NSW is experiencing unprecedented losses of marine macrophytes from shallow coastal ecosystems and the emergence of species native species with invasive characteristics (e.g. Caulerpa filiformis).

Changes are particularly apparent around the Sydney metropolitan region but Caulerpa is now found as far north as Ballina, 100’s of kilometres outside its previously known distribution.  Because it is chemically defended and structurally very different from many of the seaweed species it is possibly replacing, the spread of Caulerpa filiformis may severe consequences for native coastal biodiversity.

This project will determine the role of coastal pollution and sedimentation in contributing to the spread of highly adaptive species in NSW, and also investigate the effects of the spread of this species on native biota.

Whilst native to NSW, Caulerpa filiformis shares many characteristics of invasive species such as rapid growth and asexual fragmentation. Although the reasons for its spread are unclear, it appears to prefer areas of high sedimentation (often found in highly urbanised areas). Thus a large part of our research is determining the reasons behind its spread.

In addition, because it is inedible  to many species of invertebrates and fish that occur in NSW’s aquatic ecosystems it has the potential to alter the structure of coastal marine communities. New research by A/Professor Paul Gribben of UNSW Australia suggests that Caulerpa filiformis is having a large impact on urchin populations.

The research will provide the answers why some important habitat-forming species are being lost and replaced by others, and what the consequences of these changes are for coastal biodiversity. Ultimately, the outcomes of this research will provide information key to prevention of the loss of many important species.