a
Add
ing
a N
ew D
imen
sion
to th
e S
tudy
of C
alca
reou
s P
lank
ton
Res
pons
e to
Oce
an A
cidi
ficat
ion
Ros
ie L
. Oak
es1 ,
Jeffr
ey M
. Urb
ansk
i2 , an
d Ti
mot
hy J
. Bra
low
er1
1 Dep
artm
ent o
f Geo
scie
nces
, The
Pen
nsyl
vann
ia S
tate
Uni
vers
ity, U
nive
rsity
Par
k, P
A, U
SA
2 GE
Mea
sure
men
t & C
ontro
l, Le
wis
tow
n, P
A, U
SA
PP
11A
- 132
3
• A
nthr
opog
enic
act
iviti
es a
re in
crea
sing
at
mos
pher
ic c
arbo
n di
oxid
e le
vels
at
unpr
eced
ente
d ra
tes
• It
is th
ough
t tha
t, si
nce
1800
, ~30
% o
f th
is c
arbo
n di
oxid
e ha
s be
en a
bsor
bed
into
the
ocea
ns (
Sabi
ne e
t al.,
200
4)•
The
dis
solu
tion
of c
arbo
n di
oxid
e in
to
the
ocea
n af
fect
s oc
ean
chem
istr
y by
de
crea
sing
the
conc
entr
atio
n of
car
bona
te
ions
and
dec
reas
ing
the
pH•
Pter
opod
s ar
e ho
lopl
akto
nic
gast
ropo
d m
ollu
scs
whi
ch li
ve in
the
surf
ace
ocea
ns
and
form
thei
r sh
ells
out
of
arag
onite
, the
m
ore
solu
ble
form
of
calc
ium
car
bona
te.
• B
ecau
se p
tero
pods
for
m a
rago
nite
sh
ells
, the
y w
ill b
e am
ong
the
firs
t or
gani
sms
to b
e im
pact
ed b
y oc
ean
acid
ific
atio
n.•
Cul
ture
and
incu
batio
n ex
peri
men
ts
have
sho
wn
that
ele
vate
d ca
rbon
dio
xide
le
vels
and
dec
reas
ed c
arbo
nate
ion
conc
entr
atio
ns (
or s
atur
atio
n) a
re
detr
imen
tal t
o pt
erop
od c
alci
fica
tion
(Com
eau
et a
l., 2
009,
201
0, B
edna
ršek
et
al.,
2012
a, 2
012b
). T
here
are
eve
n so
me
pter
opod
s in
the
mod
ern
ocea
n fe
elin
g th
e ef
fect
s of
thes
e ch
angi
ng c
ondi
tions
(B
erna
ršek
et a
l., 2
014)
.
The
Que
stio
n30
00
2500
2000
1500
1000
500
0
60O
40O
20O
0O 20O
40O
60O
30OE
60OE
90OE
120O
E15
0OE
180O
150O
W12
0OW
90OW
60OW
30OW
0O
JR27
1
Caria
co
JR27
4
• W
e ar
e in
tere
sted
in h
ow p
lank
ton
reac
ted
to p
ast c
hang
e an
d th
eref
ore
be a
ble
to p
redi
ct h
ow th
ey m
ay
resp
ond
to f
utur
e ch
ange
. In
orde
r to
do
this
, we
firs
t nee
d to
und
erst
and
wha
t the
ir c
ondi
tion
is in
the
mod
ern
ocea
n.H
ow d
oes
the
shel
l thi
ckne
ss a
nd s
hell
volu
me
of p
tero
pods
var
y w
ith
vary
ing
ocea
n ch
emis
try
in t
he
mod
ern
ocea
n?•
Thu
s fa
r th
e co
nditi
ons
of m
oder
n pt
erop
ods
and
cultu
red
pter
opod
s ha
ve b
een
asse
ssed
usi
ng li
ght
mic
rosc
opy
and
SEM
imag
ery
(e.g
. Ger
hard
t and
Hen
rich
, 200
1, B
edna
ršek
et a
l., 2
012a
, 201
2b, 2
014)
. •
Futu
re c
hang
es in
pte
ropo
d sh
ell m
orph
olog
y ar
e lik
ely
to b
e sm
all a
nd n
on-l
etha
l (B
edna
ršek
et a
l., 2
012b
).
• A
dvan
ces
in c
ompu
ter
tom
ogra
phy
mea
n th
at it
is n
ow p
ossi
ble
to im
age
thes
e sh
ells
in 3
D a
t mic
ron
scal
e re
solu
tion,
add
ing
a ne
w d
imen
sion
to th
e st
udy
of m
oder
n pt
erop
ods.
