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King L, Wienhues G, Misra P, Tylmann W, Lami A, Bernasconi SM, Jaggi M, Courtney-Mustaphi C, Muschick M, Ngoepe N, Mwaiko S, Kishe MA, Cohen A, Heiri O, Seehausen O, Vogel H, Grosjean M, Matthews B. Anthropogenic Eutrophication Drives Major Food Web Changes in Mwanza Gulf, Lake Victoria. Ecosystems 2024; 27:577-591. [PMID: 38899133 PMCID: PMC11182866 DOI: 10.1007/s10021-024-00908-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/29/2024] [Indexed: 06/21/2024]
Abstract
Discerning ecosystem change and food web dynamics underlying anthropogenic eutrophication and the introduction of non-native species is necessary for ensuring the long-term sustainability of fisheries and lake biodiversity. Previous studies of eutrophication in Lake Victoria, eastern Africa, have focused on the loss of endemic fish biodiversity over the past several decades, but changes in the plankton communities over this same time remain unclear. To fill this gap, we examined sediment cores from a eutrophic embayment, Mwanza Gulf, to determine the timing and magnitude of changes in the phytoplankton and zooplankton assemblages over the past century. Biogeochemical proxies indicate nutrient enrichment began around ~ 1920 CE and led to rapid increases in primary production, and our analysis of photosynthetic pigments revealed three zones: pre-eutrophication (prior to 1920 CE), onset of eutrophication with increases in all pigments (1920-1990 CE), and sustained eutrophication with cyanobacterial dominance (1990 CE-present). Cladoceran remains indicate an abrupt decline in biomass in ~ 1960 CE, in response to the cumulative effects of eutrophication and lake-level rise, preceding the collapse of haplochromine cichlids in the 1980s. Alona and Chydorus, typically benthic littoral taxa, have remained at relatively low abundances since the 1960s, whereas the abundance of Bosmina, typically a planktonic taxon, increased in the 1990s concurrently with the biomass recovery of haplochromine cichlid fishes. Overall, our results demonstrate substantial changes over the past century in the biomass structure and taxonomic composition of Mwanza Gulf phytoplankton and zooplankton communities, providing a historical food web perspective that can help understand the recent changes and inform future resource management decisions in the Lake Victoria ecosystem. Supplementary Information The online version contains supplementary material available at 10.1007/s10021-024-00908-x.
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Affiliation(s)
- Leighton King
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Giulia Wienhues
- Institute of Geography and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
| | - Pavani Misra
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Wojciech Tylmann
- Faculty of Oceanography and Geography, University of Gdańsk, Gdańsk, Poland
| | - Andrea Lami
- National Research Council Water Research Institute (IRSA), Verbania, Italy
| | | | - Madalina Jaggi
- Department of Earth Sciences, ETH Zürich, Zurich, Switzerland
| | - Colin Courtney-Mustaphi
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
- Nelson Mandela African Institution of Science and Technology (NM-AIST), Arusha, Tanzania
| | - Moritz Muschick
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Nare Ngoepe
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Salome Mwaiko
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Mary A. Kishe
- Tanzania Fisheries Research Institute (TAFIRI), Dar es Salaam, Tanzania
| | - Andrew Cohen
- Department of Geosciences, University of Arizona, Tucson, Arizona USA
| | - Oliver Heiri
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Ole Seehausen
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
- Aquatic Ecology and Evolution, Institute of Ecology and Evolution, University of Bern, Bern, Switzerland
| | - Hendrik Vogel
- Institute of Geological Sciences and Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Martin Grosjean
- Institute of Geography and Oeschger Center for Climate Change Research, University of Bern, Bern, Switzerland
| | - Blake Matthews
- Department of Fish Ecology and Evolution, Swiss Federal Institute for Aquatic Science and Technology (EAWAG), Kastanienbaum, Dübendorf, Switzerland
