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Stable isotope evidence of food web connectivity by a top predatory fish (Argyrosomus japonicus: Sciaenidae: Teleostei) in the Kowie Estuary, South Africa

Stable isotope evidence of food web connectivity by a top predatory fish (Argyrosomus japonicus:... In this study, food web connectivity within the Kowie Estuary on the south-east coast of South Africa was evidenced by the trophic behaviour of the predominantly piscivorous Argyrosomus japonicus. We examined stable isotopes of carbon (δ13C) and nitrogen (δ15N) in the dominant consumers (zooplankton, invertebrates and fishes) and food sources (particulate organic matter, epibionts and benthic microalgae) in the system. An SIAR (Stable Isotope Analysis in R) mixing model was used to interpret the possible food sources for this dominant top predatory fish. Small fishes and large epibenthic invertebrates dominated the diet of A. japonicus. Based on the contrasting diet of these prey fish and invertebrates, we propose that organic matter enters the predatory fish community via two major pathways: (1) a littoral pathway dominated by benthic microalgae production and epibionts, and (2) a channel pathway dominated by suspended particulate organic matter (including phytoplankton). We conclude that the highly mobile A. japonicus consumes both pelagic and benthic fauna from the littoral and channel zones of the estuary, thereby playing a key functional role in linking food webs. This dietary diversity may help explain the success of A. japonicus as a dominant top predator in the system, primarily by increasing the energy available to this species. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png African Journal of Marine Science Taylor & Francis

Stable isotope evidence of food web connectivity by a top predatory fish (Argyrosomus japonicus: Sciaenidae: Teleostei) in the Kowie Estuary, South Africa

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Stable isotope evidence of food web connectivity by a top predatory fish (Argyrosomus japonicus: Sciaenidae: Teleostei) in the Kowie Estuary, South Africa

Abstract

In this study, food web connectivity within the Kowie Estuary on the south-east coast of South Africa was evidenced by the trophic behaviour of the predominantly piscivorous Argyrosomus japonicus. We examined stable isotopes of carbon (δ13C) and nitrogen (δ15N) in the dominant consumers (zooplankton, invertebrates and fishes) and food sources (particulate organic matter, epibionts and benthic microalgae) in the system. An SIAR (Stable Isotope Analysis in R) mixing model was used...
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Publisher
Taylor & Francis
Copyright
Copyright © NISC (Pty) Ltd
ISSN
1814-2338
eISSN
1814-232X
DOI
10.2989/1814232X.2014.923782
Publisher site
See Article on Publisher Site

Abstract

In this study, food web connectivity within the Kowie Estuary on the south-east coast of South Africa was evidenced by the trophic behaviour of the predominantly piscivorous Argyrosomus japonicus. We examined stable isotopes of carbon (δ13C) and nitrogen (δ15N) in the dominant consumers (zooplankton, invertebrates and fishes) and food sources (particulate organic matter, epibionts and benthic microalgae) in the system. An SIAR (Stable Isotope Analysis in R) mixing model was used to interpret the possible food sources for this dominant top predatory fish. Small fishes and large epibenthic invertebrates dominated the diet of A. japonicus. Based on the contrasting diet of these prey fish and invertebrates, we propose that organic matter enters the predatory fish community via two major pathways: (1) a littoral pathway dominated by benthic microalgae production and epibionts, and (2) a channel pathway dominated by suspended particulate organic matter (including phytoplankton). We conclude that the highly mobile A. japonicus consumes both pelagic and benthic fauna from the littoral and channel zones of the estuary, thereby playing a key functional role in linking food webs. This dietary diversity may help explain the success of A. japonicus as a dominant top predator in the system, primarily by increasing the energy available to this species.

