Course
Instruction: ENVI
110 Intro to Environmental Science, GEOL 160 Intro to Earth and Sky,
GEOL 270 Historical Geology,
GEOL 361 Oceanography,
ENVI 376 Dinosaurs, Earthquakes and Volcanoes, GEOL 389 Introduction to Field Geology,
GEOL 470/570 Principles of Paleontology,
GEOL 666 Early
Life On Earth,
GEOL 661 Seminar in Paleoceanography,
GEOL 661 Seminar in Paleoecology,
GEOL 683 Coastal Environments
Research
Interests: Paleoceanography, Paleoecology, Micropaleontology, Geobiology and Biogeochemistry of
Methane Seeps
Research
Profile:
My current work primarily
focuses on the ecology and geochemistry of
modern foraminifera and the calibration of proxies for
use in paleoceanography, and environmental change. I am involved in several
projects that examine the relationships between
ambient conditions, and the ecology and geochemistry
of biomineralization in calcareous foraminifera.
Each of these projects incorporates student research.
Summary of Current Projects:
1) Collaborative
Research: Calibration of a new approach to
reconstruct ancient bottom water oxygen levels
(A.E. Rathburn, B. H. Corliss (Duke University),
Co-PIs) Funded by NSF Marine Geology and Geophysics
We intend to use living (stained or labeled)
specimens collected from a wide variety of habitats,
including a 2011 transect across the oxygen minimum
zone off San Diego, to examine the relationship
between foraminiferal morphology and ambient
dissolved oxygen. Together with graduate and
undergraduate students and a research technician, we
are using scanning electron imaging technology to
compare pore characteristics of calcareous
foraminiferal tests (shells) with dissolved oxygen
contents of the water they are living in. The focus
of this study is on epifauna (species that live on
or above the sediment-water interface), but infaunal
foraminiferal distribution and morphologies will
also be examined, and compared with bottom water and
pore water chemistry. To examine the relationships
between test morphology and dissolved oxygen in a
broad spectrum of environments, we will also
evaluate the morphologies of epifauna from archived
samples from around the world.
2)
Pre-industrial
sea-surface temperature reconstructions in the
Tasman Sea.
A. E. Rathburn Co-PI with
P. DeDeckker, (Australian National University, S.
Schmidt (Université Bordeaux, France) and S.
Schouten (Royal Netherlands Institute For Sea
Research, The Netherlands). Ship time funding by
the Marine National Facility, Australia; ISU funding
provided by the University Research Council. Using
samples collected along a transect on the Australian
margin from Tasmania to Brisbane, we will examine
microfauna collected in the water column and from
seafloor sediments. ISU students will examine the
distribution, ecology and stable isotopic
composition of benthic foraminifera from multicorer
samples and compare results with those of
environmental parameters and planktonic
micro-organisms.
3.)
Interdisciplinary approach to understand stable
isotopic
disequilibrium in benthic foraminifera (A.E.
Rathburn, J. M. Bernhard
(Woods Hole Oceanographic Institution), and J. B.
Martin (Univ. Florida)
Co-PIs) Funded by NSF Marine Geology and Geophysics
Using the remotely operated vehicle, JASON, we
collected samples
from clam beds associated with seafloor methane
seeps in Monterey Bay,
off the coast of California. Together with graduate
and undergraduate
students and a postdoctoral researcher, we are using
a variety of
recently developed techniques to understand why the
isotopic
geochemistry of benthic foraminiferal carbonate is
so very different
from that of the water they are living in.
Foraminiferal chemistry and
distribution will be compared with foramininferal
biology (food
vacuoles, symbionts, etc.), and pore water chemical
and isotopic
composition. To examine a broad spectrum of isotopic
environments, we
propose a coupled study of both non-seep sediments
and nearby cold
methane seep environments, where steep geochemical
gradients occur. The
specific hypotheses to be tested are:
A) The carbon isotopic composition of foraminiferal
carbonate is
influenced by clustering of individuals within
sub-millimeter seep
microenvironments.
B) The carbon isotopic composition of foraminiferal
carbonate is
influenced by diet.
C) The carbon isotopic composition of benthic
foraminiferal carbonate is
influenced by prokaryotic, non-photosynthetic
symbionts.
4) Testing the impact of seasonality on benthic
foraminifera as
paleoceanographic proxies. (A. E. Rathburn,
Co-PI with Scott Ishman
(Univ. of South. Illinois) and Jon Martin (Univ. of
Florida)) Funded by
NSF Polar Programs
Together with graduate and undergraduate
participants, we sampled
seafloor sites along a gradient of productivity
(food availability) off
the Antarctic Penninsula in April (bloom time) and
July(non-bloom time)
2008. By comparing the distribution and
biogeochemistry of living and
dead foraminiferal assemblages with environmental
characteristics
through time and space at these locations we will be
able to discern
foraminiferal responses to seasonal and spatial
changes in food
availability in this region. This information is
critical to understand
how seafloor ecosystems will respond to future
change, and to provide
modern analog data that can be used to assess
environmental changes in
the past based on foraminiferal fossil assemblages.
5) Structure, function
and evolution of authigenic, methane-derived
carbonate ecosystems (A. E. Rathburn Co-PI with
Lisa Levin and Greg
Rouse (Scripps Inst. Of Oceanography) and Victoria
Orphan (California
Inst. of Technology)). An interdisciplinary team
including graduate and
undergraduate participants is studying newly
recognized ecosystems
associated with carbonate rocks generated in
seafloor methane seepage
environments. The site chosen are known locations of
methane seep
habitats off Costa Rica and off Oregon (Hydrate
Ridge). In a series of
cruises in 2009 and 2010, we will deploy experiments
and recover samples
from seep and non-seep habitats in order to compare
carbonate rock
ecosystems with those in nearby seep and non-seep
environments.
