conserving the species, which could then be expanded to encapsulate many other marine species and ecosystems.Â
Buultjens, Jeremy,Ratnayke, Iraj,Gnanapala, Athula
Whale watching in Sri Lanka: Perceptions of sustainability Journal Article
In: Tourism Management Perspectives, vol. 18, no. 62, pp. 125-133, 2016, ISBN: 2211-9736.
Abstract | BibTeX | Tags: Arabian Sea, impact, management, regulations, Sri Lanka, Sustainability, Whale watching
@article{,
title = {Whale watching in Sri Lanka: Perceptions of sustainability},
author = {Buultjens, Jeremy,Ratnayke, Iraj,Gnanapala, Athula},
issn = {2211-9736},
year = {2016},
date = {2016-01-01},
journal = {Tourism Management Perspectives},
volume = {18},
number = {62},
pages = {125-133},
abstract = {Whale watching creates an economic value for whales beyond consumption and therefore assists in the conservation of the species. However sustainable management is needed to avoid deleterious impacts on the whales and the industry. This paper uses a range of qualitative methods to examine the characteristics, management and perceived sustainability of the relatively newly established whale watching industry in Sri Lanka. It is clear that the laissez faire development of the industry has resulted in some poor conservation outcomes for the
whales as well as variable tourist experiences. The Sri Lankan government has introduced legislated regulations aimed at managing the industry however it must ensure adequate human and financial resources are provided to ensure the effective implementation of the regulations and therefore the sustainability of the industry.},
keywords = {Arabian Sea, impact, management, regulations, Sri Lanka, Sustainability, Whale watching},
pubstate = {published},
tppubtype = {article}
}
Whale watching creates an economic value for whales beyond consumption and therefore assists in the conservation of the species. However sustainable management is needed to avoid deleterious impacts on the whales and the industry. This paper uses a range of qualitative methods to examine the characteristics, management and perceived sustainability of the relatively newly established whale watching industry in Sri Lanka. It is clear that the laissez faire development of the industry has resulted in some poor conservation outcomes for the
whales as well as variable tourist experiences. The Sri Lankan government has introduced legislated regulations aimed at managing the industry however it must ensure adequate human and financial resources are provided to ensure the effective implementation of the regulations and therefore the sustainability of the industry.
whales as well as variable tourist experiences. The Sri Lankan government has introduced legislated regulations aimed at managing the industry however it must ensure adequate human and financial resources are provided to ensure the effective implementation of the regulations and therefore the sustainability of the industry.
Nanayakkara, Ranil P.,Herath, H. M. J. C. B.,Mel, Ruvinda K. de,Kusuminda, T. G. Tharaka
Molecular Genetic Identification of Beached Whales in Sri Lanka from Mitochondrial DNA Sequence Data Journal Article
In: Ceylon Journal of Science, vol. 43, no. 179, pp. 73, 2015.
Abstract | BibTeX | Tags: Arabian Sea, balaenoptera musculus, Blue whale, genetics, Indian Ocean, mtDNA, Sri Lanka
@article{,
title = {Molecular Genetic Identification of Beached Whales in Sri Lanka from Mitochondrial DNA Sequence Data},
author = {Nanayakkara, Ranil P.,Herath, H. M. J. C. B.,Mel, Ruvinda K. de,Kusuminda, T. G. Tharaka},
year = {2015},
date = {2015-01-01},
journal = {Ceylon Journal of Science},
volume = {43},
number = {179},
pages = {73},
abstract = {In the current study we attempt to identify eight baleen whale carcasses that were washed ashore to the Western, Northwestern and Southern coasts of Sri Lanka in 2010, using molecular phylogenetic techniques. Initial physical examination suggested that these carcasses belonged to blue whales ( Balaenoptera musculus ). Analysis of sequences of the mitochondrial control region from baleen whales confirmed that the samples belonged to blue whales ( Balaenoptera musculus ). However, it was impossible to identify the population of blue whales the individuals belonged to, due to the lack of strong population genetic signals in the mitochondrial control region sequences.},
keywords = {Arabian Sea, balaenoptera musculus, Blue whale, genetics, Indian Ocean, mtDNA, Sri Lanka},
pubstate = {published},
tppubtype = {article}
}
In the current study we attempt to identify eight baleen whale carcasses that were washed ashore to the Western, Northwestern and Southern coasts of Sri Lanka in 2010, using molecular phylogenetic techniques. Initial physical examination suggested that these carcasses belonged to blue whales ( Balaenoptera musculus ). Analysis of sequences of the mitochondrial control region from baleen whales confirmed that the samples belonged to blue whales ( Balaenoptera musculus ). However, it was impossible to identify the population of blue whales the individuals belonged to, due to the lack of strong population genetic signals in the mitochondrial control region sequences.
de Vos, A.,Pattiaratchi, C. B.,Wijeratne, E. M. S.
Surface circulation and upwelling patterns around Sri Lanka Journal Article
In: Biogeosciences, vol. 11, no. 85, pp. 5909-5930, 2014, ISBN: 1726-4189.