•
We
are
wor
king
tow
ards
mak
ing
a hi
gh r
esol
utio
n, m
oder
n da
y ba
selin
e da
tase
t to
whi
ch f
utur
e ch
ange
s ca
n be
com
pare
d.
Intr
oduc
tion
Met
hods
• Pt
erop
ods
wer
e st
udie
d fr
om th
ree
loca
tions
: the
Arc
tic O
cean
(JR
271)
(L
eaky
et a
l., 2
012)
, the
Car
iaco
Bas
in
(Thu
nell
lab)
, and
the
Sout
hern
Oce
an
(JR
274)
(Ta
rlin
g et
al.,
201
3).
• In
divi
dual
pte
ropo
ds w
ere
wei
ghed
on
a M
ettle
r To
ledo
mic
roba
lanc
e (a
ccur
ate
to +
/- 0
.1μ
g) a
nd im
aged
in
two
dim
ensi
ons
on a
Zei
ss S
tem
i 20
00-C
ligh
t mic
rosc
ope
usin
g a
Can
on
Pow
ersh
ot G
9.•
Indi
vidu
al s
peci
men
s w
ere
then
m
ount
ed o
nto
carb
on ta
pe a
nd s
cann
ed
usin
g a
phoe
nix
v|to
me|
x m
at G
E
Mea
sure
men
t & C
ontr
ol in
Lew
isto
wn,
PA
(Fi
gure
2d,
e).
• E
ach
scan
take
s ~1
hou
r an
d th
e da
ta
is ~
2 G
B. T
he v
oxel
siz
e is
1 –
2 μ
m
depe
ndin
g on
the
size
of
the
pter
opod
. •
Dat
a w
as r
econ
stru
cted
usi
ng G
E
Dat
os a
nd V
G S
tudi
o M
ax 2
.2 s
oftw
are.
Fig
ure
1: S
ampl
e lo
catio
ns f
or th
is s
tudy
ove
rlai
n on
a m
ap a
rago
nite
com
pens
atio
n de
pth
adap
ted
from
F
eele
y et
al,
(200
4)
Res
ults
• A
tota
l of 5
1 pt
erop
ods w
ere
scan
ned
from
thre
e lo
catio
ns.
• Th
ere
is n
o tre
nd b
etw
een
the
norm
alis
ed sh
ell v
olum
e an
d om
ega
arag
onite
(Fig
ure
3).
• Th
e sc
an im
ages
show
shel
ls c
ondi
tion
does
n’t s
eem
to c
orre
late
with
om
ega
arag
onite
.
• She
ll vo
lum
e is
cal
cula
ted
as th
e su
m o
f vo
xels
whi
ch f
all w
ithin
a s
elec
ted
grey
scal
e ra
nge.
• T
he s
elec
ted
grey
scal
e ra
nge
is d
iffe
rent
for
eac
h sa
mpl
e an
d is
des
igna
ted
usin
g th
e au
tom
atic
su
rfac
e de
term
inat
ion
mod
ule
in V
G S
tudi
o M
ax 2
.2 s
oftw
are.
• The
dia
met
er o
f the
shel
l is m
easu
red
acro
ss th
e w
ides
t par
t of t
he w
horl,
par
alle
l to
the
botto
m o
f th
e sh
ell u
sing
the
mea
sure
men
t too
l in
VG
Stu
dio
Max
2.2
softw
are.
Dis
cuss
ion
• A
ll pt
erop
od sa
mpl
es c
ame
from
are
as
of th
e oc
ean
whi
ch a
re c
urre
ntly
su
pers
atur
ated
(Ω a
rago
nite
>1)
. The
re
seem
s to
be n
o tre
nd in
nor
mal
ised
shel
l vo
lum
e w
ith in
crea
sing
ly su
pers
atur
ated
w
ater
s.•
Ther
e ar
e so
me
chan
ges i
n sh
ells
whi
ch
are
visi
ble
by e
ye (F
igur
e 3)
that
don
’t co
rrel
ate
to c
hang
es in
Ω a
rago
nite
. •
The
calc
ifica
tion
dept
h of
pte
ropo
ds is
st
ill u
nkno
wn.
We
focu
sed
on th
e w
ater
ch
emis
try a
t 5 m
and
100
m a
s pte
ropo
ds
are
know
n to
be
dom
inan
t in
the
top
hund
red
met
res (
Bat
hman
n et
al.,
199
1;
Soils
and
von
Wes
tern
hage
n, 1
978)
. H
owev
er, p
tero
pods
are
kno
wn
to h
ave
a st
rong
ver
tical
mig
ratio
n pa
ttern
s and
hav
e be
en fo
und
as d
eep
as 1
000
m (B
erna
ršek
et
al.,
201
2c).
