The Future of Coral Reefs

Coral reefs have been degrading faster than they have been recovering (Done 1992; Ginsburg 1994; Hughes 1994; Grigg and Birkeland 1997; McManus and Vergara 1998; Wilkinson 1993, 1998) and they have been accruing in their degraded states because they achieve alternate stable states of algae instead of corals (Knowlton et al. 1981; Knowlton 1992; Done 1992; Hughes 1994), and because rates of damage are much greater than rates of recovery (Muzik 1985; Birkeland 1997a). With the accumulation of reefs in alternative stable states, the total area of some reefs previously dominated by coral is decreasing over time (Muzik 1985; Knowlton et al. 1981, 1990; Wilkinson 1993), and the balance has been continuously in the negative for corals over the past few decades (LaPointe 1989; Hallock et al. 1993; Birkeland 1997a). Furthermore, human activities are now bringing about environmental changes on a global scale (Smith and Buddemeier 1992; Hoegh-Guldberg 1999; Tsuchiya 1999; Wilkinson et al. 1999) which alter the basic conditions and nature of environmental processes in the domain.