Zostera muelleri is a southern hemisphere temperate species[5] of seagrass native to the seacoasts of South Australia, Victoria and Tasmania.

[8] Zostera muelleri is a perennial species, meaning populations of it endure year round.

[12] They are mostly found in places such as littoral or sublittoral sand flats,[12] sheltered coastal embayments,[12] soft, muddy, sandy areas near a reef,[8] estuaries,[9] shallow bays,[9] and in intertidal shoals.

[9] Zostera muelleri is widespread in Southern Australia, and its also found in New Zealand and Papua New Guinea.

[1] This species has long strap-shaped leaves,[5] rounded leaf tips[9] and thin rhizomes that are <3 mm in diameter.

[9] Young rhizomes are typically yellow, but the leaves of this plant can turn red if they're under high sunlight.

[1] The species Z. muelleri evolved from terrestrial plants, but adapted to marine life around 140 million years ago during the Cretaceous period.

[12] Reproducing sexually increases genetic variation, which can enhance a plant's ability to adapt to a changing environment, but asexual reproduction requires less effort and is what Z. muelleri typically uses to maintain its population.

[9] Zostera muelleri can reproduce asexually via rhizome encroachment,[13] which is a form clonal reproduction.

[13] Threats to this species include coastal development,[1] eutrophication,[11] boat mooring,[11] dredging,[11] agricultural/urban runoff,[11] and sedimentation.

[1] Meadows of Z. muelleri have been lost in areas of Port Phillip Bay and New Zealand due to habitat disturbance, sedimentation, and turbidity.