Short Talk (7,5 mins) Australian Marine Sciences Association 2022

Characterising the Diets of an Invasive Marine Predator through DNA Metabarcoding (#290)

Morgan R Ellis 1
  1. Deakin University, Queenscliff, VIC, Australia

With invasive species being one of the leading threats to biodiversity globally, understanding their diets is crucial to understanding their impacts on native species. Traditional methods of diet analysis involving observing gut contents present and identifying organisms visually. While this method can be effective for identifying the consumption of hard-bodied organisms, such as the hard shell of molluscs, bones of vertebrates, and other hard body parts, this method is susceptible to observers overlooking soft-bodied organisms that are more prone to digestion and various states of decomposition that make many prey items unrecognisable. DNA metabarcoding can fill in this gap by sequencing the digested stomach contents to identify what species are present. This study investigated the diets of the invasive Northern Pacific Seastar (Asterias amurensis). It combined both traditional and metabarcoding approaches to determine what species this voracious predator preys upon in Port Phillip Bay, Victoria, and compares that to the diet of the native 11 arm seastar (Coscinasterias muricata). This insight can help determine what native species are most at threat and be used to help prioritise responses to future invasions along the southeast Australian coast.