Publication Date:
2022-05-25
Description:
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution February 2013
Description:
Coastal
and
estuarine
environments
experience
large
variability
and
rapid
shifts
in
pCO2
levels.
Elevated
pCO2,
or
ocean
acidification,
often
negatively
affects
early
life
stages
of
calcifying
marine
invertebrates,
including
bivalves,
but
it
is
unclear
which
developmental
stage
is
most
sensitive.
I
hypothesized
that
initial
calcification
is
a
critical
stage
during
which
high
pCO2
exposure
has
severe
effects
on
larval
growth
and
development
of
bay
scallop
(Argopecten
irradians).
Using
five
experiments
varying
the
timing
of
exposure
of
embryonic
and
larval
bay
scallops
to
high
CO2,
this
thesis
identifies
two
distinct
stages
of
development
during
which
exposure
to
high
CO2/low
pH
causes
different
effects
on
bay
scallop
larvae.
I
show
that
any
exposure
to
high
CO2
consistently
reduces
survival
of
bay
scallop
larvae.
I
also
show
that
high
CO2
exposure
during
initial
calcification
(12-24
h
post-fertilization)
results
in
significantly
smaller
shells,
relative
to
ambient
conditions,
and
this
size
decrease
persists
through
the
first
week
of
development.
High
CO2
exposure
at
2-12
h
post-
fertilization
(pre-calcification),
does
not
impact
shell
size,
suggesting
that
the
CO2
impact
on
size
is
a
consequence
of
water
chemistry
during
calcification.
However,
high
CO2
exposure
prior
to
shell
formation
(2-12
h
post-fertilization)
causes
a
high
incidence
of
larval
shell
deformity,
regardless
of
CO2
conditions
during
initial
calcification.
This
impact
does
not
occur
in
response
to
high
CO2
exposure
after
the
2-12
h
period.
The
observations
of
two
critical
stages
in
early
development
has
implications
for
both
field
and
hatchery
populations.
If
field
populations
were
able
to
time
their
spawning
to
occur
during
the
night,
larvae
would
undergo
initial
calcification
during
the
daytime,
when
CO2
conditions
are
more
favorable,
resulting
in
larger
veliger
larvae.
Hatcheries
could
invest
minimal
resources
to
monitor
and
modify
water
chemistry
only
during
the
first
day
of
development
to
ensure
larva
are
exposed
to
favorable
conditions
during
that
critical
period.
Description:
This
work
was
funded
by
a
National
Defense
Science
and
Engineering
Graduate
Fellowship
the
WHOI
Academic
Programs
Office;
NSF
grant
OCE-0326734
to
L.
Mullineaux,
H.
Caswell,
C.
Dibacco,
J.
Lerczak,
S.
Thorrold,
and
M.
Neubert;
a
Woods
Hole
Oceanographic
Institution
Interdisciplinary
Award
to
L.
Mullineaux
and
D.
McCorkle;
and
awards
to
L.
Mullineaux
and
M.
White,
to
D.
McCorkle,
and
to
A.
Cohen
and
D.
McCorkle
through
NOAA
Sea
Grant
#NA10OAR4170083.
White
received
additional
funding
from
WHOI’s
Coastal
Ocean
Institute
Student
Research
Funds
and
Woods
Hole
Sea
Grant
New
Initiative
Funds.
Keywords:
Seawater
;
Carbon dioxide content
;
Bay scallop
Repository Name:
Woods Hole Open Access Server
Type:
Thesis
Format:
application/pdf
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