TY - JOUR
T1 - Paleolimnological investigations of anthropogenic environmental change in Lake Tanganyika
T2 - IV. Lacustrine paleoecology
AU - Palacios-Fest, Manuel R.
AU - Alin, Simone R.
AU - Cohen, Andrew S.
AU - Tanner, Brandon
AU - Heuser, Heather
N1 - Funding Information:
We thank the United Nations Development Programme’s Lake Tanganyika Biodiversity Project for providing the bulk of the financing for this research. Additional student project support came from the US National Science Foundation (NSF Grant #s EAR 9510033 and ATM 9619458). We especially thank Drs. Andy Menz, Graeme Patterson and Kelly West of the LTBP for all of their gracious support at all stages of this project, and the crew of the R/V Tanganyika Explorer for their tireless efforts on our behalf during the coring cruise. We gratefully acknowledge the Tanzanian Council for Scientific Research (COSTECH), the Tanzanian Fisheries Research Institute (TAFIRI), and the University of Burundi, for their support of this research program. We are in debt with Dr. Sarah E. Metcalfe and an unknown reviewer for their insightful comments during the peer-review process. This is contribution #167 of the International Decade of East African Lakes (IDEAL).
PY - 2005/7
Y1 - 2005/7
N2 - Fossil invertebrates from cores collected in Lake Tanganyika provide a record of probable nearshore ecological response to recent watershed deforestation and sediment erosion in several East African watersheds. We compared paleoecological profiles (primarily from ostracodes) from watersheds spanning a range of sizes and present-day deforestation disturbance levels to understand the timing and magnitude of faunal changes, and their relationship in time to terrestrially-derived disturbance indicators. Profiles from the Lubulungu and Nyasanga/Kahama Rivers (Tanzania) provide a record of faunal variability in watersheds that are currently undisturbed with respect to deforestation. These records indicate continuous faunal turnover through time. However, this pattern of turnover is accompanied by relatively high levels of diversity throughout the record, with no wholesale extinction events. Ostracode taphonomic data and other fossil abundance data from the Lubulungu area provide strong evidence in support of at least two episodes of lower lake levels, associated with episodes of Late Holocene aridity. Records from deltas of disturbed watersheds at the Kabesi River (Tanzania) and those of Northern Burundi all show a combination of profound and abrupt faunal turnover, in some cases accompanied by local extinction and establishment of a few dominant taxa. At the Mwamgongo River delta, fed from a very small, disturbed watershed, species turnover was subtler. In disturbed watershed cores showing abrupt faunal changes the transitions mostly occurred in the late 19th to early 20th centuries, predating the major mid-20th century increase in sediment mass accumulation rates, with the latter only correlated with changing fossil abundance and flux. However, the earlier faunal community changes are contemporaneous with both palynological and geochemical changes in the core profiles indicative of changing land-use patterns. This suggests that lacustrine ecosystem response to deforestation was a two-stage process, with an earlier phase of response to changing quality of sediments or dissolved matter being discharged from the watershed, and a subsequent phase responding to increased quantity of sediment.
AB - Fossil invertebrates from cores collected in Lake Tanganyika provide a record of probable nearshore ecological response to recent watershed deforestation and sediment erosion in several East African watersheds. We compared paleoecological profiles (primarily from ostracodes) from watersheds spanning a range of sizes and present-day deforestation disturbance levels to understand the timing and magnitude of faunal changes, and their relationship in time to terrestrially-derived disturbance indicators. Profiles from the Lubulungu and Nyasanga/Kahama Rivers (Tanzania) provide a record of faunal variability in watersheds that are currently undisturbed with respect to deforestation. These records indicate continuous faunal turnover through time. However, this pattern of turnover is accompanied by relatively high levels of diversity throughout the record, with no wholesale extinction events. Ostracode taphonomic data and other fossil abundance data from the Lubulungu area provide strong evidence in support of at least two episodes of lower lake levels, associated with episodes of Late Holocene aridity. Records from deltas of disturbed watersheds at the Kabesi River (Tanzania) and those of Northern Burundi all show a combination of profound and abrupt faunal turnover, in some cases accompanied by local extinction and establishment of a few dominant taxa. At the Mwamgongo River delta, fed from a very small, disturbed watershed, species turnover was subtler. In disturbed watershed cores showing abrupt faunal changes the transitions mostly occurred in the late 19th to early 20th centuries, predating the major mid-20th century increase in sediment mass accumulation rates, with the latter only correlated with changing fossil abundance and flux. However, the earlier faunal community changes are contemporaneous with both palynological and geochemical changes in the core profiles indicative of changing land-use patterns. This suggests that lacustrine ecosystem response to deforestation was a two-stage process, with an earlier phase of response to changing quality of sediments or dissolved matter being discharged from the watershed, and a subsequent phase responding to increased quantity of sediment.
KW - Fish bones
KW - Lake Tanganyika
KW - Molluscs
KW - Ostracodes
KW - Sediment pollution
KW - Sponges
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U2 - 10.1007/s10933-005-2397-1
DO - 10.1007/s10933-005-2397-1
M3 - Article
AN - SCOPUS:21044450425
SN - 0921-2728
VL - 34
SP - 51
EP - 71
JO - Journal of Paleolimnology
JF - Journal of Paleolimnology
IS - 1
ER -