Understanding
long-term movements of pelagic sharks is important for proper
management of their populations, but has been a difficult task
to achieve in the past. We
are taking advantage of new technology and to date have tagged
five mako sharks (Isurus oxyrinchus) with “pop-up”
satellite archival tags. These tags have computer controlled
sensors programmed to sample and store depth, temperature and
geographical location data every hour. The tags are
programmed to detach from the shark after a predetermined length
of time and “pop-up” to the surface.
The tags float at the surface and transmit stored
information to the
Argos
data collection system aboard orbiting NOAA weather satellites.
The
information is then provided to the research team for analysis.
This technology gives intimate details of the life of the tagged
shark while it goes about its every day business, undisturbed
within its natural environment. Two sharks were tagged off
Martha’s Vineyard
and had moved south when the transmitters popped up and began
transmitting data. Another
shark tagged off
Block Island
had moved south of
Martha’s Vineyard
at the time the transmitter popped up.
A fourth shark tagged off
Martha’s Vineyard
had moved at least 500 miles to the east at the time the
transmitter popped up a month later (see map to the right).
These data represent the first long-term and detailed
record of the movements of mako sharks in the
Atlantic
. More transmitters
will be deployed on mako sharks during the future.
For further details or for information on participating
in this project contact Dr. Wetherbee at wetherbee@uri.edu.
