Change in fish and benthic communities in Belizean patch reefs in and outside of a marine reserve, across a parrotfish capture ban

Abstract

The role of a marine reserve and fisheries regulations in restoring fish populations on reefs disturbed by climate impacts was evaluated. Eight patch reefs, divided equally between no-fishing and fished zones in the remote Glover’s Reef atoll lagoon, were studied for 22 yr: 13 yr before and 9 yr after a ban on parrotfish capture. Findings indicate that the main effect of the fisheries closure was the recovery of targeted carnivorous species, notably snappers, jacks, and groupers. Recovery continued for most of the time series, including the later period when parrotfish capture was banned. Parrotfish abundance slowly declined in both management zones and across the ban period. The loss occurred for both small non-fished species, such as the striped parrotfish Scarus iserti, and for larger fished species, such as the stoplight Sparisoma viride and red-band parrotfish Sparisoma aurofrenatum. Consequently, parrotfish abundance appeared to be controlled by the ecology of these patch reefs rather than fishing mortality. We suggest that the high and persistent cover of late-successional algae reduces the renewal rates of algae, which had negative consequences for all studied parrotfish populations. Low ocean currents and physical energy in the lagoon appeared to promote algal persistence. Thus, parrotfish bans may be more effective in promoting reef recovery in environments that promote rapid algal turnover. Fisheries regulations are unlikely to rapidly restore hard corals on these patch reefs, which have slowly transitioned to algal dominance since first described in 1970.