PALEO RECORDS OF BIOTIC AND ABIOTIC PARTICLES IN POLAR ICE CORES

John Priscu, Christine Foreman, Joe McConnellMontana State University & DRI, Reno, NV

Where Am I Going?

•Methods

•WAIS particle characteristics (biotic andWAIS particle characteristics (biotic and abiotic)

Dissolved Organic Carbon (food for bugs!)•Dissolved Organic Carbon (food for bugs!)

•Metabolic activity

•Microbial habitats in ice

•Geochemistry (DOC, Sr, Ca)

Flow cytometry uses the principles of light scattering , light excitation, and emission of fluorochrome molecules to generate specific multi-

FLOW CYTOMETRY

parameter data from particles and cells in the size range of ~0.2 µm to 15µm diameter.

(Differentially stained to ( yDetect DNA-SYTO 60)

Comparison of a sample from Lake Vostok ice core 2334, using a coulter counter and the flow cytometer Coulter counter data kindly provided by Ellen Moseley Thompson of Byrd Polarcytometer.  Coulter counter data kindly provided by Ellen Moseley‐Thompson of Byrd Polar Research Center, Ohio State University.

Method Vostok core 2334

Coulter Counter(particles ml-1) 24994(particles ml 1) 24994

Flow cytometerFlow cytometer(particles ml-1) 27818

Fl C t t D tWAIS Divide Core WDC05Q Stick D

Flow Cytometer Data

Fig. X. Biotic (bacteria) and abiotic particle distribution from a shallow WAIS Di id ti bt i d ith Mi t fl t tWAIS Divide core section obtained with a Microcyte flow cytometer.

Abiotic V1686

4000

Abiotic V2334 Abiotic V3612

300

Vostoc Ice Core Particle Characterizationue

ncy

2000

3000

4000

uenc

y

400

600

uenc

y 200

300

A C E

Avg size (µm) = 0.60 Avg size (µm) = 1.24Avg size (µm) = 2.63

Freq

0

1000

2000

Freq

0

200 Freq

0

100

Avg size (µm)   0.60

Size (µm)

0 3 6 9 12 15

Biotic V1686

Size (µm)

0 3 6 9 12 15

Biotic 2334

Size (µm)

0 3 6 9 12 15

Biotic V3612

ency

75

100

ency 75

100

ency

20

30B D FAvg size (µm) = 2.45 Avg size (µm) = 1.60Avg size (µm) = 3.74

Freq

ue

0

25

50

Freq

ue

0

25

50

Freq

ue0

10

20

Size (µm)

0 3 6 9 12 150

Size (µm)

0 3 6 9 12 150

Size (µm)

0 3 6 9 12 150

CORE ID: WDC05Q Stick D

Epifluorescence microscope countsDNA stained sample (SYBR GOLD)

WDC 05Q Stick D; 86 96 mWDC 05Q Stick D; 86.96 m

Epifluorescence microscope countsEpifluorescence microscope countsDNA stained sample (SYBR GOLD)

WDC 05Q Stick D; 86.96 m

“ATTACHED BACTERIA”

5 µm

3 µm

BACTERIAL ACTIVITY IN ICY SYSTEMS1000 G k ll A t i

h-1 ) 100

1000 snow, Gossenkollesee, Austrialake ice, Gossenkollensee, Austrialakewater, Piburgersee, Austrialakewater, Tai Hu, Chinacloud droplets Austria (3100 m)

on (n

g C

l-1

1

10

cloud droplets, Austria (3100 m)snow, Austria (3100 m)lakewater Gossenkollesee, Austrialake ice, Lake BonneyBlood Falls, Taylor Glacier

rial P

rodu

ctio

0.1

1 , ysnow, North Polesnow, South PoleColle Gnifetti Gl, SwitzerlandRotmoos Glacier, Austria

WAIS

Bact

er

0.01

Canada GlacierRhone GlacierTaylor Glacierleast squares fit

Bacterial C (ng C l-1)

1 10 100 1000 10000 100000 10000000.001

Data from B. Sattler Average carbon turnover time = 63 days and J. Priscu (melted

Cores; ~1 oC incubation)

1 micron fluorescent beads in an ice vein.  

1 micron fluorescent beads in an ice vein subjected to a 0.2 oC temperature gradient  (Avg ice temp = ‐15 oC)p g ( g p )

GEOCHEMISTRY

GEOCHEMISTRY

DOC of Seawater Origin?

TAKE HOME LESSON: OLD VIEW

Typical Numbers of Prokaryotic Typical Numbers of Prokaryotic C ll i N t l H bit tC ll i N t l H bit tCells in Natural HabitatsCells in Natural Habitats

Habitat Cells ml -1Colon/Rumen 0.1-1 x 1010

Soil 0.1-100 x 107

Marine (open water) 0.05 - 460 x 106( p )Fresh and saline lakes 1.0 x 106

Rivers 1.0 x 106Rivers 1.0 x 10Ocean sediments 0.34 - 220 x 106

Glacial ice 1 0 2 0 X 103Glacial ice 1.0 - 2.0 X 103

Background data from Whitman et al. 1998, “Prokaryotes: the unseen majority”, PNAS, 95:6578-6583.

Future PlansFuture Plans

•Try to make continuous measurements (or discrete samples using aTry to make continuous measurements (or discrete samples using a fraction collector)?

→Or would it be best to work on annual cycles (i.e., melt a l th f i ti )?length of ice representing one year)?

•Examine diversity using genomic methods (most easily done if we worked on ice cores integrated over a year)

•Directly measure the mass of particulate organic C and NDirectly measure the mass of particulate organic C and N

•Continue our attempts to measure metabolism in situ