Document ID: chunk:federal_register_of_legislation:F2025L00071:body:0:p10
Version: federal_register_of_legislation:F2025L00071
Segment Type: other
Provision Reference: 
Character Range: 28597–31611

the southern atoll lagoon ecosystem. Scattered across the sandy habitats of the lagoon, the blue holes are encircled by coral and contain coral rubble in the centre, providing deeper and more complex habitats. They support cucut (sharks), gong gong (spider conch), gelek burik (coral trout), dongol (bumphead parrotfish) and ikan hijau (humphead Māori wrasse). The southern blue holes in particular provide shelter for invertebrates and juvenile fish at low tide when the shallow southern lagoon flats are exposed. The blue holes are also culturally important to Cocos Malay fishers, who have named each individual kolam and associate different holes with particular species.
Image: Cocos (Keeling) Islands southern atoll showing the kolam (blue holes) (Esri, Maxar, Earthstar Geographics, and the GIS User Community)

Lumut (seagrass)
Seagrass is a key habitat of the lagoon  it is important for many species, including penyu (green and hawksbill turtles), ikan terompet (pipefish), juvenile blacktip anak cucut (reef sharks), rajugan (mud crabs) and gerita (night octopus), and provides nursery habitat for a range of fish species. It is also important for the overall lagoon ecosystem, as it stabilises sediment and filters nutrients  functions that help with water quality. Seagrass at Cocos (Keeling) Islands is under significant pressure, with around 80% of seagrass in the southern atoll lagoon estimated to have been lost between 2006 and 2018 due to multiple causes, including high temperature events, sediment disturbance from the development of the Rumah Baru Jetty and increased grazing pressure from turtles (Buckee et al. 2021). Given this concerning decline, at the time this plan is made, Parks Australia is working with partner organisations on seagrass restoration trials in the Cocos lagoon.
Cucut (sharks)
Cucut (sharks), including blacktip, cucut batu (whitetip reef sharks) and cucut itam (grey reef sharks), are common in and around Cocos (Keeling) Islands. Four other shark species have been recorded in the area: the tiger, scalloped hammerhead, pelagic thresher and silky. Sharks play a key role in marine ecosystems by helping to maintain balance in the food chain. The shallow inner lagoon provides important nursery habitat for juvenile blacktip reef sharks and the blue holes provide an important nursery habitat for grey reef sharks.
         Image: Grey reef shark (Rohan Newton)

Penyu (marine turtles)
Cocos (Keeling) Islands provides important habitat for internationally significant populations of resident green and hawksbill turtles. Green turtles recruit from a diverse range of rookeries, including Pulu Keeling National Park, the Australian mainland, Indonesia and Malaysia. Hawksbill turtles recruit from rookeries to the west, including the Seychelles and the Chagos Archipelago. Cocos (Keeling) Islands Marine Park, together with Pulu Keeling National Park, captures areas that are important to both green and hawksbill turtles for foraging and resting. The moderate