Escalle, L.,Capietto, A.,Chavance, P.,Dubroca, L.,Delgado De Molina, A.,Murua, H.,Gaertner, D.,Romanov, E.,Spitz, J.,Kiszka, J. J.,Floch, L.,Damiano, A.,Merigot, B.
Cetaceans and tuna purse seine fisheries in the Atlantic and Indian Oceans: interactions but few mortalities Journal Article
In: Marine Ecology Progress Series, vol. 522, no. 370, pp. 255-268, 2015.
Abstract | Links | BibTeX | Tags: Atlantic, Bycatch, cetaceans, Humpback Whale, Indian Ocean, megaptera novaeangliae, purse-Seine, tuna fishery
@article{,
title = {Cetaceans and tuna purse seine fisheries in the Atlantic and Indian Oceans: interactions but few mortalities},
author = {Escalle, L.,Capietto, A.,Chavance, P.,Dubroca, L.,Delgado De Molina, A.,Murua, H.,Gaertner, D.,Romanov, E.,Spitz, J.,Kiszka, J. J.,Floch, L.,Damiano, A.,Merigot, B.},
url = {http://www.int-res.com/abstracts/meps/v522/p255-268/},
year = {2015},
date = {2015-01-01},
journal = {Marine Ecology Progress Series},
volume = {522},
number = {370},
pages = {255-268},
abstract = {ABSTRACT: Fisheries bycatch is considered to be one of the most significant causes of mortality for many marine species, including vulnerable megafauna. In the open ocean, tuna purse seiners are known to use several cetacean species to detect tuna schools. This exposes the cetaceans to encirclement which can lead to incidental injury or death. While interactions between fishers and cetaceans have been well documented in the eastern tropical Pacific Ocean, little is known about these interactions and potential mortalities in the tropical Atlantic and Indian Oceans. Here, we provide the first quantification of these interactions in both oceans by analyzing a large database of captain’s logbooks (1980 to 2011) and observations collected by onboard scientific observers (1995 to 2011). Distribution maps of sightings per unit effort highlighted main areas of relatively high co-occurrence: east of the Seychelles (December to March), the Mozambique Channel (April to May) and the offshore waters of Gabon (April to September). The percentage of cetacean-associated fishing sets was around 3% in both oceans and datasets whereas 0.6% of sets had cetaceans encircled. Of the 194 cetaceans encircled in a purse seine net (122 baleen whales, 72 delphinids), immediate apparent survival rates were high (Atlantic: 92%, Indian: 100%). Among recorded mortalities, 8 involved pantropical spotted dolphins \textit{Stenella attenuata} and 3 involved humpback whales \textit{Megaptera novaeangliae}. These high survival rates suggest that setting nets close to cetaceans has a low immediate apparent impact on the species involved. Our findings will contribute to the development of an ecosystem approach to managing fisheries and accurate cetacean conservation measures.},
keywords = {Atlantic, Bycatch, cetaceans, Humpback Whale, Indian Ocean, megaptera novaeangliae, purse-Seine, tuna fishery},
pubstate = {published},
tppubtype = {article}
}
Rosenbaum,H.C.,Pomilla,C.,Olavarria,C.,Baker,C.S.,Leslie,M.,Mendez,M.C.,Caballero,S.,Brasseur,M,Bannister,J.L,Best,P.B.,Bonatto,S.,Collins,T.J.Q.,Engel,M.H.,Ersts,P.J.,Findlay,K.P.,Florez-Gonzalez,L.,Garrigue,C.,Hauser,N.,Jenner,C.,Meyer,M.,Minton,G.,Poole,M.M.,Razafindrakoto,Y.
A first and preliminary analysis of mtDNA sequences from humpback whales for breeding stocks A-G and X Technical Report
no. 461, 2006, ISBN: SC/A06/HW59.
