Planktonic foraminifera in the sea of Okhotsk : population and stable isotopic analysis from a sediment trap
Alderman, Susan E.
MetadataShow full item record
The relationship of planktonic foraminiferal populations and stable isotopes to synoptic sea surface temperatures (SST's) was examined in the Sea of Okhotsk, using sediment trap samples (trap deployed Aug. '90 - Aug. '91; 53°19'N, 149°50'E) and AVHRR satellite sea surface temperature data. Synoptic SST's for the deployment ranged between -1.2 and 14.8°C. Two species dominated total yearly foraminiferal flux: N. pachyderma (left) and G. bulloides, with 57% and 31% of yearly flux, respectively. Calcification depths (from δ180eq. calcite) for these species ranged between 20 and 40 meters. Due to the highly stratified water column in the Sea of Okhotsk, these foraminifera experienced temperatures much colder than SST, and use of standard paleotemperature proxies significantly underestimates SST. The average paleotemperatures calculated from both δ180pachy and δ18Dbull were 5-6°C lower than average synoptic SST. Faunal indicators were consistent with this finding, with the N. pachyderma left-to-right coiling ratios >98% for the entire trap deployment. These ratios would suggest maximum seasonal SST's no greater than 10°C, nearly 5°C colder than the actual sea surface temperature maximum. The results from this study indicate that in highly stratified water columns, standard paleotemperature proxies may yield results as much as 5°C cooler than actual sea surface conditions.
Submitted in partial fulfillment of the requirements for the degree of Master of Science at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution May 1996
Suggested CitationThesis: Alderman, Susan E., "Planktonic foraminifera in the sea of Okhotsk : population and stable isotopic analysis from a sediment trap", 1996-05, DOI:10.1575/1912/5673, https://hdl.handle.net/1912/5673
Showing items related by title, author, creator and subject.
Hu, Qiao (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2006-06)A fundamental problem in limnology and oceanography is the inability to quickly identify and map distributions of plankton. This thesis addresses the problem by applying statistical machine learning to video images ...
The distribution, abundance and ecology of mixotrophic algae in marine and freshwater plankton communities Arenovski, Andrea L. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1994-09)Mixotrophic algae are algae that combine photosynthesis with phagotrophy to satisfy nutritional requirements. Mixotrophic algae have been found to dominate the nanoplankton assemblage in some aquatic environments, and ...
Caron, David A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1984-06)The distribution and feeding behavior of bacterivorous micro flagellates (2-20 μm protozoa) and their ingestion by copepods were examined in an attempt to assess the importance of these protozoa as a trophic link ...