Table of Contents

• Coverage
• Dataset Description
  • Methods & Sampling
  • Data Processing Description
• Data Files
• Related Publications
• Parameters
• Instruments
• Deployments
• Project Information
• Program Information
• Funding

Record of d²H of dinosterol variability in down core lake sediments from Clear Lake, Palau.

These data are published in the following journal article:
Richey, J. N., & Sachs, J. P. (2016). Precipitation changes in the western tropical Pacific over the past millennium. Geology, 44(8), 671–674. doi:10.1130/g37822.1 

Sampling and analytical procedures:
Clear Lake sediments were extracted using a Dionex Accelerated Solvent Extractor (ASE 200), and the resulting total lipid extract was separated into neutral and polar fractions using column chromatography with aminopropyl gel as the stationary phase. The neutral fraction was then separated into hydrocarbon, wax ester, sterol and polar fractions via a silica gel column chromatography. Dinosterol was isolated then from the sterol fraction via reverse phase (RP)- high-performance liquid chromatography (HPLC)
.

Instruments:
Dinosterol was isolated from the sterol fraction via reverse phase (RP)- high performance liquid chromatography (HPLC). An Agilent 1100 HPLC with an integrated autoinjector, quaternary pump, and fraction collector was coupled to an Agilent 1100 LC/MSD SL mass spectrometer with a multimode source that was operated in positive atmospheric pressure chemical ionization (APCI+) mode. The HPLC method used is outlined in Nelson and Sachs (2013). Subsequently to HPLC separation the fraction containing dinosterol was analyzed via GC-MSD to verify sufficient baseline separation. Adjacent HPLC fractions were also analyzed to ensure that no dinosterol eluted into those fractions.

After the dinosterol was sufficiently isolated from co-eluting compounds, the sample was injected onto a GC-irms for determination of the d2H of dinosterol.  Hydrogen isotope determinations were made using a Finnigan Delta V Plus Isotope Ratio Mass Spectrometer (irMS) coupled to a Thermo Trace GC Ultra with a Varian VF-17ms FactorFour capillary column (60 m x 0.32 mm x 0.25 m) and a pyrolysis reactor. Samples were injected into a split/splitless inlet in splitless mode at 310 C. The oven temperature was ramped from 100 C to 220 C at a rate of 20 C/min, then at 2 C /min up to 325 C where it was held for 17 min. The carrier gas, He, was held constant at 2.6 mL/min. The pyroloysis reactor was maintained at 1400 C. Isotope values, expressed as D values, were calculated in Isodat software relative to VSMOW using a co-injection standard containing nC28 nC32, nC40, and nC44 of known ∂2H values (obtained from Arndt Schimmelmann, Indiana University, Bloomington, IN, USA). The measured isotope values of dinosterol were corrected for the addition of hydrogen atoms (of known D value) that occurred during acetylation. Each sample was analyzed in at least duplicate, and error bars represent standard deviations of replicate measurements.

BCO-DMO Processing:
- modified parameter names to conform to BCO-DMO naming conventions;
- replaced "NaN" with "nd".

This project will survey the taxonomic, genetic, and functional diversity of the organisms found in marine lakes, and investigate the processes that cause gains and losses in this biodiversity. Marine lakes formed as melting ice sheets raised sea level after the last glacial maximum and flooded hundreds of inland valleys around the world. Inoculated with marine life from the surrounding sea and then isolated to varying degrees for the next 6,000 to 15,000 years, these marine lakes provide multiple, independent examples of how environments and interactions between species can drive extinction and speciation. Researchers will survey the microbes, algae, invertebrates, and fishes present in 40 marine lakes in Palau and Papua, and study how diversity has changed over time by retrieving the remains of organisms preserved in sediments on the lake bottoms. The project will test whether the number of species, the diversity of functional roles played by organisms, and the genetic diversity within species increase and decrease in parallel; whether certain species can greatly curtail diversity by changing the environment; whether the size of a lake determines its biodiversity; and whether the processes that control diversity in marine organisms are similar to those that operate on land.

Because biodiversity underlies the ecosystem services on which society depends, society has a great interest in understanding the processes that generate and retain biodiversity in nature. This project will also help conserve areas of economic importance. Marine lakes in the study region are important for tourism, and researchers will work closely with governmental and non-governmental conservation and education groups and with diving and tourism businesses to raise awareness of the value and threats to marine lakes in Indonesia and Palau.

(adapted from the NSF Synopsis of Program)
Dimensions of Biodiversity is a program solicitation from the NSF Directorate for Biological Sciences. FY 2010 was year one of the program.  [MORE from NSF]

The NSF Dimensions of Biodiversity program seeks to characterize biodiversity on Earth by using integrative, innovative approaches to fill rapidly the most substantial gaps in our understanding. The program will take a broad view of biodiversity, and in its initial phase will focus on the integration of genetic, taxonomic, and functional dimensions of biodiversity. Project investigators are encouraged to integrate these three dimensions to understand the interactions and feedbacks among them. While this focus complements several core NSF programs, it differs by requiring that multiple dimensions of biodiversity be addressed simultaneously, to understand the roles of biodiversity in critical ecological and evolutionary processes.