BibTeX | Tags: Atlantic, Atlantic Ocean, breeding grounds, DNA, dolphin, Humpback Whale, humpback whales, Indian Ocean, mitochondrial DNA, Oman, population, South Atlantic, Southern Hemisphere, stocks, whale, whales
@techreport{,
title = {A first and preliminary analysis of mtDNA sequences from humpback whales for breeding stocks A-G and X},
author = {Rosenbaum,H.C.,Pomilla,C.,Olavarria,C.,Baker,C.S.,Leslie,M.,Mendez,M.C.,Caballero,S.,Brasseur,M,Bannister,J.L,Best,P.B.,Bonatto,S.,Collins,T.J.Q.,Engel,M.H.,Ersts,P.J.,Findlay,K.P.,Florez-Gonzalez,L.,Garrigue,C.,Hauser,N.,Jenner,C.,Meyer,M.,Minton,G.,Poole,M.M.,Razafindrakoto,Y.},
issn = {SC/A06/HW59},
year = {2006},
date = {2006-01-01},
journal = {Report presented to the Comprehensive Assessment of Southern Hemisphere Humpback Whales, Hobart, Tasmania},
volume = {SC/A06/HW59},
number = {461},
keywords = {Atlantic, Atlantic Ocean, breeding grounds, DNA, dolphin, Humpback Whale, humpback whales, Indian Ocean, mitochondrial DNA, Oman, population, South Atlantic, Southern Hemisphere, stocks, whale, whales},
pubstate = {published},
tppubtype = {techreport}
}
Zemsky,V.A.
Extermination of populations of commercial whale species and its possible biological consequences Technical Report
no. 268, 2005.
Abstract | BibTeX | Tags: Arabian Sea, Atlantic, Atlantic Ocean, baleen whale, baleen whales, biological consequences, cetacean, cetaceans, depletion, extermination, mammals, marine, marine mammal, Marine mammals, oil, population, populations, Southern Hemisphere, Soviet whaling, sperm whale, status, whale, whales, whaling
@techreport{,
title = {Extermination of populations of commercial whale species and its possible biological consequences},
author = {Zemsky,V.A.},
year = {2005},
date = {2005-01-01},
number = {268},
pages = {249-259},
abstract = {Cetaceans inhabit practically all seas and oceans of the world and their role in ocean biocenoses is doubtless. Being the source of nutrition and technical resources - oil, meat, etc., - this numrous group of marine mammals had also substantial meaning for the man's economic activity. In a number of coastal regions, some whales are still an important, if not one, source of protein food. All cetaceans can be subdivided into two conditional categories: those which are caught for commerial needs and those which are not. The first group comprises practically all baleen whales, the size of most of which has no analogous in terrestrial mammals, and the sperm whale - the only one of toothed whales. All other cetaceans can be referred to the second group. They are much smaller in size, but more numerous and play not less important role in biocenoses. Some of them were of commercial value in the past and now have lost it almost completely. This brief review pursues three goals: firstly, to reveal the relationship between the population number of the commercial whales and whaling in a historical aspect; secondly, to determine the significance for the estimation of the current status of the large whales' populations of the materials, pulished in 1995, on the largest falsification of statistical data on the Soviet whaling operations in the Southern Hemisphere and in some regions of the Atlantic Ocean, including the Arabian Sea and equatorial waters; thirdly, to try to reveal possible consequences of the drastic depletion of number of the large commerical whales for the ocean biogeocenoses.},
keywords = {Arabian Sea, Atlantic, Atlantic Ocean, baleen whale, baleen whales, biological consequences, cetacean, cetaceans, depletion, extermination, mammals, marine, marine mammal, Marine mammals, oil, population, populations, Southern Hemisphere, Soviet whaling, sperm whale, status, whale, whales, whaling},
pubstate = {published},
tppubtype = {techreport}
}
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}
}
Farrenkopf,A.M.,Luther III,G.W.
Iodine chemistry reflects productivity and denitrification in the Arabian Sea: evidence for flux of dissolved species from sediments of western India into the OMZ Journal Article
In: Deep-Sea Research Part II, vol. 49 , no. 91, pp. 2303-2318, 2002.
