Relative abundance and behavior of marine mammals exposed to transmissions from the Heard Island Feasibility Test

A summary of participation of the New Zealand group in the ATOC (Acoustic Thermometry of Ocean Climate) program over a five year period is presented. Transmissions from Heard Island were observed in the Tasman Sea during the Heard Island Feasibility Test in 1991. The California-New Zealand underwater sound path was verified with explosive sources in 1992. Single hydrophone observations were made of transmissions to New Zealand from California from an electrically driven source first suspended beneath a floating platform in 1994 and later placed on the ocean bottom at Pioneer Seamount in 1995. Results from these experiments show that acoustic propagation to ranges of order 10 Mm appears to be characterised by large fluctuations occurring with a time scale of a few minutes.

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Occurrence, habitat use, and behavior of seabirds, marine mammals, and arctic cod at the Pond Inlet [Northwest Territories] ice edge

Deep Sea Research Part B Oceanographic Literature Review ◽

10.1016/0198-0254(82)90265-5 ◽

1982 ◽

Vol 29 (12) ◽

pp. 786

Keyword(s):

Habitat Use ◽

Northwest Territories ◽

Marine Mammals ◽

Arctic Cod ◽

Ice Edge ◽

And Behavior

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Heard Island Feasibility Test: Long‐range sound transmission from Heard Island to Krylov underwater mountain

The Journal of the Acoustical Society of America ◽

10.1121/1.410118 ◽

1994 ◽

Vol 96 (4) ◽

pp. 2458-2463 ◽

Cited By ~ 1

Author(s):

S. V. Burenkov ◽

A. N. Gavrilov ◽

A. Y. Uporin ◽

A. V. Furduev

Keyword(s):

Long Range ◽

Sound Transmission ◽

Heard Island ◽

Feasibility Test

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Summary of temporal trends in pollutant levels observed in marine mammals

J. Cetacean Res. Manage. ◽

10.47536/jcrm.v1i1.265 ◽

1999 ◽

pp. 149-155 ◽

Cited By ~ 1

Author(s):

Assumpción Borrel ◽

Petter J.H. Reijnders

Keyword(s):

Relative Abundance ◽

Time Trends ◽

Marine Mammals ◽

Temporal Trends ◽

Canadian Arctic ◽

The Future ◽

Available Information

The present paper reviews reported time trends in concentrations and relative abundance of pollutants in marine mammals. Available information refers only to pinnipeds and cetaceans, mainly covers the period 1969-1988 and focuses on DDTs, PCBs and mercury. Although data are limited, there are indications that in the Canadian Arctic, mercury levels in marine mammals have increased in recent decades. By contrast, during the late 1970s and the 1980s, concentrations of DDTs and PCBs in marine mammals from highly polluted areas have tended to decrease. While this trend is likely lo continue for DDTs in the future, it is foreseen that until at least the first decades of the next century, PCB levels will stabilise as degradation is compensated by new inputs caused by the recycling of the fraction currently present in non-marine compartments.

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The diving physiology of bottlenose dolphins (Tursiops truncatus). II. Biomechanics and changes in buoyancy at depth

Journal of Experimental Biology ◽

10.1242/jeb.202.20.2749 ◽

1999 ◽

Vol 202 (20) ◽

pp. 2749-2761 ◽

Cited By ~ 16

Author(s):

R.C. Skrovan ◽

T.M. Williams ◽

P.S. Berry ◽

P.W. Moore ◽

R.W. Davis

Keyword(s):

Tursiops Truncatus ◽

Marine Mammals ◽

Bottlenose Dolphins ◽

Neutral Buoyancy ◽

Swimming Mode ◽

Locomotor Patterns ◽

The Cost ◽

Physical Changes ◽

And Behavior ◽

Limited Oxygen

During diving, marine mammals must balance the conservation of limited oxygen reserves with the metabolic costs of swimming exercise. As a result, energetically efficient modes of locomotion provide an advantage during periods of submergence and will presumably increase in importance as the animals perform progressively longer dives. To determine the effect of a limited oxygen supply on locomotor performance, we compared the kinematics and behavior of swimming and diving bottlenose dolphins. Adult bottlenose dolphins (Tursiops truncatus) were trained to swim horizontally near the water surface or submerged at 5 m and to dive to depths ranging from 12 to 112 m. Swimming kinematics (preferred swimming mode, stroke frequency and duration of glides) were monitored using submersible video cameras (Sony Hi-8) held by SCUBA divers or attached to a pack on the dorsal fin of the animal. Drag and buoyant forces were calculated from patterns of deceleration for horizontally swimming and vertically diving animals. The results showed that dolphins used a variety of swimming gaits that correlated with acceleration. The percentage of time spent gliding during the descent phase of dives increased with depth. Glide distances ranged from 7.1+/−1.9 m for 16 m dives to 43.6+/−7.0 m (means +/− s.e.m.) for 100 m dives. These gliding patterns were attributed to changes in buoyancy associated with lung compression at depth. By incorporating prolonged glide periods, the bottlenose dolphin realized a theoretical 10–21 % energetic savings in the cost of a 100 m dive in comparison with dives based on neutral buoyancy models. Thus, modifying locomotor patterns to account for physical changes with depth appears to be one mechanism that enables diving mammals with limited oxygen stores to extend the duration of a dive.

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