TY - JOUR
T1 - Modern distribution of ostracodes and other limnological indicators in southern Lake Malawi
T2 - Implications for paleocological studies
AU - Blome, Margaret Whiting
AU - Cohen, Andrew S.
AU - Lopez, Matthew J.
N1 - Funding Information:
Acknowledgments Funding for the field work for this project was provided by the U.S. National Science Foundation-Earth System History Program (EAR-0602350). Funding for sample preparation and sedimentological analyses was provided to author Lopez by the SAGUARO (Southern Arizona Geosciences Union for Academics, Research and Outreach) program at the University of Arizona. SEM imaging was performed on a Hitachi S-3400 N housed in the Geosciences Department at the University of Arizona. Funding for the SEM facility was through the Arizona LaserChron Center Grant NSF EAR-0929777. Lead author Blome would like to thank a number of people for their invaluable assistance during the 2010 field season in Cape MacLear, Malawi including: Linkston Chataka (captain), Bernard Gulo (diver), Reidwel Nyirenda (geologist at Malawi Geological Survey Department), and Jeffery Stone (fellow researcher), as well as Jay Stauffer and
PY - 2014/5
Y1 - 2014/5
N2 - This modern distribution study from the southwest arm of Lake Malawi quantitatively relates variables of the lake environment to surficial assemblages of ostracodes and other paleoenvironmental indicators (molluscs, Botryococcus, fish, and charcoal) from 102 sites, across a gradient of littoral to shallow profundal conditions. The goal of this research is to use the resultant relationships to help quantify paleoecological interpretations of the fossil record from sediment cores. Site locations varied by depth (1-60 m) and adjacent shoreline environment. Thirty-three ostracode species are identified from 54 sites including four new, undescribed species of Cypridopsinae (2) and Limnocythere (2). Ostracodes are extremely abundant between 1 and 25 m water depth, but are rare to absent between 30 and 60 m. This disappearance is probably taphonomically controlled, with carbonate dissolution in the death assemblage since abundant live ostracodes have been found in the lake at greater than 30 m depth, where bottom sediments lack calcium carbonate. Constrained correspondence analysis (CCA) of ostracode species abundance suggests depth and dissolved oxygen (DO) content to be the primary environmental variables affecting their distribution. Additional CCA models using all biological indicators suggest limnologic variables correlated with depth (e.g., bottom water temperature and DO) and adjacent shoreline environment were most significant.
AB - This modern distribution study from the southwest arm of Lake Malawi quantitatively relates variables of the lake environment to surficial assemblages of ostracodes and other paleoenvironmental indicators (molluscs, Botryococcus, fish, and charcoal) from 102 sites, across a gradient of littoral to shallow profundal conditions. The goal of this research is to use the resultant relationships to help quantify paleoecological interpretations of the fossil record from sediment cores. Site locations varied by depth (1-60 m) and adjacent shoreline environment. Thirty-three ostracode species are identified from 54 sites including four new, undescribed species of Cypridopsinae (2) and Limnocythere (2). Ostracodes are extremely abundant between 1 and 25 m water depth, but are rare to absent between 30 and 60 m. This disappearance is probably taphonomically controlled, with carbonate dissolution in the death assemblage since abundant live ostracodes have been found in the lake at greater than 30 m depth, where bottom sediments lack calcium carbonate. Constrained correspondence analysis (CCA) of ostracode species abundance suggests depth and dissolved oxygen (DO) content to be the primary environmental variables affecting their distribution. Additional CCA models using all biological indicators suggest limnologic variables correlated with depth (e.g., bottom water temperature and DO) and adjacent shoreline environment were most significant.
KW - East Africa
KW - Lake Malawi
KW - Modern distribution study
KW - Ostracodes
KW - Paleoecology
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U2 - 10.1007/s10750-014-1817-5
DO - 10.1007/s10750-014-1817-5
M3 - Article
AN - SCOPUS:84895833599
VL - 728
SP - 179
EP - 200
JO - Journal of Aquatic Ecosystem Health
JF - Journal of Aquatic Ecosystem Health
SN - 0018-8158
IS - 1
ER -