Abstract | BibTeX | Tags: Arabian Sea, Atlantic, Hawaii, India, Oceanic, oxygen minimum, productivity
@article{,
title = {Iodine chemistry reflects productivity and denitrification in the Arabian Sea: evidence for flux of dissolved species from sediments of western India into the OMZ},
author = {Farrenkopf,A.M.,Luther III,G.W.},
year = {2002},
date = {2002-01-01},
journal = {Deep-Sea Research Part II},
volume = {49 },
number = {91},
pages = {2303-2318},
abstract = {Dissolved iodine species and total iodine concentrations were measured in the Arabian Sea during the Spring Intermonsoon of 1995. Two separate regimes of iodine chemistry are highlighted in this study: (1) the well-oxygenated surface layer (WOSL) where iodide concentrations were in the range of 158-558 nM, and (2) the oxygen minimum zone (OMZ) where total iodine concentrations [primarily as iodide and in excess to the oceanic iodine/salinity ratio of ~13] varied from ~200 to 950 nM. Iodine data in the WOSL of the Arabian Sea are contrasted with data from the Bermuda Atlantic Time-series Station (BATS), the Hawaii Ocean Time-series Station ALOHA (HOT), VERTEX in the Pacific and the Black Sea. Total iodine concentrations in excess of 400nM were observed in eastern portions of the OMZ. The eastern portion of the basin has a permanent denitrification zone as well as high concentrations of dissolved Mn2+ (d- Mn2+) and iodide. While there is precedent for high values of iodide and total iodine in several other isolated basins, this is the first report of such values in open-ocean waters. Potential sources of excess total iodine to the OMZ include advection along isopycnals, from hydrothermal vents or margin sediments; atmospheric deposition; and remineralization of sinking particulate organic iodine (POI) associated with elevated productivity in surface waters. We estimate that only 3.6% of the excess total iodine can result from remineralization of sinking POI from the WOSL to the OMZ. Advection from margin sediments off of India is the most plausible source of iodine to the OMZ and contributes ~96% of the total excess iodine to the OMZ. I- is maintained as the dominant form of iodine via in situ reduction of iodate by bacteria.},
keywords = {Arabian Sea, Atlantic, Hawaii, India, Oceanic, oxygen minimum, productivity},
pubstate = {published},
tppubtype = {article}
}
Barber,R.T.,Marra,J.,Bidigare,R.C.,Codispoti,L.A.,Halpern,D.,Johnson,Z.,Latasa,M.,Goericke,R.,Smith,S.L.
Primary productivity and its regulation in the Arabian Sea during 1995 Journal Article
In: Deep-Sea Research Part II, vol. 48, no. 323, pp. 1127-1172, 2001.
Abstract | BibTeX | Tags: abundance, Arabian Sea, Atlantic, location, North Atlantic, Oman, Pacific Ocean, performance, productivity, Upwelling
@article{,
title = {Primary productivity and its regulation in the Arabian Sea during 1995},
author = {Barber,R.T.,Marra,J.,Bidigare,R.C.,Codispoti,L.A.,Halpern,D.,Johnson,Z.,Latasa,M.,Goericke,R.,Smith,S.L.},
year = {2001},
date = {2001-01-01},
journal = {Deep-Sea Research Part II},
volume = {48},
number = {323},
pages = {1127-1172},
abstract = {The annual cycle of monsoon-driven variability in primary productivity was studied in 1995 during the Arabian Sea Expedition as part of the United States Joint Global Ocean Flux Studies (US JGOFS). This paper describes the seasonal progression of productivity and its regulation on a section which ran from the coast of Oman to about 1000km offshore in the centralArabian Sea at 65§E. During the SW Monsoon (June-mid-September), the coolest water and highest nutrient concentrations were close to the coast, although they extended offshore to about 800 km; during the January NE Monsoon, deep convective mixing provided nutrients to the mixed layer in the region 400 - 1000km o!shore. As expected, the SW Monsoon was the most productive season (123ñ9mmolC m-2d-1) along the southern US JGOFS section from the coast to 1000km offshore, but productivity in the NE Monsoon was surprisingly high (112ñ7mmol C m-2d-1). There was no onshore/offshore gradient in primary productivity from 150 to 1000km o! the Omani coast in 1995, and there was no evidence of light limitation of either primary productivity or photosynthetic performance (PBopt) from deep convective mixing during the NE Monsoon, deep wind mixing during the SW Monsoon or offshore Ekman downwelling during the SW Monsoon. Productivity during the Spring Intermonsoon (86ñ6mmolC m-2d-1) was much higher than in oligotrophic regions such as the tropical Pacific Ocean (29ñ2 mmolC m-2 d-1) or the North Pacific gyre region (32ñ8 mmolC m-2 d-1). The 1995 