The Ramsar Convention is an international treaty that focuses on the conservation and wise use of internationally important wetlands. The Convention was signed by representatives from 18 nations in the town of Ramsar, Iran in 1971 and is overseen by the Secretariat in Gland, Switzerland. Australia has 64 Ramsar sites (12 in WA and 1 in Broome).
As a Contracting Party to the Ramsar Convention, Australia has given an undertaking to ensure that its internationally important wetlands are conserved. These obligations are met through Commonwealth and State/Territory legislation. The Department of Parks and Wildlife play a key role in protecting Western Australia’s Ramsar sites, including Roebuck Bay.
The Roebuck Bay Ramsar site is a “no fly” area for aircraft. The occasional disturbance of shorebirds is part of nature. However the repeated and increasing number of disturbances has a cumulative effect on the birds. Important aspects such as feeding and breeding are disrupted, creating a stressful environment for the birds.
Helicopters may cause birds to ‘flight’ from their roosts. This response to perceived predators requires large amounts of energy from birds, making it even more difficult for shorebirds to gain the critical weight needed for their migratory journeys. Find out more »
Roebuck Bay was nominated to become a Ramsar site in June 1990, with the criteria for listing updated in October 2003 and December 2008.
Roebuck Bay, Western Australia, Ramsar Site No. 479.
The Roebuck Bay Ramsar site extends from the location “Campsite”, east of the town of Broome (population ca. 14,500 in 2006), to south of Sandy Point (Bennelongia, 2009). The area is approximately 34,119 ha. The location in coordinates is:
Latitude 17° 58′ S to 18° 16′ S.
Longitude 122° 08′ E to 122° 27′ E.
The Ramsar site does not extend over the entire Roebuck Bay wetland ecosystem. As Bennelongia (2009)¹ points out, most of the extensive grasslands east of the Bay referred to as Roebuck Plains are excluded from the Ramsar site. However “they are contiguous with the Bay and hydrologically connected.” They note also that, “the western boundary of the Ramsar site along the northern shore stops short of the Dampier Creek system.”
The Department of Environment and Conservation (DEC), who are active members of the RBWG, successfully applied for grant funds (NHT/NAP) in 2008 to assist the RBWG to develop a management plan for the Ramsar Site. In 2009 the RBWG engaged consultants to develop a Preliminary Draft Roebuck Bay Ramsar Site Management Plan which was completed in 2010.
It is currently proposed that Roebuck Bay meets seven criteria:
Criterion 1: Wetland values. The site is a superb example of a tropical marine embayment within the Northwest (IMCRA) bioregion. It is one of only a dozen intertidal flats worldwide where benthic food sources are found in sufficient densities that they regularly support internationally significant numbers of waders.
Criterion 2: Threatened species/communities. Loggerhead Turtles Caretta caretta (nationally endangered) and Green Turtles Chelonia mydas (nationally vulnerable) regularly use the site as a seasonal feeding area and as a transit area on migration. Flatback Turtles Natator depressus (nationally vulnerable) regularly nest in small numbers around Cape Villaret during the summer months. Sawfish Pristis clavata (nationally endangered) regularly use the tidal creeks and mangrove areas for breeding and refuge.
Criterion 3: Regional biodiversity. The site supports a significant component of the regional (Northwest IMCRA bioregion) intertidal and shallow marine biodiversity in terms of the marine mammals (Dugong, turtles and dolphin), marine invertebrate fauna, and avian fauna across the site. The total density of macrobenthic animals (1,287 individuals/m2) is high by global standards for a tropical mudflat and species richness is very high (estimated to be between 300 – 500 species).
Criterion 4: Key habitat in life cycle. The site is one of the most important migration stopover areas for shorebirds both in Australia and globally. It is the arrival and departure point for large proportions of the Australian populations of several shorebird species, notably Bar-tailed Godwit Limosa lapponica and Great Knot Calidris tenuirostris. The site provides essential energy replenishment for many migrating species, some of which fly non-stop between continental East Asia and Australia.
Criterion 5: Supports >20,000 waterbirds. The site regularly supports over 100,000 waterbirds. The highest number of shorebirds counted at the site was 170,915 in October 1983 and allowing for turnover, the total number of shorebirds using the site may exceed 300,000 annually. It is the fourth most important site for waders in Australia in terms of absolute numbers and the most important in terms of the number of species it supports in internationally significant numbers (see Criterion 6).
