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.
Willson, A.,Baldwin, R.,Cerchio, S,Collins, T.,Findlay, K.,Gray, H.,Godley, B.J.,Al Harthi, S.,Kennedy, A.,Minton, G.,Sucunza, F.,Zerbini, A. N.,Witt, M.J.
Research update on satellite tagging studies of the Arabian Sea humpback whales in the Sultanate of Oman Technical Report
no. 500, 2016.
Abstract | BibTeX | Tags: Distribution, feeding, humpback whales, megaptera novaeangliae, Oman, photo identification, Satellite telemetry, seasonal change
@techreport{,
title = {Research update on satellite tagging studies of the Arabian Sea humpback whales in the Sultanate of Oman},
author = {Willson, A.,Baldwin, R.,Cerchio, S,Collins, T.,Findlay, K.,Gray, H.,Godley, B.J.,Al Harthi, S.,Kennedy, A.,Minton, G.,Sucunza, F.,Zerbini, A. N.,Witt, M.J.},
year = {2016},
date = {2016-01-01},
journal = {Report presented to the Scientific Committee meeting of the International Whaling Commission},
number = {500},
pages = {23},
publisher = {IWC},
abstract = {Three surveys focusing on Arabian Sea humpback whales (Megaptera novaeangliae) were conducted from
two field sites off the southern coast of Oman between February 2014 and December 2015. We present a
summary of boat-based survey data and satellite telemetry activities generated by these surveys. Our
findings provide insight into the spatial ecology of Arabian Sea humpback whales (ASHW) and salient
threats to the population. Ninety hours of on-effort vessel-based surveys resulted in 29 sightings of ASHW
groups. Analysis of fluke and dorsal fin images indicates that these sightings involved 40 different
individuals. Tagging efforts resulted in successful deployment of nine satellite tags, six of which provided
data on dive behaviour and vertical distribution within the water column. Tagged whales that were
resighted (n = 5) during subsequent surveys exhibited signs of healing following tag rejection. Satellite
tracking data reveals whales ranging within a 1,150 km corridor along the southern coast of Oman and
northern Yemen, the first transboundary movement recorded for this population. Individuals spent an
average of 83% (SD = 17%) of their time engaged in localised or ‘area restricted search’ (ARS) that is
likely associated with foraging, breeding and resting behaviour. Tracked individuals spent much of their
time over the continental shelf with 73% of satellite-derived locations attributed to waters <200 m depth.
Gathered dive data reveal that tracked whales spent 83% of time in the top 20 m of the water column, most
frequently (39%; SD = 11%) engaged in dives with durations between 5 and 10 minutes. The average
maximum depth recorded by the tags was 199 m (SD = 95 m). Further spatial analysis indicated that 35%
of location points in the study were within the Gulf of Masirah, habitat that co-occurs with emerging
industrial activity and existing artisanal fisheries. Dive behavior in offshore waters beyond the continental
shelf also likely indicates foraging activity. The growing knowledge base for this population supports need
for on-going research and putative mitigation measures to address a wide spectrum of anthropogenic threats
for humpback whales in Oman and the wider region.},
keywords = {Distribution, feeding, humpback whales, megaptera novaeangliae, Oman, photo identification, Satellite telemetry, seasonal change},
pubstate = {published},
tppubtype = {techreport}
}
Three surveys focusing on Arabian Sea humpback whales (Megaptera novaeangliae) were conducted from
two field sites off the southern coast of Oman between February 2014 and December 2015. We present a
summary of boat-based survey data and satellite telemetry activities generated by these surveys. Our
findings provide insight into the spatial ecology of Arabian Sea humpback whales (ASHW) and salient
threats to the population. Ninety hours of on-effort vessel-based surveys resulted in 29 sightings of ASHW
groups. Analysis of fluke and dorsal fin images indicates that these sightings involved 40 different
individuals. Tagging efforts resulted in successful deployment of nine satellite tags, six of which provided
data on dive behaviour and vertical distribution within the water column. Tagged whales that were
resighted (n = 5) during subsequent surveys exhibited signs of healing following tag rejection. Satellite
tracking data reveals whales ranging within a 1,150 km corridor along the southern coast of Oman and
northern Yemen, the first transboundary movement recorded for this population. Individuals spent an
average of 83% (SD = 17%) of their time engaged in localised or ‘area restricted search’ (ARS) that is
likely associated with foraging, breeding and resting behaviour. Tracked individuals spent much of their
time over the continental shelf with 73% of satellite-derived locations attributed to waters <200 m depth.
