Emergent intraspecific multiple predator effects shape estuarine trophic dynamics across a gradient of habitat complexity

Mariah C. Livernois, Fredrick Joel Fodrie, Kenneth L. Heck, Sean P. Powers

Research output: Contribution to journalArticle

Abstract

Estuarine ecosystems are characterized by heterogeneity in species assemblages and habitat complexity, so prey in these systems are often threatened by multiple predators across a mosaic of habitats. When several predator species or conspecifics co-occur, behavioral interactions between them can introduce non-independence to their predator-prey dynamics, which can alter the fate of shared prey. Habitat complexity may regulate these interactions and further impact prey survivorship. We conducted an experiment that manipulated the densities and identities of two ecologically similar estuarine-dependent predators, Red Drum (Sciaenops ocellatus) and Spotted Seatrout (Cynoscion nebulosus), within three habitat complexities. The resulting survivorships of two shared prey types were utilized to determine whether these predators are substitutable, to examine their inter- and intra-specific trophic interactions, and to investigate the impact of habitat structural complexity on their trophic dynamics. The predators differed in their prey preferences and predation pressures, indicating they are generally not substitutable. Interactions between conspecific predators were particularly important in shaping trophic dynamics, and often resulted in combined predation impacts that either enhanced or reduced the survivorship of shared prey as compared to expected values based on foraging rates of individuals. Minimal evidence of interspecific trophic interactions was detected. The observed emergent multiple predator effects differed among the habitats, and were generally intense in intermediate habitat complexity but were either intense or weak in high habitat complexity, depending on the predator combination. These results collectively indicate that prey regulation in this estuarine trophic system is highly dependent on the predator-prey assemblage and habitat context, and enhances our understanding of how multiple predators interactively shape their shared ecosystem.

LanguageEnglish (US)
Pages120-128
Number of pages9
JournalJournal of Experimental Marine Biology and Ecology
Volume511
DOIs
StatePublished - Feb 1 2019

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predator
predators
habitat
habitats
survivorship
Cynoscion nebulosus
Sciaenops ocellatus
trophic interaction
survival rate
effect
predation
prey preference
estuarine ecosystem
ecosystems
foraging
ecosystem

Keywords

  • Estuarine landscape ecology
  • Fish ecology
  • Habitat complexity
  • Multiple predator effects
  • Predator-prey interactions

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science

Cite this

Emergent intraspecific multiple predator effects shape estuarine trophic dynamics across a gradient of habitat complexity. / Livernois, Mariah C.; Fodrie, Fredrick Joel; Heck, Kenneth L.; Powers, Sean P.

In: Journal of Experimental Marine Biology and Ecology, Vol. 511, 01.02.2019, p. 120-128.

Research output: Contribution to journalArticle

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