Three‐dimensional passive acoustic tracking of sperm whale behavior with widely separated vertical arrays in the Gulf of Alaska

This paper presents the development of a three dimensional model of the Gulf of Alaska. The model extends between the Vancouver Island and the Aleutian Islands covering approximatedly 1.5 million square kilometers over the northern Pacific Ocean. Formulated on an ellipsoidal horizontal grid and variable vertical grid, the model is schematized over a 81 x 53 x 10 grid structure. The solution scheme is implicit over the vertical and is programmed using one-dimensional dynamic array for the efficient use of machine storage. The turbulence closure scheme for the non-homogeneous vertical shear is formulated so that the potential and kinetic energetics are monitored and transferred in a closed form. The hydrodynamic model is coupled to a two-dimensional stochastic weather model and an oil-spill trajectory/weathering model. The former also simulates stochastically the cyclogenetic/cyclolytic processes within the modeled area. The paper also compares the computed results with the available field data. Good agreements are found in tidal amplitude and phases as well as currents.

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The crystal structure of myoglobin. VI. Seal myoglobin

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1960.0181 ◽

1960 ◽

Vol 258 (1293) ◽

pp. 181-201 ◽

Cited By ~ 16

Keyword(s):

Tertiary Structure ◽

Heavy Atom ◽

Three Dimensional ◽

Sperm Whale ◽

Fourier Synthesis ◽

Heavy Atoms ◽

Isomorphous Replacement ◽

Unit Cells ◽

The Common ◽

Sperm Whale Myoglobin

Myoglobin from the common seal ( Phoca vitulina ) when crystallized from ammonium sulphate forms monoclinic crystals with space group the unit cell, a = 57·9Å, b = 29·6Å, c = 106·4Å, β = 102°15', contains four molecules. The method of isomorphous replacement has been used in an investigation of the centrosymmetric b -axis projection in which it has been possible to determine signs for nearly all the h0l reflexions having spacings greater than 4Å. Three independent heavy-atom derivatives were employed and the signs so determined have been used to compute a map of the electron density projected on the (010) plane. This projection has been interpreted in terms of the molecule of sperm-whale myoglobin, as deduced by Bodo, Dintzis, Kendrew & Wyckoff (1959) from a three-dimensional Fourier synthesis to 6Å resolution. The results of the interpretation show that the two myoglobin molecules are very similar in form (tertiary structure) in spite of the differences in their amino-acid composition. The relative orientation of the two unit cells with respect to the myoglobin molecule is given and a comparison is made of the positions of the heavy atoms in each molecule.

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Acoustic tracking of sperm whales in the Gulf of Alaska using a two-element vertical array and tags

The Journal of the Acoustical Society of America ◽

10.1121/1.4816565 ◽

2013 ◽

Vol 134 (3) ◽

pp. 2446-2461 ◽

Cited By ~ 19

Author(s):

Delphine Mathias ◽

Aaron M. Thode ◽

Jan Straley ◽

Russel D. Andrews

Keyword(s):

Gulf Of Alaska ◽

Sperm Whales ◽

Vertical Array ◽

Acoustic Tracking

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Foraging dives of sperm whales in the north-western Mediterranean Sea

Journal of the Marine Biological Association of the United Kingdom ◽

10.1017/s0025315412001087 ◽

2012 ◽

Vol 92 (8) ◽

pp. 1799-1808 ◽

Cited By ~ 5

Author(s):

Alexandre Gannier ◽

Estelle Petiau ◽

Violaine Dulau ◽

Luke Rendell

Keyword(s):

Prey Capture ◽

Sperm Whale ◽

Western Mediterranean ◽

Sperm Whales ◽

The North ◽

Western Mediterranean Sea ◽

Single Animal ◽

Components Analysis ◽

Passive Acoustic ◽

North Western

Oceanic odontocetes rely on echolocation to forage on pelagic or benthic prey, but their feeding ecology is difficult to study. We studied sperm whale foraging dives during summer in the north-western Mediterranean, using visual and passive acoustic observations. Clicking and creaking activities were recorded during dives of focal whales, at distances <3000 m using a towed hydrophone and DAT recorder. A total of 52 sperm whales were recorded over at least one full dive cycle. Data were obtained for 156 complete dives in total, including sequences of up to nine consecutive dives. Various dive and environmental variables were entered in multiple linear regression and principal components analysis, as well as estimated mass of whales. Creak rate was 0.80 creak/minute on average, with moderate variance. Bigger whales tended to dive longer at greater depths (as suggested by ascent durations), and emitted more creaks during a dive: 20.2 creaks/dive on average for individuals <24 tons, compared to 25.6 creaks/dive for animals >24 tons of estimated mass. For individual whales, creak rates did not vary significantly with size (range 0.78–0.80 creak/minute), but decreased with time of the day, and increased for shorter foraging phases. For different dives, higher creak rates were also observed earlier in the day, and linked to shorter foraging phases and surface durations. Although the exact significance of creak emissions (i.e. foraging attempt or prey capture) is not precisely determined, creak rates may be reliably used to quantify sperm whale foraging when single animal dives can be followed acoustically.

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