Abstracts: Bottlenose whales - MPA planning & Acoustics (fwd)

From: Pita Admininstrator (pita@whale.wheelock.edu)
Date: Fri Mar 29 2002 - 12:24:06 EST

Recent publications.

Hooker, SK; Whitehead, H; Gowans, S (2002) Ecosystem
consideration in conservation planning: energy demand of foraging
bottlenose whales (Hyperoodon ampullatus) in a marine protected
area. Biological Conservation 104: 51-58.

The Gully, a submarine canyon off eastern Canada, was nominated as
a pilot Marine Protected Area (MPA) in 1998, largely to safeguard the
vulnerable population of northern bottlenose whales (Hyperoodon
ampullatus) found there. The boundaries and ultimate management
regime for the MPA for this area remain under review. We have
estimated the energy consumption of bottlenose whales in the Gully
based on the number of whales present at any time, their trophic level,
the food requirements of each whale, and the rates of energy transfer
between trophic levels. These calculations suggest that there must be
a substantial spatial subsidy in the underlying foodweb of the
submarine canyon to support the bottlenose whales using the Gully. A
substantial area beyond the distribution of bottlenose whales in the
area will therefore require protection. Conservation priorities to protect
such subsidies will primarily involve additional protection at the level of
the sea floor. Spatial subsidies are probably common in the marine
environment, urging careful ecological analysis in the establishment of
marine reserves and suggesting that conservation priorities need to
take into account key ecological linkages and processes that are vital
for sustaining species and habitats of concern.

Keywords: Ecosystem; Marine protected area; Northern bottlenose
whale; Spatial subsidy; Submarine canyon

Hooker, SK; Whitehead, H (2002) Click characteristics of northern
bottlenose whales (Hyperoodon ampullatus). Marine Mammal Science
18: 69-80.

Sounds produced by northern bottlenose whales (Hyperoodon
ampullatus) recorded in the Gully, a submarine canyon off Nova Scotia,
consisted predominately of clicks. In 428 minutes of recordings no
whistles were heard which could unequivocally be attributed to
bottlenose whales. There were two major types of click series, initially
distinguished by large differences in received amplitude. Loud clicks
(produced by nearby whales socializing at the surface) were rapid, with
short and variable inter-click intervals (mean 0.07s; CV 71%). The
frequency spectra of these were variable and often multimodal, with
peak frequencies ranging between 2 and 22 kHz (mean 11 kHz, CV
59%). Clicks received at low amplitude (produced by distant whales,
presumably foraging at depth) had more consistent inter-click intervals
(mean 0.40s, CV 12.5%), generally unimodal frequency spectra with a
mean peak frequency of 24 kHz CV 7%) and 3 dB bandwidth of 4 kHz.
Echolocation inter-click intervals may reflect the approximate search
distance of an animal, in this case 300 m, comparable to that found for
sperm whales. The relationship between click frequency and the size
of object being investigated, suggests that 24 kHz would be optimal for
an object of approximately 6 cm or more, consistent with the size
range of their squid prey.

Key Words: Acoustic behavior; Echolocation; Frequency spectra; Inter-
click interval; Northern bottlenose whale.

Reprints available from Sascha Hooker: s.hooker@st-andrews.ac.uk
(Please note new address and email)

Sascha K. Hooker, PhD
Sea Mammal Research Unit, University of St Andrews, St Andrews,
Fife, KY16 8LB, UK
Phone: 44-1334-467201
Fax: 44-1334-462630
Email: s.hooker@st-andrews.ac.uk

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