MEPS 343:77-85 (2007)  -  DOI: https://doi.org/10.3354/meps06915

RETRACTION: Some of the conclusions in this article are incorrect, due to errors in entry of urchin abundance data prior to statistical analysis. These errors were discovered after publication. Reanalysis by the authors of the corrected dataset shows that (1) the main predators of slate-pencil urchins are slipper lobsters (not Mexican hogfish), and predation by spiny lobsters is of minor importance; (2) site-specific differences exist mainly between rocky and sandy habitats, whereas temperature effects are minor. The central conclusion of the study remains valid: the fishery on urchin predators causes a dramatic shift in the algal community toward crustose barrens. The errors are the authors' responsibility; they were impossible to detect by the reviewers or the editor. A corrected version of the article has been published after additional review by the original referees as MEPS 375:209-218.

KEY WORDS: Trophic cascade · Fishing · Predation · Population structure · Eucidaris galapagensis · Galapagos Marine Reserve · Ecuador