Mehta,A.V.
How important are baleen whales as prey for killer whales (Orcinus orca) in high-latitude waters? PhD Thesis
2004.
Abstract | BibTeX | Tags: Alaska, Antarctic, Atlantic, Australia, baleen whales, Blue whale, blue whales, Gulf of Maine, Humpback Whale, humpback whales, killer whale, killer whales, New Caledonia, New Zealand, North Atlantic, North Atlantic right whale, North Pacific, Oman, Orca, Orcinus orca, population, prey, pygmy blue whale, Pygmy blue whales, right whale, right whales, whale, whales, whaling
@phdthesis{,
title = {How important are baleen whales as prey for killer whales (Orcinus orca) in high-latitude waters?},
author = {Mehta,A.V.},
year = {2004},
date = {2004-01-01},
number = {403},
pages = {1-15},
publisher = {Boston University},
abstract = {Data on humpback whales were collected from twenty-one regions: eleven in the North Atlantic and three in the North Pacific, as well as American Samoa, Vava'u (Tonga), New Zealand, New Caledonia, western Australia, the Antarctic Peninsula, and Oman. The other species and subspecies included in this project were sampled from a single population each (Fig. 1): North Atlantic right whales, blue whales off southeastern Australia, and pygmy blue whales (Balaenoptera musculus brevicauda) off western Australia. The proportion of whales in different sampling regions bearing rake marks ranged from 0% to over 40%. The Gulf of Maine population had a scarring rate of 9.9-11%, while SW Alaska had a rate of 21.1 to 21.9%. Oman had a rate of 9.1% (3 of 33 animals). The highest rate of scarring was the "Mexico" population with a scarring rate of over 40%. Of those scarred animals with multi-year sighting histories, 82.8% to 100% had those scars the first time they were sighted. Of the total number of whales sampled from these regions, 0% to only 4.8% acquired new or additional rake marks after their first sighting, supporting the hypothesis that most whales aquire their scars as calves, and that adult baleen whales do not constitute a major prey source for killer whales.Overall, the present study suggests that the hypothesis presented by Springer et al. (2003) - that killer whales in the North Pacific were forced by industrial whaling to switch prey from baleen whales to pinnipeds and sea otters - is untenable.},
keywords = {Alaska, Antarctic, Atlantic, Australia, baleen whales, Blue whale, blue whales, Gulf of Maine, Humpback Whale, humpback whales, killer whale, killer whales, New Caledonia, New Zealand, North Atlantic, North Atlantic right whale, North Pacific, Oman, Orca, Orcinus orca, population, prey, pygmy blue whale, Pygmy blue whales, right whale, right whales, whale, whales, whaling},
pubstate = {published},
tppubtype = {phdthesis}
}
Data on humpback whales were collected from twenty-one regions: eleven in the North Atlantic and three in the North Pacific, as well as American Samoa, Vava'u (Tonga), New Zealand, New Caledonia, western Australia, the Antarctic Peninsula, and Oman. The other species and subspecies included in this project were sampled from a single population each (Fig. 1): North Atlantic right whales, blue whales off southeastern Australia, and pygmy blue whales (Balaenoptera musculus brevicauda) off western Australia. The proportion of whales in different sampling regions bearing rake marks ranged from 0% to over 40%. The Gulf of Maine population had a scarring rate of 9.9-11%, while SW Alaska had a rate of 21.1 to 21.9%. Oman had a rate of 9.1% (3 of 33 animals). The highest rate of scarring was the "Mexico" population with a scarring rate of over 40%. Of those scarred animals with multi-year sighting histories, 82.8% to 100% had those scars the first time they were sighted. Of the total number of whales sampled from these regions, 0% to only 4.8% acquired new or additional rake marks after their first sighting, supporting the hypothesis that most whales aquire their scars as calves, and that adult baleen whales do not constitute a major prey source for killer whales.Overall, the present study suggests that the hypothesis presented by Springer et al. (2003) - that killer whales in the North Pacific were forced by industrial whaling to switch prey from baleen whales to pinnipeds and sea otters - is untenable.
Phillip Clapham, Sharon Young, Robert L. Brownell Jr
Baleen whales: conservation issues and the status of the most endangered populations Journal Article
In: Mammal Review, vol. 29 , no. 69, pp. 35-60, 1999.
