The interactive role of predation, competition and habitat conditions in structuring an intertidal bivalve population

Jimmy de Fouw*, Els M. van der Zee, Jan A. van Gils, Britas Klemens Eriksson, Ellen J. Weerman, Serena Donadi, Henk W. van der Veer, Han Olff, Theunis Piersma, Tjisse van der Heide

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

2 Citations (Scopus)
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Abstract

Habitat characteristics, predation and competition are known to interactively drive population dynamics. Highly complex habitats, for example, may reduce predation and competition, allowing more individuals living together in a certain area. However, the strength and direction of such interactions can differ strongly and are context dependent. Furthermore, as habitat characteristics are rapidly changing due to anthropogenic impacts, it becomes increasingly important to understand such interactions. Here, we studied the interactive effects of predation and competition on common cockle (Cerastoderma edule) recruitment, growth and survival under different habitat characteristics in the Wadden Sea, one of the world's largest intertidal ecosystems. In a predator-exclosure experiment, we manipulated cockle densities (100 vs. 1000 individuals m-2) and shorebird predation at two sites differing in habitat characteristics, namely at the wake of a blue mussel bed (Mytilus edulis) and at an adjacent sandy site. We found that recruitment was higher in the mussel-modified habitat, most likely due to reduction of hydrodynamic stress. Although bird predation strongly reduced recruit density, the combined effects still yielded more recruitment at the vicinity of the mussel bed compared to the sandy area. Furthermore, we found that high cockle densities combined with high densities of other potential prey (i.e. mussels) at the mussel-modified site, mitigated predation effects for adult cockles. Apart from these positive effects on adults, mussel-modified habitat reduced cockle growth, most likely by reducing hydrodynamics in the wake of the mussel bed and by increasing inter-specific competition for food. Our study experimentally underpins the importance of habitat characteristics, competition and predation in interactively structuring intertidal communities.

Original languageEnglish
Article number151267
Number of pages7
JournalJournal of Experimental Marine Biology and Ecology
Volume523
Early online date25-Nov-2019
DOIs
Publication statusPublished - Feb-2020

Keywords

  • Cerastoderma edule
  • Ecosystem engineer
  • Intraspecific and interspecific competition
  • Mytilus edulis
  • Population responses
  • Predation
  • Shorebirds
  • Wadden Sea
  • SUSPENSION-FEEDING BIVALVES
  • WADDEN SEA
  • INTERSPECIFIC COMPETITION
  • CERASTODERMA-EDULE
  • MYTILUS-EDULIS
  • ECOLOGY
  • ECOSYSTEM
  • COMPLEXITY
  • TRANSFORMATIONS
  • SHOREBIRDS

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