Ponnampalam,L.,Collins,T.J.Q.,Minton,G.,Baldwin,R
Feeding ecology of small cetaceans in the Sultanate of Oman Journal Article
In: Poster presented at the 17th meeting of the Society for Marine Mammals in Cape Town, no. 433, 2007.
Abstract | BibTeX | Tags: bottlenose dolphin, bottlenose dolphins, cephalopod, cetacean, cetaceans, conservation, diet, Distribution, dolphin, dolphins, ecology, feeding, feeding ecology, fish, habitat, humpback dolphins, occurrence, Oman, prey, Spinner dolphin, Stenella longirostris, stomach contents, survey, tursiops
@article{,
title = {Feeding ecology of small cetaceans in the Sultanate of Oman},
author = {Ponnampalam,L.,Collins,T.J.Q.,Minton,G.,Baldwin,R},
year = {2007},
date = {2007-01-01},
journal = {Poster presented at the 17th meeting of the Society for Marine Mammals in Cape Town},
number = {433},
abstract = {Beach surveys were conducted along the coast of Oman between 2000 and 2006 to locate and examine cetacean remains. This study examines the stomach contents of 11 bottlenose dolphins (Tursiops sp.), 5 Indo-Pacific humpback dolphins (Sousa chinensis) and 2 spinner dolphins (Stenella longirostris) that were found beach-cast along the Omani coastline. Across the three species examined, a total of 4796 fish otoliths and 214 cephalopod beaks were found, representing 36 species in 23 families. No crustacean remains were found. Prey item importance was calculated using the percentage by number (%N), and percentage by frequency of occurrence (%FO) methods, and a modified index of relative importance (IRI). Percentage similarity was also calculated to examine interspecific and intraspecific dietary overlap. All three species of dolphins examined here ate mainly fish. The fish families Apogonidae and Carangidae were the most numerically important prey in the diet of bottlenose dolphins. Sciaenidae was the most numerically important fish family for humpback dolphins. Mesopelagic fishes comprised the diet of spinner dolphins, with the myctophid Benthosema pterotum forming the bulk of the prey items. The cephalopod preys found in the stomach samples were represented by the families Sepiidae, Loliginidae and Onychoteuthidae. The frequency distribution of prey items indicate that the bottlenose dolphins fed in a wide variety of habitats, and may reflect the occurrence of at least two species or ecotypes of Tursiops in Oman. The humpback dolphin prey items indicate feeding in coastal, nearshore areas with soft substrate. Spinner dolphins appeared to feed in the upper 200m of the water column on nocturnal vertically migrating prey. Although most of the prey species do not appear to be of commercial importance, the findings of this study indicated that all three species of dolphins were feeding in areas where fishing occurs and this is likely to have conservation implications. },
keywords = {bottlenose dolphin, bottlenose dolphins, cephalopod, cetacean, cetaceans, conservation, diet, Distribution, dolphin, dolphins, ecology, feeding, feeding ecology, fish, habitat, humpback dolphins, occurrence, Oman, prey, Spinner dolphin, Stenella longirostris, stomach contents, survey, tursiops},
pubstate = {published},
tppubtype = {article}
}
Beach surveys were conducted along the coast of Oman between 2000 and 2006 to locate and examine cetacean remains. This study examines the stomach contents of 11 bottlenose dolphins (Tursiops sp.), 5 Indo-Pacific humpback dolphins (Sousa chinensis) and 2 spinner dolphins (Stenella longirostris) that were found beach-cast along the Omani coastline. Across the three species examined, a total of 4796 fish otoliths and 214 cephalopod beaks were found, representing 36 species in 23 families. No crustacean remains were found. Prey item importance was calculated using the percentage by number (%N), and percentage by frequency of occurrence (%FO) methods, and a modified index of relative importance (IRI). Percentage similarity was also calculated to examine interspecific and intraspecific dietary overlap. All three species of dolphins examined here ate mainly fish. The fish families Apogonidae and Carangidae were the most numerically important prey in the diet of bottlenose dolphins. Sciaenidae was the most numerically important fish family for humpback dolphins. Mesopelagic fishes comprised the diet of spinner dolphins, with the myctophid Benthosema pterotum forming the bulk of the prey items. The cephalopod preys found in the stomach samples were represented by the families Sepiidae, Loliginidae and Onychoteuthidae. The frequency distribution of prey items indicate that the bottlenose dolphins fed in a wide variety of habitats, and may reflect the occurrence of at least two species or ecotypes of Tursiops in Oman. The humpback dolphin prey items indicate feeding in coastal, nearshore areas with soft substrate. Spinner dolphins appeared to feed in the upper 200m of the water column on nocturnal vertically migrating prey. Although most of the prey species do not appear to be of commercial importance, the findings of this study indicated that all three species of dolphins were feeding in areas where fishing occurs and this is likely to have conservation implications.
