ABSTRACT: Interpretations of ecological relationships are often influenced by the scale of observation. Scale independence is a useful null hypothesis against which to test scale-dependent alternative hypotheses. This study examined the interaction between predatory fishes and the ophiuroids on which they prey in back-reef habitats in the Caribbean. Predation potential was measured as the mortality of tethered ophiuroids at shallow, rubble-dominated sites in Jamaica and St. Croix on 2 temporal scales: seasonally over 3 yr and annually over a decade. Diel variations within sites and differences between sites were similar between scales. Hurricanes had no effect on predation potential on either scale. Predation potential at a third back-reef site, in Belize, was consistently different from the sites in Jamaica and St. Croix on the annual scale. The results suggest that some ecological relationships are stable at multiple temporal scales. For cases in which scale independence can be demonstrated over a particular range of scales, it should be possible to make long-term predictions on the basis of short-term observations.

KEY WORDS: Predation · Scale · Stability · Ophiuroidea · Coral reefs

Published in MEPS Vol. 172 (1998) on October 22
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1998