Dataset: Summed coral cover along the four accessory transects in St. John from 1989 to 2017

The shallow reefs (≤ 14-m depth) of St. John have been subjects of time-series analyses since December 1987. Study plots first were established at 9-m depth at Yawzi Point, and at 14-m depth at Tektite, both of which provide examples of reefs dominated by Orbicella annularis. The initial sampling evaluated the impacts of coral bleaching in 1987, and each site consisted of three, 10-m transects placed at a constant depth, parallel to one another (and 5-m apart), and permanently marked. Ten contiguous photoquadrats (1 × 1 m) have been recorded along each transect annually, and here results from 1988 (March) and 1989 (April and October) are used to evaluate the effects of Hurricane Hugo, from 1995 (May) and 1996 (May) to evaluate the effects of Hurricanes Luis and Marilyn, and from 2017 (July and November) to evaluate the effects of Hurricanes Irma and Maria. The damage from Hurricane Hugo at Yawzi Point was extensive, and to capture this spatial scale of damage, the analysis was expanded with four, unmarked 20-m transects. In 1989, these transects were recorded using Hi-8 video (Sony Corporation), but starting in 1992, they were recorded as contiguous photoquadrats using underwater cameras. Surveys of these 20-m transects from 1989 (October), 1995 (May), 1996 (May), and 2017 (July and November) are used here to expand the spatial scale of the present analysis.