Shoal Bay is a shallow bay lying adjacent to, and north of, the city of Darwin in the

Northern Territory The Northern Territory (commonly abbreviated as NT; formally the Northern Territory of Australia) is an states and territories of Australia, Australian territory in the central and central northern regions of Australia. The Northern Territory ...

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

. Encompassing Hope Inlet at its eastern end, it is characterised by extensive areas of intertidal

mudflat Mudflats or mud flats, also known as tidal flats or, in Ireland, slob or slobs, are coastal wetlands that form in intertidal areas where sediments have been deposited by tides or rivers. A global analysis published in 2019 suggested that tidal fl ...

s and

mangrove A mangrove is a shrub or tree that grows in coastal saline water, saline or brackish water. The term is also used for tropical coastal vegetation consisting of such species. Mangroves are taxonomically diverse, as a result of convergent evoluti ...

s and is an important site for

wader 245px, A flock of Dunlins and Red knots">Red_knot.html" ;"title="Dunlins and Red knot">Dunlins and Red knots Waders or shorebirds are birds of the order Charadriiformes commonly found wikt:wade#Etymology 1, wading along shorelines and mudflat ...

s, or shorebirds. The bay is situated within the

Shoal Bay Coastal Reserve Shoal Bay Coastal Reserve is a protected area in the Northern Territory of Australia. It is situated approximately east of Darwin and protects a large area of eucalypt woodland and saline wetlands. The area is bounded by the Howard River to ...

, a protected area that was established in 2000. Shoal Bay is also known for accommodating the

Shoal Bay Receiving Station Shoal Bay Receiving Station is a signals intelligence-gathering facility in the Northern Territory of Australia located on the shores of Shoal Bay about north-east of the Darwin CBD. The site is managed by the Australian Signals Directorate ( ...

, a signals-intelligence collection facility that contributes to the

NSA The National Security Agency (NSA) is a national-level intelligence agency of the United States Department of Defense, under the authority of the Director of National Intelligence (DNI). The NSA is responsible for global monitoring, collecti ...

's global data collection program.

Description

The bay comprises the lower reaches of the Howard River and several small tidal creeks that drain into Hope Inlet. Much of the bay is exposed at low tide, with about of tidal mud and sand flats. Unlike most other bays in the Northern Territory, it is not associated with large rivers, nor freshwater coastal

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s. It does include some swamps and remnants of

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...

al vine forest on the margins. Because of its proximity to Darwin it is threatened by urbanisation and land development. It is also affected by

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

, frequent fires and largely uncontrolled recreational use of the area.

Flora and fauna

Plants

Some 61 plant species endemic to the Northern Territory are found around the bay. Of these, three, '' Cycas armstrongii'', ''

Ptychosperma macarthurii ''Ptychosperma macarthurii'', commonly known as the Macarthur palm, is a species of tree in the palm family Arecaceae. Its native range is northern Cape York Peninsula in Queensland with a number of disjunct populations in the Northern Territ ...

'' and ''

Utricularia dunstaniae ''Utricularia dunstaniae'' is an annual terrestrial carnivorous plant that belongs to the genus ''Utricularia'' (family Lentibulariaceae). Its distribution ranges from northern Western Australia to the Northern Territory.Taylor, Peter. (1989). ...

'', are considered threatened. Two, ''

Utricularia holtzei ''Utricularia holtzei'' is an annual affixed aquatic carnivorous plant that belongs to the genus ''Utricularia'' (family Lentibulariaceae). It is endemic to the Northern Territory.Taylor, Peter. (1989). '' The genus Utricularia - a taxonomic mo ...

'' and ''

Typhonium praetermissum ''Typhonium praetermissum'' is a species of plant in the arum family that is endemic to the Northern Territory of Australia. In 2022, Hay and others resurrected the genus, ''Lazarum'', and renamed the species as ''Lazarum praetermissum'' (a n ...

'', are only known from the Darwin Coastal

bioregion A bioregion is an ecologically and geographically defined area that is smaller than a biogeographic realm, but larger than an ecoregion or an ecosystem, in the World Wide Fund for Nature classification scheme. There is also an attempt to use the ...