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Cocquyt C, Verschuren D. Checklist of the diatoms (Bacillariophyta) from Lake Naivasha, Kenya, with some historical notes. PHYTOKEYS 2023; 224:101-174. [PMID: 37251510 PMCID: PMC10209617 DOI: 10.3897/phytokeys.224.98168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 02/20/2023] [Indexed: 05/31/2023]
Abstract
Lake Naivasha is one of only two large freshwater lakes in the Eastern Rift Valley of Kenya, East Africa. Together with its satellite lakes Crescent Island Crater, Oloidien and Sonachi, it comprises a great variety of pelagic and benthic habitats for aquatic biota, and its sediment record represents a unique archive of past climate change and long-term ecosystem dynamics in equatorial East Africa. This is particularly so because local paleoenvironmental reconstructions can be checked against historical data on the composition of aquatic fauna and flora collected in Lake Naivasha since the early 20th century. Some of the most prominent biological proxies for reconstructing past changes in lakes are diatoms (Bacillariophyta), a group of unicellular autotrophic eukaryotes of which the siliceous skeletons (valves) preserve well in lake sediments and are good indicators for, among others, climate-driven changes in salinity. However, diatom taxonomy and species concepts have changed a lot in recent decades, making it sometimes difficult for non-taxonomists to know which species are concerned in different published studies. This paper provides the currently accepted taxonomic names of the 310 specific and infraspecific diatom taxa reported from Lake Naivasha and its satellite lakes to date, together with their synonyms used in literature concerning these lakes as well as other, commonly used synonyms. Further, a short overview is given of the history of diatom research conducted on materials from Lake Naivasha and its satellite lakes. The present checklist may facilitate the identification and interpretation aspects of future diatom studies on the wider Lake Naivasha ecosystem and on other East African lakes that are less well studied.
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Affiliation(s)
- Christine Cocquyt
- Research Department, Meise Botanic Garden, 1860 Meise, BelgiumGhent UniversityGhentBelgium
- Limnology Unit, Ghent University, 9000 Gent, BelgiumMeise Botanic GardenMeiseBelgium
| | - Dirk Verschuren
- Limnology Unit, Ghent University, 9000 Gent, BelgiumMeise Botanic GardenMeiseBelgium
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Sun Z, Wu D, Lv Y. Effects of water salinity on the multi-angular polarimetric properties of light reflected from smooth water surfaces. APPLIED OPTICS 2022; 61:4527-4534. [PMID: 36256294 DOI: 10.1364/ao.458737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/05/2022] [Indexed: 06/16/2023]
Abstract
Salinity is an important environmental factor regulating the aquatic system structure of lakes and other water bodies. Changes in salinity, which can be caused by human activities, can adversely impact the life of water organisms. The refractive index, which can be directly related to water salinity, also controls the polarimetric properties of light reflected from the water surface. In this study, polarimetric measurements of smooth water surfaces with different salinity content were performed at different viewing zenith angles in the wavelength range of 450-1000 nm in the specular reflection directions. The results show that the light reflected from the water surface (defined as reflectance factor) in one measurement direction can be replaced by the reflectance factor derived from polarimetric measurements, and if the polarizer absorptance is considered, the average relative difference is less than 3%. The degree of linear polarization (DOLP) was used to retrieve the refractive indices of water with different salinities based on the Fresnel reflection coefficient. The inverted refractive indices not only have high accuracy (uncertainty from 0.9% to 1.8%) but also have a very strong relationship with the water salinity content. Our study shows the possibility of estimating the variation in water salinity using multi-angular polarimetric measurements.
