The Victorian Department of Sustainability and Environment is calling for any sightings of Undaria pinnatifida, also known as Japanese Kelp or Wakame.

Undaria is a golden brown seaweed that grows between 0.5 and 3 metres in length. Key features of Undaria are frilly growth at the base and a stripe up the middle of the frond. It is native to Japan, Korea and some parts of China and Russia, and used as the food product wakame.

Undaria is a fast-growing marine pest and poses a threat to the Victorian marine environment. It has been nominated as among 100 of the world’s worst invasive species according to the Global Invasive Species Database.

Undaria is already within Port Phillip Bay and has recently been discovered in Apollo Bay Harbour. DSE is working closely with the Department of Primary Industries, Parks Victoria and Colac Otway Shire to manage the infestation in Apollo Bay Harbour. More about Undaria on the ALA’s species page and the National Introduced Marine Pest Information System (NIMPIS) website.

Please report any sightings of Undaria from outside Port Phillip Bay or Apollo Bay Harbour to DSE’s Customer Service Centre by phoning 136 186 or

Please send details of sightings (using our standard data recording templates) to or report it to DSE’s Customer Service Centre by phoning 136 186. Data recording templates can be obtained from the above email address.

Undaria pinnatifida. Diagram courtesy of National Introduced Marine Pest Information System (NIMPIS), Sanderson 1990.

Undaria pinnatifida, Japanese Kelp. Photo: Crimp, CSIRO Marine Research.