Sclerosponges: A New Proxy Indicator of...
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Sclerosponges: A New Proxy Indicator of Climate NOOAA Climate and Global Change Program Special Report No. 12
Transcript of Sclerosponges: A New Proxy Indicator of...
Sclerosponges: A New Proxy Indicator of
Climate
NOOAA Climate and Global Change Program
Special Report No. 12
Cover: Slab of the sclerosponge Ceraptorella nicholsoni with a carbon isotopic profile
superimposed. The pronounced 13C Suess effect is evident. This particular sample is about 400
years old
Sclerosponges: A New Proxy Indicator of Climate
Report from the Workshop on the Use of Sclerosponges as Proxy Indicators ofClimate
March 22 -24, 1998Miami, Florida
By
Peter K. SwartJames L. Rubenstone
Chris CharlesJoachim Reitner
Organizers
September, 1998
This publication is funded in part by a cooperative agreement from the National Oceanic and AtmosphericAdministration. The views expressed herein are those of the authors and do not necessarily reflect the viewsof NOAA or any of its subagencies
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TABLE OF CONTENTS
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ii
Organizer’s Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iii
Consensus Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . iv
Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v
Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1Dating and Proxies
Radiometric Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3Banding . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Chemical Proxies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Stable Isotopes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5Oxygen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7Trace Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Oceanographic and Climate Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Carbon-13 Suess Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11Changes in the Carbon and Oxygen Isotopic Composition of the Mixed
Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12Comparison of long-term regional SST variability in SE Asia . . . . . . . . . . . 13
Calcification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
SCLEROSPONGE WORKSHOP PARTICIPANTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
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Mike Grammer (left) and Peter Swart with large specimen of the sclerosponge(Calcifibrospongia ). Sample measured 50 cm from top to bottom. Unfortunately thisspecies does not appear to be suitable for paleoclimatic analysis as a result of unevenand distorted growth structure which may indicate secondary calcification.
Acknowledgements
I would like to thank the many persons who helped make this workshop possible, especially, Dr.Zimmerman (NSF) and Dr. M. Eakin (NOAA) who provided financial support (NSF grant ATM-95xxxx). Thanks should also go to Avis Miller who did an excellent job of organizing the logisticsfor the meeting. Gratitude also must be paid to Dr. M. Grammer and Dr. McNeill who helped collectthe sclerosponges from the Bahamas and who were involved during early stages of the sclerospongework. Finally thanks to all the participants of the sclerosponge workshop, especially Philippe Willenz,who provided critical input and photographs, Ted McConnaughey, who edited the calcificationsection and provided many good ideas, Stewart Fallon for trace element data, Florian Bohm for theuse of his data and figures, Chris Charles and Mike Moore for use of their data, Jim Rubenstone forcontributions to the dating section, Ellen Druffel for editing and constructive comments, and GretaMacKenzie for final editing.
Peter K. Swart, Miami September 23, 1998
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ORGANIZER’S SUMMARY
Sclerosponges are slow growing calcareous
organisms who secrete their skeletons in
carbon and oxygen isotopic equilibrium with
their environment, and can therefore provide
proxy records of salinity and water
temperature over a 100 to 1000 year time
range. In this regard they have the capability
to augment and in some instances replace
records obtained from coral skeletons which
are structurally and biologically much more
complex and secrete their skeletons well
outside chemical equilibrium with their
ambient environments.
This report summarizes the findings of a
recent workshop on the current state of
knowledge regarding sclerosponges and their
potential application towards the study of
global change. In contrast to scleractinian
corals, to which sclerosponge research is
intimately linked, the study of sclerosponges is
very much in its infancy. For example, there
have been numerous published studies on
calibration aspects of the geochemistry of
coral skeletons, including over the past five
years 10 studies calibrating Sr/Ca ratios in the
skeletons of various species of corals with
temperature. In contrast, there has not been
one study calibrating the chemical
composition of sclerosponges.
The workshop, which met in Miami in March
1998, had as its mandate to establish the
current state of knowledge regarding the use
of sclerosponges for paleoclimatic purposes.
In particular, the following questions were
posed:
1) Do sclerosponges have a dateable
chronology in their skeletons? If so, with what
methods can the skeleton be dated?
2) Does the skeleton of sclerosponges form in
chemical equilibrium with the ambient
seawater?
3) What is the mechanism of calcification?
4) Can high resolution records be obtained
from the skeletons of sclerosponges?
5) Which paleoceangraphic and climatic
processes are the most suitable for study using
sclerosponges?
This report summarizes the views of workshop
participants on these and other issues.
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CONSENSUS VIEWS
<< Sclerosponges are long lived marine
sources of proxy climate data
which can augment and in some
instances replace coral records.
They are therefore well suited for
providing continuous proxy
records of ocean/atmospheric
variability over the past 100 to 800
years.
<< Sclerosponges, like corals,
incorporate numerous chemical
parameters which can not only
provide an indication of water
temperature and salinity, but also
incorporate tracers typically
studied in coral skeletons (δδ13C,
∆∆14C, Ba, Cd, and Mn) .
<< Sclerosponges can provide this
information over a range of water
depths, thereby providing unique
information on the history of the
upper water column.
<< Sclerosponges, by virtue of their
slow growth rate, can provide
information over time ranges much
longer (500 to 1000 years) than
accessible using coral skeletons,
where records are limited to 200 to
300 years.
<< Sclerosponges, unlike scleractinian
corals, form their skeletons in
isotopic equilibrium with their
ambient environment, eliminating
the need for any type of corrections
for species effects or differential
growth rates.