Gathered dive data reveal that tracked whales spent 83% of time in the top 20 m of the water column, most
frequently (39%; SD = 11%) engaged in dives with durations between 5 and 10 minutes. The average
maximum depth recorded by the tags was 199 m (SD = 95 m). Further spatial analysis indicated that 35%
of location points in the study were within the Gulf of Masirah, habitat that co-occurs with emerging
industrial activity and existing artisanal fisheries. Dive behavior in offshore waters beyond the continental
shelf also likely indicates foraging activity. The growing knowledge base for this population supports need
for on-going research and putative mitigation measures to address a wide spectrum of anthropogenic threats
for humpback whales in Oman and the wider region.
two field sites off the southern coast of Oman between February 2014 and December 2015. We present a
summary of boat-based survey data and satellite telemetry activities generated by these surveys. Our
findings provide insight into the spatial ecology of Arabian Sea humpback whales (ASHW) and salient
threats to the population. Ninety hours of on-effort vessel-based surveys resulted in 29 sightings of ASHW
groups. Analysis of fluke and dorsal fin images indicates that these sightings involved 40 different
individuals. Tagging efforts resulted in successful deployment of nine satellite tags, six of which provided
data on dive behaviour and vertical distribution within the water column. Tagged whales that were
resighted (n = 5) during subsequent surveys exhibited signs of healing following tag rejection. Satellite
tracking data reveals whales ranging within a 1,150 km corridor along the southern coast of Oman and
northern Yemen, the first transboundary movement recorded for this population. Individuals spent an
average of 83% (SD = 17%) of their time engaged in localised or ‘area restricted search’ (ARS) that is
likely associated with foraging, breeding and resting behaviour. Tracked individuals spent much of their
time over the continental shelf with 73% of satellite-derived locations attributed to waters <200 m depth.
Gathered dive data reveal that tracked whales spent 83% of time in the top 20 m of the water column, most
frequently (39%; SD = 11%) engaged in dives with durations between 5 and 10 minutes. The average
maximum depth recorded by the tags was 199 m (SD = 95 m). Further spatial analysis indicated that 35%
of location points in the study were within the Gulf of Masirah, habitat that co-occurs with emerging
industrial activity and existing artisanal fisheries. Dive behavior in offshore waters beyond the continental
shelf also likely indicates foraging activity. The growing knowledge base for this population supports need
for on-going research and putative mitigation measures to address a wide spectrum of anthropogenic threats
for humpback whales in Oman and the wider region.
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.
Baldwin, R.,Collins, T.J.Q.,Minton, G.,Willson, A.,Corkeron, P.
Arabian Sea humpback whales 2011 update: resights, bubble feeding and hotspots Journal Article
In: Document presented to the Scientific Committee of the International Whaling Commission, vol. SC/54/O4, no. 23, pp. 5, 2011.
Abstract | BibTeX | Tags: Arabian Sea, blue whales, breeding, feeding, Humpback Whale, megaptera novaeangliae, photo identification, sperm whales
@article{,
title = {Arabian Sea humpback whales 2011 update: resights, bubble feeding and hotspots},
author = {Baldwin, R.,Collins, T.J.Q.,Minton, G.,Willson, A.,Corkeron, P.},
year = {2011},
date = {2011-01-01},
journal = {Document presented to the Scientific Committee of the International Whaling Commission},
volume = {SC/54/O4},
number = {23},
pages = {5},
abstract = {The 2010 report of the Scientific Committee (IWC/62/Rep 1) expressed grave concern for the resident ‘Arabian
Sea humpback whale population’. The Committee made strong recommendations for additional research to
monitor the status of this Endangered population which has a restricted range, is reproductively isolated, has a
very small population size (n=82 (95% CI=60-111)) and is known to interact with humans with negative
consequences. A survey during March 2011 resulted in 47 sightings of humpback whales representing
approximately12 individuals. Sightings included a mother-calf pair, observation of competitive behaviour and
frequent feeding including use of ‘bubble cloud’ and ‘bubble net’ structures, all of which have been rarely
witnessed in Oman on previous surveys. At least three known individuals were identified, among them those that
have been re-sighted as many as four times previously and those that have been previously photographed at the
same location. Song was recorded on numerous occasions from the survey vessel and one Cornell MARU was
deployed resulting in acquisition of over 20 days of continuous recordings which are undergoing analysis.
