ABSTRACT
Climate change is having a dramatic effect on coral reefs, and is leading to the poleward range expansions of coral reef organisms and the tropicalization of marginal reef communities. These changes have led to suggestions that marginal reefs may act as refugia from climate change. We already know that parrotfishes are essential for the health of tropical reefs, but are they equally important on marginal reefs? This chapter provides an overview of what is currently known of the ecology of parrotfishes on these marginal, high latitude reefs. The chapter starts with a description of the biotic and abiotic conditions that characterize high latitude reefs, and how these may influence various aspects of parrotfish ecology within these systems. It then uses case studies from four marginal reef systems (the Arabian Peninsula, eastern Australia, southern Japan, and Brazil) to explore the ecology of parrotfishes in these unique environments in greater detail. Together, these case studies highlight that declines in the abundance and diversity of parrotfishes with increasing latitude are widespread, and pronounced among excavating parrotfishes. While parrotfishes often dominate herbivore biomass on low latitude reefs, they appear to be relatively minor players on marginal reefs.