<< Sclerosponges can be easily dated
using carbon-14 (∆∆14C) or uranium
disequilibrium methods. High
resolution analyses of the chemical
composition of sclerosponges reveal
the presence of annual cycles in
color and chemical composition
which can be used to further date
the sclerosponges in a manner
analogous to the density banding in
coral skeletons.
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RECOMMENDATIONS
1) The workshop participants propose that
several calibration studies be initiated
which test the ability of sclerosponges to
record variations in salinity and
temperature. This calibration should be
conducted along the following lines:
<< First, to grow sclerosponges in the
field, closely monitoring the
environmental conditions and then
relating these changes to variations
in the chemical composition of the
skeleton. In particular it should be
determined whether the skeleton of
sclerosponges can reproduce inter
and intra annual variations in
temperature.
<< Second, to test the ability of
sclerosponges to reconstruct
changes in the mixed layer caused
by variations in wind stress.
<< Third, to determine the
reproducibility of the stable isotopic
composition in sclerosponges at a
particular location.
2) Sclerosponges are probably
geographically widely distributed, but
collecting samples is difficult because of the
need to use expensive submersibles. We
recommend that ship time be allocated for
the search and collection of sclerosponges
in climatically important areas.
3) Examine sclerosponge responses to
naturally occurring climatic anomalies such
as the 1997-98 El Nino. Measurements
should include population level responses
(mortality, new settling, etc.), physiological
responses (growth rates, and regeneration,
etc.) and the behavior of skeletal climatic
proxies (δδ18O, strontium, and magnesium)
4) Investigate the phenomena of partial
die-back and regeneration. Partial
die-backs weaken the skeleton, complicate
chronological assignments, and may be
associated with shifts in isotopic or
chemical composition. If partial die-backs
and regeneration are associated with
particular climatic conditions, their
expression in sclerosponges can provide
evidence for climatic changes. Field studies
should look for evidence of synchronous
die-backs and regenerations. Correlations
with climatic anomalies should be
investigated in collections.
5) Determine what causes the visible
banding in sclerosponge skeletons. Banding
is important both for determining
chronology within a skeleton, and for
cross-correlating different skeletons and
developing stacked chronologies.
Correlations may be possible between
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skeletal bands and known past
environmental anomalies, and for
correlations between bands and
environmentally sensitive skeletal
indicators including the abundance of
organics, trace metals, and stable isotopes.
6) Measure skeletal growth of individual
sclerosponges under various environmental
conditions, especially temperature.
7) Quantify the vertical distribution of
calcification within sclerosponge skeletons,
using dyes and isotopic tracers. It is
especially important to determine where
"time zero" lies within the skeleton - is it at
the top surface, or closer to the bottoms of
the growing pseudocalices? Then develop
mathematical models to describe the
slurring of environmental signals as
recorded by the sclerosponge, and
techniques for deconvoluting as much of
the slurred signal as possible. Also develop
sampling strategies that will minimize
vertical smearing of signals detected with
microsampling protocols such as laser
ablation.
8) Investigate why sclerosponges make
their skeletons. This may influence skeletal
growth rates and possibly skeletal
chemistry. The motivation for
skeletogenesis is not necessarily trivial -
McConnaughey's "proton hypothesis"
McConnaughey and Whelan, 1997)
suggests that corals and calcareous algae
calcify largely to generate protons for use in
assimilating.
9) Develop a simple "field guide" to
sclerosponges and their habitats so that
geochemists can collect the most desirable
specimens. This should include keys to
species recognition and visual indications
that particular individuals do or don't
suffer from strong bioerosion. It might
also include criteria for judging whether a
particular cave departs from climatically
relevant marine conditions in significant
ways, as for example through ground-water
seepage or generation of higher alkalinities
due to sulfate reduction.
1
Figure 1: Specimen of Ceratoporella nicholsoni from Jamaica. Sample is about 10 cm x 20 cm in size[Photograph from Willenz].
Background
It has been more than three decades
since Goreau [1959] described the ecology of
the deep Jamaican reefs and found them to
contain large populations of the sponge
Ceratoporella nicholsoni. Although such
sponges have been known for a long time, the
extent of their diversity has only been realized
in the last several decades [Hartman, 1969;
Hartman and Goreau, 1966, 1970, 1972, 1975,
1976; Vacelet, 1977a, 1977b, 1979a, 1979b,
1980, 1981, 1984]. Although the calcareous
sponges with siliceous spicules were initially
ascribed to a separate class, the
sclerospongiae , a variety of similarities with
sponges lacking calcareous skeletons led to
their incorporation into pre-existing groups of
Demospongiae [Vacelet, 1981, 1983a, 1983b,
1985; van Soest, 1984]. At the present time,
15 species belonging to 2 classes, 4
subclasses, 8 families, and 11 genera are
known. The biology and ecology of the
sponges has been well described by Lang et
al. [1975], Dustan et al. [1975], Hartman and
Goreau [1970], Scoffin and Hendry [1984],
Wood [1990], while their growth has been
studied by Dustan and Sacco [1982] and
Benavides and Druffel [1986]. Lang et al.
2
Figure 2: Polished slab of a section of a sclerosponge (Ceratoporella nicholsoni) from Lee Stocking Island inthe Bahamas. The variation in banding can be clearly seen. The age of this specimen is about 400 years oldbased on preliminary U/Th dates. The sample is 10 cm high (Photograph by Grammer].
