Effects of Consumer Interactions on Benthic Resources and Ecosystem Processes in a Neotropical Stream

Michael C. Marshall, Andrew J. Binderup, Eugenia Zandonà, Sandra Goutte, Ronald D. Bassar, Rana W. El-Sabaawi, Steven A. Thomas, Alexander S. Flecker, Susan S. Kilham, David N. Reznick, Cathy M. Pringle

Research output: Contribution to journalArticlepeer-review

21 Scopus citations


The effect of consumers on their resources has been demonstrated in many systems but is often confounded by trophic interactions with other consumers. Consumers may also have behavioral and life history adaptations to each other and to co-occurring predators that may additionally modulate their particular roles in ecosystems. We experimentally excluded large consumers from tile periphyton, leaves and natural benthic substrata using submerged electrified frames in three stream reaches with overlapping consumer assemblages in Trinidad, West Indies. Concurrently, we assessed visits to (non-electrified) control frames by the three most common large consumers-primarily insectivorous killifish (Rivulus hartii), omnivorous guppies (Poecilia reticulata) and omnivorous crabs (Eudaniela garmani). Consumers caused the greatest decrease in final chlorophyll a biomass and accrual rates the most in the downstream reach containing all three focal consumers in the presence of fish predators. Consumers also caused the greatest increase in leaf decay rates in the upstream reach containing only killifish and crabs. In the downstream reach where guppies co-occur with predators, we found significantly lower benthic invertebrate biomass in control relative to exclosure treatments than the midstream reach where guppies occur in the absence of predators. These data suggest that differences in guppy foraging, potentially driven by differences in their life history phenotype, may affect ecosystem structure and processes as much as their presence or absence and that interactions among consumers may further mediate their effects in these stream ecosystems.

Original languageEnglish (US)
Article numbere45230
JournalPloS one
Issue number9
StatePublished - Sep 28 2012
Externally publishedYes

ASJC Scopus subject areas

  • General


Dive into the research topics of 'Effects of Consumer Interactions on Benthic Resources and Ecosystem Processes in a Neotropical Stream'. Together they form a unique fingerprint.

Cite this