Seasonality and stable isotopes in planktonic foraminifera off Cape Cod, Massachusetts
Keigwin, Lloyd D.
Copley, Nancy J.
MetadataShow full item record
Monthly samples of stratified plankton tows taken from the slope waters off Cape Cod nearly 25 years ago are used to describe the seasonal succession of planktonic foraminifera and their oxygen isotope ratios. The 15°C seasonal cycle of sea surface temperature (SST) accounts for a diverse mixture of tropical to subpolar species. Summer samples include various Globigerinoides and Neogloboquadrina dutertrei, whereas winter and early spring species include Globigerina bulloides and Neogloboquadrina pachyderma (dextral). Globorotalia inflata lives all year but at varying water depths. Compared with the fauna in 1960–1961 (described by R. Cifelli), our samples seem warmer. Because sea surface salinity varies little during the year, δ18O is mostly a function of SST. Throughout the year, there are always species present with δ18O close to the calculated isotopic equilibrium of carbonate with surface seawater. This raises the possibility that seasonality can be estimated directly from the range of δ18O in a sediment sample provided that the δ18O-salinity relationship is the same as today.
Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 20 (2005): PA4011, doi:10.1029/2005PA001150.
Showing items related by title, author, creator and subject.
The influence of differential production and dissolution on the stable isotope composition of planktonic foraminifera Erez, Jonathan (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1978-11)Planktonic foraminifera from plankton tows, sediment traps and sediments from the central North Atlantic were studied in order to understand how they acquire their oxygen and carbon isotope compositions. Shallow dwelling ...
Comparison of two methods to identify live benthic foraminifera : a test between Rose Bengal and CellTracker Green with implications for stable isotope paleoreconstructions Bernhard, Joan M.; Ostermann, Dorinda R.; Williams, David S.; Blanks, Jessica K. (American Geophysical Union, 2006-12-01)The conventional method to distinguish live from dead benthic foraminifers uses Rose Bengal, a stain that reacts with both live and dead cytoplasm. CellTracker Green CMFDA is a fluorogenic probe causing live cells to ...
Fry, Brian; Cieri, Matthew; Hughes, Jeff; Tobias, Craig R.; Deegan, Linda A.; Peterson, Bruce J. (Inter-Research, 2008-10-13)Salt marshes are important coastal ecosystems whose trophic function can be monitored with stable isotopes of abundant fish biosentinel species such as the mummichog Fundulus heteroclitus and the Atlantic silverside Menidia ...