Birds

Some of the bay has been identified by

BirdLife International BirdLife International is a global partnership of non-governmental organizations that strives to conserve birds and their habitats. BirdLife International's priorities include preventing extinction of bird species, identifying and safeguarding ...

as an

Important Bird Area An Important Bird and Biodiversity Area (IBA) is an area identified using an internationally agreed set of criteria as being globally important for the conservation of bird populations. IBA was developed and sites are identified by BirdLife Int ...

(IBA) because it supports, with its low-tide feeding habitat and high-tide roosting sites, over 1% of the world population of

great knot __NOTOC__ The great knot (''Calidris tenuirostris'') is a small wader. It is the largest of the calidrid species. The genus name is from Ancient Greek ''kalidris'' or ''skalidris'', a term used by Aristotle for some grey-coloured waterside bird ...

s. Other birds recorded from the bay in significant numbers include

black-tailed godwit The black-tailed godwit (''Limosa limosa'') is a large, long-legged, long-billed shorebird first described by Carl Linnaeus in 1758. It is a member of the godwit genus, ''Limosa''. There are four subspecies, all with orange head, neck and chest ...

greater sand plover The greater sand plover (''Charadrius leschenaultii'') is a small wader in the plover family of birds. The spelling is commonly given as "greater sandplover" or "greater sand-plover", but the official British Ornithologists' Union spelling is "Gre ...

Terek sandpiper The Terek sandpiper (''Xenus cinereus'') is a small migratory Palearctic wader species and is the only member of the genus ''Xenus''. It is named after the Terek River which flows into the west of the Caspian Sea, as it was first observed aroun ...

s and

beach stone-curlew The beach stone-curlew (''Esacus magnirostris'') also known as beach thick-knee is a large, ground-dwelling bird that occurs in Australasia, the islands of South-east Asia. At and , it is one of the world's largest shorebirds. At a mean of in ...

s.BirdLife International. (2011). Important Bird Areas factsheet: Shoal Bay (Darwin). Downloaded from http://www.birdlife.org on 2011-10-08. Chestnut rails inhabit the mangroves.

Other animals

Apart from birds, threatened animals recorded from the bay and its surrounds include

northern quoll The northern quoll (''Dasyurus hallucatus''), also known as the northern native cat, the North Australian native cat or the satanellus is a carnivorous marsupial native to Australia. Taxonomy The northern quoll is a member of the family Das ...

Mertens' water monitor Mertens' water monitor (''Varanus mertensi''), also called commonly Mertens's water monitor, and often misspelled Mertin's water monitor, is a species of lizard in the family Varanidae. The species is endemic to northern Australia, and is a wide ...

argus monitor The yellow-spotted monitor (''Varanus panoptes''), also known as the Argus monitor, is a monitor lizard found in northern and western regions of Australia and southern New Guinea. Taxonomy The first description of the species was provided in a ...

s, flatback and

olive ridley turtle The olive ridley sea turtle (''Lepidochelys olivacea''), also known commonly as the Pacific ridley sea turtle, is a species of turtle in the family Cheloniidae. The species is the second-smallest and most abundant of all sea turtles found in th ...

dwarf Dwarf or dwarves may refer to: Common uses *Dwarf (folklore), a being from Germanic mythology and folklore * Dwarf, a person or animal with dwarfism Arts, entertainment, and media Fictional entities * Dwarf (''Dungeons & Dragons''), a humanoid ...

and longcomb sawfish, and Dodd's azure butterflies.

Feral pig The feral pig is a domestic pig which has gone feral, meaning it lives in the wild. They are found mostly in the Americas and Australia. Razorback and wild hog are Americanisms applied to feral pigs or boar-pig hybrids. Definition A feral pi ...

s and

water buffalo The water buffalo (''Bubalus bubalis''), also called the domestic water buffalo or Asian water buffalo, is a large bovid originating in the Indian subcontinent and Southeast Asia. Today, it is also found in Europe, Australia, North America, So ...

es are present. There is an ongoing program to monitor and remove

saltwater crocodile The saltwater crocodile (''Crocodylus porosus'') is a crocodilian native to saltwater habitats and brackish wetlands from India's east coast across Southeast Asia and the Sundaic region to northern Australia and Micronesia. It has been listed ...

s from the bay.

References

Bays of the Northern Territory Darwin, Northern Territory Important Bird Areas of the Northern Territory {{NorthernTerritory-geo-stub