Abstract | Links | BibTeX | Tags: currents, Indian Ocean, oceanography, productivity, remote sensing, Sri Lanka
@article{,
title = {Surface circulation and upwelling patterns around Sri Lanka},
author = {de Vos, A.,Pattiaratchi, C. B.,Wijeratne, E. M. S.},
url = {https://www.biogeosciences.net/11/5909/2014/},
issn = {1726-4189},
year = {2014},
date = {2014-01-01},
journal = {Biogeosciences},
volume = {11},
number = {85},
pages = {5909-5930},
publisher = {Copernicus Publications},
abstract = {Sri Lanka occupies a unique location within the equatorial belt in the northern Indian Ocean, with the Arabian Sea on its western side and the Bay of Bengal on its eastern side, and experiences bi-annually reversing monsoon winds. Aggregations of blue whale (Balaenoptera musculus) have been observed along the southern coast of Sri Lanka during the northeast (NE) monsoon, when satellite imagery indicates lower productivity in the surface waters. This study explored elements of the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka using satellite imagery and numerical simulations using the Regional Ocean Modelling System (ROMS). The model was run for 3 years to examine the seasonal and shorter-term (~10 days) variability. The results reproduced correctly the reversing current system, between the Equator and Sri Lanka, in response to the changing wind field: the eastward flowing Southwest Monsoon Current (SMC) during the southwest (SW) monsoon transporting 11.5 Sv (mean over 2010–2012) and the westward flowing Northeast Monsoon Current (NMC) transporting 9.6 Sv during the NE monsoon, respectively. A recirculation feature located to the east of Sri Lanka during the SW monsoon, the Sri Lanka Dome, is shown to result from the interaction between the SMC and the island of Sri Lanka. Along the eastern and western coasts, during both monsoon periods, flow is southward converging along the southern coast. During the SW monsoon, the island deflects the eastward flowing SMC southward, whilst along the eastern coast, the southward flow results from the Sri Lanka Dome recirculation. The major upwelling region, during both monsoon periods, is located along the southern coast, resulting from southward flow converging along the southern coast and subsequent divergence associated with the offshore transport of water. Higher surface chlorophyll concentrations were observed during the SW monsoon. The location of the flow convergence and hence the upwelling centre was dependent on the relative strengths of wind-driven flow along the eastern and western coasts: during the SW (NE) monsoon, the flow along the western (eastern) coast was stronger, migrating the upwelling centre to the east (west).},
keywords = {currents, Indian Ocean, oceanography, productivity, remote sensing, Sri Lanka},
pubstate = {published},
tppubtype = {article}
}
Sri Lanka occupies a unique location within the equatorial belt in the northern Indian Ocean, with the Arabian Sea on its western side and the Bay of Bengal on its eastern side, and experiences bi-annually reversing monsoon winds. Aggregations of blue whale (Balaenoptera musculus) have been observed along the southern coast of Sri Lanka during the northeast (NE) monsoon, when satellite imagery indicates lower productivity in the surface waters. This study explored elements of the dynamics of the surface circulation and coastal upwelling in the waters around Sri Lanka using satellite imagery and numerical simulations using the Regional Ocean Modelling System (ROMS). The model was run for 3 years to examine the seasonal and shorter-term (~10 days) variability. The results reproduced correctly the reversing current system, between the Equator and Sri Lanka, in response to the changing wind field: the eastward flowing Southwest Monsoon Current (SMC) during the southwest (SW) monsoon transporting 11.5 Sv (mean over 2010–2012) and the westward flowing Northeast Monsoon Current (NMC) transporting 9.6 Sv during the NE monsoon, respectively. A recirculation feature located to the east of Sri Lanka during the SW monsoon, the Sri Lanka Dome, is shown to result from the interaction between the SMC and the island of Sri Lanka. Along the eastern and western coasts, during both monsoon periods, flow is southward converging along the southern coast. During the SW monsoon, the island deflects the eastward flowing SMC southward, whilst along the eastern coast, the southward flow results from the Sri Lanka Dome recirculation. The major upwelling region, during both monsoon periods, is located along the southern coast, resulting from southward flow converging along the southern coast and subsequent divergence associated with the offshore transport of water. Higher surface chlorophyll concentrations were observed during the SW monsoon. The location of the flow convergence and hence the upwelling centre was dependent on the relative strengths of wind-driven flow along the eastern and western coasts: during the SW (NE) monsoon, the flow along the western (eastern) coast was stronger, migrating the upwelling centre to the east (west).
Nanayakkara, Ranil,de Mel, Ruvinda,Kusuminda, Tharaka,Cabral de Mel, Surendranie
Surface and dive times of the Blue Whale ( Journal Article
In: NeBIO I An international journal of environment and biodiversity, vol. Vol. 5, No. 4, no. 177, pp. 1-3, 2014.
Abstract | BibTeX | Tags: Arabian Sea, balaenoptera musculus, Blue whale, dive duration, dive time, feeding, Indian Ocean, Sri Lanka, Surfacing behaviour
@article{,
title = {Surface and dive times of the Blue Whale (},
author = {Nanayakkara, Ranil,de Mel, Ruvinda,Kusuminda, Tharaka,Cabral de Mel, Surendranie},
year = {2014},
date = {2014-01-01},
journal = {NeBIO I An international journal of environment and biodiversity},
volume = {Vol. 5, No. 4},
number = {177},
pages = {1-3},
abstract = {Dive times of a single Blue Whale observed in Trincomalee Bay, Sri Lanka, in relation to the abiotic parameters of the bay’s waters and its ability to support large densities of krill from May 2011 to July 2011. Thirty five total dives were observed and its mean dive time was 9.6 ± 0.31 min. The observed whale’s feeding dives lasted longer than what has been previously recorded for blue whales in the Pacific Ocean. The mean salinity, Mean Total Suspended Solids (TSS) and mean temperature of Trincomalee Bay was respectively 28.1± 4.8 ppt, 9.92 ± 0.3 mg/L and 28.81 ± 0.96 0 C. All studied abiotic parameters of Trincomalee Bay show that it is able to support large concentrations of krill. Trincomalee Bay thus seems to serve as a highly productive hunting ground for Blue Whales in the northern Indian Ocean.},
keywords = {Arabian Sea, balaenoptera musculus, Blue whale, dive duration, dive time, feeding, Indian Ocean, Sri Lanka, Surfacing behaviour},
pubstate = {published},
tppubtype = {article}
}
Dive times of a single Blue Whale observed in Trincomalee Bay, Sri Lanka, in relation to the abiotic parameters of the bay’s waters and its ability to support large densities of krill from May 2011 to July 2011. Thirty five total dives were observed and its mean dive time was 9.6 ± 0.31 min. The observed whale’s feeding dives lasted longer than what has been previously recorded for blue whales in the Pacific Ocean. The mean salinity, Mean Total Suspended Solids (TSS) and mean temperature of Trincomalee Bay was respectively 28.1± 4.8 ppt, 9.92 ± 0.3 mg/L and 28.81 ± 0.96 0 C. All studied abiotic parameters of Trincomalee Bay show that it is able to support large concentrations of krill. Trincomalee Bay thus seems to serve as a highly productive hunting ground for Blue Whales in the northern Indian Ocean.
Nanayakkara, Ranil,Kusuminda, Tharaka,Jefferson, Thomas
Can the Indian Ocean Humpback Dolphin ( Journal Article
In: Aquatic Mammals, vol. 40, no. 178, pp. 398-406, 2014.
