search google and this website:

AUSTRALASIAN Temperate Ocean
"plants"

The plants and plant-y things under the waters of the southern temperate oceans of New Zealand and southern Australia...

Kingdom Chromista

Class Phaeophyceae: Brown Algae

Order Laminariales: Kelps

Family Lessoniaceae 

Ecklonia radiata 'Common Kelp' (Rottnest Island). Can form dense underwater forests. Found from shallow waters down to 25 metres. Widespread in temperate waters of southern hemisphere.

Kingdom Plantae

Order Asimatales

Family Poisidoniaceae

Posidonia sp. 'Strapweed' (Rottnest Island). A group of seagrass with a disjunct distribution; they are found in the Mediterranean and in southern Australian waters.

For the page on the Australasian temperate oceans

Updates
Throughout the virus I am working in Australia on and off as local borders close, mostly in the Kimberley with Coral Expeditions (May-September). If you can't go travelling until everything settles down, then until then, here I am doing online guided walks for Noble Caledonia and online lectures for Silversea.