DISCUSSION
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THE STATUS OF THE WORLD’S REEFS A research expedition of this magnitude provides a plethora of data that can be used to better understand global trends on coral reefs. The GRE allowed us to map and collect vital data on the status of the world’s reefs in some of the most remote locations that had never been studied before. The data collected on the GRE provides valuable insight into the world’s reef dynamics, threats to coral reefs, and the ability of reefs to rebound from acute disturbances, which can help communities and managers battle the ongoing coral reef crisis.
5.1 CARIBBEAN REEFS AND IMPLICATIONS OF SHIFTING REEF DYNAMICS
Many factors have contributed to the phase shift from Caribbean reefs had some of the lowest live coral cover, coral to macroalgae in the Caribbean, and understanding highest macroalgal cover, and lowest fish density and the recovery mechanisms of these reefs will be an biomass of all the sites visited on the GRE (Figure ongoing task for scientists and managers. One of the 22). Our findings from the Caribbean show that despite most interesting discoveries from the Precht et al. (2020) widespread correlation between coral and macroalgae, study was that herbivorous regional or country-wide fish do not seem to have studies will be more useful a significant effect on the in understanding shifting abundance of live coral reef dynamics. A study by or macroalgae. Our data Precht et al. (2020) used generally supported this coral and macroalgal survey generally had low hypothesis when looking at data, collected between 1977 Caribbean-wide findings, and 2001, from 197 sites , few , and lots as we saw a weak negative throughout the Caribbean to of relationship between better understand the possible herbivorous fish density and phase shift from coral- to biomass and macroalgal macroalgal-dominated reefs85. cover. However, when looking They found that in some at country-wide trends, we locations, macroalgae was instead found the relationship more dominant than coral, was more variable. In areas where macroalgae was more while in others, such as Jamaica, the reef dominance prevalent, such as in The Bahamas and Navassa, there shifted back to coral after a recovery period. The was a much stronger relationship between macroalgal data collected on the GRE in Jamaica supports this cover and herbivorous fish biomass, suggesting that the hypothesis, as it showed no significant relationship relationship between herbivorous fish and benthic cover between coral and macroalgae. Instead, the Jamaican is more nuanced and that Caribbean-wide conclusions reefs had a more even spread of algae groups than seen about this correlation cannot be made. in other Caribbean countries. At the time of this study, it is possible Jamaican reefs were undergoing a phase shift from macroalgal-dominated reefs back to coraldominated reefs, as suggested by Precht et al. (2020).
Caribbean reefs coral cover fish algae.
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