Invasive species, such as urchins, that degrade kelp habitat may be contributing to declines in weedy seadragons.
Invasive species including urchins that degrade kelp habitat are an issue for weedy seadragons and may be contributing to declines.
In Tasmania, the macroalgae-covered reefs on which seadragons occur face another threat. Over the last 20 years, the sea urchin Centrostephanus rodgersii, has become more common and increased its range around the state. The increase in sea urchins is considered to have resulted from harvesting of rock lobster, a known predator of urchins, and climate change. Grazing by urchins reduces the abundance of kelp and other macroalgae through the formation of urchin barrens.