annual mean productivity (111ñ11mmolC m-2 d-1) along this section from the Omani coast to the central Arabian Sea was about equal to the spring bloom maximum (107ñ23mmolC m-2 d-1) during the 1989 North Atlantic Bloom Experiment (NABE) and the equatorial, 1§N-1§S wave guide maximum (95ñ6mmolC m-2 d-1) in the Pacific Ocean during the 1992 EqPac study. The 1995 SW Monsoon primary productivity was similar to the mean value observed in the same region in 1994 by the Arabesque Expedition (127ñ14mmolC m-2 d-1) and in 1964 by the ANTON BRUUN Expedition (115ñ27 mmol C m-2 d-1). During the 1995 SW Monsoon, strong, narrow and meandering current filaments extended from the region of coastal upwelling to about 700km offshore; these filaments had levels of biomass, primary productivity, chlorophyll-specific productivity and diatom abundance that were elevated relative to other locations during the SW Monsoon. The SW Monsoon was the most productive period, but SW Monsoon primary productivity values were lower than predicted because effcient grazing by mesozooplankton kept diatoms from accumulating the biomass necessary for achieving the high levels of primary productivity characteristic of other coastal upwelling regions. The high rates of chlorophyll-specific productivity (PBopt>10mmolC mg Chl-1 d-1) observed in the 1995 SW Monsoon, together with the observed dust flux and iron concentrations, indicate that the Arabian Sea was more iron replete than the equatorial Pacific Ocean or the Southern Ocean },
keywords = {abundance, Arabian Sea, Atlantic, location, North Atlantic, Oman, Pacific Ocean, performance, productivity, Upwelling},
pubstate = {published},
tppubtype = {article}
}
Witter,A.E.,Lewis,B.L.,Luther III,G.W.
Iron speciation in the Arabian Sea Journal Article
In: Deep-Sea Research Part II, vol. 47, no. 264, pp. 1517-1539, 2000.
Abstract | BibTeX | Tags: Arabian Sea, Atlantic, Atlantic Ocean, depth, marine, oxygen minimum, Upwelling
@article{,
title = {Iron speciation in the Arabian Sea},
author = {Witter,A.E.,Lewis,B.L.,Luther III,G.W.},
year = {2000},
date = {2000-01-01},
journal = {Deep-Sea Research Part II},
volume = {47},
number = {264},
pages = {1517-1539},
abstract = {Fe(III) speciation was measured in seawater collected as part of the United States Joint Global Ocean Flux (US JGOFS) Arabian Sea Process Study, Cruise TN045, March 14-April 10, 1995. The Fe-binding capacity of organic seawater ligands was measured in filtered seawater (<0.4 æm) collected from surface depths and throughout the oxygen minimum zone (OMZ). Seawaters from three stations on the southern line (S2, S9, and S11) were examined. Total Fe concentrations measured at the three sites ranged from: 1.25 ñ 0.21 nM to 1.30 ñ 0.01 nM (S2); 1.67 ñ 0.50 nM to 2.63 ñ 0.54 nM (S9); and 1.40 ñ 0.11 nM to 1.70 ñ 0.29 nM (S11). Cathodic stripping voltammetry (CSV) with 1-nitroso-2-napthol (1N2N) as the competitive ligand (pH 6.9) was used to determine conditional stability constants and Fe-binding ligand concentrations in seawater. Conditional stability constants for FeL complexes ranged from log KFeL = 21.6 ñ 0.1 to 22.5 ñ 0.9 at the three sites. Total ligand concentrations ranged from 1.47 ñ 0.06 nM to 6.33 ñ 1.16 nM over all sites, but increased by a factor of 2-3 from the surface to the oxygen minimum zone (OMZ), suggesting that Fe-binding ligands may be produced during organic matter degradation. Ligand concentrations were consistently higher than total iron concentrations at every site measured, with an average "excess" ligand concentration of 2.15 ñ 1.50 (n = 10). "Excess" ligand concentrations in the OMZ were 2 to 20 times higher than surface waters (upper 100 m). Formation-rate constants (kf ) and dissociation-rate constants (kd) between added Fe3+ and seawater ligands were measured using a kinetic approach at ambient seawater pH, allowing independent calculation of the conditional stability constant, since K = kf/kd. Using the kinetic approach, conditional stability constants ranged from log KFeL = 20.5 ñ 0.1 to 22.9 ñ 0.1. Although log K values are comparable in magnitude to those reported in the Pacific and Northwestern Atlantic Oceans, measured total ligand concentrations in the Arabian Sea are higher. This suggests that in areas that receive high Fe inputs through upwelling and/or atmospheric deposition, marine organisms may produce 'excess' ligands to keep Fe soluble in seawater for extended intervals. },
keywords = {Arabian Sea, Atlantic, Atlantic Ocean, depth, marine, oxygen minimum, Upwelling},
pubstate = {published},
tppubtype = {article}
}
Lento,G.M.,Dalebout,M.L.,Baker,C.S.