Abstract | Links | BibTeX | Tags: abundance, Arabian Sea, Arctic, Balaena mysticetus, baleen whale, baleen whales, Blue whale, bowhead whale, bowhead whales, conservation, contaminants, disease, endangered, Entanglement, Eubalaena glacialis, fishing gear, gray whales, habitat degradation, Humpback Whale, humpback whales, mortality, Okhotsk Sea, population, populations, right whale, right whales, ship-strike, southern right whales, status, stocks, whale, whales, whaling
@article{,
title = {Baleen whales: conservation issues and the status of the most endangered populations },
author = {Phillip Clapham, Sharon Young, Robert L. Brownell Jr},
doi = {https://doi.org/10.1046/j.1365-2907.1999.00035.x},
year = {1999},
date = {1999-01-01},
urldate = {1999-01-01},
journal = {Mammal Review},
volume = {29 },
number = {69},
pages = {35-60},
abstract = {Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions: populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right N hales Eubalaena glacialis. Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations. western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and. where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling. existing data indicate strong recovery in most studied populations of these species.},
keywords = {abundance, Arabian Sea, Arctic, Balaena mysticetus, baleen whale, baleen whales, Blue whale, bowhead whale, bowhead whales, conservation, contaminants, disease, endangered, Entanglement, Eubalaena glacialis, fishing gear, gray whales, habitat degradation, Humpback Whale, humpback whales, mortality, Okhotsk Sea, population, populations, right whale, right whales, ship-strike, southern right whales, status, stocks, whale, whales, whaling},
pubstate = {published},
tppubtype = {article}
}
Most species of baleen whales were subject to intensive overexploitation by commercial whaling in this and previous centuries, and many populations were reduced to small fractions of their original sizes. Here, we review the status of baleen whale stocks, with an emphasis on those that are known or thought to be critically endangered. Current data suggest that, of the various threats potentially affecting baleen whales, only entanglement in fishing gear and ship strikes may be significant at the population level, and then only in those populations which are already at critically low abundance. The impact of some problems (vessel harassment, and commercial or aboriginal whaling) is at present probably minor. For others (contaminants, habitat degradation, disease), existing data either indicate no immediate cause for concern, or are insufficient to permit an assessment. While the prospect for many baleen whales appears good, there are notable exceptions: populations that are of greatest concern are those suffering from low abundance and associated problems, including (in some cases) anthropogenic mortality. These include: all Northern Right N hales Eubalaena glacialis. Bowhead Whales Balaena mysticetus of the Okhotsk Sea and various eastern Arctic populations. western Gray Whales Eschrichtius robustus, and probably many Blue Whale Balaenoptera musculus populations. We review the status of these populations and. where known, the issues potentially affecting their recovery. Although Humpback Whales Megaptera novaeangliae and Southern Right Whales Eubalaena australis were also heavily exploited by whaling. existing data indicate strong recovery in most studied populations of these species.
Slijper,E.J.,Van Utrecht,W.L.,Naaktgeboren,C.
Remarks on the distribution and migration of whales Journal Article
In: Bijdragen tot de Dierkunde, vol. 34, no. 475, pp. 4-86, 1964.
Abstract | BibTeX | Tags: Arabian Gulf, Arabian Sea, Atlantic, density, Distribution, fin whale, Gulf of Aden, Humpback Whale, humpback whales, India, Indian Ocean, Maldives, migration, minke whale, minke whales, North Pacific, Oman, Pakistan, productivity, right whale, right whales, Southern Hemisphere, sperm whale, sperm whales, Strandings, whale, whales
@article{,
title = {Remarks on the distribution and migration of whales},
author = {Slijper,E.J.,Van Utrecht,W.L.,Naaktgeboren,C.},
year = {1964},
date = {1964-01-01},
journal = {Bijdragen tot de Dierkunde},
volume = {34},
number = {475},
pages = {4-86},
abstract = {The authors gained the cooperation of the Netherlands Association of Ship Owners and the Royal Netherlands Navy in a project to collect all whale sightings from vessels sailing around the globe between 1954 and 1957. A total of 4500 reports of 11,000 animals were received, with the majority of observations coming from the Atlantic and Indian Oceans. Vessels were given identification guides and all reported observations were scored on the perceived reliability of the identification. All Rorqual whales were grouped together, and a further distinction was made between humpback, sperm, right whales and "little piked whales" (minke whales). Sightings were plotted in 10 degree squares according to number of whales observed per 1000 hours steamed in daylight. Special attention is given to the observations of Captain W.F.J. Morzer Bruins, who the authors describe as a keen naturalist whose observations hold more credibility than those of others. His observations in the Indian Ocean include a high number of sperm whales off the southern coast of Oman and the Gulf of Aden in January-March and April-June, a scattering of stranded blue and fin whales along the W coast of India, and only 2 stranded and 2 live humpback whales (strandings both in India, and live sightings near Yemen/Oman border? and off S tip of India (near Maldives?). The larger number of compiled sightings from vessels are presented by species. Rorqual sightings were plentiful in the Gulf of Aden, Arabian Sea coasts of Oman and Pakistan, and in the Arabian Gulf (but not as plentiful as they were in the area between 30 and 40 degrees S. The