Tagging
White sharks: Neale
March 2001 (last update July 2001)
Where's Neale's fin?
The tag attached to Neale the white shark has not transmitted
since 9 July and we have not had a position since 23 June. It
appears, at this stage, that contact has been lost. Although
disappointing for the research team, the project has been a
remarkable success and has provided a new insight into the movement
patterns of white sharks. The team now believe that the most
likely reasons for the loss of contact are that either the tag
has been damaged or the batteries are running down. The team
will keep monitoring the satellite network for signals but it
is becoming less likely that Neale will reappear as time goes
on.
For his fans, here are some of Neale's statistics for
the track:
-
Neale's tag transmitted 227 times on 71 different
days over over a 129 day period.
-
The highest number of transmissions in a 24 h period was
17 and this occurred on 9-10 May when Neale was off
north east Tasmania where seemed to be on the surface for
most of the day.
-
The total distance over which Neale was tracked
was 2,946km.
-
His journey took him from southeast Victoria, across Bass
Strait to Tasmania's east coast, before returning to the
Victorian coast and heading north, giving his last position
close to the Solitary Islands near Coffs Harbour.
-
The longest period between transmissions was seven days
and this occurred twice during the track.
-
Neale's swimming speed generally ranged between
1.2-3.3 km per hour and he was usually between 5 and15 km
from shore when he surfaced.
At this stage we will not be providing further updates on Neale's
web site.
Following Neale has become a popular exercise for people
world-wide and the research team would like to thank all those
who contacted them with comments and suggestions. The team hope
to continue improving the tag and track further white sharks
as part of their on-going research into white shark movement
patterns in Australian waters. |
About the project
Scientists at CSIRO Marine Research (CMR) are studying the movement
patterns of white sharks in southern Australian waters using a variety
of different tags and from the observations of both recreational and
commercial fishers.
The scientists hope to discover:
-
whether white sharks mix between different areas within Australia
and whether they leave Australian waters (for example do the white
sharks off South Australia move and mix with white sharks in NSW);
-
where they go in different seasons and whether that changes between
years;
-
what areas are important to them (such as feeding, breeding or
nursery grounds);
-
what pathways they follow; and
-
how long they stay in and how frequently they visit particular
places.
About Neale
Neale is a male white shark who is about 2.4 metres in length
and 150 kg in weight. He is estimated to be four to five years old.
Neale is still a juvenile and will not reach adulthood until
he is about 3.6 m long and about eight or nine years old. He may one
day grow to at least 5 m in length and 1250 kg (female white sharks
grow somewhat bigger and may reach up to six or seven metres and 2000—3000
kg). White sharks of Neale’s size feed primarily on fish,
small sharks and rays.
Why Neale?
Neale was named after Neale Blunden, the fisher who helped
CSIRO scientists catch and tag the shark in coastal waters off Corner
Inlet on the eastern side of Wilson's Promontory in Victoria. This is
also the area where the same research team put a satellite transmitter
on a small female white shark (nicknamed Heather) in March 2000.
Information on Heather.
How was Neale tagged?
Neale was captured and tagged with an ARGOS satellite transmitter
on 2 March, 2001. The process involved catching the shark on a baited
line and carefully bringing him on-board the fishing vessel Sea Pride.
Neale was placed on a foam mat on the deck while CMR scientists,
Barry Bruce and John Stevens, removed the hook and attached the satellite
tag. Neale was then returned to the water. The tagging operation
took about six minutes. The tag is attached to Neale's dorsal
fin (the large triangular fin on top of the body) and positioned so
that the aerial will protrude from the water when Neale comes
to the surface.
White sharks are fully protected in all Australian waters and tagging
Neale required a special permit from the Department of Natural
Resources and Environment (Victoria).
Video of shark tagging courtesy Discovery Channel
How does the tag work?
The tag consists of an ARGOS satellite transmitter, long life batteries,
aerial and a saltwater switch, all in a waterproof plastic pod. The
pod was designed and made by engineers at CMR. It is streamlined in
design and weighs very little in water. This is so it will not interfere
with Neale's fin when he swims.
The transmitter sends a unique identifying code via radio waves to
polar orbiting satellites that are fitted with ARGOS receivers. The
signal from the tag is then sent to a receiving station in France where
the tag's position on the earth's surface is calculated. CMR scientists
receive the positions and plot Neale's track. Radio waves do
not travel very well through seawater so the tag will only transmit
to the satellites when the aerial is out of the water. This is why the
scientists placed the tag on Neale's dorsal fin, and why there
is not a position for Neale every day.
On average, the tag transmits Neale's position every two to
three days. The accuracy of the position depends on how long the aerial
is out of the water. The best positions can place Neale to within
150 m of where ever he goes in the world. The saltwater switch on the
tag ensures that it does not transmit when underwater, thereby saving
battery power.
Follow Neale's progress
Bookmark this site to follow Neale's track (below). Neale's
track will be updated every week. The scientists hope that the tag will
continue to transmit Neale's position for up to a year. The tag
is, however, a delicate piece of equipment and can be damaged. When
that happens it usually stops working. This is what the scientists believed
happened to Heather's tag about seven weeks after she was released
last year. Both Neale and Heather's tags will eventually
fall off, so they will not carry them forever.
At this stage, we can not provide further
updates on Neale's progress.
Neale's last position still hasn't
changed but..... see below for details.
2 March - 31 May |
21 June - 23 June |
|
NEALE'S PROGRESS
Period between tagging and last fix: 113 days
Distance travelled: 2946 km
Neale's average speed when travelling: 1.2 km/h
Neale - stop teasing!The last day for which
we have a position for Neale is still 23 June
2001. Once again we have heard from him this week (on
Monday 9 July at 9:14pm), but there was no position.So
what do we think? We are still hoping that Neale is
spending less time at the surface, now that he is in
the northern NSW - southern Queensland area, and that
he will give a position soon. It is also possible that
the tag has developed a problem - but let's hope not!Given
his last position and assuming that he was still heading
north at his last average swimming speed, then he should
be somewhere between Coffs Harbour and Fraser Island.
Small white sharks are known to occur in this area
from July to December. |
|
Acknowledgments and other website links