Specifically, we are examining the ecology, biology
and biogeochemistry
of foraminifera from these habitats.
6) Development of faunal and
biogeochemical pollution proxies in the
Venice Lagoon, Italy (part of an
interdisciplinary ScrippCo-PIs). Together with a
team of Scripps Institution of Oceanography
scientists and Italian scientists (SIOSED Project),
we examined
responses of organisms to contaminants and
redistribution of seafloor
sediments in the Venice Lagoon, Italy. Specifically,
we are studying
the ecological and trace metal biogeochemical
responses of benthic
foraminifera over time and space within the Lagoon.
By examining
recovery of foraminiferal assemblages on sediment
banks artificially
created for the project, we are better able to
understand the ecological
and geochemical consequences of sediment
redistribution in the Lagoon.
One goal of this project is to develop microfaunal
and biogeochemical
indicators of contaminants in order to monitor
pollution impact and
recovery in this and other lagoons with a history of
contamination.
Selected Publications
The following are examples of
publications over time. For a more
complete listing, contact Dr. Rathburn.
Basak, C., Rathburn, A. E., Pérez, M.E.
Martin, J. B., Kluesner, J. W.,
Levin, L.A., De Deckker, P., Gieskes, J.M., and Abriani,
M. (2009)
Carbon and oxygen isotope geochemistry of live (stained)
benthic
foraminifera from the Aleutian Margin and the southern
Australian
Margin. Marine Micropaleontology. 70 (2009) 89–101.
doi:10.1016/j.marmicro.2008.11.002
Rathburn, A. E., L. A. Levin, M. Tryon,
W. Ziebis, J. M. Gieskes, J. B.
Martin, M. E. Pérez, F. J. Fodrie, C. Neira, G. Mendoza,
P. A. McMillan,
J. Adamic, J. Kluesner (2009) Geological and Biological
Heterogeneity of
the Aleutian Margin (1965-4822 m). Progress in
Oceanography, 80: 22-50.
Gieskes, J., Mahn, C., Day, S., Martin, J., B., Greinert,
J., Rathburn,
A. E., McAdoo, B. (2005) A study of the
chemistry of pore fluids and
authigenic carbonates in methane seep environments:
Kodiak Trench ,
Hydrate Ridge, Monterey Bay, and Eel River Basin.
Chemical Geology 220
(2005) 329-345
Martin, J. B., Day, S. A., Rathburn, A. E.,
Perez, M. E., Mahn, C,
Gieskes, J., 2004. Relationships between the stable
isotopic signatures
of living and fossil foraminifera in Monterey Bay,
California.
Geochemistry, Geophysics and Geosystems, 5, Q04004,
doi:10.1029/2003GC000629.
Rathburn, A.E., Perez, M. E., Martin,
J. B., Day, S. A., Gieskes, J.,
Mahn, C., Ziebis, W., Williams, D., Bahls, A. (2003)
Relationships
between the distribution and stable isotopic composition
of living
foraminifera and cold methane seep biogeochemistry in
Monterey Bay,
California. Geochemistry, Geophysics and Geosystems
4(12), 1106,
doi:10.1029/2003GC000595.
Levin, L. A., Rathburn, A. E., Neira,
C., Sellanes, J., Munoz, P.,
Gallardo, V., Salamanca, M., (2002) Benthic Processes on
the Peru
Margin: A transect across the oxygen minimum zone during
the 1997-1998
El Ni?o, Progress in Oceanography 53: 1-27.
Rathburn, A. E., Perez, M. E., and
Lange, C., 2001, Benthic-Pelagic
Coupling in The Southern California Bight: Relationships
Between Sinking
Organic Material, Diatoms and Benthic Foraminifera:
Marine
Micropaleontology, v. 43, p. 261-271.
Rathburn, A. E., Levin, L. A., Held, Z.
A., Lohmann, K. C., 2000,
Benthic Foraminifera Associated with Cold Methane Seeps
on the Northern
Californian Margin: Ecology and Stable Isotopic
Composition: Marine
Micropaleontology, v. 38 p. 247-266.
Gooday, A. J., and Rathburn, A. E.,
1999, Temporal Variability in Living
Deep-Sea Benthic Foraminifera: a Review, Earth-Science
Reviews, v. 46,
p. 187-212.
Rathburn, A. E., Pichon, J-. J., Ayress,
M. A., and De Deckker, P.,
(1997) Microfossil and Stable Isotope Evidence for
Changes in Late
Holocene Paleoproductivity and PaleoceanographBay Region
of Antarctica. Palaeogeography, Palaeoclimatology,
Palaeoecology, 131 (3/4): 485-510.
Rathburn, A. E., and De Deckker, P.,
(1997) Magnesium and Strontium
Compositions of Recent Benthic Foraminifera from the
Coral Sea,
Australia, and Prydz Bay, Antarctica. Marine
Micropaleontology, 32:
231-248.
Rathburn, A.E., B.H. Corliss, K. D.
Tappa, and K.C. Lohmann, (1996).
Comparisons of the Ecology and Stable Isotopic
Compositions of Living
(Stained) Deep-Sea Benthic Foraminifera from the Sulu
and South China
Seas. Deep-Sea Research, 43 (10): 1617-1646.
Rathburn, A.E. and B.H. Corliss,
(1994). The Ecology of Living (Stained)
Benthic Foraminifera from the Sulu Sea. Paleoceanography,
9, (1):
87-150.
Abstracts Since
2002 Presented with Student Co-Authors
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