[1975] found the sponges growing within the
framework and under coral talus in the
shallower portions of the reef (above 55m),
while below 55m they are found on the steep
surfaces of the deep fore-reef. They have been
reported growing to depths of 145 m. Of the
six sclerosponges described by Lang et al.
[1975], the largest and most visible is
Ceratoporella nicholsoni. In Jamaica this
sponge was estimated to cover between 25 to
50% of the available space, attaining sizes in
excess of 1 m in diameter (Figs. 1 & 2). The
ultra-structure of this species has been
described by Willenz and Hartman [1985].
Stromatospongia vermicola also grows to a
reasonable size (40 cm in diameter) and can be
locally more abundant than C. nicholsoni.
The remaining species of sponges
(Hispidopetra miniana, S. norae, Goreauiella
auriculatra, and Merlia sp.) are relatively
small but can be locally abundant.
3
0.00 4.00 8.00 12.00Distance (cm)
0.00
200.00
400.00
600.00
800.00
Age
(yr
s)
Figure 3: Growth rate of a sample from theBahamas as determined using U-Th dating. Growth rate on this sample is approximately 200µµm a year [Swart and Rubenstone, unpublisheddata].
Figure 4 :Growth rates from sclerospongescollected from TOTO, LSI, and Belize [Swart, Julland others, unpublished data]. Error barsrepresent C-14 uncertainties [Swart et al., 1994].
Dating and ProxiesRadiometric Methods
The growth rates of sclerosponges
have been studied both by direct staining
using Alizarin Red-S [Dustan and Sacco,
1982], Calcein [Willenz and Hartman, 1985],.
and by using 14C and 210Pb [Benavides and
Druffel, 1986]. Both studies were conducted
on sponges from Jamaica. In the staining
study, specimens of sponges were stained and
collected some six years later. Dustan and
Sacco [1982] estimated a growth rate of 0.1
to 0.2 mm/yr. The radiometric methods gave
slightly higher growth rates (0.27 mm/yr using14C and 0.22 mm/yr using 210Pb). Data on
growth rates presented at the workshop
generally supported these estimates (Figs. 3 &
4).
Radiometric techniques remain the most
reliable methods for long term dating of
sclerosponges. Radiocarbon has been utilized
successfully, although regional variations in
sea-surface 14C (and bomb effects in samples
less than 30 years old) add uncertainty to the
m e t h o d ( F i g . 4 ) . A t p r e s e n t ,
mass-spectrometric measurements of U-series
4
Figure 6: Carbon isotopic profile from a sclerosponge fromJamaica (Montego Bay) showing the Carbon-13 Suess effect. Compare this profile to figure 8. Similar patterns are seen betweenthe two records extending to around 1500. Prior to 1500 the recordin figure 1 shows an even greater increase which may be related tosome diagenesis in the sclerosponge [Data from Bohm,unpublished].
19201930194019501960197019801990Date
-0.3
-0.2
-0.1
0
0.1
0.2
0.3
Annual signal
Figure 5: Single spectral analysis of the annual component from a sclerospongecollected from 143 m water depth in the Tongue of the Ocean. Annual range variesfrom less than 1oC to greater than 2oC between 1970 and 1960 and again in the late1930s. This type of variation could reflect changes in the thermocline [Swart,unpublished].
i s o t o p e s
(2 3 8U-234U-230Th)
a p p e a r m o s t
definitive (Fig. 3).
Relatively high
uranium (up to 7
ppm; Rubenstone
et al., 1996] and
low initial Th
c o n c e n t r a t i o n s
make this method
very useful; age
uncertainties of
only a few years are
obtainable even for
v e r y y o u n g
specimens. Growth
rates calculated from multiple U-Th
ages on individual sponges agree well
with biological rate estimates.
Banding Despite an intensive
examination using CAT-scan and X-
radiographic methods, data presented
at the meeting (Lang) suggest that
sclerosponges do not have any
variations in density which can be
used for dating purposes. However,
c e r t a i n s p o n g e s s u c h a s
Ceratoporella nicholsoni have a
visible banding pattern, the
significance of which is still
uncertain(Fig. 2). Data presented at
the Sclerosponge Workshop by
5
Figure 7: Carbon isotopic profiles from Pacific sclerosponges showing the C-13 Suess effect over a range ofdifferent locations. Compare these profiles to similar data from the Atlantic [Data from Moore and Charles,unpublished].
Dodge and Swart suggests that there is an
annual cyclicity in these banding patterns
which might be used for data purposes. In
this study Dodge and Swart applied a ∆14C
age model to a digitized spectrum of the color
patterns in a slab of a sclerosponge. A
spectral analysis of these data suggested an
annual signal which could be tuned to refine
an age model. Spectral analysis of oxygen
isotopic data from sclerosponges suggests a
yearly cycle which could be used for dating
purposes (See later discussion Fig. 5).