Abstract | BibTeX | Tags: Arabian Sea, Distribution, humpback dolphin, Indian Ocean, Indian Ocean humpback dolphin, Individual identification, photo identification, population, Sousa plumbea, Sri Lanka
@article{,
title = {Can the Indian Ocean Humpback Dolphin (},
author = {Nanayakkara, Ranil,Kusuminda, Tharaka,Jefferson, Thomas},
year = {2014},
date = {2014-01-01},
journal = {Aquatic Mammals},
volume = {40},
number = {178},
pages = {398-406},
abstract = {Until the last few years, the only records of Indian Ocean humpback dolphins (Sousa plumbea) in Sri Lanka were a small number of older stranding records and one unconfirmed sighting, but repeated verified sightings have been made since the early 2000s in the Puttalam Lagoon area of northwestern Sri Lanka. To determine dolphin status and distribution patterns, we conducted monthly surveys of the lagoon from July 2010 to June 2011 and sighted humpback dolphins in the lagoon in every month of the year. Repeated sightings of the same six individuals were made; and in March 2011, one of these humpback dolphins was killed by dynamite fishing. It appears that the population is very small, possibly now consisting only of these five individuals, and is resident in the lagoon. Although it is likely the species was more widespread and abundant in the past, it appears that Puttalam Lagoon may be the only location where this species persists in Sri Lanka at present. Additional research is needed to investigate possible mixing with populations in India, and urgent conservation measures are recommended to ensure the long-term survival of this enigmatic species in Sri Lanka.},
keywords = {Arabian Sea, Distribution, humpback dolphin, Indian Ocean, Indian Ocean humpback dolphin, Individual identification, photo identification, population, Sousa plumbea, Sri Lanka},
pubstate = {published},
tppubtype = {article}
}
Until the last few years, the only records of Indian Ocean humpback dolphins (Sousa plumbea) in Sri Lanka were a small number of older stranding records and one unconfirmed sighting, but repeated verified sightings have been made since the early 2000s in the Puttalam Lagoon area of northwestern Sri Lanka. To determine dolphin status and distribution patterns, we conducted monthly surveys of the lagoon from July 2010 to June 2011 and sighted humpback dolphins in the lagoon in every month of the year. Repeated sightings of the same six individuals were made; and in March 2011, one of these humpback dolphins was killed by dynamite fishing. It appears that the population is very small, possibly now consisting only of these five individuals, and is resident in the lagoon. Although it is likely the species was more widespread and abundant in the past, it appears that Puttalam Lagoon may be the only location where this species persists in Sri Lanka at present. Additional research is needed to investigate possible mixing with populations in India, and urgent conservation measures are recommended to ensure the long-term survival of this enigmatic species in Sri Lanka.
Nanayakkara, Ranil P.,Herath, Jayampathi,de Mel, Ruvinda K.
Cetacean Presence in the Trincomalee Bay and Adjacent Waters, Sri Lanka Journal Article
In: Journal of Marine Biology, vol. 2014, no. 180, pp. 819263, 2014, ISBN: 2633-4666.
Abstract | Links | BibTeX | Tags: Arabian Sea, balaenoptera edeni, balaenoptera musculus, Blue whale, Bryde’s whale, Distribution, diversity, Indian Ocean, Physeter macrocephalus, sperm whale, Spinner dolphin, Sri Lanka, Stenella longirostris
@article{,
title = {Cetacean Presence in the Trincomalee Bay and Adjacent Waters, Sri Lanka},
author = {Nanayakkara, Ranil P.,Herath, Jayampathi,de Mel, Ruvinda K.},
url = {https://doi.org/10.1155/2014/819263},
issn = {2633-4666},
year = {2014},
date = {2014-01-01},
journal = {Journal of Marine Biology},
volume = {2014},
number = {180},
pages = {819263},
publisher = {Hindawi Publishing Corporation},
abstract = {In Sri Lanka thirty species of cetaceans have been recorded to date. The canyon at Trincomalee bay is a multiple submarine canyon complex and anecdotal reports suggest that the Trincomalee bay and its adjacent waters are utilised by a number of cetacean species. Though Cetaceans are known to be abundant in the waters off Trincomalee there is a dearth of research and data pertaining to the abundance and species frequenting the Trincomalee bay and its adjacent waters. As such the current study was initiated, to get a consensus of the abundance and occurrences of species in Trincomalee Bay and its adjacent waters. Field surveys were carried out for 19 months and the research platform was a 35-foot commercial fishing vessel. 177 cetacean encounters were recorded on 67 of the 75 field days. Remarkably a total of 11 species of cetaceans which composed of two species of Baleen Whales and nine species of Toothed Whales were recorded. Delphinidae was the most common family recorded, followed by Balaenopteridae, Ziphiidae, Physeteridae, and Kogiidae. Spinner Dolphins were the most abundant cetacean owing to the large pods observed and the regularity of the sightings. They were the only species seen feeding/traveling with birds and fish (tuna). Sperm Whales, Blue Whales, and Bryde’s Whales were also relatively common. Two records of interspecific association between cetaceans were recorded. The increase in the human population in the study area has resulted in the overexploitation of marine resources which has dire repercussions on the marine mammal communities found in these waters.},
keywords = {Arabian Sea, balaenoptera edeni, balaenoptera musculus, Blue whale, Bryde’s whale, Distribution, diversity, Indian Ocean, Physeter macrocephalus, sperm whale, Spinner dolphin, Sri Lanka, Stenella longirostris},
pubstate = {published},
tppubtype = {article}
}
In Sri Lanka thirty species of cetaceans have been recorded to date. The canyon at Trincomalee bay is a multiple submarine canyon complex and anecdotal reports suggest that the Trincomalee bay and its adjacent waters are utilised by a number of cetacean species. Though Cetaceans are known to be abundant in the waters off Trincomalee there is a dearth of research and data pertaining to the abundance and species frequenting the Trincomalee bay and its adjacent waters. As such the current study was initiated, to get a consensus of the abundance and occurrences of species in Trincomalee Bay and its adjacent waters. Field surveys were carried out for 19 months and the research platform was a 35-foot commercial fishing vessel. 177 cetacean encounters were recorded on 67 of the 75 field days. Remarkably a total of 11 species of cetaceans which composed of two species of Baleen Whales and nine species of Toothed Whales were recorded. Delphinidae was the most common family recorded, followed by Balaenopteridae, Ziphiidae, Physeteridae, and Kogiidae. Spinner Dolphins were the most abundant cetacean owing to the large pods observed and the regularity of the sightings. They were the only species seen feeding/traveling with birds and fish (tuna). Sperm Whales, Blue Whales, and Bryde’s Whales were also relatively common. Two records of interspecific association between cetaceans were recorded. The increase in the human population in the study area has resulted in the overexploitation of marine resources which has dire repercussions on the marine mammal communities found in these waters.