Baldwin,R.M.,Collins,T.J.Q.,Van Waerebeek,K.,Minton,G.
The Indo-Pacific humpback dolphin of the Arabian region: a status review Journal Article
In: Aquatic Mammals, vol. 30, no. 319, pp. 111-124, 2004.
Abstract | Links | BibTeX | Tags: abundance, Arabian Gulf, Arabian region, Arabian Sea, associations, behaviour, Boat traffic, cetacean, cetaceans, conservation, development, Distribution, dolphin, dolphins, ecology, Fisheries, Gulf of Aden, Gulf of Oman, humpback dolphins, incidental capture, military, museum specimens, nets, Oman, pollution, population, populations, Red Sea, status, Stock identity, Strandings, tursiops
@article{,
title = {The Indo-Pacific humpback dolphin of the Arabian region: a status review},
author = {Baldwin,R.M.,Collins,T.J.Q.,Van Waerebeek,K.,Minton,G.},
url = {https://www.aquaticmammalsjournal.org/index.php?option=com_content&view=article&id=247:the-indo-pacific-humpback-dolphin-of-the-arabian-region-a-status-review&catid=13&Itemid=157},
year = {2004},
date = {2004-01-01},
journal = {Aquatic Mammals},
volume = {30},
number = {319},
pages = {111-124},
abstract = {Records of Indo-Pacific humpback dolphin sightings, strandings, and museum specimens in the Arabian region were compiled and used to review the distribution and status of this species. Nominal usage of Sousa chinensis (Osbeck, 1765) has been retained as a pragmatic measure, although the species present in the region resembles Sousa plumbea (G. Cuvier, 1828). Little is known about the ecology of this species in the region. Most available information on S. chinensis in the region originates from the Sultanate of Oman, where this species is among the most commonly recorded cetaceans. However, there is no absolute measure of abundance for anywhere in the region and the status of the species is unknown. Distribution is described for the region to include much of the Arabian (Persian) Gulf, Arabian Sea, Gulf of Aden, and Red Sea, but notably excludes the Gulf of Oman. This discontinuous distribution suggests the possible presence of discrete populations within the region. Beach-cast/dead individuals represent nearly two-thirds of all records (n=303) of this species in Oman. Live sightings indicate unusually large group sizes (up to 100 individuals) in the Arabian Sea and Arabian Gulf. Occasional associations with Tursiops sp. and Delphinus capensis tropicalis were documented. Mating behaviour and the presence of calves were recorded in the months of April and May and calves are also reported in June, October, November and December. Threats to humpback dolphins in the Arabian region include incidental capture in fishing nets, coastal and offshore development (e.g. land reclamation, dredging, port and harbour construction), pollution, boat traffic, oil and gas exploration (including seismic surveying), military exercises and biotoxins associated with red tide events. Evidence for historic and current directed catches of S. chinensis is limited, but opportunistic hunting may occur. Intraspecific variation in cranial measurements of individuals from the Arabian Sea coast of Oman fall within relative values found in individuals from the Saudi Arabian Gulf coast. Cranial abnormalities were few. Recommendations are made for conservation management-oriented research focusing on stock identity and status assessments, as well as for monitoring of fisheries bycatch, clearer definition of other threats, continued specimen and sample collection and training of local scientists.},
keywords = {abundance, Arabian Gulf, Arabian region, Arabian Sea, associations, behaviour, Boat traffic, cetacean, cetaceans, conservation, development, Distribution, dolphin, dolphins, ecology, Fisheries, Gulf of Aden, Gulf of Oman, humpback dolphins, incidental capture, military, museum specimens, nets, Oman, pollution, population, populations, Red Sea, status, Stock identity, Strandings, tursiops},
pubstate = {published},
tppubtype = {article}
}
