Habitat and Ecology
Posidonia sinuosa has inflorescences born on flattened, leafless peduncles, with reduced, hermaphroditic flowers and filiform pollen. Inflorescence of P. sinuosa are well hidden below the "umbrella-like" meadow canopy at ~10 cm above the sediment. Anthesis and fruiting occurs from August to January (Womersley 1984).
Posidonia sinuosa meadows have a high number of tightly packed shoots with overhanging semi-permanently bent top portions. This species has high leaf density surrounding the flowers which may prevent the pollen from escaping out of the meadow into the overlying water column. This likely leads to greater neighbour to neighbour pollination in this species (Smith and Walker 2002).
IUCN Red List Assessment
Red List Category
Red List Criteria
In one area of P. sinuosa's distribution, Cockburn Sound has been subjected to steady degradation since 1954, with the establishment of an oil refinery and the successive establishments of steel works, fertilizer factories, sewage-treatment facilities, and a power station. This has lead to contaminated effluents and increased nutrient loads. Between 1954 and 1978 the meadow in this region reduced from 4,200 to 900 ha (Cambridge and McComb 1984).
Seagrass loss (Posidonia australis and P. sinuosa) in Oyster Harbour between 1962 and 1988 was the culmination of diffuse nutrient and sediment influx from rural catchments (Cambridge et al. 2002).