Background
The authors write that "strong storms including cyclones, hurricanes, typhoons and strong wind events have catastrophic impacts on coral reefs worldwide," and that "Yu et al. (2004) suggested that the surface ages of well-preserved transported coral blocks could indicate the ages of past storm occurrences," which inference, as they continue, "was further confirmed by the analysis of sedimentation rates and grain sizes of lagoon sediments from the same reef (Yu et al., 2006; Yu et al., 2009)."

What was done
In November of 2008, Yu et al. (2012) sampled 102 individual coral colonies (coral blocks) and four reef blocks that they found distributed across the northern reef flat of Heron Reef, precisely dating them via the thermal ionization mass spectrometry (TIMS) U-series method, in an attempt to further explore their utility as indicators of historical storm activities around the southern end of the Great Barrier Reef, which is an area that is frequently visited by cyclones and storms, as noted by Done (1993) and Puotinen (2004).

What was learned
The age distribution and relative probability frequency analysis of the dated coral and reef blocks suggested, in the words of the seven scientists, that "there were eight relatively stormy periods since AD 1900, i.e., 1904-1909, 1914-1916, 1935-1941, 1945-1960, 1965-1967, 1976-1977, 1983-1988 and 2001-2007." And their yearly plot of the data clearly shows the very center of the 20th century (1935-1965) to have been that century's most sustained stormy period in the vicinity of Heron Reef.

What it means
Yu et al. (2012) conclude their report by stating that their findings suggest that "coral reefs in the southern Great Barrier Reef are frequently influenced by periods of high storm activity," and that the reefs in that part of the world "show strong resilience to natural disturbances over the past century," indicative of the fact that the continued existence of that region's corals is not nearly as tenuous as many climate alarmists have made it out to be.

References
Done, T. 1993. On tropical cyclones, corals and coral-reefs. Coral Reefs 12: 126-126.

Puotinen, M.L. 2004. Tropical cyclones in the Great Barrier Reef, Australia, 1910-1999: a first step towards characterizing the disturbance regime. Australian Geographical Studies 42: 378-392.

Yu, K.F., Zhao, J.X., Collerson, K.D., Shi, Q., Chen, T.G., Wang, P.X. and Liu, T.S. 2004. Storm cycles in the last millennium recorded in Yongshu Reef, southern South China Sea. Palaeogeography, Palaeoclimatology, Palaeoecology 210: 89-100.

Yu, K.F., Zhao, J.X., Shi, Q. and Meng, Q.S. 2009. Reconstruction of storm/tsunami records over the last 4000 years using transported coral blocks and lagoon sediments in the southern South China Sea. Quaternary International 195: 128-137.

Yu, K.F., Zhao, J.X., Wang, P.X., Shi, Q., Meng, Q.S., Collerson, K.D. and Liu, T.S. 2006. High-precision TIMS U-series and AMS C-1 4 dating of a coral reef lagoon sediment core from the southern South China Sea. Quaternary Science Reviews 25: 2420-2430.