Journal

African Journal of Marine Science – Taylor & Francis

Published: Apr 3, 2014

Keywords: diet diversity; food webs; stable isotopes; trophic connectivity

References

  • Food web structure in a near-pristine mangrove area of the Australian Wet Tropics
  • Identification of trophic interactions within an estuarine food web (northern New Zealand) using fatty acid biomarkers and stable isotopes
  • Spatial variation in organic matter utilization by benthic communities from Yura River-Estuary to offshore of Tango Sea, Japan
  • Examination of coupling between primary and secondary production in a river-dominated estuary: Apalachicola Bay, Florida, USA
  • Pathways of organic matter through food webs of diverse habitats in the regulated Nakdong River estuary (Korea)
  • Estuarine habitat use in juvenile dusky kob Argyrosomus japonicus (Sciaenidae), with implications for management
  • The role of standing dead Spartina alterniflora and benthic microalgae in salt marsh food webs: considerations based on multiple stable isotope analysis
  • Fish ecology and terrestrial carbon use in coastal areas: implications for marine fish production
  • Trophodynamic linkage between river runoff and coastal fishery yield elucidated by stable isotope data in the Gulf of Lions (NW Mediterranean)
  • Evidence for spatial variability in estuarine food webs
  • Biodiversity loss, trophic skew and ecosystem functioning
  • The functional role of biodiversity in ecosystems: incorporating trophic complexity
  • Differentiation between littoral and pelagic food webs in lakes using stable carbon isotopes
  • Stable isotope (δ13C) composition of the food web of the temperate Kariega estuary (Eastern Cape)
  • Population demographics of Palaemon peringueyi (Macpherson 1990) (Decapoda: Palaemonidae) in a small intermittently open Eastern Cape estuary
  • The influence of prolonged mouth closure on selected components of the hyperbenthos in the littoral zone of the temporarily open/closed Kasouga Estuary, South Africa
  • Life history of the dusky kob Argyrosomus japonicus (Sciaenidae) off the east coast of South Africa
  • Influence of prey availability on the distribution of dusky kob Argyrosomus japonicus (Sciaenidae) in the Great Fish River Estuary, with notes on the diet of early juveniles from three other estuarine systems
  • Dietary segregation of pelagic and littoral fish assemblages in a highly modified tidal freshwater estuary
  • Lunar influence on distribution of a calanoid copepod in the water column of a shallow, temperate estuary
  • Sample collection. Version 2.1. Unpublished DARES (Diatom for Assessing River Ecological Status)/DALES (Diatoms for Assessing Lake Ecological Status) protocol
  • Food web analysis of southern California coastal wetlands using multiple stable isotopes
  • Life history strategies of estuarine nekton: the role of marsh macrophytes, benthic microalgae, and phytoplankton in the trophic spectrum
  • Feeding ecology of major carnivorous fish from four eastern Cape estuaries
  • The dynamics of spatially coupled food webs
  • Variation in trophic shift for stable isotope ratios of carbon, nitrogen, and sulfur
  • Trophic importance of epiphytic algae in subtropical seagrass beds: evidence from multiple stable isotope analyses
  • Source partitioning using stable isotopes: coping with too much variation
  • Determination of fish trophic levels in an estuarine system
  • A stable carbon isotope study of the food-web in a freshwater-deprived South African estuary, with particular emphasis on the ichthyofauna
  • Stable isotopes in ecosystem studies
  • Sulfur, carbon and nitrogen isotopes used to trace organic matter flow in the salt-marsh estuaries of Sapelo Island, Georgia
  • Using stable isotopes to estimate trophic position: models, methods, and assumptions
  • Getting to the fat of the matter: models, methods and assumptions for dealing with lipids in stable isotope analyses
  • The response of Grandidierella lignorum (Barnard) (Crustacea: Amphipoda) to episodic flooding in three eastern Cape estuaries
  • Assessment of spatial variation in carbon utilization by benthic and pelagic invertebrates in a temperate South African estuary using stable isotope signatures
  • Habitat coupling in lake ecosystems
  • Tidal flow structures and sedimentation in the lower Kowie estuary, Port Alfred, South Africa
  • Acid washing effect on elemental and isotopic composition of whole beach arthropods: implications for food web studies using stable isotopes
  • Effects of altered estuarine submerged macrophyte bed cover on the omnivorous Cape stumpnose Rhabdosargus holubi
  • Recommendations for the collection, preparation and enumeration of diatoms from riverine habitats for water quality monitoring in South Africa
  • Feeding ecology of the early life-history stages of two dominant gobiid species in the headwaters of a warm-temperate estuary
  • The Swartvlei estuary fish community and the influence of food availability on resource utilization
  • The benthic invertebrate community of a southern Cape estuary: structure and possible food sources
  • Biology and ecology of fishes in South African estuaries
  • Food and feeding ecology of piscivorous fishes at Lake St Lucia, Zululand
  • A comparison of the ichthyofaunas in two permanently open eastern Cape estuaries
  • Tracing Mississippi River influences in estuarine food webs of coastal Louisiana