Criterion 6: Supports >1% of waterbird species. The site regularly supports ~ 1% of the population of at least 22 wader species (20 migratory and 2 resident species):
– Greater Sand Plover Charadrius leschenaultii
– Oriental Plover C. veredus
– Lesser Plover C. mongolus
– Red-capped Plover C. ruficapillus (resident)
– Grey Plover Pluvialis squatarola
– Bar-tailed Godwit Limosa lapponica
– Black-tailed Godwit L. limosa
– Red Knot Calidris canutus
– Great Knot C. tenuirostris
– Red-necked Stint C. ruficollis
– Curlew Sandpiper C. ferruginea
– Sanderling C. alba
– Eastern Curlew Numenius madagascariensis
– Little Curlew N. minutus
– Whimbrel N. phaeopus
– Common Greenshank Tringa nebularia
– Common Redshank T. totanus
– Grey-tailed Tattler T. brevipes
– Terek Sandpiper T. terek
– Ruddy Turnstone Arenaria interpres
– Asian Dowitcher Limnodromus semipalmatus
– Pied Oystercatcher Haematopus longirostris (resident).
Criterion 7: Significant for indigenous fish. The 2003 RIS stated that criterion 7 was met on the basis of benthic invertebrate occurrence. This is considered to be mis-applying the criterion. The currently documented values of the Bay for indigenous fish species do not appear to make it outstanding or different from other parts of the Kimberley region.
Criterion 8: Key habitat in fish life cycle. The site is important as a nursery and/or breeding and/or feeding ground for at least five species of fish and for mudcrabs and prawns. The site’s mangal system is particularly important as a nursery area for marine fishes and prawns.
Criterion 9: Supports >1% of non avian species. Insufficient information for assessment.
Under the Ramsar classification system there are numerous categories of “wetland” ranging from shallow areas of ocean, to inland freshwater lakes, to man-made water bodies. The Roebuck Bay Ramsar site has four different wetland types and all are marine or coastal:
The extensive seagrass beds in Roebuck Bay are dominated by Halophila ovalis and Halodule uninervis (Prince 1986). The most vigorous stands grow in areas that are exposed for less than two hours at low tide. These meadows are important feeding grounds for Dugong and Green Turtle.
The dominant wetland type within the Ramsar site is the intertidal mud and sand flats that cover approximately 45% of the total Bay area. The sediments of these flats grade from silty muds in the north-east to fine or very fine sands in the north-west and to coarse sands in the south of the Bay. Near the mouth of Crab Creek the flats comprise waterlogged and thixotropic (gel-like) muds that are more than knee-deep (Pepping et al. 1999).
The mud and sand flats are among the widest in Western Australia: the intertidal flats extend up to 13 km offshore at the south-western end of the Bay where sandbanks are common, offering an important roost for shorebirds. Most of the intertidal mudflat area is inundated each high tide, and at times, spring tides and/or cyclones may cause the adjoining coastal flats to become inundated, flooding the samphire and saline grasslands.
Intertidal forested wetlands are widespread at Roebuck Bay. They comprise mangroves in low closed-forest to open-scrub in narrow arrangement along the shore in the east and south of the Bay. More extensive areas occur around the main tidal creeks, with about 6 square kms of mangroves around Dampier Creek.
Eleven mangrove species are known to occur in the Bay (Semeniuk et al. 1978). Within Roebuck Bay, Johnstone (1990) divides the mangroves into a northern and southern section. The northern section consists of a low open to closed forest. The common species on the landward and seaward edge of the mangroves is Avicennia marina. The southern section contains narrow linear stands fringing the shoreline in the Thangoo area. The mangroves have highest species diversity and tallest trees around Dampier and Crab Creeks and in Yardoogarra Creek, the inlet between Bush Point and Sandy Point. In these areas there is distinct zonation of the mangroves. The typical sequence of species in landward direction is Avicennia, Rhizophora and Ceriops (Chalmers and Woods 1987).
Landward of the mangroves are areas of bare salt flats that are inundated on high spring tides. The hyper-salinity of the soil in these areas inhibits the establishment of vegetation.
Samphire flats and saline grasslands occur landward from the edge of the bare salt flats behind the mangle (Chalmers and Woods 1987). The saline grass plains occur at slightly higher in elevation than the samphire flats, where the soil has a lower salinity.
The dominant grass species is Saltwater Couch Sporobolus virginicus, which forms a dense grassland 15-20 cm tall. These grasslands may be inundated by some high tides. Towards the edge of the grass plains, at the interface with pindan soils at higher elevation, low woodlands or thickets of Melaleuca acacioides grow up to 10m in height. These woodlands mark the inland boundary of the grasslands.
References: ¹ 2008, (Bennelongia Pty Ltd) Ecological Character Description for Roebuck Bay. More references required for text citations
Roebuck Bay Working Group is comprised of Traditional Owners and government, local community, conservation groups and business. We work collaboratively to solve issues, raise awareness and encourage research and monitoring which supports responsible management and protection of Roebuck Bay.