But the sea wrack at Hillarys Beach and the MAAC this morning was primarily made up of an algae called sargassum. This brown algae has a distinctive stem-like structure and can generally be identified by its small bubble-like floats.
Left: The seawrack made up of Sargassum. Right: Float bubbles from Sargassum.
Find out more about what’s washed up on WA beaches at http://beachcombers-kit.fish.wa.gov.au/species-list/.