| Summary: | In this study, size-based matrix models for the reef-building coral Orbicella annularis at 14-m depth on the Tektite reef in St. John, U.S. Virgin Islands, were used to: (1) explore the demography of changing coral cover over 25 yr, (2) test for spatial homogeneity in demographic properties through a contrast with a previous study (at Yawzi Point, Edmunds and Elahi 2007), and (3) evaluate the potential for future population stability. During three, five year intervals from 1988 to 2002, St. John was affected by hurricanes and bleaching, yet coral cover at Tektite increased from 33% to 49%; from 2002 to 2007, it declined to 27%; and from 2010 to 2013, it stabilized at ∼ 28%. Over a quarter-century, colonies > 50 cm2 became rare, the abundance of colonies ≤ 50 cm2 increased from 58% (1988) to 92% (2013), and population density doubled to 67 colonies m-2 by 2013. Population growth (λ) was greater at Tektite (1.152 ≥ λ ≥ 1.018) than Yawzi Point (0.679 ≥ λ ≥ 0.586), and while population size at Tektite declined due to bleaching and disease in 2005 (λ = 0.753 over 2003–2008), it recovered between 2008 and 2013 (λ = 0.966); the population at Yawzi Point declined from 1988 to 2003 without signs of recovery. Projections suggest a continuation of recent conditions could allow O. annularis at Tektite to retain ∼ 9% cover after 100 yr, but with a return to the rates of growth and survival of 1993–1998, it could attain coverage similar to that of 1988 (33%) in ∼ 15 yr.
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