Chemical Proxies
Stable Isotopes
The first work on the C and O isotopic
composition (δ13C and δ18O) of sclerosponges
was conducted by Druffel and Benavides
[1986]. These workers analyzed a 160 year
old specimen of C. nicholsoni collected from
Jamaica, at a resolution of approximately one
sample every 2.5 years. They concluded that
there was no vital effect in the accretion of the
skeleton. In contrast to non-zooxanthellate
corals which normally possess a positive
covariance between C and O in their skeletons,
6
0
2 0 0
4 0 0
6 0 0
8 0 0
0 0 . 5 1 1 . 5 2 2 . 5
3 . 5 4 4 . 5 5 5 . 5
Age
Bef
ore
Col
lect
ion
O xyg e n Is o to p i c C o m p o s i t io n
C a r b o n Is o to p i c C o m p o s i t i o n
C a r b o n
O xyg e n
Figure 8: Stable C and O isotopic record from LSI-BB-19 illustrating thepotential of sclerosponges. This record based on a U-Th determined growth rateof 200 um a year is approximately 700 years! The C-13 Suess affect as well ascooling and warming trends in the O signal can be clearly seen. The maximumin the oxygen isotopic record at 1700 corresponds to the minimum in theManley temperature record from the U.K.
the study of Druffel and
Benavides [op. cit.]
showed no correlation,
which they suggested was
further proof of the
absence of vital isotopic
effects in the secretion of the
skeleton. While they did
not observe any age-
dependent trend in the
oxygen isotopic data, their
results showed an average
0.5 ‰ decrease in the δ13C
with increasing age. This
decrease which was similar
to the decline in δ13C seen
in a coral from Bermuda
analyzed by Nozaki et al.
[1978], is probably a result
of CO2 added to the
atmosphere from fossil fuel
burning (the C-13 Suess
effect). Similar findings
have recently been
reported by Bohm et al.
[1996] (Fig. 6) and Moore
et al., [1996] (Fig. 7) in
sclerosponges from the
Caribbean and the Pacific.
At the workshop several
other groups presented
additional data confirming
the trend in sclerosponges
from the Bahamas and
Belize (Fig. 8). In fact the
7
Figure 9: Observed and predicted oxygen isotopic equilibrium for sclerosponges from a number of locationsthroughout the world [Moore and Charles, unpublished]. Sites are Kapoposang Is. (KAP), Bunaken Is. (BUN),and Kapota Is. (KPT) in the Indonesian seaway; Naru (NAR), Palau (PAL), and the Solomon Is. (SOL) in theWest Pacific; Lee stocking Island in the Bahamas (LSI), Jamaica (JAM)[Data from Druffel and Benavides[1986] and Bohm et al. [1996]]. Estimates of mean annual temperatures and δ δ 18O are based on fieldobservations or atlas data.
trend seems to be so reproducible in
sclerosponges that it has been suggested that
the change can be used as a method whereby
the sclerosponges can be dated.
Oxygen
In contrast to the abundant work on
the calibration of the oxygen isotopic
composition of scleractinian corals [Weber
and Woodhead, 1972; Dunbar and
Wellington, 1981; Leder et al., 1996;
Wellington et al., 1996], there have been no
reported calibration studies on sclerosponges.
Nevertheless, based on the reproducibility of
the 13C Suess effect, there is good reason for
optimism that sclerosponges secrete their
skeletons in oxygen isotopic equilibrium.
Based on preliminary data presented at the
meeting the following advances have been
made:
8
< Several workers have been able to
correlate the oxygen isotopic
composition of bulk skeletons with
mean water temperatures from the
localities where the sclerosponges
were collected (Fig. 9).
< Long term records appear to correlate
with COADS temperature series
[Swart unpublished].
< Based on high resolution sampling
(10 samples a year), a seasonal cycle
was identified in the skeleton (Fig . 5).
Based on literature data from Druffel and
Benavides [1986] and unpublished analyses
from the Caribbean and the Pacific the oxygen
isotopic composition can be compared with
the annual water temperature data for these
locations (Fig. 9).
Data from one sclerosponge site in the
Bahamas which has a record extending back
in time to 1940 can be correlated with local
COADS data. The chronology of this
sclerosponge, which is based on C-14 age
dating, shows a remarkable correspondence
with long term variations in the COADS data
set. This sclerosponge was also sampled at a
resolution of one sample every 37 µm using a
microdrill. This is equivalent to
approximately one sample every month (Fig.
5). The oxygen isotopic data were
subsequently subjected to spectral analyses to
test whether annual variations in the oxygen
isotopic record were present. If such
variations were present then this would be
strong evidence that the oxygen isotopic
variations were controlled by temperature. In
addition the presence of annual patterns in the
skeleton could be useful as an independent
mechanism for dating sclerosponges. Using
Single Spectral analysis we were able to show
the presence of signals corresponding to 0.7
to 1.7 years accounting for 12% of the
variance in the oxygen isotopic signal (Fig. 5).
The occurrence of a significant peak between
0.7 and 1.2 years in the spectral analysis of the
oxygen isotopic signal strongly supports
estimates of growth rates based on 14C and
uranium series methods. If there are annual
signals in the stable oxygen isotopic signal it
might be possible to accurately and relatively
inexpensively date sclerosponges to +/- 1 year.
Trace Elements
In scleractinian corals the elements B,
Mg, Sr, Ba and U show seasonal variations
consistent with environmental parameters,
predominantly sea surface temperature and
variations in upwelling. These elements have
9
12 14 16Distance from Top (mm)
.01
.011
Sr/C
a (m
ol/m
ol)
1.6E-4
2.0E-4
9E-4
1.1E-3
2.8E-6
3.4E-6
B/C
a(m
ol/m
ol)
Mg/
Ca
(mol
/mol
) Ba/Ca (m
ol/mol)
Ba
Sr
Mg
B
Figure 10 :This figure shows the B/Ca, Sr/Ca, Mg/Ca and Ba/Ca (in mol/mol) vs. Distance from the topsurface (in mm) of the sclerosponge Astrosclera willeyana, from Truk Lagoon (Data from Fallon,unpublished).
now been analyzed from the sclerosponge
(Astrosclera willeyana). Samples were
collected from Taveuni, Fiji, Ruby Reef, GBR
and Truk, Caroline Islands have been
analyzed at a sampling resolution of ~40 µm
to try to document an annual signal. Without
confirmation from an independent dating
method we are unable to confirm an annual
cycle, although a significant (>99%) spectral
peak was observed using singular spectral
analysis [Dettinger et al., 1995] at a distance
of ~0.2mm. This distance is consistent with
previous estimates of annual growth using
∆14C and U/Th dating methods [Benavides
and Druffel, 1986, Druffel and Benavides,
1986, Bohm et al., 1996, Worheide et al.,
1997; Worheide, 1998].