author concludes that the majority of the whales observed in the NIO do not belong to the Southern Hemisphere stock, but suggests that they migrate from the North Pacific through the Indonesian Archipelago and the Strait Malaya (despite very few observations here). He briefly considers, but discards as unlikely, the hypothesis of a resident NIO stock.The total number of humpback whale sightings in the IO amounted to 500 (compared to 1618 rorqual sightings and 799 "whale" sightings). The majority of animals were observed in coastal waters, and NIO sightings were generally concentrated in the months of Aug-Nov and Jan-April. some of the highest recorded densities in the NIO are off of Pakistan in the months of March, Aug, Oct, and December, but it is not clear how closely related this is to observer effort. Observations are very few in May, June, July and September, and the authors do not link this to the monsoon -but rather conclude that the whales are not present at that time. Although few calves were observed in the NIO, those that were observed, were all observed in November, January or September (but no indication is given of calf size). The authors conclude that this is evidence that the observed whales do not belong to the S. Hem stock, but are more likely from the N.Pacific, despite the fact that there are "no sightings of humpbacks in the south China Sea or the Indonesian Archipelago that could support this assumption". Sperm whales were observed with regularity throughout the year in the NIO, but in lower densities than Rorquals. A low number of sightings in the NIO during summer months again leads the author to conclude that the animals either migrate South or to the N. Pacific. This species, according to the authors is always associated with areas of high productivity.Minke whales were recorded in low densities in the Gulf of Aden and off the coast of Pakistan, but not in the central or Northern coasts of Oman.},
keywords = {Arabian Gulf, Arabian Sea, Atlantic, density, Distribution, fin whale, Gulf of Aden, Humpback Whale, humpback whales, India, Indian Ocean, Maldives, migration, minke whale, minke whales, North Pacific, Oman, Pakistan, productivity, right whale, right whales, Southern Hemisphere, sperm whale, sperm whales, Strandings, whale, whales},
pubstate = {published},
tppubtype = {article}
}
The authors gained the cooperation of the Netherlands Association of Ship Owners and the Royal Netherlands Navy in a project to collect all whale sightings from vessels sailing around the globe between 1954 and 1957. A total of 4500 reports of 11,000 animals were received, with the majority of observations coming from the Atlantic and Indian Oceans. Vessels were given identification guides and all reported observations were scored on the perceived reliability of the identification. All Rorqual whales were grouped together, and a further distinction was made between humpback, sperm, right whales and "little piked whales" (minke whales). Sightings were plotted in 10 degree squares according to number of whales observed per 1000 hours steamed in daylight. Special attention is given to the observations of Captain W.F.J. Morzer Bruins, who the authors describe as a keen naturalist whose observations hold more credibility than those of others. His observations in the Indian Ocean include a high number of sperm whales off the southern coast of Oman and the Gulf of Aden in January-March and April-June, a scattering of stranded blue and fin whales along the W coast of India, and only 2 stranded and 2 live humpback whales (strandings both in India, and live sightings near Yemen/Oman border? and off S tip of India (near Maldives?). The larger number of compiled sightings from vessels are presented by species. Rorqual sightings were plentiful in the Gulf of Aden, Arabian Sea coasts of Oman and Pakistan, and in the Arabian Gulf (but not as plentiful as they were in the area between 30 and 40 degrees S. The author concludes that the majority of the whales observed in the NIO do not belong to the Southern Hemisphere stock, but suggests that they migrate from the North Pacific through the Indonesian Archipelago and the Strait Malaya (despite very few observations here). He briefly considers, but discards as unlikely, the hypothesis of a resident NIO stock.The total number of humpback whale sightings in the IO amounted to 500 (compared to 1618 rorqual sightings and 799 "whale" sightings). The majority of animals were observed in coastal waters, and NIO sightings were generally concentrated in the months of Aug-Nov and Jan-April. some of the highest recorded densities in the NIO are off of Pakistan in the months of March, Aug, Oct, and December, but it is not clear how closely related this is to observer effort. Observations are very few in May, June, July and September, and the authors do not link this to the monsoon -but rather conclude that the whales are not present at that time. Although few calves were observed in the NIO, those that were observed, were all observed in November, January or September (but no indication is given of calf size). The authors conclude that this is evidence that the observed whales do not belong to the S. Hem stock, but are more likely from the N.Pacific, despite the fact that there are "no sightings of humpbacks in the south China Sea or the Indonesian Archipelago that could support this assumption". Sperm whales were observed with regularity throughout the year in the NIO, but in lower densities than Rorquals. A low number of sightings in the NIO during summer months again leads the author to conclude that the animals either migrate South or to the N. Pacific. This species, according to the authors is always associated with areas of high productivity.Minke whales were recorded in low densities in the Gulf of Aden and off the coast of Pakistan, but not in the central or Northern coasts of Oman.