| NSF Org: |
OCE Division Of Ocean Sciences |
| Recipient: |
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| Initial Amendment Date: | October 28, 2013 |
| Latest Amendment Date: | October 28, 2013 |
| Award Number: | 1401349 |
| Award Instrument: | Standard Grant |
| Program Manager: |
David Garrison
OCE Division Of Ocean Sciences GEO Directorate for Geosciences |
| Start Date: | August 15, 2013 |
| End Date: | September 30, 2015 (Estimated) |
| Total Intended Award Amount: | $61,026.00 |
| Total Awarded Amount to Date: | $61,026.00 |
| Funds Obligated to Date: |
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| History of Investigator: |
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| Recipient Sponsored Research Office: |
202 HIMES HALL BATON ROUGE LA US 70803-0001 (225)578-2760 |
| Sponsor Congressional District: |
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| Primary Place of Performance: |
LA US 70803-2701 |
| Primary Place of
Performance Congressional District: |
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| Unique Entity Identifier (UEI): |
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| Parent UEI: |
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| NSF Program(s): | CRI-Ocean Acidification |
| Primary Program Source: |
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| Program Reference Code(s): |
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| Program Element Code(s): |
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| Award Agency Code: | 4900 |
| Fund Agency Code: | 4900 |
| Assistance Listing Number(s): | 47.050 |
ABSTRACT
Intellectual merit: This project will develop a new interdisciplinary partnership between connectivity ecology (Levin at SIO), metal isotope geochemistry (Anbar and Gordon at ASU), and paleoclimatology (Herrmann at ASU) to identify new proxies for ocean acidification that can be used to assess pH exposures in living organisms and, potentially to interpret the geologic record. The investigators hypothesize that the isotopic composition of larval calcium carbonates reflects changes in seawater chemistry driven by ocean acidification and, in some instances, with associated decline in oxygen levels. The large extent to which these two parameters vary in concert in the modern and past ocean (and thus have joint influence), and the extent to which they may be uncoupled by anthropogenic CO2 inputs, merits considerable attention. Thus, the integration of pH and oxygen in proxy development would be an important advance.
The focus of this project is on proxy development to determine pH exposure history for living organisms in their larval state, and will center on calcium, boron, and uranium isotopes as well as multi-elemental fingerprints. For this project, the investigators will target open coast, front bay and backbay mytilid mussel species, each living naturally under a different pH regime, and statoliths of encapsulated market squid larvae from the open shelf. Larvae with known pH, oxygen and temperature exposure histories will be obtained from (1) laboratory larval rearing experiments that manipulate pH and oxygen and (2) in situ out planting of lab-spawned larvae in larval homes onto existing moorings where pH, T and oxygen are being monitored. Analyses will employ SIMS (for del 11B), multicollector (for del 44Ca, del 238 U), and laser ablation ICP-MS (targeting B, Cu, U, Pb, Mo, and a suite of additional pH- and redox-sensitive trace elements). Multivariate statistical tools will define ability to detect pH-induced signatures and to determine species or taxon-specific vital effects. The investigators are exploring proxies for invertebrate larvae that are untested in the context of acidification geochemistry. Targeting larvae is critical as many marine organisms produce larval carbonate structures and these stages may be most affected by ocean acidification. The retention of larval shell and statoliths after recruitment may ultimately allow us to test the importance of larval pH and O2 exposure to survival and population persistence. An ability to assess past exposures through geochemical proxies will provide information about relative pH tolerances and ecosystem-level change in response to changes in the ocean¡¦s carbonate chemistry.
Broader impacts: This project will: (1) engaging young scientists in new collaborations (2) involving underrepresented students through UC summer diversity programs and (3) conveying the science to students via UCSD IGERT courses in the program Global Change, Marine Science and Society, as well as via courses taught by Levin, Anbar and Herrmann. Translation of ecological results to the fields of marine geochemistry and paleoclimatology (and back) will provide the seed for future collaboration and advances.
PROJECT OUTCOMES REPORT
Disclaimer
This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.
Changes in the amount of dissolved oxygen and acidity of the surface ocean threaten the health of fisheries in several coastal environments in the US. This exploratory research award enabled a set of laboratory experiments to develop single and multi-elemental geochemical proxies for mussel larval exposure to high pCO2 and low O2 conditions. In particular, the emphasis of this project was to develop geochemical fingerprints that would allow researchers to determine pH exposure history for living organisms in their larval state. Is the chemical composition of mussel larvae a faithful recorder of such chemical changes in seawater? In order to assess this possibility, this research project aimed at establishing differences in the chemical composition of mussel larvae reared under different environmental conditions using a range of instruments.
- Measurement of boron isotopes using secondary ion mass spectrometry.
- Measurement of calcium isotopes using multi-collector inductively coupled mass spectrometry.
- Measurement of boron-to-calcium ratios using laser ablation inductively coupled mass spectrometry.
The major results of this project (presented at meetings, written up as undergraduate theses, or in preparation as papers) assess all aspects of this research project. The results of this research project indicate that there is little change in the calcium isotopic or boron isotopic composition of mussel larvae in response to changes in pH or O2 conditions. While the results of the laser ablation inductively coupled mass spectrometry measurements indicate that the elemental composition of mussel larvae holds promise as an indicator of environmental change, the lack of an appropriate standard hampers progress in this area of research. Hence, from the current results, it is inconclusive as to whether elements ratios record environmental conditions in mussel larvae. Further work is needed to determine whether new standard material can help improve accuracy and precision of such measurements.
The award supported several related secondary projects that provided further baseline information about elemental chemistry of calcareous shells and improved analytical approaches. The award contributed substantially to the training of two undergraduate students in field and laboratory methods, as well as in mass spectrometric analyses, enhancing the skilled scientific workforce. Lastly, PI Herrmann conveyed the results and importance of this research project to students in the undergraduate class he teaches at LSU (“History of the Biosphere”).
Last Modified: 04/12/2016
Modified by: Achim D Herrmann
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