| Zusammenfassung: | ABSTRACT: A replicated comparison of heavily and lightly fished areas in the Galapagos suggested that fishing predators led to an increase in herbivores and a dramatic shift in the algal community toward crustose barrens. We sampled 10 highly fished and 10 lightly fished shallow rocky reefs in the southeastern area of the Galapagos Marine Reserve, Ecuador. Negative associations between consumers and resources suggested top-down control. At cold sites, there was a negative association between slate-pencil urchinsEucidaris galapagensisand non-coralline algae. In addition, at cold sites, pencil urchins were less abundant where there were many predators. An indirect positive association between predators and non-coralline algae occurred at warm and cold sites. Fishing appeared to affect this trophic cascade. The spiny lobsterPanulirus penicillatus, the slipper lobsterScyllarides astori, and the Mexican hogfishBodianus diplotaeniawere significantly less abundant at highly fished sites. Urchin density was higher at highly fished sites. Non-coralline algae were nearly absent from highly fished sites where a continuous carpet of the anemoneAiptasiasp. was recorded and the algal assemblage was mainly structured by encrusting coralline and articulated calcareous algae.
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