When samples are compared at ~100
µm resolution, longer term (annual to several
year) patterns appear, which are consistent
between the B/Ca, Mg/Ca, Sr/Ca and Ba/Ca
cycles (Figure 10). This suggests a common
10
3.60 4.00 4.40 4.80 5.20 5.60Carbon Isotopic Composition
1200
1400
1600
1800
2000D
ate
Lee Stocking
Belize
Jamaica (Bohm)
Tongue of the Ocean
7.50 8.00 8.50 9.00 9.50 10.00Temperature
Figure 11: Comparison of the carbon isotopic composition from sclerosponges from the Bahamas [Swartunpublished] and from Jamaica [Bohm, unpublished] together with Manley temperature record from theU.K. Note the period of greatest cooling during the little-ice age also corresponds to a maximum in thecarbon-13 isotope record as well as a maximum in the oxygen isotopic record (Fig. 6).
forcing mechanism for these four elements.
One significant difference between corals and
sclerosponges is the Mg/Ca cycles are
positively correlated to Sr/Ca. Hence it
appears that Mg and Sr do not follow the same
positive and inverse relation ships with
temperature which have been documented in
corals [Beck et al., 1992; Mitsuguchi et al.,
11
20
22
24
26
28
30
32
11/14/84
8/11/87
5/7/90 1/31/93
10/28/95
7/24/98
105' 480' 340' 700'
700
480
Figure 12: Water temperature data from Lee Stocking Island in the Bahamas from different water depths overthe past eight years. Sclerosponges collected from this locality should be able to reconstruct variations in thethermocline.
1996]. In addition the boron, magnesium and
barium concentrations in these sclerosponges
are 2-5 times lower than in corals, with
concentrations of ~20 ppm, ~200 ppm and ~4
ppm, respectively. However, the strontium
and uranium concentrations are 1-2.5 times
higher than in corals with concentrations of
~9000 ppm and ~8 ppm respectively. The
variations in the U/Ca cycles appear to be
more complicated than that documented in
corals [Shen and Dunbar, 1995], being both in
and out of phase with respect to the other
elemental ratios suggesting a more
c o m p l i c a t e d i n c o r p o r a t i o n o f
uranium into the skeleton.
Oceanographic and Climate Issues
Carbon-13 Suess Effect
The fact that sclerosponges apparently secrete
their skeletons in isotopic equilibrium (Figs.
12
Figure 13: Comparison of long-term regional SST variability in S.E. Asia (A) to the δ δ 18O records ofsclerosponges from the Indonesian Seaway (B-D). Surface waater flowing through the Indonesian Seaway tothe Indian Ocean is mostly derived from the N. Pacific and transits via the Sulawesi Sea and the MakassarStrait. Sclerosponge records from Bunaken (B) abd Lapoposang (C) are expected, and are observed, to besimilar. Data from Kaspota (D) in the Banda sea shows a different pattern of variability [Moore and Charles,unpublished]
6,7,8 & 10) with respect to their environment
allows them to be used to address a variety of
climatic and oceanographic issues. The
coincidence of the decrease in the carbon
isotopic composition of 1 to 1.5 ‰ detected
in sclerosponges from both the Pacific and the
Atlantic Oceans suggests that sclerosponges
(Fig. 10 and 12) can be used to determine the
timing of the penetration of the anthropogenic
increase in the CO2 of the oceans. For
example figure 10 shows a comparison of
perhaps the two best records measured to
date, one from Jamaica and one from the
Bahamas. Both show remarkable coherency,
although there appears to be a real offset
between the two records. Similarly, records
from the Pacific also show real and significant
differences in the carbon-13 profiles between
different locations. Although similar changes
in the carbon isotopic composition have been
seen in corals, the changes are often masked
and confused making sclerosponges ideal for
studying the decrease in the carbon isotopic
composition of the oceans related to the build
up of fossil derived CO2 in the atmosphere
(Carbon-13 Suess effect).
13
Figure 14: Calcein staining in the skeleton of asclerosponge showing growth structure (field ofview 1 x 2 mm) (Willenz, unpublished).
Changes in the Carbon and Oxygen
Isotopic Composition of the Mixed Layer
As a result of the wide depth distribution of
sclerosponges, they can be used in
conjunction with scleractinian corals to
determine variations in the temperature and
salinity of the water column as a function of
depth and time. This would therefore provide
information on the thickness of the mixed
layer which in turn can be related to wind
stress. An example of the type of temperature
record which might be reconstructed is shown
in Figure 12.
Comparison of long-term regional SST
variability in SE AsiaFigure 13 shows a comparison of long-term
regional SST variability in SE Asia to δ18O
records from sclerosponges in the
Indonesian seaway. Sclerosponge
records from Bunaken(B) and
Kappoposang(C) are expected to be
similar as both sites are influenced
b y t h e s a m e w a t e r m a s s .
Furthermore, the records reproduce
the regional SST response, in
particular the strong cooling trend.