Nanayakkara, Ranil P,Kusuminda, Tharaka,Jefferson, Thomas A
Can the Indian Ocean Humpback Dolphin ( Journal Article
In: Aquatic Mammals, vol. 40, no. 182, pp. 398, 2014, ISBN: 0167-5427.
Abstract | BibTeX | Tags: Arabian Sea, humpback dolphin, Indian Ocean, photo identification, population status, sousa, Sousa plumbea, Sri Lanka, Threat assessment
@article{,
title = {Can the Indian Ocean Humpback Dolphin (},
author = {Nanayakkara, Ranil P,Kusuminda, Tharaka,Jefferson, Thomas A},
issn = {0167-5427},
year = {2014},
date = {2014-01-01},
journal = {Aquatic Mammals},
volume = {40},
number = {182},
pages = {398},
abstract = { Until the last few years, the only records of Indian Ocean humpback dolphins (Sousa plumbea) in Sri Lanka were a small number of older stranding records and one unconfirmed sighting, but repeated verified sightings have been made since the early 2000s in the Puttalam Lagoon area of northwestern Sri Lanka. To determine dolphin status and distribution patterns, we conducted monthly surveys of the lagoon from July 2010 to June 2011 and sighted humpback dolphins in the lagoon in every month of the year. Repeated sightings of the same six individuals were made; and in March 2011, one of these humpback dolphins was killed by dynamite fishing. It appears that the population is very small, possibly now consisting only of these five individuals, and is resident in the lagoon. Although it is likely the species was more widespread and abundant in the past, it appears that Puttalam Lagoon may be the only location where this species persists in Sri Lanka at present. Additional research is needed to investigate possible mixing with populations in India, and urgent conservation measures are recommended to ensure the long-term survival of this enigmatic species in Sri Lanka.},
keywords = {Arabian Sea, humpback dolphin, Indian Ocean, photo identification, population status, sousa, Sousa plumbea, Sri Lanka, Threat assessment},
pubstate = {published},
tppubtype = {article}
}
Until the last few years, the only records of Indian Ocean humpback dolphins (Sousa plumbea) in Sri Lanka were a small number of older stranding records and one unconfirmed sighting, but repeated verified sightings have been made since the early 2000s in the Puttalam Lagoon area of northwestern Sri Lanka. To determine dolphin status and distribution patterns, we conducted monthly surveys of the lagoon from July 2010 to June 2011 and sighted humpback dolphins in the lagoon in every month of the year. Repeated sightings of the same six individuals were made; and in March 2011, one of these humpback dolphins was killed by dynamite fishing. It appears that the population is very small, possibly now consisting only of these five individuals, and is resident in the lagoon. Although it is likely the species was more widespread and abundant in the past, it appears that Puttalam Lagoon may be the only location where this species persists in Sri Lanka at present. Additional research is needed to investigate possible mixing with populations in India, and urgent conservation measures are recommended to ensure the long-term survival of this enigmatic species in Sri Lanka.
Ilangakoon, A. D.
Impacts of Whale-Watching on Blue Whales (Balaenoptera musculus) off Southern Sri Lanka Conference
no. 115, 2013.
Abstract | Links | BibTeX | Tags: Arabian Sea, balaenoptera musculus, Blue whale, impact, management, Northern Indian Ocean, risk assessment, ship strike, shipping, Sri Lanka, tourism, Whale watching
@conference{,
title = {Impacts of Whale-Watching on Blue Whales (Balaenoptera musculus) off Southern Sri Lanka},
author = {Ilangakoon, A. D. },
url = {https://repository.kulib.kyoto-u.ac.jp/dspace/bitstream/2433/176191/1/12thseastar_045.pdf},
year = {2013},
date = {2013-01-01},
journal = {PROCEEDINGS of the Design Symposium on Conservation of Ecosystem (2013) (The 12th SEASTAR2000 workshop)},
number = {115},
pages = {45-50},
abstract = {Blue whales inhabit the coastal waters off southern Sri Lanka throughout the year, due to a narrow
continental shelf and upwelling, related feeding opportunities. A busy, international shipping lane also
lies off the south coast. While blue whales are listed on the IUCN Red List of Threatened Species, the
subspecies status and genetic affinities of this northern Indian Ocean population is not well
understood. Since 2009 a rapidly expanding, boat-based, commercial whale-watching industry has
developed off the south coast, but remains unregulated due to the non-existence of national
regulations or codes of conduct. As a result, unethical practices are leading to harassment of the
targeted whales. Comparison of sightings data from before and after whale-watching began, shows a
shift in the area of occurrence and concentration of whales. Simultaneously there is an increase in the
number of stranding and vessel collision related mortality. These factors indicate that current whalewatching
practices are displacing whales from their preferred feeding areas and inadvertently pushing
them offshore into the shipping lane, causing an increase in fatal vessel collisions. It is recommended
that a precautionary principal is followed and whale-watching activities are regulated as a priority, in
order to mitigate any adverse impacts. },
keywords = {Arabian Sea, balaenoptera musculus, Blue whale, impact, management, Northern Indian Ocean, risk assessment, ship strike, shipping, Sri Lanka, tourism, Whale watching},
pubstate = {published},
tppubtype = {conference}
}
Blue whales inhabit the coastal waters off southern Sri Lanka throughout the year, due to a narrow
continental shelf and upwelling, related feeding opportunities. A busy, international shipping lane also
lies off the south coast. While blue whales are listed on the IUCN Red List of Threatened Species, the
subspecies status and genetic affinities of this northern Indian Ocean population is not well
understood. Since 2009 a rapidly expanding, boat-based, commercial whale-watching industry has
developed off the south coast, but remains unregulated due to the non-existence of national
regulations or codes of conduct. As a result, unethical practices are leading to harassment of the
targeted whales. Comparison of sightings data from before and after whale-watching began, shows a
shift in the area of occurrence and concentration of whales. Simultaneously there is an increase in the
number of stranding and vessel collision related mortality. These factors indicate that current whalewatching
practices are displacing whales from their preferred feeding areas and inadvertently pushing
them offshore into the shipping lane, causing an increase in fatal vessel collisions. It is recommended
that a precautionary principal is followed and whale-watching activities are regulated as a priority, in
order to mitigate any adverse impacts.
