scholarly journals Minke whale abundance estimation from the NASS 1987 and 2001 aerial cue–counting surveys taking appropriate account of distance estimation errors

2009 ◽  
Vol 7 ◽  
pp. 95 ◽  
Author(s):  
David L Borchers ◽  
Daniel G Pike ◽  
Thorvaldur Gunnlaugsson ◽  
Gísli A Víkingsson
Keyword(s):  
Measurement Error ◽  
North Atlantic ◽  
Measurement Errors ◽  
Distance Estimation ◽  
Minke Whale ◽  
Balaenoptera Acutorostrata ◽  
Estimation Errors ◽  
Random Measurement Error ◽  
Minke Whales ◽  
Coastal Shelf

We estimate the abundance of minke whales (Balaenoptera acutorostrata) from the Icelandic coastal shelf aerial surveys carried out as part of the 1987 and 2001 North Atlantic Sightings Surveys (NASS). In the case of the 1987 survey, the probability of detecting animals at distance zero (g(0)) is very close to 1 but there is substantial random measurement error in estimating distances. To estimate abundance from these data, we use methods which assume g(0)=1 but which includea distance measurement error model. In the case of the 2001 survey, measurement errors were sufficiently small to be negligible, and we use double platform methods which estimate g(0) and assume no measurement error to estimate abundance. From the 1987 survey, we estimate abundance to be 24,532 animals, with 95% CI (13,399; 44,916). From the 2001 NASS survey data, minke whale abundance is estimated to be 43,633 animals, with 95% CI (30,148; 63,149).

scholarly journals Changes in blood testosterone and progesterone concentrations of the North Atlantic minke whale (Balaenoptera acutorostrata) during the feeding season

2004 ◽  
Vol 61 (2) ◽  
pp. 230-237 ◽  
Author(s):  
Matthías Kjeld ◽  
Árni Alfredsson ◽  
Örn Ólafsson ◽  
Morten Tryland ◽  
Ivar Christensen ◽  
...  
Keyword(s):  
Frequency Distribution ◽  
North Atlantic ◽  
Minke Whale ◽  
Balaenoptera Acutorostrata ◽  
Hunting Season ◽  
P Values ◽  
The North ◽  
Minke Whales ◽  
The North Atlantic ◽  
Cyclic Changes

An opportunity to study seasonal changes of sex hormones in the North Atlantic minke whale (common minke whale, Balaenoptera acutorostrata) arose when we obtained access to fresh postmortem blood samples from 104 females and 83 males. The whales were caught in the North Atlantic during May–September 1992–1995. Serum progesterone (P) and testosterone (T) concentrations were measured and compared with anatomical data. The frequency distribution of female serum P values showed two clusters, one consisting mainly of immature animals and the second of pregnant ones, with mean serum values of about 0.49 ± 0.04 (SE) and 44.2 ± 2.84 nmol·L–1, respectively. The frequency distribution of male serum T did not show any group-specific distribution during the hunting season. The mean serum T value for the males was 0.63 ± 0.13 nmol·L–1. Contrary to earlier reports on the Antarctic minke whale (Balaenoptera bonaerensis), serum T values rose during the hunting season in mature males (p < 0.0001). Serum P values in immature females increased during the season (p = 0.015). This increase agrees with the predominantly annual reproduction cycle of minke whales. Blood sex hormone measurements seem to be useful for detecting cyclic changes and pregnancy of minke whales.

scholarly journals A Multi-elemental Approach to Identification of Subpopulations of North Atlantic Minke Whales Balaenoptera Acutorostrata

2007 ◽  
Vol 13 (1) ◽  
pp. 84-97 ◽  
Author(s):  
Erik W. Born ◽  
Michael C. S. Kingsley ◽  
Frank F. Rigét ◽  
Rune Dietz ◽  
Per Møller ◽  
...  
Keyword(s):  
North Atlantic ◽  
Balaenoptera Acutorostrata ◽  
Minke Whales

scholarly journals Distance estimation experiment for aerial minke whale surveys

2009 ◽  
Vol 7 ◽  
pp. 111 ◽  
Author(s):  
Lars Witting ◽  
Daniel G Pike
Keyword(s):  
Linear Regression ◽  
Distance Estimation ◽  
Minke Whale ◽  
Estimation Bias ◽  
Positive Bias ◽  
Absolute Abundance ◽  
Minke Whales ◽  
Log Normal ◽  
Log Normal Distribution ◽  
Good Agreement

