Karamu, Coprosma robusta is an introduced and highly invasive plant from New Zealand that is having devastating consequences for natural ecosystems on the Mornington Peninsula. It grows very rapidly to form dense thickets that outcompete other vegetation, leaving the ground beneath completely bare. Areas infested with Karamu are unable to support native wildlife because Karamu does not provide the suitable shelter, nesting material or year-round supply of food required. In addition, where Karamu covers sufficient ground, it disrupts the ability for animals to move freely through the wider landscape. Worryingly, Karamu can hybridise with another local indigenous plant, Coprosma quadrifida, polluting the gene pool of this native species. Karamu can also be easily confused with the rare and indigenous Muttonwood plant, and care and expertise is required when undertaking control.

Karamu occurs in the Main Ridge, Red Hill and Flinders regions of the Mornington Peninsula, where it is establishing itself in areas of remnant roadside vegetation, private property, biolinks, national park and bushland reserves. Main Creek Catchment Landcare aims to address this threat to local biodiversity by eradicating Karamu from the Mornington Peninsula altogether. This will be done by raising the profile of Karamu as a serious weed threat, conducting education campaigns using various forms of media, working with all key stakeholders, undertaking large scale control using skilled bushland regenerators, and hosting regular working bees for community volunteers.