continental shelf and upwelling, related feeding opportunities. A busy, international shipping lane also
lies off the south coast. While blue whales are listed on the IUCN Red List of Threatened Species, the
subspecies status and genetic affinities of this northern Indian Ocean population is not well
understood. Since 2009 a rapidly expanding, boat-based, commercial whale-watching industry has
developed off the south coast, but remains unregulated due to the non-existence of national
regulations or codes of conduct. As a result, unethical practices are leading to harassment of the
targeted whales. Comparison of sightings data from before and after whale-watching began, shows a
shift in the area of occurrence and concentration of whales. Simultaneously there is an increase in the
number of stranding and vessel collision related mortality. These factors indicate that current whalewatching
practices are displacing whales from their preferred feeding areas and inadvertently pushing
them offshore into the shipping lane, causing an increase in fatal vessel collisions. It is recommended
that a precautionary principal is followed and whale-watching activities are regulated as a priority, in
order to mitigate any adverse impacts.
Ilangakoon, A. D.
Exploring anthropogenic activities that threaten endangered blue whales (Balaenoptera musculus) off Sri Lanka Journal Article
In: Journal of Marine Animals and their Ecology, vol. 5, no. 114, pp. 3-7, 2012.
Abstract | Links | BibTeX | Tags: Arabian Sea, balaenoptera musculus, Blue whale, impacts, Northern Indian Ocean, shipping, Sri Lanka, Whale watching
@article{,
title = {Exploring anthropogenic activities that threaten endangered blue whales (Balaenoptera musculus) off Sri Lanka},
author = {Ilangakoon, A. D.},
url = {http://www.oers.ca/journal/volume5/issue1/Ilangakoon_Gallery.pdf},
year = {2012},
date = {2012-01-01},
journal = {Journal of Marine Animals and their Ecology},
volume = {5},
number = {114},
pages = {3-7},
abstract = {The waters off Sri Lanka, an island in the northern Indian
Ocean, are an important habitat for blue whales, a species listed as
Endangered in the IUCN Red List of Threatened Species. The
subspecies status, genetic affinities and movement patterns of this
northern Indian Ocean population of blue whales is not yet clearly
understood but off Sri Lanka they can be found throughout the
year. Sri Lanka also lies on a busy international shipping lane. Since
2009 a boat-based commercial whale-watching industry targeting
the blue whale, has been developing off the south coast, with
annual growth in numbers of boats and visitors. This industry
however remains unregulated in any formal or informal manner due
to the absence of regulatory mechanisms in this small, developing,
island nation. Consequently unethical practices are leading to
harassment resulting in direct and indirect impacts on the targeted
whales. Sighting and stranding data from before and after the
inception of whale watching activities indicate a spatial shift in the
area of occurrence and concentration of whales and a corresponding
increase in fatal vessel collisions along the southwest coastline of
the island. There are clear indications of displacement from
preferred near-shore feeding areas to the vicinity of the adjacent
shipping lane, causing an increase in collision risk. Although these
findings are based on limited data, it is recommended that a
precautionary principal is followed and anthropogenic activities are
quickly regulated to mitigate adverse impacts on these endangered
blue whales. },
keywords = {Arabian Sea, balaenoptera musculus, Blue whale, impacts, Northern Indian Ocean, shipping, Sri Lanka, Whale watching},
pubstate = {published},
tppubtype = {article}
}
The waters off Sri Lanka, an island in the northern Indian
Ocean, are an important habitat for blue whales, a species listed as
Endangered in the IUCN Red List of Threatened Species. The
subspecies status, genetic affinities and movement patterns of this
northern Indian Ocean population of blue whales is not yet clearly
understood but off Sri Lanka they can be found throughout the
year. Sri Lanka also lies on a busy international shipping lane. Since
2009 a boat-based commercial whale-watching industry targeting
the blue whale, has been developing off the south coast, with
annual growth in numbers of boats and visitors. This industry
however remains unregulated in any formal or informal manner due
to the absence of regulatory mechanisms in this small, developing,
island nation. Consequently unethical practices are leading to
harassment resulting in direct and indirect impacts on the targeted
whales. Sighting and stranding data from before and after the
inception of whale watching activities indicate a spatial shift in the
area of occurrence and concentration of whales and a corresponding
increase in fatal vessel collisions along the southwest coastline of
the island. There are clear indications of displacement from
preferred near-shore feeding areas to the vicinity of the adjacent
shipping lane, causing an increase in collision risk. Although these
findings are based on limited data, it is recommended that a
precautionary principal is followed and anthropogenic activities are
quickly regulated to mitigate adverse impacts on these endangered
blue whales.
Ocean, are an important habitat for blue whales, a species listed as
Endangered in the IUCN Red List of Threatened Species. The
subspecies status, genetic affinities and movement patterns of this
northern Indian Ocean population of blue whales is not yet clearly
understood but off Sri Lanka they can be found throughout the
year. Sri Lanka also lies on a busy international shipping lane. Since
2009 a boat-based commercial whale-watching industry targeting
the blue whale, has been developing off the south coast, with
annual growth in numbers of boats and visitors. This industry
however remains unregulated in any formal or informal manner due
to the absence of regulatory mechanisms in this small, developing,
island nation. Consequently unethical practices are leading to
harassment resulting in direct and indirect impacts on the targeted
whales. Sighting and stranding data from before and after the
inception of whale watching activities indicate a spatial shift in the
area of occurrence and concentration of whales and a corresponding
increase in fatal vessel collisions along the southwest coastline of
the island. There are clear indications of displacement from
preferred near-shore feeding areas to the vicinity of the adjacent
shipping lane, causing an increase in collision risk. Although these
findings are based on limited data, it is recommended that a
precautionary principal is followed and anthropogenic activities are
quickly regulated to mitigate adverse impacts on these endangered
blue whales.
