Species → Stoplight parrotfish
Stoplight parrotfish
Sparisoma viride
What if it disappeared?
Impact HighBy grazing on algae growing on dead coral, the parrotfish keeps algae from covering and smothering living coral colonies — without this grazing pressure, algae take over.
DocumentedDetail
Mumby, P.J., Dahlgren, C.P., Harborne, A.R. et al. (2006). Fishing, trophic cascades, and the process of grazing on coral reefs. Science, 311(5757), 98–101.
The authors show that in the absence of parrotfish and other herbivores, coral shifts toward a state dominated by fleshy algae, a state change that is difficult to reverse once established. Overfishing of large predators that keep other competing herbivorous fish in check amplifies this effect further.
Overfishing of parrotfish is associated with reduced reef resilience to coral bleaching: reefs with more parrotfish recover better after a disturbance.
DocumentedDetail
Mumby, P.J. (2006). The impact of exploiting grazers (Scaridae) on the dynamics of Caribbean coral reefs. Ecological Applications, 16(2), 747–769.
By modeling the effect of different levels of parrotfish exploitation on Caribbean reef dynamics, the author shows that beyond a certain fishing threshold, the reef loses its ability to return to a coral-dominated state after a disturbance such as a bleaching event.
Documentation
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Sparisoma viride — The IUCN Red List of Threatened Species
Accessed August 10, 2026
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Mumby et al. (2006) — Fishing, trophic cascades, and the process of grazing on coral reefs, Science
Accessed August 7, 2026
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Mumby (2006) — The impact of exploiting grazers (Scaridae) on the dynamics of Caribbean coral reefs, Ecological Applications
Accessed August 7, 2026
Last verified: August 7, 2026