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Van der Meeren T, Verschuren D. Zoobenthos community turnover in a 1650‐yr lake‐sediment record of climate‐driven hydrological change. Ecosphere 2021. [DOI: 10.1002/ecs2.3333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Affiliation(s)
| | - Dirk Verschuren
- Limnology Unit Department of Biology Ghent University GentB‐9000Belgium
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Tibby J, Barr C, McInerney FA, Henderson ACG, Leng MJ, Greenway M, Marshall JC, McGregor GB, Tyler JJ, McNeil V. Carbon isotope discrimination in leaves of the broad-leaved paperbark tree, Melaleuca quinquenervia, as a tool for quantifying past tropical and subtropical rainfall. GLOBAL CHANGE BIOLOGY 2016; 22:3474-3486. [PMID: 27090595 DOI: 10.1111/gcb.13277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 02/19/2016] [Indexed: 06/05/2023]
Abstract
Quantitative reconstructions of terrestrial climate are highly sought after but rare, particularly in Australia. Carbon isotope discrimination in plant leaves (Δleaf ) is an established indicator of past hydroclimate because the fractionation of carbon isotopes during photosynthesis is strongly influenced by water stress. Leaves of the evergreen tree Melaleuca quinquenervia have been recovered from the sediments of some perched lakes on North Stradbroke and Fraser Islands, south-east Queensland, eastern Australia. Here, we examine the potential for using M. quinquenervia ∆leaf as a tracer of past rainfall by analysing carbon isotope ratios (δ(13) C) of modern leaves. We firstly assess Δleaf variation at the leaf and stand scale and find no systematic pattern within leaves or between leaves due to their position on the tree. We then examine the relationships between climate and Δleaf for a 11-year time series of leaves collected in a litter tray. M. quinquenervia retains its leaves for 1-4 years; thus, cumulative average climate data are used. There is a significant relationship between annual mean ∆leaf and mean annual rainfall of the hydrological year for 1-4 years (i.e. 365-1460 days) prior to leaf fall (r(2) = 0.64, P = 0.003, n = 11). This relationship is marginally improved by accounting for the effect of pCO2 on discrimination (r(2) = 0.67, P = 0.002, n = 11). The correlation between rainfall and Δleaf , and the natural distribution of Melaleuca quinquenervia around wetlands of eastern Australia, Papua New Guinea and New Caledonia offers significant potential to infer past rainfall on a wide range of spatial and temporal scales.
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Affiliation(s)
- John Tibby
- Geography, Environment and Population, University of Adelaide, Adelaide, SA, Australia
- Sprigg Geobiology Centre, University of Adelaide, Adelaide, SA, Australia
| | - Cameron Barr
- Geography, Environment and Population, University of Adelaide, Adelaide, SA, Australia
- Sprigg Geobiology Centre, University of Adelaide, Adelaide, SA, Australia
| | - Francesca A McInerney
- Sprigg Geobiology Centre, University of Adelaide, Adelaide, SA, Australia
- Department of Earth Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Andrew C G Henderson
- School of Geography, Politics & Sociology, Newcastle University, Newcastle upon Tyne, NE1 7RU, UK
| | - Melanie J Leng
- NERC Isotope Geosciences Facilities, British Geological Survey, Keyworth Nottingham, NG12 5GG, UK
- Centre for Environmental Geochemistry, University of Nottingham, Nottingham, NG7 2RD, UK
| | - Margaret Greenway
- Griffith School of Engineering, Environmental Engineering, Griffith University, Brisbane, QLD, Australia
| | - Jonathan C Marshall
- Queensland Department of Science, Information Technology and Innovation, Brisbane, QLD, Australia
| | - Glenn B McGregor
- Queensland Department of Science, Information Technology and Innovation, Brisbane, QLD, Australia
| | - Jonathan J Tyler
- Sprigg Geobiology Centre, University of Adelaide, Adelaide, SA, Australia
- Department of Earth Sciences, University of Adelaide, Adelaide, SA, Australia
| | - Vivienne McNeil
- Queensland Department of Science, Information Technology and Innovation, Brisbane, QLD, Australia
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Gelorini V, Verschuren D. Historical climate-human-ecosystem interaction in East Africa: a review. Afr J Ecol 2012. [DOI: 10.1111/aje.12045] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Vanessa Gelorini
- Limnology Unit; Department of Biology; Ghent University; K.L. Ledeganckstraat 35; B-9000; Gent; Belgium
| | - Dirk Verschuren
- Limnology Unit; Department of Biology; Ghent University; K.L. Ledeganckstraat 35; B-9000; Gent; Belgium
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Mergeay J, De Meester L, Eggermont H, Verschuren D. Priority effects and species sorting in a long paleoecological record of repeated community assembly through time. Ecology 2012; 92:2267-75. [PMID: 22352166 DOI: 10.1890/10-1645.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
We studied the relative roles of environmental species sorting and priority effects in the assembly of ecological communities on long time scales, by analyzing community turnover of water fleas (Daphnia) in response to strong and recurrent environmental change in a fluctuating tropical lake. During the past 1800 years, Lake Naivasha (Kenya) repeatedly fluctuated between a small saline pond habitat during lowstands and a large freshwater lake habitat during highstands. Starting from a paleoecological reconstruction, we estimated the role of priority effects in Daphnia community assembly across 16 of these habitat turnovers and compared this with the response of the community to reconstructed changes in three environmental variables important for species sorting. Our results indicate that the best predictor of Daphnia community composition during highstands was the community composition just prior to the transition from lowstands to highstands. This reflects a long-lasting priority effect of late lowstand communities on highstand communities, arising when remnant lowstand populations fill newly available ecological space in the rapidly expanding lake habitat. Species sorting and priority effects had a comparable but relatively small influence on community composition during the lowstands. Moreover, these priority effects decayed rapidly with time as Daphnia communities responded to environmental change, in contrast with the highstand communities where priority effects lasted for several decades.