The dotted line in (b) shows a
replicate transect. The record shown
in panel D, from the Banda Sea
s h o w s a d i f f e r e n t p a t t e r n o f
variability as might be expected
given its different water supply.
CALCIFICATION
Sclerosponges appear to grow in a
manner analogous to scleractinian
corals, with the living organism
inhabiting the upper portion of the
skeleton of the sclerosponge, and the
lower portion being devoid of living
tissue. In the species Ceraptorella
nicholsoni, the tissue layer occupies the
upper 1 mm of the skeleton. This
essentially represents three to four
14
years worth of skeletal growth. In
contrast , the l iving port ion of
s c l e r a c t i n i a n c o r a l s t y p i c a l l y
occupies 50% of one year’s worth of
skeletal growth. Calcification in
sclerosponges occurs essentially at
t w o s i t e s , t h e b a s e o f t h e
pseudocalices(primary calcification)
(Fig. 14) and the apex of the walls
s e p a r a t i n g t h e p s e u d o c a l i c e s
(secondary calcification). However,
t h e r e l a t i v e p r o p o r t i o n o f
calcification at these two sites is not
known and may vary between
species, rendering certain species
m o r e s u i t a b l e f o r
paleoenvironmental reconstruction
t h a n o t h e r s . S e c o n d a r y
c a l c i f i c a t i o n h a s a l s o b e e n
documented to take place in the
interstices of some species. Evidence
to this effect was presented at the
Sclerosponge meeting (Reitner).
However, it is not known to what
extent this phenomenon occurs in
the skeletons of all sclerosponges
and it does not seem to take place in
species such as Ceraptorella nicholsoni.
Sclerosponges are clearly excellent
environmental recorders and in
many respects, have significant
advantges over scleractinian corals.
T h e c l o s e a g r e e m e n t w i t h
e q u i l i b r i u m v a l u e s w h i c h i s
apparently shown by these organisms
is undoubtedly a result of the slow
growth ra te o f these an imals .
Sclerosponges are unlikely to remain
passive at all times. Active behavior
is especially likely during climatic
extremes, and failure to recognize
t h i s m i g h t c a u s e c l i m a t i c
mis-interpretations at precisely the
most interesting climatic periods.
We therefore advocate special efforts
to determine the limits of accurate
climatic recording by sclerosponges.
15
REFERENCES
Beck J. W., Edwards R. L., Ito E., Taylor F.
W., Recy J., Rougerie F., Joannot P., and
Henin C. (1992) Sea-surface temperature from
coral skeletal strontium/calcium ratios. Science
257, 644-647.
Benavides L. M. and Druffel E. R.
M. 1986. Sclerosponge growth rate
as determined by 210 Pb and ∆14C
chronologies. Coral Reefs 4, 221-224.
Bohm F., Joachimski M. M., Lehnert
H., Morgenroth G., Kretschmer W.,
Vacelet J., and Dullo W.-C. 1996.
Carbon isotope records from extant
C a r i b b e a n a n d S o u t h P a c i f i c
sponges: Evolution of δ13C in surface
water DIC. Earth Planet. Sci. Lett. 139,
291-303.
Dettinger M. D., Ghil M., Strong C.
M., Weibel W., and Yiou P. (1995)
S o f t w a r e e x p e d i t e s
singular-spectrum analysis of noisy
time series. EOS 76 (2), 12, 14, 21.
Druffel E. R. M. and Benavides L.
M. 1986. Input of excess CO2 to the
surface ocean based on 13C/12C ratios
in a banded Jamaican sclerosponge.
Nature 321(1 May 1986), 58-61.
Dunbar, R.B., and Wellington, G.M.,
1981, Stable isotopes in a branching
coral monitor seasonal temperature
variation: Nature, v. 293, p. 453-455.
Dustan, P., Jaap. W, and Halas, J. 1976. The
distribution of the class Sclerospongia,
Lethaia, 9:419-420.
Dustan P and Sacco, WK, 1982. The
sclerosponges of Chalet Caribe Reef.
Discovery, 16:13-17.
Goreau, TF, 1959. The ecology of
J a m a i c a n r e e f s . I . S p e c i e s
composition and zonation. Ecology,
40:67-90.
Grossman, E.T. and Ku, T.L., 1981.
A r a g o n i t e - w a t e r i s o t o p i c
paleotemperature scale based on
benthic foraminifera Hoeglund ia
elegans, Geol. Soc. Amer. Absrt. with
Prog., 13:464
Hartman, W. D., 1969. New genera
and species of coralline sponges
(Porifera) from Jamaica. Postilla
(Yale Univ.) 137: 1-39
Hartman, W.D. & Goreau, T.F.,
1966. Ceratoporella, a living sponge
with stromatoporoid affinities. Amer.
Zool. 6 : 262
Hartman, W.D. & Goreau, T.F.,
16
1970. Jamaican coralline sponges:
Their morphology, ecology and fossil
relatives. Symp. Zool. Soc. Lond. 25:
205-243.
Hartman, W.D. & Goreau, T.F.,
1 9 7 2 . C e r a t o p o r e l l a ( P o r i f e r a :
S c l e r o s p o n g i a e ) a n d t h e
chaetetid'corals'. Trans. Conn. Acad.
Arts Sci. 44: 133-148
Hartman, W.D. and Goreau, T.F.,
1975. A Pacific tabulate sponge,
living representative of a new order
of sclerosponges. Posti l la (Yale
Univ.) 167: 1-21
Hartman, W.D. & Goreau, T.F.,
1976. A new Ceratoporellid sponge
(Porifera: Sclerospongiae) from the
Pacific. In: Aspects of Sponge
Biology, F.W. Harrison and R.R.