Records of Indo-Pacific humpback dolphin sightings, strandings, and museum specimens in the Arabian region were compiled and used to review the distribution and status of this species. Nominal usage of Sousa chinensis (Osbeck, 1765) has been retained as a pragmatic measure, although the species present in the region resembles Sousa plumbea (G. Cuvier, 1828). Little is known about the ecology of this species in the region. Most available information on S. chinensis in the region originates from the Sultanate of Oman, where this species is among the most commonly recorded cetaceans. However, there is no absolute measure of abundance for anywhere in the region and the status of the species is unknown. Distribution is described for the region to include much of the Arabian (Persian) Gulf, Arabian Sea, Gulf of Aden, and Red Sea, but notably excludes the Gulf of Oman. This discontinuous distribution suggests the possible presence of discrete populations within the region. Beach-cast/dead individuals represent nearly two-thirds of all records (n=303) of this species in Oman. Live sightings indicate unusually large group sizes (up to 100 individuals) in the Arabian Sea and Arabian Gulf. Occasional associations with Tursiops sp. and Delphinus capensis tropicalis were documented. Mating behaviour and the presence of calves were recorded in the months of April and May and calves are also reported in June, October, November and December. Threats to humpback dolphins in the Arabian region include incidental capture in fishing nets, coastal and offshore development (e.g. land reclamation, dredging, port and harbour construction), pollution, boat traffic, oil and gas exploration (including seismic surveying), military exercises and biotoxins associated with red tide events. Evidence for historic and current directed catches of S. chinensis is limited, but opportunistic hunting may occur. Intraspecific variation in cranial measurements of individuals from the Arabian Sea coast of Oman fall within relative values found in individuals from the Saudi Arabian Gulf coast. Cranial abnormalities were few. Recommendations are made for conservation management-oriented research focusing on stock identity and status assessments, as well as for monitoring of fisheries bycatch, clearer definition of other threats, continued specimen and sample collection and training of local scientists.
Rosenbaum,H.C.,Glaberman,S.,Jefferson,T.,Collins,T.,Minton,G.,Peddemors,V.,Baldwin,R.M.
Phylogenetic relationships and population structure among humpback dolphins based on mtDNA variation Technical Report
no. 459, 2002, ISBN: SC/54/SM34.
Abstract | BibTeX | Tags: control region, dolphin, dolphins, humpback dolphins, International Whaling Commission, mtDNA, Oman, Pacific Ocean, phylogenetic, population, population structure, South Africa, status, taxonomy, whaling
@techreport{,
title = {Phylogenetic relationships and population structure among humpback dolphins based on mtDNA variation},
author = {Rosenbaum,H.C.,Glaberman,S.,Jefferson,T.,Collins,T.,Minton,G.,Peddemors,V.,Baldwin,R.M.},
issn = {SC/54/SM34},
year = {2002},
date = {2002-01-01},
journal = {Document presented to the 54th meeting of the International Whaling Commission},
volume = {SC/54/SM34},
number = {459},
pages = {1-8},
abstract = {The taxonomy, systematic relationships, and population structure of humpback dolphins (genus Sousa) have been controversial. Various nominal species have been described or subsumed. Recent reports have suggested the division of Sousa into one to three distinct species or sub-species. However, many of these analyses have not been conducted in a proper systematics framework, did not include all representative putative taxa or were lacking specimens from parts of their geographic range, and have not been in published in peer-reviewed journals (typically necessary for revising taxonomy). In order to address relationships and taxonomic status among Sousa species, we present a preliminary genetic analysis of humpback dolphins primarily from Southeast Asia, the coast of Oman, and South Africa. A total of 110 samples were sequenced for 501 by of mtDNA control region and significant population structuring at the regional level was revealed. Population Aggregation and phylogenetic analyses of mtDNA control region lineages and a subset of lineages analyzed for a 358 by fragment of Cytochrome B revealed a series of complex relationships among humpback dolphins in the Indian and Pacific Oceans. These preliminary data are a critical first step to better understanding the taxonomy and systematics in the genus Sousa. Additional molecular character data from other mitochondria) and nuclear genes will be essential for resolving relationship and taxonomic status for humpback dolphins.},