Threats from fishing activity, coastal development and vessel traffic were documented, and an apparent attack on
a humpback whale by false killer whales was witnessed. Numerous other cetacean species were recorded,
including other large whales (blue whales, Bryde’s whales and sperm whales – all with calves – and numerous
small cetaceans). The majority of sightings were clustered around Ras Hasik and all feeding behaviour, including
that by humpback, blue and Bryde’s whales occurred within 2-3 kilometers of this apparent ‘hotspot’. Further
research is recommended which may be best determined via the Conservation Management Planning process.},
keywords = {Arabian Sea, blue whales, breeding, feeding, Humpback Whale, megaptera novaeangliae, photo identification, sperm whales},
pubstate = {published},
tppubtype = {article}
}
The 2010 report of the Scientific Committee (IWC/62/Rep 1) expressed grave concern for the resident ‘Arabian
Sea humpback whale population’. The Committee made strong recommendations for additional research to
monitor the status of this Endangered population which has a restricted range, is reproductively isolated, has a
very small population size (n=82 (95% CI=60-111)) and is known to interact with humans with negative
consequences. A survey during March 2011 resulted in 47 sightings of humpback whales representing
approximately12 individuals. Sightings included a mother-calf pair, observation of competitive behaviour and
frequent feeding including use of ‘bubble cloud’ and ‘bubble net’ structures, all of which have been rarely
witnessed in Oman on previous surveys. At least three known individuals were identified, among them those that
have been re-sighted as many as four times previously and those that have been previously photographed at the
same location. Song was recorded on numerous occasions from the survey vessel and one Cornell MARU was
deployed resulting in acquisition of over 20 days of continuous recordings which are undergoing analysis.
Threats from fishing activity, coastal development and vessel traffic were documented, and an apparent attack on
a humpback whale by false killer whales was witnessed. Numerous other cetacean species were recorded,
including other large whales (blue whales, Bryde’s whales and sperm whales – all with calves – and numerous
small cetaceans). The majority of sightings were clustered around Ras Hasik and all feeding behaviour, including
that by humpback, blue and Bryde’s whales occurred within 2-3 kilometers of this apparent ‘hotspot’. Further
research is recommended which may be best determined via the Conservation Management Planning process.
Sea humpback whale population’. The Committee made strong recommendations for additional research to
monitor the status of this Endangered population which has a restricted range, is reproductively isolated, has a
very small population size (n=82 (95% CI=60-111)) and is known to interact with humans with negative
consequences. A survey during March 2011 resulted in 47 sightings of humpback whales representing
approximately12 individuals. Sightings included a mother-calf pair, observation of competitive behaviour and
frequent feeding including use of ‘bubble cloud’ and ‘bubble net’ structures, all of which have been rarely
witnessed in Oman on previous surveys. At least three known individuals were identified, among them those that
have been re-sighted as many as four times previously and those that have been previously photographed at the
same location. Song was recorded on numerous occasions from the survey vessel and one Cornell MARU was
deployed resulting in acquisition of over 20 days of continuous recordings which are undergoing analysis.
Threats from fishing activity, coastal development and vessel traffic were documented, and an apparent attack on
a humpback whale by false killer whales was witnessed. Numerous other cetacean species were recorded,
including other large whales (blue whales, Bryde’s whales and sperm whales – all with calves – and numerous
small cetaceans). The majority of sightings were clustered around Ras Hasik and all feeding behaviour, including
that by humpback, blue and Bryde’s whales occurred within 2-3 kilometers of this apparent ‘hotspot’. Further
research is recommended which may be best determined via the Conservation Management Planning process.
Roman, J,McCarthy, JJ,Roopnarine, P
The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin Journal Article
In: PLoS ONE, vol. 5, no. 449, pp. 47-123, 2010, ISBN: 1932-6203.