• If
pte
ropo
ds c
alci
fy d
eepe
r tha
n 10
0 m
, w
e w
ill m
iss t
he c
hem
ical
sign
al th
at is
dr
ivin
g th
is c
hang
e as
Ω a
rago
nite
doe
s no
t dec
reas
e lin
erly
with
dep
th.
• Pt
erop
ods h
ave
an a
nnua
l life
cycl
e an
d th
eref
ore
we
may
be
look
ing
at sh
ell
chan
ge e
ffect
s whi
ch w
ere
caus
ed b
y a
wat
er m
ass t
hat t
he p
tero
pod
was
in
cont
act w
ith m
onth
s bef
ore.
Con
clus
ions
• Th
ere
is n
o si
gnifi
cant
qua
ntifi
able
effe
ct
of Ω
ara
goni
te a
t 5m
or 1
00m
on
pter
opod
s sh
ells
from
supe
rsat
urat
ed w
ater
s.•
Shel
l thi
ckne
ss d
istri
butio
ns c
ould
be
used
to h
ighl
ight
spec
imen
s whi
ch a
re a
t ris
k of
bei
ng d
amag
ed.
• Spe
cim
ens f
rom
und
ersa
tura
ted
regi
ons
need
to b
e m
easu
red
to c
ompl
ete
this
stud
y.
• C
T sc
anni
ng w
ill b
e an
ess
entia
l too
l en
ablin
g us
not
onl
y to
mea
sure
cha
nge
but
to p
inpo
int t
he lo
catio
n of
this
cha
nge.
Fig
ure
3: V
olum
e of
ara
goni
te in
the
shel
l nor
mal
ised
to s
hell
diam
eter
fro
m th
ree
site
s co
mpa
red
to th
e om
ega
arag
onite
at 5
m (
open
sym
bols
) an
d 10
0m (
fille
d sy
mbo
ls).
The
3D
imag
es s
how
a
grad
ient
in s
peci
men
t qua
lity
at th
ese
omeg
a ar
agon
ite v
alue
s.
Fig
ure
2: S
ampl
e pr
epar
atio
n a)
ligh
t m
icro
scop
e im
age;
b)
mou
nt o
n ca
rbon
tape
; c)
raw
2D
dat
a fr
om C
T s
cann
er;
d) in
tern
al
set u
p of
sca
nner
; e)
ext
erna
l im
age
of
phoe
nix
v|to
me|
x m
Fig
ure
4: S
hell
thic
knes
ses
in s
ampl
es f
rom
the
Arc
tic O
cean
(L
imac
ina
hele
cina
) an
d th
e C
aria
co
Bas
in (
Lim
acin
a in
flat
a). T
he m
ode
valu
es b
etw
een
thes
e tw
o sa
mpl
e ar
e st
atis
tical
ly d
iffe
rent
.
Fig
ure
5: S
hell
thic
knes
s di
stri
butio
n in
one
sam
ple.
Sh
ells
with
hig
her
mod
e va
lues
(pu
rple
box
) lo
ok m
ore
pris
tine
than
thos
e w
ith lo
wer
mod
e va
lues
(re
d bo
x).
• W
ithin
eac
h sa
mpl
e, th
ere
is v
aria
tion
betw
een
diffe
rent
spec
imen
s.•
Pter
opod
s with
hig
her m
ode
valu
es (p
urpl
e bo
x)
look
mor
e pr
istin
e th
an th
ose
with
low
er m
ode
valu
es (r
ed b
ox).
• Th
is te
chni
que
seem
s to
be m
ore
diag
nost
ic a
t hi
ghlig
htin
g vu
nera
ble
spec
imen
s tha
n th
e no
rmal
ised
vol
ume
mea
sure
men
ts.
Shel
l thi
ckne
ss a
naly
sis
We
need
you
r hel
p!W
e w
ant t
o m
ake
a gl
obal
dat
abas
e of
the
stat
e of
pte
ropo
ds in
the
mod
ern
ocea
nD
o yo
u ha
ve:
• Pt
erop
od sa
mpl
es fr
om o
lder
co
llect
ions
?•
Pter
opod
sam
ples
from
upw
ellin
g zo
nes?
If so
, ple
ase
get i
n to
uch!
a b c
d e
Ack
now
ledg
emen
tsTh
e au
thor
s wou
ld li
ke to
than
k B
. M
arsh
all a
nd R
. Thu
nell
(USC
) for
sam
ples
fr
om th
e C
aria
co B
asin
, and
C. M
anno
, V.
Peck
and
G. T
arlin
g (B
AS)
for t
he A
rctic
an
d So
uthe
rn O
cean
sam
ples
.
Volu
me
Ana
lysi
s
