TY - JOUR
T1 - Determining the absolute abundance of dinoflagellate cysts in recent marine sediments III
T2 - Identifying the source of Lycopodium loss during palynological processing and further testing of the Lycopodium marker-grain method
AU - Price, Andrea Michelle
AU - Gurdebeke, Pieter Roger
AU - Mertens, Kenneth Neil
AU - Pospelova, Vera
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/3/1
Y1 - 2016/3/1
N2 - Lycopodium clavatum marker-grain tablets are often added before palynological processing to calculate the absolute abundance of organic-walled microfossils in sediments. In this study we investigate the reproducibility of dinoflagellate cyst concentrations by performing nine different tests: varying dinoflagellate cyst/. Lycopodium spore ratios, sample weights, centrifuge speeds and times, sonication times, and mesh sizes; manually powdering the sediment using a mortar and pestle prior to processing, using a water jug instead of squirt bottles during sieving, decanting over a 6 μm sieve and adding Lycopodium tablets at the end. Previous studies have reported loss of Lycopodium spores during processing. In this study we investigate sources of this loss by microscopically analyzing residue on stir sticks and sieves, and what is lost through the sieves and decanting. We document an average loss of 8.2 % of Lycopodium spores during processing, with the greatest loss occurring through the fine sieve and resulting in only a 4.8% overestimation of the cyst concentration. Results using powdered sediment and sonicating for more than 5 min are less reproducible. Large cyst/. Lycopodium spore ratios were found to have higher cyst concentrations and standard deviations, thus we recommend ratios of less than five, and ideally ratios between 0.5 and 2 to facilitate counting.
AB - Lycopodium clavatum marker-grain tablets are often added before palynological processing to calculate the absolute abundance of organic-walled microfossils in sediments. In this study we investigate the reproducibility of dinoflagellate cyst concentrations by performing nine different tests: varying dinoflagellate cyst/. Lycopodium spore ratios, sample weights, centrifuge speeds and times, sonication times, and mesh sizes; manually powdering the sediment using a mortar and pestle prior to processing, using a water jug instead of squirt bottles during sieving, decanting over a 6 μm sieve and adding Lycopodium tablets at the end. Previous studies have reported loss of Lycopodium spores during processing. In this study we investigate sources of this loss by microscopically analyzing residue on stir sticks and sieves, and what is lost through the sieves and decanting. We document an average loss of 8.2 % of Lycopodium spores during processing, with the greatest loss occurring through the fine sieve and resulting in only a 4.8% overestimation of the cyst concentration. Results using powdered sediment and sonicating for more than 5 min are less reproducible. Large cyst/. Lycopodium spore ratios were found to have higher cyst concentrations and standard deviations, thus we recommend ratios of less than five, and ideally ratios between 0.5 and 2 to facilitate counting.
KW - Dinoflagellate cyst
KW - Lycopodium clavatum tablet
KW - Palynological preparation
KW - Reproducibility
KW - Spike
KW - Standardization
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U2 - 10.1016/j.revpalbo.2015.12.009
DO - 10.1016/j.revpalbo.2015.12.009
M3 - Article
AN - SCOPUS:84955089375
SN - 0034-6667
VL - 226
SP - 78
EP - 90
JO - Review of Palaeobotany and Palynology
JF - Review of Palaeobotany and Palynology
ER -