Ulva australis, the southern sea lettuce, is a species of bright green coloured seaweed in the family Ulvaceae that can be found in waters around Australia and was first described by Swedish botanist Johan Erhard Areschoug.

[2] It has been researched for a number of scientific properties in distinct fields such as environmental protection, medicine, and pharmacology.

[2] Once considered to be a temperate species, Ulva pertusa is one of the most common green algae in Japan that lives in the intertidal coast, and it is native to northeastern Asia.

However, the researchers hypothesize that the U. australis was not directly introduced from Japan to Australia, but rather from non-indigenous populations elsewhere in northeastern Asia.

It was experimentally shown that the growth and photosynthesis of Ulva australis increases when the levels of carbon dioxide and nutrient are higher, i.e. 750 ppm and PES medium in the experiment.

[10] Ulva australis, as an edible seaweed, is very rich in minerals, vitamins, and noncaloric dietary fiber,[11] and has many uses in medical and biotechnological fields.

Moreover, Ulva australis also shows inhibitory effects on the pathogenic factors of Alzheimer's disease, hyperpigmentation, Type-2 diabetes mellitus and skin sagging.

This shows that Ulva australis as a common food source can be used to treat, prevent or alleviate a variety of diseases.

Some researchers have carried out experiments with different control measures and found that the reproductive capacity of Ulva australis in low salinity water is inhibited.