keywords = {control region, dolphin, dolphins, humpback dolphins, International Whaling Commission, mtDNA, Oman, Pacific Ocean, phylogenetic, population, population structure, South Africa, status, taxonomy, whaling},
pubstate = {published},
tppubtype = {techreport}
}
The taxonomy, systematic relationships, and population structure of humpback dolphins (genus Sousa) have been controversial. Various nominal species have been described or subsumed. Recent reports have suggested the division of Sousa into one to three distinct species or sub-species. However, many of these analyses have not been conducted in a proper systematics framework, did not include all representative putative taxa or were lacking specimens from parts of their geographic range, and have not been in published in peer-reviewed journals (typically necessary for revising taxonomy). In order to address relationships and taxonomic status among Sousa species, we present a preliminary genetic analysis of humpback dolphins primarily from Southeast Asia, the coast of Oman, and South Africa. A total of 110 samples were sequenced for 501 by of mtDNA control region and significant population structuring at the regional level was revealed. Population Aggregation and phylogenetic analyses of mtDNA control region lineages and a subset of lineages analyzed for a 358 by fragment of Cytochrome B revealed a series of complex relationships among humpback dolphins in the Indian and Pacific Oceans. These preliminary data are a critical first step to better understanding the taxonomy and systematics in the genus Sousa. Additional molecular character data from other mitochondria) and nuclear genes will be essential for resolving relationship and taxonomic status for humpback dolphins.
Khani,A.M.Q.
Sea Dolphins of Pakistan Journal Article
In: Biopsphere Quarterly Magazine, vol. Oct-Dec, no. 132, pp. 4-9, 1998.
Abstract | BibTeX | Tags: Arabian Sea, bottlenose dolphin, Common dolphin, conservation, humpback dolphins, Indian Ocean, Pakistan
@article{,
title = {Sea Dolphins of Pakistan},
author = {Khani,A.M.Q.},
year = {1998},
date = {1998-01-01},
journal = {Biopsphere Quarterly Magazine},
volume = {Oct-Dec},
number = {132},
pages = {4-9},
abstract = {The article describes some of the results of a privately funded (amateur enthusiasts?) survey for dolphins on the Pakistan coastline in 1997. Motorized boats and aircraft were used. Descriptions of encounters with bottlenose, common, and humpback dolphins are described. No details of effort or encounter rate are provided. There is some discussion of potential threats and conservation concerns.},
keywords = {Arabian Sea, bottlenose dolphin, Common dolphin, conservation, humpback dolphins, Indian Ocean, Pakistan},
pubstate = {published},
tppubtype = {article}
}
The article describes some of the results of a privately funded (amateur enthusiasts?) survey for dolphins on the Pakistan coastline in 1997. Motorized boats and aircraft were used. Descriptions of encounters with bottlenose, common, and humpback dolphins are described. No details of effort or encounter rate are provided. There is some discussion of potential threats and conservation concerns.
Lal Mohan,R.S.
Osteology of dolphins Journal Article
In: Proc. Symp. Endangered Mairne Animals and Marine Parks, vol. 1, no. 140, pp. 93-99, 1985.
Abstract | BibTeX | Tags: Arabian Sea, bottlenose dolphin, Common dolphin, gillnet, humpback dolphins, India, Indian Ocean, skull, Spinner dolphin
@article{,
title = {Osteology of dolphins},
author = {Lal Mohan,R.S.},
year = {1985},
date = {1985-01-01},
journal = {Proc. Symp. Endangered Mairne Animals and Marine Parks},
volume = {1},
number = {140},
pages = {93-99},
abstract = {Osteology of four dolphins (Common, Spinner, Bottlenose and Humpback) are studied from the south-west coast of India. The measurements of the skulls are compared with information available from other parts of the world. Specimens were obtained from bycatch in gillnets off the Calicut coast.},
keywords = {Arabian Sea, bottlenose dolphin, Common dolphin, gillnet, humpback dolphins, India, Indian Ocean, skull, Spinner dolphin},
pubstate = {published},
tppubtype = {article}
}
Osteology of four dolphins (Common, Spinner, Bottlenose and Humpback) are studied from the south-west coast of India. The measurements of the skulls are compared with information available from other parts of the world. Specimens were obtained from bycatch in gillnets off the Calicut coast.