Split spawning increases robustness of coral larval supply and inter-reef connectivity

• Published in: Nature communications Vol. 10; no. 1; pp. 3463 - 10
• Main Authors: Hock, Karlo, Doropoulos, Christopher, Gorton, Rebecca, Condie, Scott A., Mumby, Peter J.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.08.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 631/158/1144; 631/158/2446; 631/158/2446/837; 704/158/2446/837; Animal reproduction; Animals; Anthozoa - physiology; Australia; Biodiversity; Breeding success; Connectivity; Coral Reefs; Corals; Dispersal; Dispersion; Ecosystem; Environmental conditions; Humanities and Social Sciences; Industrial research; Larva - physiology; Larvae; multidisciplinary; Ocean currents; Oceans and Seas; Reliability; Reproduction; Science; Science (multidisciplinary); Spawning; Time Factors; Australia
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-11367-7

Many habitat-building corals undergo mass synchronous spawning events. Yet, despite the enormous amounts of larvae produced, larval dispersal from a single spawning event and the reliability of larval supply are highly dependent on vagaries of ocean currents. However, colonies from the same population will occasionally spawn over successive months. These split spawning events likely help to realign reproduction events to favourable environmental conditions. Here, we show that split spawning may benefit corals by increasing the reliability of larval supply. By modelling the dispersal of coral larvae across Australia’s Great Barrier Reef, we find that split spawning increased the diversity of sources and reliability of larval supply the reefs could receive, especially in regions with low and intrinsically variable connectivity. Such increased larval supply might help counteract the expected declines in reproductive success associated with split spawning events. Corals occasionally split their spawning over two consecutive months rather than utilising a single annual event. Here, the authors model coral larval dispersal to show that split spawning may increase the reliability of larval supply to reefs, with implications for recovery from disturbances.