Abstract | BibTeX | Tags: feeding, nitrogen, productivity, whales
@article{,
title = {The Whale Pump: Marine Mammals Enhance Primary Productivity in a Coastal Basin},
author = {Roman, J,McCarthy, JJ,Roopnarine, P},
issn = {1932-6203},
year = {2010},
date = {2010-01-01},
journal = {PLoS ONE},
volume = {5},
number = {449},
pages = {47-123},
publisher = {Public Library of Science San Francisco, USA},
abstract = {It is well known that microbes, zooplankton, and fish are important sources of recycled nitrogen in coastal waters, yet
marine mammals have largely been ignored or dismissed in this cycle. Using field measurements and population data, we
find that marine mammals can enhance primary productivity in their feeding areas by concentrating nitrogen near the
surface through the release of flocculent fecal plumes. Whales and seals may be responsible for replenishing 2.36104 metric
tons of N per year in the Gulf of Maine’s euphotic zone, more than the input of all rivers combined. This upward ‘‘whale
pump’’ played a much larger role before commercial harvest, when marine mammal recycling of nitrogen was likely more
than three times atmospheric N input. Even with reduced populations, marine mammals provide an important ecosystem
service by sustaining productivity in regions where they occur in high densities.},
keywords = {feeding, nitrogen, productivity, whales},
pubstate = {published},
tppubtype = {article}
}
It is well known that microbes, zooplankton, and fish are important sources of recycled nitrogen in coastal waters, yet
marine mammals have largely been ignored or dismissed in this cycle. Using field measurements and population data, we
find that marine mammals can enhance primary productivity in their feeding areas by concentrating nitrogen near the
surface through the release of flocculent fecal plumes. Whales and seals may be responsible for replenishing 2.36104 metric
tons of N per year in the Gulf of Maine’s euphotic zone, more than the input of all rivers combined. This upward ‘‘whale
pump’’ played a much larger role before commercial harvest, when marine mammal recycling of nitrogen was likely more
than three times atmospheric N input. Even with reduced populations, marine mammals provide an important ecosystem
service by sustaining productivity in regions where they occur in high densities.
marine mammals have largely been ignored or dismissed in this cycle. Using field measurements and population data, we
find that marine mammals can enhance primary productivity in their feeding areas by concentrating nitrogen near the
surface through the release of flocculent fecal plumes. Whales and seals may be responsible for replenishing 2.36104 metric
tons of N per year in the Gulf of Maine’s euphotic zone, more than the input of all rivers combined. This upward ‘‘whale
pump’’ played a much larger role before commercial harvest, when marine mammal recycling of nitrogen was likely more
than three times atmospheric N input. Even with reduced populations, marine mammals provide an important ecosystem
service by sustaining productivity in regions where they occur in high densities.
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.
Butler,M.,Bollens,S.M.,Burghalter,B.,Madin,L.P.,Horgan,E.
Mesopelagic fishes of the Arabian Sea: distribution, abundance and diet of Journal Article
In: Deep-Sea Research Part II, vol. 48, no. 61, pp. 1369-1383, 2001.
Abstract | BibTeX | Tags: abundance, Arabian Sea, diel, diet, diets, Distribution, ecology, feeding, migration, oxygen minimum, population, populations, predation, south
@article{,
title = {Mesopelagic fishes of the Arabian Sea: distribution, abundance and diet of },
author = {Butler,M.,Bollens,S.M.,Burghalter,B.,Madin,L.P.,Horgan,E.},
year = {2001},
date = {2001-01-01},
journal = {Deep-Sea Research Part II},
volume = {48},
number = {61},
pages = {1369-1383},
abstract = {Four species of predatory fishes - Chauliodus pammelas, Chauliodus sloani, Stomias afffnis and Stomias nebulosus - were collected on two cruises to the Arabian Sea during 1995. We present data on the abundances, horizontal and vertical distributions, and diet of these fishes. We also discuss briefly the importance of the oxygen minimum zone and predation on myctophid fishes to the ecology of these mesopelagic predators. Chauliodus pammelas and C. sloani appear to have only partially overlapping horizontal distributions in the Arabian Sea, with C. pammelas more common to the north and C. sloani more common to the south. Our data support previous results suggesting that diel vertical migration is the norm for these species, with smaller individuals usually nearer to the surface and larger individuals tending to stay deeper. In contrast to Chauliodus, Stomias affinis and S. nebulosus appear to have largely overlapping horizontal distributions in the Arabian Sea. However, they may have slightly di!erent vertical distributions, with S. affinis living slightly shallower (especially at night) than S. nebulosus. All four species spend most of their time in the oxygen minimum zone, entering the surface oxygenated waters (100-150 m) only at night (if at all). The diets of C. pammelas, C. sloani, and S. affinis consisted mainly of lantern fishes, Myctophidae, and other fishes. In contrast, S. nebulosus, the smaller of the two Stomias species, ate mostly copepods and other crustaceans. This differential feeding may allow the two Stomias species to co-occur. Three of these four stomiids appear to play an important role in predation on myctophid fish populations in the Arabian Sea.},
keywords = {abundance, Arabian Sea, diel, diet, diets, Distribution, ecology, feeding, migration, oxygen minimum, population, populations, predation, south},