Cowden (eds) Academic Press N.Y.
pp. 329-347.
Lang, J.C., Hartman, W.D., Land,
L.S., 1975. Sclerosponges:Primary
f ramework cons t ruc to r s on the
Jamaican fo re - ree f . Mar . Res . ,
33:223-231.
Leder, J.J., P. Swart, A. Szmant, and
R. Dodge, The origin of variations in
the isotopic record of scleractinian
corals :I Oxygen, Geochimica et
Cosmochimica Acta, 60, 2857-2870,
1996.
McConnaughey, T.A. 1989a,b. C-13
and O-18 isotopic disequilibrium in
biological carbonates: 1. Patterns.
II. In vitro simulation of kinetic
isotope effects. Geochim. Cosmochim.
Acta 53: 151-162, 163-171.
McConnaughey, T.A., J. Burdett,
J.F. Whelan, and C.K. Paull 1997.
C a r b o n i s o t o p e s i n b i o l o g i c a l
c a r b o n a t e s : R e s p i r a t i o n a n d
photosynthesis. Geochim. Cosmochim.
Acta 61: 611-622.
M c C o n n a u g h e y , T . A . a n d J . F .
W h e l a n 1 9 9 7 . C a l c i f i c a t i o n
generates protons for nutrient and
bicarbonate uptake. Earth-Science
Reviews 42: 95-117.
Mitsuguchi, T., Matsumoto, E., Abe, O.,
Uchida, T. And Isdale, P.J., 1996. Mg/Ca
thermometry in coral skeletons, Science,
274:961-963.
M o o r e , M D , C h a r l e s , C D ,
Rubenstone, JL, 1996. Stable isotope
records of tropical climate variability
from U/Th dated sclerosponges, EOS
Transactions AGU, F291.
Nozaki, Y, Rye, DM, Turekian, KK and
17
Dodge, RE, 1978. A 200-year record of
carbon-13 and carbon-14 variation in a
Bermuda coral. Geophys. Res. Lett.,
5:825-828.
Rubenstone, J.L, Moore, M.D., Charles, C.D.,
and Fairbanks, R.G. 1996. High precision
Th/U TIMS dating of young slcerosponges
from the equatorial Pacific ocean, EOS
Scoffin, TP and Hendry, MD, 1984.
Shallow-water sclerosponges on Jamaican
reefs and a criterion for recognition of
hurricane deposits., Nature, 307:728-729.
Shen, G. and Dunbar, R.B., 1995.
Environmental controls on uranium in reef
corals, Geochim. Cosmochim. Acta, 59:2009-
2024.
Swart, P.K., Grammer, M., Jull, T. and Beck,
W. 1994. Intra-annual, inter-annual and
decadal climate variations as recorded in the
skeletons of sclerosponges from the Bahamas,
Geol. Soc. Am. Abs with. Prog. 26:A228.
Weber, JN and Woodhead, PMJ,
1972. Temperature dependence of
oxygen-18 concentration in reef coral
carbonates, Jour. Geophys. Res. ,
77:462-472.
V a c e l e t , J . , 1 9 7 7 . É p o n g e s
p h a r é t r o n i d e s a c t u e l l e s e t
s c l é r o s p o n g e s d e P o l y n é s i e
francaise, de Madagascar et de la
Réunion. Bull Mus. Nat. Hist. Natur.
(Paris), 3rd Ser., No. 444 (Zool.
307): 345-368
Vacelet, J., 1977 . Une nouvelle
r e l i q u e d u s e c o n d a i r e : U n
représentant actuel des éponges
fossiles Sphinctozoaires. C.R. Acad.
Sci., Paris, 285: 509-511
Vacelet, J., 1979 . Quelques stades
de la reproduction sexuée d'une
éponge sph inc tozoa i r e ac tue l l e .
Colloques int. Cent. natn. Rech.
scient. 291: 95-101
Vacelet, J., 1979 . Description et
a f f i n i t é s d ' u n e é p o n g e
Sphinctozoaire actuelle. Colloques
int. Cent. natn. Rech. scient. 291:
483-493
Vacelet J., 1980. Squelette calcaire
facultatif et corps de régénération
dans le genre Mer l ia éponges
apparentées aux Chaetétidés fossiles.
C. r. hebd. Séanc. Acad. Sci. Ser. II
290: 227-230
V a c e l e t , J . , 1 9 8 1 . É p o n g e s
h y p e r c a l c i f é e s ( " P h a r é t r o n i d e s "
"Sclérosponges") des cavités des
r é c i f s c o r a l l i e n s d e N o u v e l l e -
18
Calédonie. Bull. Mus. nat. Hist. Nat., Paris
(4è Ser., Sect. A, No. 2), 3 (2): 313-
351
Vacelet, J., 1983 a. Les Eponges
calcifiées et les récifs anciens. Pour la
Science 68: 14-22
Vacelet, J., 1983 b. Les Eponges
h y p e r c a l c i f i é e s , r e l i q u e s d e s
organismes constructeurs de récifs
du Paléozoique et du Mésozoique.
Bull. Soc. zool. Fr. 108: 547-557
Vacelet, J., 1984. Les éponges dans
les récifs actuels et fossils. Océanis 10
(1): 99-110
Vacelet, J., 1985. Coralline sponges
and the evolution of Porifera. In: The
origins and relationships of lower
i n v e r t e b r a t e s . T h e s y s t e m a t i c s
Associa t ion . , S .C. Morr i s , J .D.