De Silva, Rex
Notes on a possible mas-migration of marine species off the west coast of Sri Lanka Journal Article
In: LORIS (Journal of the Wildlife and Nature Protection Society of Sri Lanka)., vol. 22 , no. 81, pp. 39-41, 2000.
Abstract | BibTeX | Tags: Arabian Sea, feeding, Humpback Whale, megaptera novaeangliae, migration, platforms of opportunity, Sri Lanka
@article{,
title = {Notes on a possible mas-migration of marine species off the west coast of Sri Lanka},
author = {De Silva, Rex},
year = {2000},
date = {2000-01-01},
journal = {LORIS (Journal of the Wildlife and Nature Protection Society of Sri Lanka).},
volume = {22 },
number = {81},
pages = {39-41},
abstract = {THis paper suggests the possibility that a mass-migration of marine species, including Humpback Whales, several species of seabirds including Bridled Terns and Scalloped Hammergead Sharks, may be a regular occurrence off Sri Lanka's coastal waters. It suggests the need for further research.},
keywords = {Arabian Sea, feeding, Humpback Whale, megaptera novaeangliae, migration, platforms of opportunity, Sri Lanka},
pubstate = {published},
tppubtype = {article}
}
THis paper suggests the possibility that a mass-migration of marine species, including Humpback Whales, several species of seabirds including Bridled Terns and Scalloped Hammergead Sharks, may be a regular occurrence off Sri Lanka's coastal waters. It suggests the need for further research.
Alling,A.
A preliminary report of marine mammal fisheries in Djibouti, Oman and Sri Lanka Technical Report
no. 280, 1992.
Abstract | BibTeX | Tags: Arctic, cetacean, cetaceans, dolphin, dolphins, Fisheries, habitat, Indian Ocean, marine, marine mammal, North Pacific, Oman, Porpoise, sanctuaries, skull, skulls, Sri Lanka, status, stomach contents, whale, whales
@techreport{,
title = {A preliminary report of marine mammal fisheries in Djibouti, Oman and Sri Lanka },
author = {Alling,A.},
year = {1992},
date = {1992-01-01},
volume = {694 },
number = {280},
pages = {1-10},
abstract = {INTRODUCTION During the 1982 and 1983 field seasons on Tulip, an effort was made to assess the status of small whale fisheries in Djibouti, Oman and Sri Lanka. In lieu of the fact that the World Wildlife Funds Indian Ocean Whale study still has one more year of field work, this preliminary report will only summarise our findings as of April, 1983. Officials and fisherman were contacted during port calls in 1982 to obtain information about local hunting and entrapment of cetaceans and members of the Tulip crew travelled to 9 harbours in Sri Lanka to interview fishermen. Dolphins seen in fish markets were measured, identified, stomach contents taken, and skulls collected for positive identification. In 1982 one fisherman on the west coast of Sri Lanka was asked to keep a daily log of all cetaceans entrapped or harpooned for a duration of one year. In 1983 we increased the number of harbours Monitored and four additional fishermen, three on the east coast and one on the west coast, were asked to keep these journals. A constant watch was kept at sea for all cetacean sightings. Species seen were identified using three identification guides: Whales, Dolphins and Porpoises of the Eastern North Pacific and Adjacent Arctic Waters (Leatherwood et al., 1982), Sea Guide to, Whales of the World (Watson, 1982), and A Field Guide to Whales and Dolphins (Captain Morzer Bruyns, 1971). When the identification was questionable, animals were photographed for confirmation of identity at a later date. },
keywords = {Arctic, cetacean, cetaceans, dolphin, dolphins, Fisheries, habitat, Indian Ocean, marine, marine mammal, North Pacific, Oman, Porpoise, sanctuaries, skull, skulls, Sri Lanka, status, stomach contents, whale, whales},
pubstate = {published},
tppubtype = {techreport}
}
INTRODUCTION During the 1982 and 1983 field seasons on Tulip, an effort was made to assess the status of small whale fisheries in Djibouti, Oman and Sri Lanka. In lieu of the fact that the World Wildlife Funds Indian Ocean Whale study still has one more year of field work, this preliminary report will only summarise our findings as of April, 1983. Officials and fisherman were contacted during port calls in 1982 to obtain information about local hunting and entrapment of cetaceans and members of the Tulip crew travelled to 9 harbours in Sri Lanka to interview fishermen. Dolphins seen in fish markets were measured, identified, stomach contents taken, and skulls collected for positive identification. In 1982 one fisherman on the west coast of Sri Lanka was asked to keep a daily log of all cetaceans entrapped or harpooned for a duration of one year. In 1983 we increased the number of harbours Monitored and four additional fishermen, three on the east coast and one on the west coast, were asked to keep these journals. A constant watch was kept at sea for all cetacean sightings. Species seen were identified using three identification guides: Whales, Dolphins and Porpoises of the Eastern North Pacific and Adjacent Arctic Waters (Leatherwood et al., 1982), Sea Guide to, Whales of the World (Watson, 1982), and A Field Guide to Whales and Dolphins (Captain Morzer Bruyns, 1971). When the identification was questionable, animals were photographed for confirmation of identity at a later date.
Gordon, Jonathan. C.D.
The World Widlife Fund's Indian Ocean Sperm Whale Project: An Example of Cetacean Research Within the Indian Ocean Sanctuary Book
UNEP Marine Mammal Technical Report Number 3. 287pp., 1991.
BibTeX | Tags: Arabian Sea, Indian Ocean, sperm whales, Sri Lanka
@book{,
title = {The World Widlife Fund's Indian Ocean Sperm Whale Project: An Example of Cetacean Research Within the Indian Ocean Sanctuary},
author = {Gordon, Jonathan. C.D.},
year = {1991},
date = {1991-01-01},
journal = {Cetaceans and Cetacean Research in the Indian Ocean Sanctuary},
number = {103},
pages = {219-240},
publisher = {UNEP Marine Mammal Technical Report Number 3. 287pp.},
keywords = {Arabian Sea, Indian Ocean, sperm whales, Sri Lanka},
pubstate = {published},
tppubtype = {book}
}
De Silva,P.H.D.H..