A comparative study between aerial cue–counting and digital photography surveys for minke whales conducted in Faxaflói Bay in September 2003 is used to check the perpendicular distances estimated by the cue-counting observers. The study involved 2 aircraft with the photo plane at 1,700 feet flying above the cue–counting plane at 750 feet. The observer–based distance estimates were calculated from head angles estimated by angle-boards and declination angles estimated by declinometers. These distances were checked against image–based estimates of the perpendicular distance to the same whale. The 2 independent distance estimates were obtained for 21 sightings of minke whale, and there was a good agreement between the 2 types of estimates. The relative absolute deviations between the 2 estimates were on average 23% (se: 6%), with the errors in the observer–based distance estimates resembling that of a log-normal distribution. The linear regression of the observer–based estimates (obs) on the image–based estimates (img) was Obs=1.1Img (R2=0.85) with an intercept fixed at zero. There was no evidence of a distance estimation bias that could generate a positive bias in the absolute abundance estimated by cue–counting.

scholarly journals Direct and indirect effects of minke whale abundance on cod and herring fisheries: A scenario experiment for the Greater Barents Sea

2000 ◽  
Vol 2 ◽  
pp. 120 ◽  
Author(s):  
Tore Schweder ◽  
Gro S Hagen ◽  
Einar Hatlebakk
Keyword(s):  
Gadus Morhua ◽  
Barents Sea ◽  
Minke Whale ◽  
Clupea Harengus ◽  
Prey Abundance ◽  
Balaenoptera Acutorostrata ◽  
Time Step ◽  
Minke Whales ◽  
Spawning Stock ◽  
Capelin Mallotus Villosus

To study the pattern of interaction between minke whale (Balaenoptera acutorostrata) abundance and the main fisheries in the Greater Barents Sea, a simulation experiment was carried out. The population model involves 4 species interconnected in a food web: cod (Gadus morhua), capelin (Mallotus villosus), herring (Clupea harengus) and minke whales. Minke whales are preying on cod, capelin andherring; cod are preying on (young) cod, capelin and herring; herring in the Barents Sea are preying on capelin; while capelin is a bottom prey in the model. The consumption function for minke whales is non-linear in available prey abundance, and is estimated from stomach content data and prey abundance data. The model is dynamic, with a time step of one month, and there are two areas: the BarentsSea and the Norwegian Sea. Minke whale abundances are kept on fixed levels, while recruitment in fish is stochastic.Cod and herring fisheries are managed by quotas targeting fixed fishing mortalities, while capelin is managed with a view to allow the cod to have enough food and leaving a sufficient spawning stock of capelin. The model is simulated over a period of 100 years for a number of fixed levels of minke whaleabundance, and simulated catches of cod, herring and capelin are recorded.The experiment showed interactions between whale abundance and fish catches to be mainly linear. For cod catches, both the direct effect of whales consuming cod, and the indirect effect due to whales competing with cod for food and otherwise altering the ecosystem, are linear and of equal importance. The net effect on the herring fishery is of the same magnitude as the net effect on the cod fishery, witheach extra whale reducing the catches of both species by some 5 tonnes. These conclusions are conditional on the model and its parameterisation.

Dwarf minke whales from the South Pacific share a matrilineal lineage distinct from Balaenoptera acutorostrata acutorostrata and B. a. scammoni

2019 ◽  
Vol 41 (2) ◽  
pp. 231
Author(s):  
Omar Ramirez-Flores ◽  
Alastair Birtles ◽  
Diana Pazmino ◽  
Kyall R. Zenger ◽  
Lynne Van-Herwerden
Keyword(s):  
Sequence Data ◽  
South Pacific ◽  
Nuclear Data ◽  
Minke Whale ◽  
Balaenoptera Acutorostrata ◽  
Conservation Action ◽  
Dna Sequence Data ◽  
Minke Whales ◽  
Satellite Tagging ◽  
Relationship Of

Dwarf minke whales are regarded as an undescribed subspecies of common minke whales (Balaenoptera acutorostrata), but appropriate conservation action requires taxonomic confirmation. The relationship of the Australian Great Barrier Reef (GBR) dwarf minke whale aggregation to other minke whales is unknown. This study aims to clarify the phylogenetic relationship of GBR dwarf minke whales, using partial mitochondrial DNA sequence data from 23 GBR dwarf minke whales, compared with other available minke whale sequences. GBR dwarf minke whales share haplotypes with other West South Pacific (WSP) dwarf minke whales. Satellite tagging studies corroborate these findings, indicating that GBR dwarf minke whales migrate south along the east Australian coast towards the Southern Ocean. Despite nuclear data not being available, GBR and WSP dwarf minke whales share a distinctive mitochondrial lineage compared with other common minke whales and should be managed independently of North Pacific and Atlantic Ocean common minke whale populations.

