PORT PHILLIP BAY


Brown Seaweed 

Macrocystis pyrifera

View scientific description and taxonomy

General Description

Long, straight, rubbery multiple stalks (stipe), with oval-shaped floats arising on short branches in a random alternate pattern giving rise to elongate flattened blades. Blades are narrow, long and have a wrinkled appearance (longitudinally corrugated). Holdfast at base is root-like with entangled branches (haptera). Medium to dark brown. Up to 10 m long (thallus).

Biology

This is the largest canopy-forming kelp species in Victoria. It has been declining in recent years and is listed as an endangered ecological community nationally under the Environment Protection and Biodiversity Conservation Act. It is the first ecological community to be listed as endangered in Australia. Recent taxonomic review found that the species previously referred to as Macrocystis angustifolia is the same as Macrocystis pyrifera.

Habitat

Subtidal rocky reefs, moderate to exposed wave action, to depth of 10 m.

Reefs

Distribution guide

North and South America, New Zealand, and south-eastern Australia.

Species Group

Seaweeds and seagrasses Brown algae

Depth

Shallow (1-30 m)

Water Column

On or near sea floor

Max Size

10 m

Diet

Photosynthetic - sunlight

Commercial Species

No

Global Dispersal

Recorded in Australia

Identify

Conservation Status

  • DSE Advisory List : Not listed
  • EPBC Act 1999 : Endangered
  • IUCN Red List : Not listed

Author

article author Pocklington, Jacqui

Jacqui Pocklington is a Research Associate with expertise in algal taxonomy.

citation

Cite this page as:
Pocklington, Jacqui, 2011, Brown Seaweed, Macrocystis pyrifera, in Taxonomic Toolkit for marine life of Port Phillip Bay, Museum Victoria, accessed 08 Jul 2025, http://136.154.202.208:8098/species/11305

Text: creative commons cc by licence