George, R. Gibson, and H.H. Platt
(eds) V. 28: 1-13, Claredon Press
Oxford.
van Soest, R.W.M., 1984. Deficient
Merlia normani Kirkpatrick, 1908, from
the Curaçao reefs, with a discussion
on the phylogenetic interpretation of
sclerosponges. Bijdr. Dierk. 54: 211-
219
Wellington, G.M., Merlen, G., and
Dunbar, R.B., 1996, Calibration of
stable oxygen isotope signatures in
Galapagos corals: Coral Reefs.
Willenz, Ph. & Hartman, W.D. 1985.
Calcification rate of Ceratoporella nicholsoni
(Porifera: Sclerospongiae): an in situ study
with calcein. Proc. Fifth Coral Reef
Congress, Tahiti, 5: 113-118.
Willenz, Ph. & Pomponi, S.A. 1996. A new
deep sea coralline sponge from Turks &
Caicos Islands : Willardia caicosensis gen.
et sp. nov. (Demospongiae : Hadromerida).
In: Recent Advances in Sponge Biodiversity
Inventory and Documentation. Ph. Willenz
(Ed.) Bulletin de l'Institut royal des Sciences
naturelles de Belgique. Biologie, 66 (Suppl):
205-218.
Wood, R., 1990. Reef-building sponges,
Amer. Scien. 78:224.235.
Wörheide, G., 1997. The reef cave
dwelling ultraconservative coralline
demosponge Astrosclera willeyana Lister
1 9 0 0 f r o m t h e I n d o - P a c i f i c .
Micromorphology, Ul t ras t ruc ture ,
Biocalcif icat ion, Isotope Record,
T a x o n o m y , B i o g e o g r a p h y ,
Phylogeny. Ph.D.thesis on CD-Rom.
Fakultät fu( r Geowissenschaften,
Georg-August-Universität Göttingen.
91 pp.; 30 pl.
19
Wörheide, G., 1998. The Reef Cave
Dwelling Ultraconservative Coralline
Demosponge Astrosclera willeyana
Lister 1900 from the Indo-Pacific.
Micromorphology , Ul t ras t ruc ture ,
Biocalcif icat ion, Isotope Record,
T a x o n o m y , B i o g e o g r a p h y ,
Phylogeny. Facies 38, 1-88.
20
SCLEROSPONGE WORKSHOP PARTICIPANTS
Dave Anderson NGDC Paleo
Group
Florian Bohm GEOMAR Forschungszentrum für Marine
Geowissenschaften Wischhofstr. 1-3,
Gebäude 4, D-24148 Kiel
Ellen Druffel U of California,
Irvine
Dept. of Earth System Science , Irvine,
CA 92697-3100
Rob Dunbar Stanford University Geological and Environmental Sciences ,
Stanford, CA 94305-2115
Anton Eisenhauer Geochemisches
Institut Goettingen
Goldschmidtstr. 1 , 37077 Goettingen [email protected]
Chris Charles Scripps 3119 Sverdrup Hall , La Jolla, Ca. 92093-
0220
Richard
Fairbanks
Columbia
University
Lamont-Doherty Earth Observatory , P.O.
Box 1000, Route 9W , Palisades, NY
10964
edu
Stewart Fallon Australian
National University
Environmental Geochemistry &
Geochronology, Research School of Earth
Science , Mills Road, Canberra , ACT
0200, Australia
Lisa Greer University of
Miami
Marine Geology & Geophysics/RSMAS ,
4600 Rickenbacker Causeway , Miami,
FL 33149
Gary Hughes University of
Pennsylvania
Department of Geology , Rm. 251
Hayden Hall 240 South 33rd Street ,
Philadelphia, PA 19104-6316
Judith C. Lang Texas Memorial
Museum
2400 Trinity , Austin, TX 78705 [email protected]
Ted
McConnaugheyCompuserve 8730 N Newport Place , Tucson AZ
85704 USA
Michael Moore Scripps Geosciences Research Division 0220
La Jolla, CA 92093-0220 USA
Joachim Reitner University of
Goettingen
IMGP, Goldschmidtstr. 3 , D-37077
Goettingen Germany
21
The sclerosponge workshop participants
Jim Rubenstone Columbia
University
Lamont-Doherty Earth Observatory P.O.
Box 1000, Route 9W , Palisades, NY
10964
Howie Spero University of
California
Department of Geology , Davis CA
95616-8605
Peter Swart University of
Miami
Marine Geology & Geophysics/RSMAS ,
4600 Rickenbacker Causeway , Miami,
FL 33149
Charles Thayer University of
Pennsylvania
Department of Geology , 240 South 33rd
Street Philadelphia, PA 19104-6316
Peter Torssander Stockholm
University
Dept. of Geology and Geochemistry , S-
106 91 Stockholm, Sweden
Courtney Turich University of
Texas/Austin
Department of Geological Sciences ,
Austin, TX 78712
u
Philippe Willenz Royal Belgian
Institute of Natural
Sciences
Department of Invertebrate Zoology ,
Vautier Street 29, B-1000 Brussels,
BELGIUM
Amos Winter University of
Puerto Rico
Department of Marine Sciences , PO Box
9013 Mayaguez, PR 00681-9013
Dirk Wischow Institut Goettingen Geochemisches , Goldschmidtstr. 1 ,
37077 Goettingen
contact thru Eisenhauser
