The introduction and establishment of invasive marine species is of significant concern globally. The ability to rapidly detect and respond to newly introduced species is essential, as once established, they are costly and difficult to control and eradicate. Therefore, new, cost-effective, and sensitive techniques are required to aid in the early detection of introduced species. Molecular tools are emerging as a cost-effective and sensitive way to detect species and can be applied to samples taken from a variety of sources including scrapings from settlement plates, plankton tows, and water samples containing environmental DNA (eDNA). This project aimed to assess and compare the effectiveness of using DNA metabarcoding to screen different types of samples (settlement plates, plankton tows and water samples) collected from several locations for invasive species to determine the most cost-effective approaches.