Aa o
Ca lisle
g asps
a
white
sha k
alo gside
a
boat
off
the
coast
of
Delawa e
(Reute s
photo)
Scie tists
i
the
US
a e
testi g
a
u usual
way
to
collect
ocea
data
that
could
eve tually
help
imp ove
hu ica e
fo ecasts,
by
usi g
sha ks
as
mobile
ocea
se so s.Resea che s
f om
the
U ive sity
of
Delawa e
a e
attachi g
small
elect o ic
tags
to
sha ks
swimmi g
off
the
US
East
Coast.
The
tags
eco d
i fo matio
such
as
wate
tempe atu e,
sali ity
a d
depth
as
the
a imals
move
th ough
the
ocea .The
aim
is
to
use
sha ks
to
collect
measu eme ts
f om
pa ts
of
the
Atla tic
that
ca
be
difficult
a d
expe sive
to
mo ito
egula ly.
Scie tists
hope
these
obse vatio s
will
add
to
existi g
ocea
data
a d
help
imp ove
u de sta di g
of
how
hu ica es
develop
a d
st e gthe .The
esea ch
is
led
by
Aa o
Ca lisle,
a
ma i e
scie tist
at
the
U ive sity
of
Delawa e.
CTD
tags
o
Sha ks
The
tags
used
i
the
esea ch
a e
called
CTD
tags.
These
small
elect o ic
devices
measu e
elect ical
co ductivity,
which
is
closely
li ked
to
the
amou t
of
salt
i
seawate ,
alo g
with
tempe atu e
a d
depth.As
sha ks
swim
a d
dive,
the
tags
eco d
these
measu eme ts.
Whe
a
tagged
sha k
comes
close
e ough
to
the
su face,
the
device
ca
commu icate
with
satellites
a d
se d
the
i fo matio
to
a
o biti g
etwo k
of
satellite
eceive s.
“A imal-bo e
se so s
have
bee
used
successfully
by
ocea og aphe s
fo
yea s,
pa ticula ly
o
elepha t
seals
i
pola
egio s
whe e
scie tific
obse vatio s
a e
sca ce,”
Ca lisle
said,
as
quoted
by
Reute s.Acco di g
to
him,
Sha ks
offe
a othe
optio
because
they
a e
fou d
widely
ac oss
the
ocea
a d
a e
easie
to
access
tha
some
p otected
ma i e
mammals.
U til
ow,
sha k
taggi g
has
mai ly
bee
used
to
t ack
whe e
the
a imals
t avel
a d
the
habitats
they
use.The
U ive sity
of
Delawa e
team
is
selecti g
sha k
species
that
ca
collect
data
useful
fo
hu ica e
esea ch
a d
that
su face
ofte
e ough
fo
thei
tags
to
t a smit
i fo matio .
Ea lie
a alyses
ide tified
sho tfi
mako
sha ks,
blue
sha ks,
smooth
hamme heads
a d
juve ile
g eat
white
sha ks
as
st o g
ca didates
fo
the
wo k
i
the
No th
Atla tic.
A
mako
sha k
caught
by
esea che s
off
the
coast
of
Lo g
Isla d,
New
Yo k
(Reute s
photo)
How
sha ks
a e
tagged
The
taggi g
wo k
begi s
i
ea ly
May,
whe
highly
mig ato y
sha k
species
move
close
to
the
coast
f om
thei
wi te
habitats
fa the
out
i
the
Atla tic,
acco di g
to
Ca oli e
Wie icki,
a
U ive sity
of
Delawa e
docto al
ca didate
i
ma i e
scie ce.Resea che s
t avel
about
30
to
40
miles,
o
50
to
65
km,
offsho e
o
a
esea ch
vessel.
They
the
put
out
baited
li es
a d
usually
wait
fo
two
to
th ee
hou s
fo
a
sha k
to
take
the
bait.O ce
a
sha k
is
caught,
the
taggi g
p ocess
is
ca ied
out
quickly.
“The
tags
a e
attached
to
the
do sal
fi .
The
eve y
time
the
sha k
fi s
(swims)
at
the
su face,
the
tag
ca
commu icate
a d
t a smit
data
to
the
o biti g
etwo k
of
satellite
eceive s,”
Ca lisle
said.
Acco di g
to
him,
the
p ocess
wo ks
“like
a
pit
c ew”
du i g
a
auto
ace
a d
usually
takes
less
tha
five
mi utes.The
esea che s
ca y
out
the
wo k
u de
i stitutio al
a imal
ca e
ove sight
to
educe
the
impact
o
the
sha ks.
The
tags
a e
attached
usi g
mate ials
desig ed
to
co ode
a d
eve tually
fall
off.Each
sha k
also
eceives
a
health
check
befo e
it
is
eleased.
Ca lisle
said
this
is
impo ta t
because
a
st essed
o
ha med
sha k
may
ot
behave
atu ally,
which
could
affect
the
quality
of
the
data
collected.
Ocea
tempe atu e
a d
hu ica es
The
esea ch
is
based
o
the
li k
betwee
the
heat
sto ed
i
the
uppe
ocea
a d
hu ica e
st e gth.
Wa m
wate
i
the
mixed
laye
p ovides
heat
that
ca
feed
a
hu ica e
as
it
moves
ove
the
ocea .”We
a e
eally
most
i te ested
i
the
heat
co te t
of
the
top
laye
of
the
ocea ,
which
is
k ow
as
the
mixed
laye ,”
Ca lisle
said.”This
is
the
pa t
of
the
wate
colum
that
eally
d ives
hu ica e
i te sity-
wa me
mixed
laye
equals
st o ge
hu ica e,
as
it
holds
the
heat
that
feeds
hu ica es,”
he
added.The
U ive sity
of
Delawa e
said
its
sha k
taggi g
wo k
is
also
helpi g
esea che s
gathe
tempe atu e
a d
sali ity
measu eme ts
f om
pa ts
of
the
Atla tic
that
a e
difficult
a d
costly
to
mo ito
co siste tly.The
data
could
help
scie tists
study
the
Mid-Atla tic’s
seaso al
‘cold
pool’,
a
laye
of
colde
wate
ea
the
bottom
of
the
ocea .
The
cold
pool
ca
i flue ce
how
quickly
hu ica es
i te sify.
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