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Affiliation(s)
- Joachim Mergeay
- Research Institute for Nature and Forest, Gaverstraat 4, 9500 Geraardsbergen, Belgium.
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Mergeay J, Vanoverbeke J, Verschuren D, Meester LD. EXTINCTION, RECOLONIZATION, AND DISPERSAL THROUGH TIME IN A PLANKTONIC CRUSTACEAN. Ecology 2007; 88:3032-43. [DOI: 10.1890/06-1538.1] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Kingston JD, Deino AL, Edgar RK, Hill A. Astronomically forced climate change in the Kenyan Rift Valley 2.7–2.55 Ma: implications for the evolution of early hominin ecosystems. J Hum Evol 2007; 53:487-503. [DOI: 10.1016/j.jhevol.2006.12.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2005] [Revised: 05/09/2006] [Accepted: 12/12/2006] [Indexed: 11/16/2022]
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Ginger SM, Hellgren EC, Kasparian MA, Levesque LP, Engle DM, Leslie DM. NICHE SHIFT BY VIRGINIA OPOSSUM FOLLOWING REDUCTION OF A PUTATIVE COMPETITOR, THE RACCOON. J Mammal 2003. [DOI: 10.1644/103] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Tibby J. Explaining lake and catchment change using sediment derived and written histories: an Australian perspective. THE SCIENCE OF THE TOTAL ENVIRONMENT 2003; 310:61-71. [PMID: 12812731 DOI: 10.1016/s0048-9697(02)00623-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Palaeolimnological records can be powerfully combined with documentary data to explain the impact of modern industry and agriculture on lake systems and their catchments. Such an approach is highly appropriate in Australia since modern society was imposed on a continent until recently populated solely by hunter-gatherers and because there is a wealth of historical data to draw upon. Confounding factors such as the influence of climate change, depopulation of the indigenous community and non-linear responses to human impact must be considered in analysis of the relative importance of various land use changes upon lake pollution.
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Affiliation(s)
- John Tibby
- Centre for Palynology and Palaeoecology, School of Geography and Environmental Science, Monash University, 3800, Vic., Australia.
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Jeppesen E, Leavitt P, De Meester L, Jensen JP. Functional ecology and palaeolimnology: using cladoceran remains to reconstruct anthropogenic impact. Trends Ecol Evol 2001; 16:191-198. [PMID: 11245942 DOI: 10.1016/s0169-5347(01)02100-0] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The field of lake palaeoecology has undergone significant changes. Powerful quantitative techniques have been developed to investigate anthropogenic impacts on lakes. Inclusion of zooplankton and benthic chydorid cladocerans has provided previously unavailable information on the historical development of planktivorous fish populations, submerged macrophytes and lake production, and has been used to document exotic species introductions, rapid genetic evolution and human disturbance of lakes. In particular, new techniques now allow a more complete evaluation of changes in past and present trophic structure to be made, and provide insights on the rapid evolutionary responses of aquatic invertebrate communities to anthropogenic perturbation of lakes.
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Walker IR. Midges: Chironomidae and Related Diptera. TRACKING ENVIRONMENTAL CHANGE USING LAKE SEDIMENTS 2001. [DOI: 10.1007/0-306-47671-1_3] [Citation(s) in RCA: 190] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
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