DNA-Based Detection and Patterns of Larval Settlement of the Corallivorous Crown-of-Thorns Sea Star (Acanthaster sp.)

219 larval settlement collectors were deployed on the Great Barrier Reef during 4 sampling periods between October 2016 and February 2020.Deployments were approx. 2.5 months in duration, coinciding with the COTS summer reproduction and spawning seasonAll larval settlement collectors were deployed at three sampling locations in northern (near Lizard Island and Cairns) and central GBR (near Townsville), at three different depths (4-6m, 7-9m and 10-12m) and at three sites per reef.Larval settlement collectors were constructed using 2 leaf baskets ¿lled with about 60–70 aquarium ¿lter Ovi-Flow bio balls. During deployment, each collector was secured to the substrate and allowed to float approx. 1m above the substrate.All larval settlement collectors were deployed at sites with relatively steep reef slopes, de-¿ned by a high cover of coral rubble encrusted with coralline algae, which is where COTS juveniles are typically observed.Following retrieval, each apparatus was processed to remove all sample material (see Doll et al. (2021) for more details). DNA extraction allowed for genetic analysis to explore spatial and temporal settlement patterns.