The search result changed since you submitted your search request. Documents might be displayed in a different sort order.
  • search hit 1 of 2
Back to Result List

Environmental variability in Lake Naivasha, Kenya, over the last two centuries

  • Lake Naivasha, Kenya, is one of a number of freshwater lakes in the East African Rift System. Since the beginning of the twentieth century, it has experienced greater anthropogenic influence as a result of increasingly intensive farming of coffee, tea, flowers, and other horticultural crops within its catchment. The water-level history of Lake Naivasha over the past 200 years was derived from a combination of instrumental records and sediment data. In this study, we analysed diatoms in a lake sediment core to infer past lacustrine conductivity and total phosphorus concentrations. We also measured total nitrogen and carbon concentrations in the sediments. Core chronology was established by (210)Pb dating and covered a similar to 186-year history of natural (climatic) and human-induced environmental changes. Three stratigraphic zones in the core were identified using diatom assemblages. There was a change from littoral/epiphytic diatoms such as Gomphonema gracile and Cymbella muelleri, which occurred during a prolonged dry period fromLake Naivasha, Kenya, is one of a number of freshwater lakes in the East African Rift System. Since the beginning of the twentieth century, it has experienced greater anthropogenic influence as a result of increasingly intensive farming of coffee, tea, flowers, and other horticultural crops within its catchment. The water-level history of Lake Naivasha over the past 200 years was derived from a combination of instrumental records and sediment data. In this study, we analysed diatoms in a lake sediment core to infer past lacustrine conductivity and total phosphorus concentrations. We also measured total nitrogen and carbon concentrations in the sediments. Core chronology was established by (210)Pb dating and covered a similar to 186-year history of natural (climatic) and human-induced environmental changes. Three stratigraphic zones in the core were identified using diatom assemblages. There was a change from littoral/epiphytic diatoms such as Gomphonema gracile and Cymbella muelleri, which occurred during a prolonged dry period from ca. 1820 to 1896 AD, through a transition period, to the present planktonic Aulacoseira sp. that favors nutrient-rich waters. This marked change in the diatom assemblage was caused by climate change, and later a strong anthropogenic overprint on the lake system. Increases in sediment accumulation rates since 1928, from 0.01 to 0.08 g cm(-2) year(-1) correlate with an increase in diatom-inferred total phosphorus concentrations since the beginning of the twentieth century. The increase in phosphorus accumulation suggests increasing eutrophication of freshwater Lake Naivasha. This study identified two major periods in the lake's history: (1) the period from 1820 to 1950 AD, during which the lake was affected mainly by natural climate variations, and (2) the period since 1950, during which the effects of anthropogenic activity overprinted those of natural climate variation.show moreshow less

Export metadata

Additional Services

Share in Twitter Search Google Scholar Statistics
Metadaten
Author:Kathleen R. Stoof-Leichsenring, Annett Junginger, Lydia A. Olaka, Ralph TiedemannORCiDGND, Martin H. Trauth
DOI:https://doi.org/10.1007/s10933-011-9502-4
ISSN:0921-2728 (print)
Parent Title (English):Journal of paleolimnolog
Publisher:Springer
Place of publication:Dordrecht
Document Type:Article
Language:English
Year of first Publication:2011
Year of Completion:2011
Release Date:2017/03/26
Tag:Conductivity; Diatoms; Eutrophication; Human impact; Lake Naivasha; Lake sediments
Volume:45
Issue:3
Pagenumber:15
First Page:353
Last Page:367
Funder:German Research Foundation (DFG) [GRK 1364]; Government of Kenya [MOST13/001/30C 59/10, 59/18, 59/22]; University of Nairobi
Organizational units:Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie
Peer Review:Referiert