Marking of Small Cetaceans Using "Discovery" Type Whale Marks

1975 ◽  
Vol 32 (7) ◽  
pp. 1237-1240 ◽  
Author(s):  
S. G. Brown
Keyword(s):  
Minke Whale ◽  
Orcinus Orca ◽  
Killer Whales ◽  
Balaenoptera Acutorostrata ◽  
Lagenorhynchus Obscurus ◽  
Minke Whales ◽  
Beaked Whales ◽  
Pilot Whales ◽  
Dusky Dolphin

All smaller cetaceans known to have been successfully marked with "Discovery" type marks are summarized. These include 67 minke whales (Balaenoptera acutorostrata), 33 killer whales (Orcinus orca), 30 pilot whales (Globicephala sp.), 7 bottlenose whales (Hyperoodon sp.), 5 other "beaked whales," and 1 dusky dolphin (Lagenorhynchus obscurus). Recoveries include 3 minke, 1 bottlenose, and 1 killer. Minke whale marks were recovered up to 4 yr 2 mo after marking.

A note on minke whales (Cetacea: Balaenopteridae) in Uruguay: strandings review

2020 ◽  
Vol 21 (1) ◽  
pp. 135-140
Author(s):  
Eduardo Juri ◽  
Meica Valdivia ◽  
Paulo Cesar Simoes-Lopes ◽  
Alfredo Le Bas
Keyword(s):  
Atlantic Ocean ◽  
Minke Whale ◽  
Balaenoptera Acutorostrata ◽  
Southwest Atlantic ◽  
Antarctic Minke Whale ◽  
Minke Whales ◽  
Important Region ◽  
The Common ◽  
The Antarctic ◽  
Common Minke Whale

The minke whale is the smallest of the living rorquals and is widely distributed in the tropical, temperate and polar waters of both hemispheres. In the western Southwest Atlantic Ocean there are two currently recognised species, the dwarf form of the common minke whale, Balaenoptera acutorostrata unnamed subsp. and the Antarctic minke whale B. bonaerensis. All stranding records and collected specimens of minke whale on the coast of Uruguay were reviewed and analysed. Between 1962 and 2018, 33 records were gathered in a non-systematic way, 22 specimens of B. acutorostrata and 11 of B. bonaerensis. It was found that most animals were discovered alive or recently dead and assigned as neonates/young calves. This supports the hypothesis that Uruguayan coasts are part of an important region for reproduction and breeding for the species.

scholarly journals Harbour porpoises (Phocoena phocoena) and minke whales (Balaenoptera acutorostrata) observed during land-based surveys in The Minch, north-west Scotland

2013 ◽  
Vol 94 (6) ◽  
pp. 1185-1194 ◽  
Author(s):  
Sarah J. Dolman ◽  
Nicola K. Hodgins ◽  
Colin D. MacLeod ◽  
Graham J. Pierce ◽  
Caroline R. Weir
Keyword(s):  
Minke Whale ◽  
Harbour Porpoise ◽  
Phocoena Phocoena ◽  
Balaenoptera Acutorostrata ◽  
Sea State ◽  
Marine Fauna ◽  
Monitoring Method ◽  
North West ◽  
Minke Whales ◽  
Cetorhinus Maximus

The waters off north-west Scotland are known to provide important habitat for the harbour porpoise (Phocoena phocoena) and the minke whale (Balaenoptera acutorostrata). Between October 2008 and April 2011, systematic land-based surveys were carried out to assess the seasonal occurrence, group size and group behaviours of both species in a study area located off Melvaig, near Gairloch. Data were collected on 47 separate days, with a total of 4543 minutes of survey effort (in sea states ≤3) recorded during the spring months and 8204 minutes of effort during the autumn. A total of 189 sightings of marine fauna were recorded, comprising 126 cetacean sightings, 50 seal sightings and 13 sightings of basking sharks (Cetorhinus maximus). Six species of cetacean were identified, with most sightings comprising harbour porpoise (N = 72) or minke whale (N = 38). Harbour porpoise abundance was higher in autumn than in spring and there was a variation between years in numbers of minke whales sighted. In porpoises, sea state and cloud cover both influenced sightings and increasing sea state influenced survey area. Foraging behaviour was exhibited in 13% of harbour porpoise sightings and 34% of minke whale sightings. Results demonstrate a regular occurrence of harbour porpoises and minke whales in nearshore waters off Gairloch. Densities are comparable to boat surveys in the region and so support the use of land-based watches as a potential longer-term monitoring method for these species in coastal waters. Given the regular use of this area by these two European Protected Species, as well as the occurrence of a range of human activities potentially affecting them in the region, it may be appropriate to consider protecting this area for their conservation.

Toxaphene in minke whales (Balaenoptera acutorostrata) from the North Atlantic

2008 ◽  
Vol 153 (1) ◽  
pp. 71-83 ◽  
Author(s):  
B. Gouteux ◽  
D.C.G. Muir ◽  
S. Backus ◽  
E.W. Born ◽  
R. Dietz ◽  
...  
Keyword(s):  
North Atlantic ◽  
Balaenoptera Acutorostrata ◽  
The North ◽  
Minke Whales ◽  
The North Atlantic
Sign in / Sign up

Export Citation Format

Share Document