pubstate = {published},
tppubtype = {article}
}
Four species of predatory fishes - Chauliodus pammelas, Chauliodus sloani, Stomias afffnis and Stomias nebulosus - were collected on two cruises to the Arabian Sea during 1995. We present data on the abundances, horizontal and vertical distributions, and diet of these fishes. We also discuss briefly the importance of the oxygen minimum zone and predation on myctophid fishes to the ecology of these mesopelagic predators. Chauliodus pammelas and C. sloani appear to have only partially overlapping horizontal distributions in the Arabian Sea, with C. pammelas more common to the north and C. sloani more common to the south. Our data support previous results suggesting that diel vertical migration is the norm for these species, with smaller individuals usually nearer to the surface and larger individuals tending to stay deeper. In contrast to Chauliodus, Stomias affinis and S. nebulosus appear to have largely overlapping horizontal distributions in the Arabian Sea. However, they may have slightly di!erent vertical distributions, with S. affinis living slightly shallower (especially at night) than S. nebulosus. All four species spend most of their time in the oxygen minimum zone, entering the surface oxygenated waters (100-150 m) only at night (if at all). The diets of C. pammelas, C. sloani, and S. affinis consisted mainly of lantern fishes, Myctophidae, and other fishes. In contrast, S. nebulosus, the smaller of the two Stomias species, ate mostly copepods and other crustaceans. This differential feeding may allow the two Stomias species to co-occur. Three of these four stomiids appear to play an important role in predation on myctophid fish populations in the Arabian Sea.
Kumar,S.P.,Ramaiah,N.,Gauns,M.,Sarma,V.V.S.S.,Muraleedharan,P.M.,Raghukumar,S.,Kumar,M.D.,Madhupratap,M.
Physical forcing of biological productivity in the Northern Arabian Sea during the Northeast Monsoon Journal Article
In: Deep-Sea Research Part II, vol. 48 , no. 139, pp. 1115-1126, 2001.
Abstract | BibTeX | Tags: Arabian Sea, chlorophyll, depth, feeding, lead, location, productivity, spatial scale, surface temperature, temperature
@article{,
title = {Physical forcing of biological productivity in the Northern Arabian Sea during the Northeast Monsoon},
author = {Kumar,S.P.,Ramaiah,N.,Gauns,M.,Sarma,V.V.S.S.,Muraleedharan,P.M.,Raghukumar,S.,Kumar,M.D.,Madhupratap,M.},
year = {2001},
date = {2001-01-01},
journal = {Deep-Sea Research Part II},
volume = {48 },
number = {139},
pages = {1115-1126},
abstract = {Time-series observations at a nominally fixed location in the northern Arabian Sea (21§N, 64§E) during the Northeast Monsoon (winter, February) of l997 showed the prevalence of cold sea-surface temperatures (SST) and deep mixed layers resulting from winter cooling and convection. The covariation of nitrate concentrations in the surface layers and concentrations of chlorophyll a and primary production in the euphotic zone with mixed-layer depth (MLD) and wind suggests that carbon fixation was controlled primarily by physical forcing. Cooler waters during winter 1997 relative to winter 1995 were associated with deeper MLDs, higher nitrate concentrations, elevated primary productivity, and higher chlorophyll a concentrations, leading to the inference that even a 1§C decrease in SST could lead to significantly higher primary productivity. Satellite data on sea surface temperature (advanced very high-resolution radiometer; AVHRR) and TOPEX/POSEl- DON altimeter data suggest that this interannual variation is of basin-wide spatial scale. After the termination of winter cooling and subsequent warming during the Spring Intermonsoon, the Arabian Sea has low primary production. During the latter period, micro-organisms, i.e. heterotrophic bacteria and microzooplankton)-proliferate, a feeding mode through the microbial loop that appears to be inherent to mesozooplankton for sustaining their biomass throughout the year in this region.},
keywords = {Arabian Sea, chlorophyll, depth, feeding, lead, location, productivity, spatial scale, surface temperature, temperature},
pubstate = {published},
tppubtype = {article}
}
Time-series observations at a nominally fixed location in the northern Arabian Sea (21§N, 64§E) during the Northeast Monsoon (winter, February) of l997 showed the prevalence of cold sea-surface temperatures (SST) and deep mixed layers resulting from winter cooling and convection. The covariation of nitrate concentrations in the surface layers and concentrations of chlorophyll a and primary production in the euphotic zone with mixed-layer depth (MLD) and wind suggests that carbon fixation was controlled primarily by physical forcing. Cooler waters during winter 1997 relative to winter 1995 were associated with deeper MLDs, higher nitrate concentrations, elevated primary productivity, and higher chlorophyll a concentrations, leading to the inference that even a 1§C decrease in SST could lead to significantly higher primary productivity. Satellite data on sea surface temperature (advanced very high-resolution radiometer; AVHRR) and TOPEX/POSEl- DON altimeter data suggest that this interannual variation is of basin-wide spatial scale. After the termination of winter cooling and subsequent warming during the Spring Intermonsoon, the Arabian Sea has low primary production. During the latter period, micro-organisms, i.e. heterotrophic bacteria and microzooplankton)-proliferate, a feeding mode through the microbial loop that appears to be inherent to mesozooplankton for sustaining their biomass throughout the year in this region.
