Variation in size-frequency distributions of branching corals between a tropical versus sub-tropical reef

Diversity in the life history of corals plays a critical role in shaping coral assemblages and reef habitats. Given difficulties in quantifying key demographic rates, valuable insights into life histories of corals are often inferred based on size-frequency distributions. The present study compares size-frequency distributions of branching coral taxa between Lord Howe Island, a subtropical reef, and Heron Island, in the southern Great Barrier Reef. Size-frequency distributions were markedly different among coral species but also varied among locations. Log-transformed size-frequency distributions of the majority of species were negatively skewed, reflecting the high levels of mortality among the smaller size classes and the persistence of the larger colonies. Among species, there were marked differences in kurtosis, reflective of fundamental variation in coral life histories; Acropora yongei had the lowest kurtosis, indicative of fast growth and high population turnover. Between locations, there was a higher proportion of smaller colonies at Heron Island, which was consistent across all coral taxa, suggesting a greater incidence of mortality at Heron Island. Size-frequency distributions provide important insights on the life-history dynamics of coral species and should be monitored over time to test how coral populations and communities will respond to global climate change, especially at high-latitude reefs