Cetaceans (whales, dolphins and porpoises) recorded off Sri Lanka, India, from the Arabian Sea and Gulf, Gulf of Aden and from the Red Sea Journal Article
In: Journal of the Bombay Natural History Society, vol. 84 , no. 357, pp. 505-525, 1987.
Abstract | BibTeX | Tags: Antarctic, Arabia, Arabian Gulf, Arabian Sea, behaviour, Blue whale, cetacea, cetacean, cetaceans, Delphinus tropicalis, dolphin, dolphins, fin whale, Gulf of Aden, Gulf of Oman, Humpback Whale, India, Indian Ocean, mammals, marine, migration, Neophocaena phocaenoides, Oceanic, Oman, Pakistan, Porpoise, Red Sea, sanctuaries, skull, Sri Lanka, stranding, Strandings, survey, whale, whales
@article{,
title = {Cetaceans (whales, dolphins and porpoises) recorded off Sri Lanka, India, from the Arabian Sea and Gulf, Gulf of Aden and from the Red Sea },
author = {De Silva,P.H.D.H..},
year = {1987},
date = {1987-01-01},
journal = {Journal of the Bombay Natural History Society},
volume = {84 },
number = {357},
pages = {505-525},
abstract = {Cetacea is a highly specialized oceanic group of mammals with several of its species undertaking long migrations, often exceeding thousand miles during a single journey. During these migrations from cold polar and subpolar seas to warmer tropical and subtropical waters and their return to polar seas in summer both individual and mass strandings have very often occurred in many parts of the world, including Sri Lanka, India and the Arabian Gulf. The Cetacean records dealt with in this paper are of countries which lie at the extreme southern margin of the vast land mass of Asia with no land other than a few islands and vast stretches of the Indian Ocean between them and the Antarctica. Sri Lanka, in view of her geographic position at the southern extremity of this vast land mass (5ø 55' and 9§51'N latitude and 79§41' and 81§ 54' E longitude) has become a passing point in the movement of oceanic species including the larger whales. It has been suggested by Deraniyagala (1945, 1960b) that the movement of larger species towards the tropics from the southern temperate zone is partly associated with the periodic influx of Antarctic water toward the tropics. It is however, now fairly established that several larger species such as the Blue whale, the Fin whale and the Humpback whale show a regular migratory cycle. The majority of strandings recorded in this paper deal with individual strandings. Nevertheless there have been instances of both mass stranding and of apparent suicidal behaviour. This paper deals with 30 Cetacean species from the region. Of these records, records from Sri Lanka total 23 species, from India 24 species, from Pakistan 17 species, from the Gulf of Oman 10 species, from the Arabian Gulf 9 species, from the Gulf of Aden 6 species and from the Red Sea 7 species. Reference is also made to a skull of Delphinus tropicalis van Bree in the Colombo Museum (Skull No. 15 B) which appears to be its first record from Sri Lanka. Mention is also made of a specimen of Neophocaena phocaenoides (G. Cuvier) collected from the Wadge Bank by the Smithsonian Carangid Survey Team in March 1970 and of two incomplete skeletons of Balaenoptera physalus (Linn‚) (probably mother and calf) in the Zoological Museum, King Saud University, Riyadh, Saudi Arabia. All these specimens were identified by me. It is evident from this study that our present knowledge of the Cetacean fauna of the Indian Ocean is far from complete and that much could be accomplished by scientific institutions in the countries in the region by diligently maintaining proper records of sightings and strandings (with photographs) and by undertaking joint study surveys. It is gratifying to note that Sri Lanka, in recent years has been making much headway in this regard. During the last few years the Tulip Expedition led by Dr. Hal Whitehead has been studying the larger whales, especially the larger whales off the east coast and Dr. Stephen Leatherwood Of Hubbs-Sea World Research Institute (Marine Science), San Diego, California has recently published (1985) a summary of available information on the Cetacea of the Indian Ocean Cetacean Sanctuary on behalf of the National Aquatic Resources Agency for Sri Lanka. It is hoped that the present paper will further stimulate interest among the scientific institutions in the region and help to increase our knowledge of a group of remarkable animals at least as far as the species which inhabit and visit our seas.has become a passing point in the movement of oceanic species including the larger whales. It has been suggested by Deraniyagala (1945, 1960b) that the movement of larger species towards the tropics from the southern temperate zone is partly associated with the periodic influx of Antarctic water toward the tropics. It is however, now fairly established that several larger species such as the Blue whale, the Fin whale and the Humpback whale show a regular migratory cycle. The majority of strandings recorded in this paper deal with individual strandings. Nevertheless there have been instances of both mass stranding and of apparent suicidal behaviour. This paper deals with 30 Cetacean species from the region. Of these records, records from Sri Lanka total 23 species, from India 24 species, from Pakistan 17 species, from the Gulf of Oman 10 species, from the Arabian Gulf 9 species, from the Gulf of Aden 6 species and from the Red Sea 7 species. Reference is also made to a skull of Delphinus tropicalis van Bree in the Colombo Museum (Skull No. 15 B) which appears to be its first record from Sri Lanka. Mention is also made of a specimen of Neophocaena phocaenoides (G. Cuvier) collected from the Wadge Bank by the Smithsonian Carangid Survey Team in March 1970 and of two incomplete skeletons of Balaenoptera physalus (Linn‚) (probably mother and calf) in the Zoological Museum, King Saud University, Riyadh, Saudi Arabia. All these specimens were identified by me. It is evident from this study that our present knowledge of the Cetacean fauna of the Indian Ocean is far from complete and that much could be accomplished by scientific institutions in the countries in the region by diligently maintaining proper records of sightings and strandings (with photographs) and by undertaking joint study surveys. It is gratifying to note that Sri Lanka, in recent years has been making much headway in this regard. During the last few years the Tulip Expedition led by Dr. Hal Whitehead has been studying the larger whales, especially the larger whales off the east coast and Dr. Stephen Leatherwood Of Hubbs-Sea World Research Institute (Marine Science), San Diego, California has recently published (1985) a summary of available information on the Cetacea of the Indian Ocean Cetacean Sanctuary on behalf of the National Aquatic Resources Agency for Sri Lanka. It is hoped that the present paper will further stimulate interest among the scientific institutions in the region and help to increase our knowledge of a group of remarkable animals at least as far as the species which inhabit and visit our seas. A key to the identification of the species recorded from the region is given in Appendix. },