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.
Ross,J.P.
Recent marine mammal sightings in the Sultanate of Oman (1980-1981) Technical Report
no. 462, 1981.
Abstract | BibTeX | Tags: breeding grounds, cetacean, cetaceans, dugong, feeding, Humpback Whale, humpback whales, Indian Ocean, marine, marine mammal, Oman, sanctuaries, Strandings, whale, whales
@techreport{,
title = {Recent marine mammal sightings in the Sultanate of Oman (1980-1981)},
author = {Ross,J.P.},
year = {1981},
date = {1981-01-01},
journal = {Report presented to the special meeting of the IWC to plan a programme of scientific research on cetaceans in the Indian Ocean Sanctuary, Zeist, Netherlands.},
volume = {Document 23},
number = {462},
abstract = {This brief report summarises observations of live cetaceans, strandings and interviews with local fishermen. The source of sighting and stranding information is not always clear - stranded specimens referred to in this report were curated at the Zoological Museum in Amsterdam and the ONHM are also summarised in Gallagher 1991. JPR describes one stranding of a Dugong near Barka. He also describes Masirah fishermen's observations of a large whale with "bumps on its head like coffee cups" and long white flippers that they slap on the surface. He concludes that these are almost certainly humpback whales "migrating between summer feeding and winter breeding grounds. He also suggests that they were feeding on sardines which were abundant in the region during "these months" (although months not specified). Although he indicates that Oman's coast is abundant in food, yet tropical and thus suitable for breeding, he does not explicitly suggest that the humpbacks are year-round residents.},
keywords = {breeding grounds, cetacean, cetaceans, dugong, feeding, Humpback Whale, humpback whales, Indian Ocean, marine, marine mammal, Oman, sanctuaries, Strandings, whale, whales},
pubstate = {published},
tppubtype = {techreport}
}
This brief report summarises observations of live cetaceans, strandings and interviews with local fishermen. The source of sighting and stranding information is not always clear - stranded specimens referred to in this report were curated at the Zoological Museum in Amsterdam and the ONHM are also summarised in Gallagher 1991. JPR describes one stranding of a Dugong near Barka. He also describes Masirah fishermen's observations of a large whale with "bumps on its head like coffee cups" and long white flippers that they slap on the surface. He concludes that these are almost certainly humpback whales "migrating between summer feeding and winter breeding grounds. He also suggests that they were feeding on sardines which were abundant in the region during "these months" (although months not specified). Although he indicates that Oman's coast is abundant in food, yet tropical and thus suitable for breeding, he does not explicitly suggest that the humpbacks are year-round residents.
Ponomareva,L.A.
Euphausiids of the Indian Ocean and the Red Sea (original title Ehvfauziidy Indijskogo okeana I krasnogo morya) Journal Article
In: Nauka, vol. 1, no. 197, 1975.
