Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa

The ecology of dryland rivers is under-studied in Africa. During seasonal droughts, these rivers cease flowing resulting in disconnected pools that restrict the movement of aquatic species. Few studies have focussed on the conditions of these refugia or their effect on fish. We investigated the infl...

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Main Authors: Strauch AM, Kapust AR, Jost, Christine
Format: Journal Article
Language:Inglés
Published: Commonwealth Scientific and Industrial Research Organisation 2015
Subjects:
Online Access:https://hdl.handle.net/10568/76600
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author Strauch AM
Kapust AR
Jost, Christine
author_browse Jost, Christine
Kapust AR
Strauch AM
author_facet Strauch AM
Kapust AR
Jost, Christine
author_sort Strauch AM
collection Repository of Agricultural Research Outputs (CGSpace)
description The ecology of dryland rivers is under-studied in Africa. During seasonal droughts, these rivers cease flowing resulting in disconnected pools that restrict the movement of aquatic species. Few studies have focussed on the conditions of these refugia or their effect on fish. We investigated the influence of pool size and water quality on the abundance and composition of fish, including body condition (BC) and a quantitative heath assessment index (HAI) of individual species in tributaries of the lower Zambezi during the dry season. Although no single species was found among all sites, species in either or both the Cichlidae or Cyprinidae families were recovered in 12 of 15 locations. Fish biomass and richness were positively correlated with refugia size. As water quality declined, Cichlidae BC declined while Cyprinidae BC improved. By contrast, both Cichlidae HAI and Cyprinidae HAI were positively related (declined) to increased dissolved oxygen while negatively related to nutrients. We conclude that refugia conditions affect fish communities but the direction of effect can be species dependent. Increasing our understanding of the effects of land-use and water-use on habitat quality and their consequences for freshwater ecosystems in general should be an important goal towards improving rural livelihoods.
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spelling CGSpace766002025-12-08T10:29:22Z Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa Strauch AM Kapust AR Jost, Christine climate change agriculture food security ecology oceanography The ecology of dryland rivers is under-studied in Africa. During seasonal droughts, these rivers cease flowing resulting in disconnected pools that restrict the movement of aquatic species. Few studies have focussed on the conditions of these refugia or their effect on fish. We investigated the influence of pool size and water quality on the abundance and composition of fish, including body condition (BC) and a quantitative heath assessment index (HAI) of individual species in tributaries of the lower Zambezi during the dry season. Although no single species was found among all sites, species in either or both the Cichlidae or Cyprinidae families were recovered in 12 of 15 locations. Fish biomass and richness were positively correlated with refugia size. As water quality declined, Cichlidae BC declined while Cyprinidae BC improved. By contrast, both Cichlidae HAI and Cyprinidae HAI were positively related (declined) to increased dissolved oxygen while negatively related to nutrients. We conclude that refugia conditions affect fish communities but the direction of effect can be species dependent. Increasing our understanding of the effects of land-use and water-use on habitat quality and their consequences for freshwater ecosystems in general should be an important goal towards improving rural livelihoods. 2015 2016-08-25T11:51:35Z 2016-08-25T11:51:35Z Journal Article https://hdl.handle.net/10568/76600 en Limited Access Commonwealth Scientific and Industrial Research Organisation Strauch AM, Kapust AR, Jost CC. 2015. Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi. Marine and Freshwater Research 66(4):343-351.
spellingShingle climate change
agriculture
food security
ecology
oceanography
Strauch AM
Kapust AR
Jost, Christine
Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa
title Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa
title_full Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa
title_fullStr Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa
title_full_unstemmed Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa
title_short Composition and health of fish in refugia habitat of ephemeral tributaries to the lower Zambezi in southern Africa
title_sort composition and health of fish in refugia habitat of ephemeral tributaries to the lower zambezi in southern africa
topic climate change
agriculture
food security
ecology
oceanography
url https://hdl.handle.net/10568/76600
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