keywords = {Antarctic, Arabia, Arabian Gulf, Arabian Sea, behaviour, Blue whale, cetacea, cetacean, cetaceans, Delphinus tropicalis, dolphin, dolphins, fin whale, Gulf of Aden, Gulf of Oman, Humpback Whale, India, Indian Ocean, mammals, marine, migration, Neophocaena phocaenoides, Oceanic, Oman, Pakistan, Porpoise, Red Sea, sanctuaries, skull, Sri Lanka, stranding, Strandings, survey, whale, whales},
pubstate = {published},
tppubtype = {article}
}
Cetacea is a highly specialized oceanic group of mammals with several of its species undertaking long migrations, often exceeding thousand miles during a single journey. During these migrations from cold polar and subpolar seas to warmer tropical and subtropical waters and their return to polar seas in summer both individual and mass strandings have very often occurred in many parts of the world, including Sri Lanka, India and the Arabian Gulf. The Cetacean records dealt with in this paper are of countries which lie at the extreme southern margin of the vast land mass of Asia with no land other than a few islands and vast stretches of the Indian Ocean between them and the Antarctica. Sri Lanka, in view of her geographic position at the southern extremity of this vast land mass (5ø 55' and 9§51'N latitude and 79§41' and 81§ 54' E longitude) has become a passing point in the movement of oceanic species including the larger whales. It has been suggested by Deraniyagala (1945, 1960b) that the movement of larger species towards the tropics from the southern temperate zone is partly associated with the periodic influx of Antarctic water toward the tropics. It is however, now fairly established that several larger species such as the Blue whale, the Fin whale and the Humpback whale show a regular migratory cycle. The majority of strandings recorded in this paper deal with individual strandings. Nevertheless there have been instances of both mass stranding and of apparent suicidal behaviour. This paper deals with 30 Cetacean species from the region. Of these records, records from Sri Lanka total 23 species, from India 24 species, from Pakistan 17 species, from the Gulf of Oman 10 species, from the Arabian Gulf 9 species, from the Gulf of Aden 6 species and from the Red Sea 7 species. Reference is also made to a skull of Delphinus tropicalis van Bree in the Colombo Museum (Skull No. 15 B) which appears to be its first record from Sri Lanka. Mention is also made of a specimen of Neophocaena phocaenoides (G. Cuvier) collected from the Wadge Bank by the Smithsonian Carangid Survey Team in March 1970 and of two incomplete skeletons of Balaenoptera physalus (Linn‚) (probably mother and calf) in the Zoological Museum, King Saud University, Riyadh, Saudi Arabia. All these specimens were identified by me. It is evident from this study that our present knowledge of the Cetacean fauna of the Indian Ocean is far from complete and that much could be accomplished by scientific institutions in the countries in the region by diligently maintaining proper records of sightings and strandings (with photographs) and by undertaking joint study surveys. It is gratifying to note that Sri Lanka, in recent years has been making much headway in this regard. During the last few years the Tulip Expedition led by Dr. Hal Whitehead has been studying the larger whales, especially the larger whales off the east coast and Dr. Stephen Leatherwood Of Hubbs-Sea World Research Institute (Marine Science), San Diego, California has recently published (1985) a summary of available information on the Cetacea of the Indian Ocean Cetacean Sanctuary on behalf of the National Aquatic Resources Agency for Sri Lanka. It is hoped that the present paper will further stimulate interest among the scientific institutions in the region and help to increase our knowledge of a group of remarkable animals at least as far as the species which inhabit and visit our seas.has become a passing point in the movement of oceanic species including the larger whales. It has been suggested by Deraniyagala (1945, 1960b) that the movement of larger species towards the tropics from the southern temperate zone is partly associated with the periodic influx of Antarctic water toward the tropics. It is however, now fairly established that several larger species such as the Blue whale, the Fin whale and the Humpback whale show a regular migratory cycle. The majority of strandings recorded in this paper deal with individual strandings. Nevertheless there have been instances of both mass stranding and of apparent suicidal behaviour. This paper deals with 30 Cetacean species from the region. Of these records, records from Sri Lanka total 23 species, from India 24 species, from Pakistan 17 species, from the Gulf of Oman 10 species, from the Arabian Gulf 9 species, from the Gulf of Aden 6 species and from the Red Sea 7 species. Reference is also made to a skull of Delphinus tropicalis van Bree in the Colombo Museum (Skull No. 15 B) which appears to be its first record from Sri Lanka. Mention is also made of a specimen of Neophocaena phocaenoides (G. Cuvier) collected from the Wadge Bank by the Smithsonian Carangid Survey Team in March 1970 and of two incomplete skeletons of Balaenoptera physalus (Linn‚) (probably mother and calf) in the Zoological Museum, King Saud University, Riyadh, Saudi Arabia. All these specimens were identified by me. It is evident from this study that our present knowledge of the Cetacean fauna of the Indian Ocean is far from complete and that much could be accomplished by scientific institutions in the countries in the region by diligently maintaining proper records of sightings and strandings (with photographs) and by undertaking joint study surveys. It is gratifying to note that Sri Lanka, in recent years has been making much headway in this regard. During the last few years the Tulip Expedition led by Dr. Hal Whitehead has been studying the larger whales, especially the larger whales off the east coast and Dr. Stephen Leatherwood Of Hubbs-Sea World Research Institute (Marine Science), San Diego, California has recently published (1985) a summary of available information on the Cetacea of the Indian Ocean Cetacean Sanctuary on behalf of the National Aquatic Resources Agency for Sri Lanka. It is hoped that the present paper will further stimulate interest among the scientific institutions in the region and help to increase our knowledge of a group of remarkable animals at least as far as the species which inhabit and visit our seas. A key to the identification of the species recorded from the region is given in Appendix.