Species and individual identification of whale and dolphin products for sale in Japan by mtDNA sequences and nuclear microsatellite profiles Technical Report
no. 399, 1998.
Abstract | BibTeX | Tags: Atlantic, baleen whale, baleen whales, beaked whales, developing, DNA, dolphin, dolphins, fin whale, Japan, Microsatellite, minke whale, mtDNA, North Atlantic, Oman, population, Porpoise, pygmy sperm whale, Southern Hemisphere, sperm whale, stocks, survey, whale, whales, whaling
@techreport{,
title = {Species and individual identification of whale and dolphin products for sale in Japan by mtDNA sequences and nuclear microsatellite profiles },
author = {Lento,G.M.,Dalebout,M.L.,Baker,C.S.},
year = {1998},
date = {1998-01-01},
volume = {SC/50/O8},
number = {399},
pages = {1-12},
abstract = {We report on species and individual identification of whale and dolphin products available on commercial markets of Japan in 1997/98 based on analysis of mitochondria) DNA (mtDNA) sequences and microsatellite variation. The total sample of 74 products included four species of baleen whales, the fin (n=4), sei (n=1), northern minke (n=15) and southern minke (n=39) whales. The remaining 15 samples included dolphins (n = 8; at least four species), Baird's beaked whales (n=5), a porpoise (n=1), and a pygmy sperm whale (n=1), all sold as "kujira" in Japan. It is noted that two new species, the sei whale, and the pygmy sperm whale, appeared for the first time in this series of market surveys. With the inclusion of the sei whale, a total of eight species of baleen whale have been found for sale in post-moratorium surveys of markets in Korea and Japan. Comparison of the sei whale mtDNA to reference sequences from the North Atlantic and Southern Hemisphere suggested that this product originated from the Southern Hemisphere. The last legal hunting of this population was in 1979-80. To investigate the stock origins of northern minke whale products sold in Japan, in 1997-98, the mtDNA haplotypes of these products were compared to those found previously in Korea, 1994-97 (Lento et al. 1998). This comparison revealed that four (33%) of the 12 haplotypes among the Japanese products were identical to those from Korea. This is not consistent with the hypothesis that northern minke whale products sold in Japan originate exclusively from the scientific hunting of a stock that is genetically distinct from the Korean coastal bycatch. Instead, these findings could suggest that whales from both stocks are being hunted illegally or that whale products are being smuggled between the two countries. To further investigate the possibility of smuggling and to estimate the total number of individual whales represented in commercial products, we are developing protocols for DNA profiling using microsatellite loci. Based on preliminary analysis of three loci, the four fin whale products, representing three mtDNA haplotypes, were shown to have originated from four individuals. The 15 northern minke whale products found in 1997-98, representing 12 mtDNA haplotypes, were shown to have originated from a minimum of 14 individuals. One of these products that shared a haplotype with a 1997 product, was also shown to be unique.},
keywords = {Atlantic, baleen whale, baleen whales, beaked whales, developing, DNA, dolphin, dolphins, fin whale, Japan, Microsatellite, minke whale, mtDNA, North Atlantic, Oman, population, Porpoise, pygmy sperm whale, Southern Hemisphere, sperm whale, stocks, survey, whale, whales, whaling},
pubstate = {published},
tppubtype = {techreport}
}
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}
}