Seasonality in planktic foraminifera of the central California coastal upwelling region
The close association between planktic foraminiferal assemblages and local hydrography make foraminifera invaluable proxies for environmental conditions. Modern foraminiferal seasonality is important for interpreting fossil distributions and shell geochemistry as paleoclimate proxies. Understanding...
Main Authors: | , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2016-09-01
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Series: | Biogeosciences |
Online Access: | http://www.biogeosciences.net/13/5139/2016/bg-13-5139-2016.pdf |
Summary: | The close association between planktic foraminiferal assemblages and local
hydrography make foraminifera invaluable proxies for environmental
conditions. Modern foraminiferal seasonality is important for interpreting
fossil distributions and shell geochemistry as paleoclimate proxies.
Understanding this seasonality in an active upwelling area is also critical
for anticipating which species may be vulnerable to future changes in
upwelling intensity and ocean acidification. Two years (2012–2014) of
plankton tows, along with conductivity–temperature–depth profiles and
carbonate chemistry measurements taken along the north-central California
shelf, offer new insights into the seasonal dynamics of planktic foraminifera
in a seasonal coastal upwelling regime. This study finds an
upwelling affinity for <i>Neogloboquadrina pachyderma</i> as well as a
seasonal and upwelling associated alternation between dominance of <i>N.
pachyderma</i> and <i>Neogloboquadrina incompta</i>, consistent with previous
observations. <i>Globigerina bulloides</i>, however, shows a strong
affinity for non-upwelled waters, in contrast to findings in Southern
California where the species is often associated with upwelling. We also find
an apparent lunar periodicity in the abundances of all species and document
the presence of foraminifera even at very low saturation states of calcite. |
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ISSN: | 1726-4170 1726-4189 |