Abstract | BibTeX | Tags: Arabian Sea, biology, Distribution, Euphausiid, feeding, Indian Ocean, migration, plankton, Red Sea, zooplankton
@article{,
title = {Euphausiids of the Indian Ocean and the Red Sea (original title Ehvfauziidy Indijskogo okeana I krasnogo morya)},
author = {Ponomareva,L.A.},
year = {1975},
date = {1975-01-01},
journal = {Nauka},
volume = {1},
number = {197},
abstract = {The study is mainly based on euphausiid material from 2390 plankton samples collected in the Indian Ocean during Oct-March 1959/60 and 1960/61. Data are presented on the sp composition, biology, vertical and quantitative distribution. The northern Indian Ocean (as far south as 40 degree S) is inhabited by typically tropical euphausiid fauna. The area most rich in euphausiids is the Arabian Sea. The spp most commonly occurring in the 0-200m layer in the Indian Ocean are Euphausia diomedeae, E. distinguenda, Stylocheiron carinatum and Thysanopoda tricuspidata. In the northern Indian Ocean eggs an early larval stages occurred from Jan to June (no observations were made later in the yr), which suggests that euphausiids spawn several times during the yr. The eggs develop very rapidly (within <24h) and so do early larval stages. On reaching the nauplius-2 stage the development slows down and it takes the larva 10-12 days to develop into furcilia-1. The feeding is varied and mixed: none of the spp were observed to feed on phyto- or zooplankton exclusively. Migratory spp show diurnal feeding rhythms. Most of the spp occurring in the upper layers ( down to 500m) are distinct migrants; interzonal spp do not perform significant migrations rarely rising close to the surface and almost never occurring above 50-40m. The Red Sea is inhabited by immigrants from teh Gulf of Aden and by some endemic spp. The spp abundant in the Arabian Sea are also predominant here with the addition of S. affine. },
keywords = {Arabian Sea, biology, Distribution, Euphausiid, feeding, Indian Ocean, migration, plankton, Red Sea, zooplankton},
pubstate = {published},
tppubtype = {article}
}
The study is mainly based on euphausiid material from 2390 plankton samples collected in the Indian Ocean during Oct-March 1959/60 and 1960/61. Data are presented on the sp composition, biology, vertical and quantitative distribution. The northern Indian Ocean (as far south as 40 degree S) is inhabited by typically tropical euphausiid fauna. The area most rich in euphausiids is the Arabian Sea. The spp most commonly occurring in the 0-200m layer in the Indian Ocean are Euphausia diomedeae, E. distinguenda, Stylocheiron carinatum and Thysanopoda tricuspidata. In the northern Indian Ocean eggs an early larval stages occurred from Jan to June (no observations were made later in the yr), which suggests that euphausiids spawn several times during the yr. The eggs develop very rapidly (within <24h) and so do early larval stages. On reaching the nauplius-2 stage the development slows down and it takes the larva 10-12 days to develop into furcilia-1. The feeding is varied and mixed: none of the spp were observed to feed on phyto- or zooplankton exclusively. Migratory spp show diurnal feeding rhythms. Most of the spp occurring in the upper layers ( down to 500m) are distinct migrants; interzonal spp do not perform significant migrations rarely rising close to the surface and almost never occurring above 50-40m. The Red Sea is inhabited by immigrants from teh Gulf of Aden and by some endemic spp. The spp abundant in the Arabian Sea are also predominant here with the addition of S. affine.
Weigmann,R.
On the ecology and feeding habits of the euphausiids (Crustacea) in the Arabian Sea (Zur Okologie und Eranhrungsbiologie der Euphausiaceen (Crustacea) im Arabischen Meer) Journal Article
In: Meteor Forschungsergeb., vol. 5, no. 498, pp. 11-52, 1970.
Abstract | BibTeX | Tags: Arabian Sea, biology, density, diet, Distribution, ecology, Euphausiid, feeding, Gulf of Aden, Gulf of Oman, marine, Oman, population, populations, predation, Red Sea, Upwelling, zooplankton
@article{,
title = {On the ecology and feeding habits of the euphausiids (Crustacea) in the Arabian Sea (Zur Okologie und Eranhrungsbiologie der Euphausiaceen (Crustacea) im Arabischen Meer)},
author = {Weigmann,R.},
year = {1970},
date = {1970-01-01},
journal = {Meteor Forschungsergeb.},
volume = {5},
number = {498},
pages = {11-52},
