Age structure of massive Porites lutea corals at Luhuitou fringing reef (northern South China Sea) indicates recovery following severe anthropogenic disturbance

Luhuitou fringing reef at Hainan Island (northern South China Sea) has experienced severe anthropogenic disturbance, with live coral cover declining by > 80 % since the 1960 s. To assess the size structure of Porites lutea, we measured the sizes of 1,857 colonies from the reef flat (0 m) and slope (2-4 m depth). Both populations were positively skewed and leptokurtic in shape, indicating a high abundance of smaller colonies (averaging 21.4 ± 2.3 cm on the flat and 31.9 ± 2.8 cm on the slope). Age structure of populations was determined through growth rates extracted from X-rays of P. lutea cores. The majority of colonies (> 95 %) were < 50 yr old, with 55 % of P. lutea on the reef flat having recruited following the establishment of a marine reserve in 1990. The abundance of younger colonies indicates significant recovery of P. lutea following the removal of chronic anthropogenic disturbance