ABSTRACT
Feeding by parrotfish is considered to play a critical role in maintaining coral cover on coral reefs. Concern exists that overfishing of parrotfish may cause benthic phase-shifts from coral to macroalgal dominated states. No-Take Marine Reserves (NTMRs) are advocated widely as one potential solution to overfishing. NTMRs are hypothesized to increase density and biomass of parrotfish targeted by fishing and subsequently reverse effects of fishing on coral reef benthos. This chapter examined evidence for both direct and indirect effects of NTMRs on parrotfish density and biomass and how NTMR protection affects interactions between parrotfish and the benthos that were top-down (parrotfish effects on benthos) and bottom-up (benthic effects on parrotfish). Evidence suggests that parrotfish density and biomass generally increased in NTMRs relative to fished areas over time, but only where fishing targeted parrotfish. Evidence that NTMRs could subsequently modify the ways in which parrotfish exert top-down control on the benthos was rare and equivocal. In contrast, bottom-up processes (benthic effects on parrotfish) influence density of parrotfish strongly, often independently of NTMR status. To assess recovery of parrotfish and parrotfish-benthos interactions inside NTMRs relative to fished areas, more well-designed Before-After-Control-Impact-Pair studies that incorporate decadal-scale monitoring are required.
