Standard Presentation (15 mins) Australian Marine Sciences Association 2022

Utilising a Novel Technique to Effectively Sample Low-Density Populations of Crown of Thorns Starfish (#326)

Josie F Chandler 1 , Morgan S Pratchett 1 , Ciemon F Caballes 1 , Deborah Burn 1 , Peter C Doll 1
  1. James Cook University, Townsville, QUEENSLAND, Australia

Effective sampling of low-density populations of crown-of-thorns starfish (CoTS) is fundamental for detecting the early onset of population irruptions and for pre-emptive management decisions. Traditional methods used to assess the abundance and occurrence of CoTS, either have constrained spatial scales or limited capacity to detect cryptic individuals. This study aimed to demonstrate the utility of a novel scooter-assisted large area diver-based (SALAD) visual survey technique. SALAD surveys have all the benefits of transect-based surveys, but with a greatly increased areal extent. In 2021, 90 SALAD visual surveys were conducted across 14 reefs in 4 distinct regions of the Great Barrier Reef, encompassing a combined survey area of 46.39 hectares. The survey method proved effective at collecting unprecedented baseline data on the abundance, distribution and behaviour of low-density CoTS populations on the Northern GBR over a large spatial scale. While significant densities of CoTS were recorded at some reefs, these data provide an important baseline for monitoring spatiotemporal changes that may occur ahead of renewed population outbreaks on the GBR.