abstract = {In the present paper, the ecology and feeding habits of euphausiids are described. The samples were taken at the time of the NE-monsoon (1964/65) by R. V. 'Meteor' in the Arabian Sea and adjacent waters. 24 spp were determined. According to distribution of the spp, the following marine areas can be distinguished: Arabian Sea: 24 spp, dominant are Euphausia diomedeae, E. tenera, E. distinguenda, Stylocheiron carinatum. Gulf of Aden: 1 0 spp, dominant are Euphausia diomedeae, E. distinguenda. Red Sea: 6 spp, dominant are Euphausia diomedeae, E. distinguena. Gulf of Oman: 5 spp, dominant are Euphausia distinguenda, Pseudeuphausia latifrons. Persian Gulf: 1 sp- Pseudeuphausia latifrons. The total number of euphausiids indicate the biomass of this group. High densities of euphausiids (200-299 and > 300 individuals/l00 m super(3)) occur in the innermost part of the Gulf of Aden, in the area south of the Euqator near the African east coast, near Karachi (Indian west coast) and in the Persian Gulf. Comparison with data relating to production biology confirms that these are eutrophic zones which coincide with areas in which upwelling occurs at the time of the NE-monsoon. The central part of the Arabian Sea differs from adjacent waters by virtue of less dense euphasiid populations (>199 individuals/lOO m super(3)). Measurements relating to production biology demonstrate a relatively low concentration of primary food sources. Food material was ascertained by analysis of stomach content. The following omnivorous species were examined: Euphausia diomedeae, E. distinguenda, E. tenera, Pseudeuphausia latifronts and Thysanopoda tricuspidata. Apart from crustacean remains large numbers of Foraminifera, Radiolaria, tintinnids, dinoflagellates were found in the stomachs. Quantitatively crustaceans form the most important item in the diet. Food selection on the basis of size an form appears to be restricted to certain genera of tintinnids. The genera Stylocheiron and Nematoscelis are predators. Only crustacean remains were found in the stomachs of Stylocheiron abbreviatum, whereas Radiolaria, Foraminifera and tintinnids occurred to some extent in Nematoscelis sp. Different euphauisiids occupy different positions in the food chain in the Arabian Sea. In omnivorous species the position is variable, since they not only feed by filtering autotrophic and heterotrophic Protista, but also by predation on zooplankton. Carnivorous spp without filtering apparatus feed exclusively on zooolankton of the size of copepods. Only these spp are well established as occupying a higher position in food chain. The parasrtlc protozoan Thalassomyces fagei was found on Euphausia diomedeae, E. tenera, E. distinguenda and E. sanzoi.},
keywords = {Arabian Sea, biology, density, diet, Distribution, ecology, Euphausiid, feeding, Gulf of Aden, Gulf of Oman, marine, Oman, population, populations, predation, Red Sea, Upwelling, zooplankton},
pubstate = {published},
tppubtype = {article}
}
In the present paper, the ecology and feeding habits of euphausiids are described. The samples were taken at the time of the NE-monsoon (1964/65) by R. V. 'Meteor' in the Arabian Sea and adjacent waters. 24 spp were determined. According to distribution of the spp, the following marine areas can be distinguished: Arabian Sea: 24 spp, dominant are Euphausia diomedeae, E. tenera, E. distinguenda, Stylocheiron carinatum. Gulf of Aden: 1 0 spp, dominant are Euphausia diomedeae, E. distinguenda. Red Sea: 6 spp, dominant are Euphausia diomedeae, E. distinguena. Gulf of Oman: 5 spp, dominant are Euphausia distinguenda, Pseudeuphausia latifrons. Persian Gulf: 1 sp- Pseudeuphausia latifrons. The total number of euphausiids indicate the biomass of this group. High densities of euphausiids (200-299 and > 300 individuals/l00 m super(3)) occur in the innermost part of the Gulf of Aden, in the area south of the Euqator near the African east coast, near Karachi (Indian west coast) and in the Persian Gulf. Comparison with data relating to production biology confirms that these are eutrophic zones which coincide with areas in which upwelling occurs at the time of the NE-monsoon. The central part of the Arabian Sea differs from adjacent waters by virtue of less dense euphasiid populations (>199 individuals/lOO m super(3)). Measurements relating to production biology demonstrate a relatively low concentration of primary food sources. Food material was ascertained by analysis of stomach content. The following omnivorous species were examined: Euphausia diomedeae, E. distinguenda, E. tenera, Pseudeuphausia latifronts and Thysanopoda tricuspidata. Apart from crustacean remains large numbers of Foraminifera, Radiolaria, tintinnids, dinoflagellates were found in the stomachs. Quantitatively crustaceans form the most important item in the diet. Food selection on the basis of size an form appears to be restricted to certain genera of tintinnids. The genera Stylocheiron and Nematoscelis are predators. Only crustacean remains were found in the stomachs of Stylocheiron abbreviatum, whereas Radiolaria, Foraminifera and tintinnids occurred to some extent in Nematoscelis sp. Different euphauisiids occupy different positions in the food chain in the Arabian Sea. In omnivorous species the position is variable, since they not only feed by filtering autotrophic and heterotrophic Protista, but also by predation on zooplankton. Carnivorous spp without filtering apparatus feed exclusively on zooolankton of the size of copepods. Only these spp are well established as occupying a higher position in food chain. The parasrtlc protozoan Thalassomyces fagei was found on Euphausia diomedeae, E. tenera, E. distinguenda and E. sanzoi.