Stable isotope analysis of consumer food webs indicates ecosystem recovery following prolonged drought in a subtropical estuarine lake

M. S. Bird, R. Perissinotto, N. A.F. Miranda, N. Peer, J. L. Raw

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)

Abstract

Assessing changes in food-web structure provides a useful monitoring tool for gauging the resilience of ecosystems in the face of climatic impacts. We consider the ecological resilience of a large estuarine lake (St Lucia Estuary, South Africa) in the wake of an extreme climatic event (prolonged drought). Using carbon and nitrogen stable isotopes, food-web structure was assessed at five sites across the estuary during the winter and spring of 2013. Sampling occurred approximately three years after heavy rains flooded the system and returned it to a relatively diluted state following an almost decade-long drought that decimated food webs in the upper parts of the estuary due to hypersalinity effects. Comparisons of niche width and variance of consumer food webs among sites revealed a general homogenisation of food webs across the entire system, contrasting with the spatial differentiation of food webs documented during the drought phase. Our results indicate that the estuary is able to maintain ecological resilience at the whole-system level in the face of an extreme drought. This is likely facilitated by source pools of species residing in the relatively stable lower estuary, which are able to rapidly recolonise areas denuded by drought in the upper estuary.

Original languageEnglish
Pages (from-to)411-422
Number of pages12
JournalAfrican Journal of Marine Science
Volume38
Issue number3
DOIs
Publication statusPublished - 23 Sept 2016
Externally publishedYes

Keywords

  • estuarine resilience
  • extreme climatic events
  • stable isotopes
  • trophic ecology

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science

Fingerprint

Dive into the research topics of 'Stable isotope analysis of consumer food webs indicates ecosystem recovery following prolonged drought in a subtropical estuarine lake'. Together they form a unique fingerprint.

Cite this