Data from: Impacts and recovery from Severe Tropical Cyclone Yasi on the Great Barrier Reef

Full recovery of coral reefs from tropical cyclone (TC) damage can take
decades, making cyclones a major driver of habitat condition where they
occur regularly. Since 1985, 44 TCs generated gale force winds (≥17
metres/second) within the Great Barrier Reef Marine Park (GBRMP). Of the
hurricane strength TCs (≥H1—Saffir Simpson scale; ≥ category 3 Australian
scale), TC Yasi (February, 2011) was the largest. In the weeks after TC
Yasi crossed the GBRMP, participating researchers, managers and rangers
assessed the extent and severity of reef damage via 841 Reef Health and
Impact Surveys at 70 reefs. Records were scaled into five damage levels
representing increasingly widespread colony-level damage (1, 2, 3) and
reef structural damage (4, 5). Average damage severity was significantly
affected by direction (north vs south of the cyclone track), reef shelf
position (mid-shelf vs outer-shelf) and habitat type. More outer-shelf
reefs suffered structural damage than mid-shelf reefs within 150 km of the
track. Structural damage spanned a greater latitudinal range for mid-shelf
reefs than outer-shelf reefs (400 vs 300 km). Structural damage was
patchily distributed at all distances, but more so as distance from the
track increased. Damage extended much further from the track than during
other recent intense cyclones that had smaller circulation sizes. Just
over 15% (3,834 km2) of the total reef area of the GBRMP is estimated to
have sustained some level of coral damage, with ~4% (949 km2) sustaining a
degree of structural damage. TC Yasi likely caused the greatest loss of
coral cover on the GBR in a 24-hour period since 1985. Severely impacted
reefs have started to recover; coral cover increased an average of 4%
between 2011 and 2013 at re-surveyed reefs. The in situ assessment of
impacts described here is the largest in scale ever conducted on the Great
Barrier Reef following a reef health disturbance.