Externally and
internally implanted sonic transmitters were used to track the
movements of eight tiger sharks (Galeocerdo cuvier)
ranging between 200 and 417 cm total length (TL), captured by
hook-and-line on the south coast of Oahu, Hawaii, between 1993
and 1997. Attachment of the transmitters was facilitated by the
fact that captured sharks exhibited tonic immobility when
restrained and inverted at the side of the tagging vessel. Three
common themes emerged from the horizontal movements of the
tracked sharks: (1) offshore movements away from the island, (2)
extended periods of directed, ``straight-line'' swimming, (3)
orientation to the Penguin Banks - a shallow bank located 35 km
from the release point. In shallow water (<300 m) the sharks
swam predominantly close to the bottom, in open water (>300
m) they swam within the mixed layer at depths of 80 m. One shark
dove briefly to 335 m. The average estimated swimming speed of
sharks traversing open water was 0.29 body length (BL) s-1.
Two sharks were recaptured after termination of the tracks; one
of these sharks was recaptured twice, with a total time at
liberty of 377 d. These data suggest that tiger sharks in
Hawaiian waters move within large home ranges and that they can
efficiently navigate between distant parts of their range, even
when this requires crossing open ocean waters.
For
p
df versions of publications resulting from this study click on
the manuscript below.
Holland,
K.N., B.M. Wetherbee, C.G. Lowe and C. Meyer. 1999. Movements of
tiger sharks along shorelines of
Oahu
,
Hawaii
. Mar. Biol. 134:665-673.
Holland,
K.N., A. Bush, S.M. Kajiura, C.G. Meyer, B.M. Wetherbee and C.G.
Lowe. 2001. Five tags applied to a single species in a single
location: The tiger shark experience. p. 230-245 In: Reviews:
Methods and Technologies in Fish Biology and Fisheries.
Vol. 1. J. Sibert and J. Nielson, eds., Kluwer Academic Press,
Dordrecht
, the
Netherlands
.