Habitat and Ecology
Posidonia angustifolia is found on substrate combining fine sand with cobble-sized fractions. Depths range from 2-50 m in open near-shore waters. At shallower depths and in relatively sheltered situations, this species occurs sympatrically with P. sinuosa and Amphibolis spp. At depths of 35 m it has been observed with sparse Heterozostera tasmanica and Halophila ovalis. In well developed meadows this species usually has continuous cover (Cambridge and Kuo 1979).
In Tasmania, it is found mainly in estuary entrances, or in sheltered bays adjacent to Bass Strait Islands (Green and Short 2003).
This species is found sublittorally at depths of from 2-35 m on substrates of fine sand with larger sized fractions. P. angustifolia occurs most frequently in open inshore waters; while reported as a meadow-forming species (Kirkman and Kuo 1996), it is frequently found together with other seagrass species, particularly in its deeper range (Robertson 1984). Robertson also noted that some plants from the eastern limit of its range are of a broad-leaved form, and may be intermediate between P. angustifolia and P. australis.
IUCN Red List Assessment
Red List Category
Red List Criteria