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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