A meso-predator release of stickleback promotes recruitment of macroalgae in the Baltic Sea

Katrin Sieben*, Lars Ljunggren, Ulf Bergstrom, Britas Klemens Eriksson

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

35 Citations (Scopus)

Abstract

In the Baltic Sea, increased populations of the three-spined stickleback are invading the coastal zone in summer, following declines in large predatory fish such as cod, pike, and perch. Here, we explore the consequences of such a meso-predator release on a near-natural scale, by manipulating stickleback densities in four large 600 m(2) enclosures: two 'removal' and two 'addition' enclosures. Higher densities of stickleback resulted in a three times higher recruitment of ephemeral green macroalgae. At the same time we found higher abundances of the dominating invertebrate grazers with lower stickleback densities: higher numbers of both amphipods and smaller gastropods were found in one stickleback 'removal enclosure and higher numbers of large gastropods occurred in the other 'removal' enclosure. Grazer abundances also depended on the macrophyte species that dominated the enclosures. Nutrient enrichment had no statistically significant effect on algal recruitment, although the mean number of algal recruits was almost doubled under enriched conditions. Our results indicate that a meso-predator release of stickleback may dramatically shift coastal food web constitution towards increased abundances of ephemeral macroalgae through a trophic cascade. (C) 2010 Elsevier B.V. All rights reserved.

Original languageEnglish
Pages (from-to)79-84
Number of pages6
JournalJournal of Experimental Marine Biology and Ecology
Volume397
Issue number2
DOIs
Publication statusPublished - 15-Feb-2011

Keywords

  • Coastal management
  • Eutrophication
  • Grazers
  • Large-scale experiment
  • Piscivorous fish
  • Trophic cascade
  • BLOOM-FORMING MACROALGAE
  • TOP-DOWN
  • TROPHIC CASCADES
  • FOOD WEBS
  • LAKE PRODUCTIVITY
  • BOTTOM-UP
  • FISH
  • ECOSYSTEMS
  • DYNAMICS
  • HABITAT

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