TY - JOUR
T1 - Ostracode stratigraphy and paleoecology from surficial sediments of Lake Tanganyika, Africa
AU - Wells, T. M.
AU - Cohen, A. S.
AU - Park, L. E.
AU - Dettman, D. L.
AU - McKee, B. A.
N1 - Funding Information:
We would like to thank our colleagues at the Faculté des Sciences, Université du Burundi and the Tanzanian Commission for Science and Technology (UTAFITI) for their support. We also thank Jean Jacques Tiercelin for providing access to GEORIFT cores, Debra Gevirtzman, Mark Johnston, Pieter Kat, Mboko Sima Keito, Koen Martens, Ellinor Michel, Gashagaza Masta Mukwaya, Kimbadi Sona, Mike Soreghan and Kelly West for assistance with field work and for their numerous insights concerning the fauna of Lake Tanganyika and its history. Erle G. Kauffman, Mary J. Kraus, Rick Forester and Dan Livingstone provided many helpful comments on the manuscript. This study was funded by NURC-UCAP Grant #92/04:UCT 8659 and NSF BSR #8415289, BSR 8696074, and EAR 9510033, as well as the Coalition to Increase Minority Degrees (CIMD) and the NSF-funded Research Training Grant Program (RTG), University of Arizona. This is contribution #52 of the International Decade Of East African Lakes (IDEAL).
PY - 1999
Y1 - 1999
N2 - We report here on the first detailed ostracode stratigraphic record to be obtained from late Holocene sediments of Lake Tanganyika. We analyzed four cores, three from the northern lake region and a fourth from a more southern lake locality, that collectively record ostracode assemblages under a variety of disturbance regimes. These cores provide a stratigraphic record of ostracode abundance and diversity, as well as depositional changes over time periods of decades to millennia. We have investigated the fossil ostracodes in these cores by looking at temporal changes of species diversity and population structure for the species present. All four cores provided distinct patterns of ostracode diversity and abundance. BUR-1, a northern lake core obtained close to the Ruisizi River delta, yielded a sparse ostracode record. Karonge 3, another northern core from a site that is closely adjacent to a river delta with high sediment loading, yielded almost no ostracodes. The third core 86-DG-14, taken from a somewhat less disturbed area of the lake, suggests that there have been recent changes in ostracode populations. Through most of the lower portion of this core, ostracode abundance is low and species richness is relatively constant. Above 7 cm there is a marked increase in ostracode abundance and a corresponding decrease in species richness, probably signaling the onset of a major community disturbance, perhaps due to human activities. The southernmost core, 86-DG-32, is from a site that is well removed from influent rivers. Ostracode abundance varies erratically throughout the core, whereas species richness is relatively constant and high throughout the core. The temporal variation evident in ostracode community makeup both within and between the studied cores may be a result of naturally patchy distributions among ostracodes, coupled with local extinctions and recolonizations, or it may reflect inadequate sampling of these high diversity assemblages. In either case, these cores illustrate the potential to obtain high resolution ostracode records from the rich, endemic fauna of Lake Tanganyika that can be used to address questions about the history of community structure and human impacts in this lake.
AB - We report here on the first detailed ostracode stratigraphic record to be obtained from late Holocene sediments of Lake Tanganyika. We analyzed four cores, three from the northern lake region and a fourth from a more southern lake locality, that collectively record ostracode assemblages under a variety of disturbance regimes. These cores provide a stratigraphic record of ostracode abundance and diversity, as well as depositional changes over time periods of decades to millennia. We have investigated the fossil ostracodes in these cores by looking at temporal changes of species diversity and population structure for the species present. All four cores provided distinct patterns of ostracode diversity and abundance. BUR-1, a northern lake core obtained close to the Ruisizi River delta, yielded a sparse ostracode record. Karonge 3, another northern core from a site that is closely adjacent to a river delta with high sediment loading, yielded almost no ostracodes. The third core 86-DG-14, taken from a somewhat less disturbed area of the lake, suggests that there have been recent changes in ostracode populations. Through most of the lower portion of this core, ostracode abundance is low and species richness is relatively constant. Above 7 cm there is a marked increase in ostracode abundance and a corresponding decrease in species richness, probably signaling the onset of a major community disturbance, perhaps due to human activities. The southernmost core, 86-DG-32, is from a site that is well removed from influent rivers. Ostracode abundance varies erratically throughout the core, whereas species richness is relatively constant and high throughout the core. The temporal variation evident in ostracode community makeup both within and between the studied cores may be a result of naturally patchy distributions among ostracodes, coupled with local extinctions and recolonizations, or it may reflect inadequate sampling of these high diversity assemblages. In either case, these cores illustrate the potential to obtain high resolution ostracode records from the rich, endemic fauna of Lake Tanganyika that can be used to address questions about the history of community structure and human impacts in this lake.
KW - Africa
KW - Lake Tanganyika
KW - Ostracodes
KW - Paleoecology
KW - Sediment core
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U2 - 10.1023/A:1008046417660
DO - 10.1023/A:1008046417660
M3 - Article
AN - SCOPUS:0032750863
SN - 0921-2728
VL - 22
SP - 259
EP - 276
JO - Journal of Paleolimnology
JF - Journal of Paleolimnology
IS - 3
ER -