Coasts and Oceans Theme Report
Australia State of the Environment Report 2001 (Theme Report)
Australian State of the Environment Committee, Authors
Published by CSIRO on behalf of the Department of the Environment and Heritage, 2001
ISBN 0 643 06751 5
Habitats and species (continued)
Birds
Seabirds [CO Indicator 1.3]
Seabirds spend most of their time at sea, apart from when they are nesting on land, and they also feed at sea. Examples include penguins, albatross, petrels and terns.
Of about 800 bird species found in Australia, approximately 142 are seabirds. New information since 1996 indicates that bird populations generally are declining. Seabird species are particularly susceptible to being caught as bycatch in longline fishing (see Albatrosses and longline fisheries). This threat, together with taxonomic revisions has resulted in the Action Plan for Australian Birds 2000 (Garnett and Crowley 2000) identifying all 20 albatross taxa and several petrels as threatened. Threats to these marine birds are concentrated in the Southern Ocean and on their breeding islands.
The action plan identifies about 65 seabird species as threatened, 35 of which have now been listed under the EPBC Act. The Threatened Species Scientific Committee established under the EPBC Act advises the Minister for the Environment and Heritage on the amendment and updating of this list.
In 1996 only six seabirds were listed under the then Endangered Species Protection Act 1996. Of those species, the Little Tern has not been included on the current list because of an increase in its numbers, and the Wandering Albatross has been downgraded to vulnerable.
Table 4 shows the marine bird species currently listed under the EPBC Act, in comparison with the 1996 list. The list reflects the increasing knowledge on the conservation status of birds and the identification of the threatened species. It does not necessarily imply a deterioration in the conservation status of the seabirds between 1996 and 2001.
| Species | Common Name | ESP Act 1996 | EPBC Act 1999 |
|---|---|---|---|
| Anous tenuirostris melanops | Australian Lesser Noddy | Vulnerable | Vulnerable |
| Diomedea exulans | Wandering Albatross | Endangered | Vulnerable |
| Fregata andrewsi | Christmas Frigatebird, Andrew's Frigatebird | Vulnerable | Vulnerable |
| Pterodroma leucoptera leucoptera | Gould's Petrel | Endangered | Endangered |
| Sterna albifrons | Little Tern | Endangered | - |
| Sula abbotti | Abbott's Booby | Endangered | Endangered |
| Diomedea amsterdamensis | Amsterdam Albatross | - | Endangered |
| Diomedea dabbenena | Tristan Albatross | - | Endangered |
| Diomedea sanfordi | Northern Royal Albatross | - | Endangered |
| Sterna vittata bethunei | Antarctic Tern (New Zealand) | - | Endangered |
| Thalassarche eremita | Chatham Albatross | - | Endangered |
| Diomedea antipodensis | Antipodean Albatross | - | Vulnerable |
| Diomedea epomophora | Southern Royal Albatross | - | Vulnerable |
| Diomedea gibsoni | Gibson's Albatross | - | Vulnerable |
| Fregetta grallaria grallaria | White-bellied Storm-Petrel (Tasman Sea), White-bellied Storm-Petrel (Australasian) | - | Vulnerable |
| Halobaena caerulea | Blue Petrel | - | Vulnerable |
| Pachyptila turtur subantarctica | Fairy Prion (southern) | - | Vulnerable |
| Phalacrocorax nivalis | Heard Shag | - | Vulnerable |
| Phalacrocorax purpurascens | Macquarie Shag | - | Vulnerable |
| Phoebetria fusca | Sooty Albatross | - | Vulnerable |
| Pterodroma mollis | Soft-plumaged Petrel | - | Vulnerable |
| Pterodroma neglecta neglecta | Kermadec Petrel (western) | - | Vulnerable |
| Sterna vittata vittata | Antarctic Tern (Indian Ocean) | - | Vulnerable |
| Thalassarche bulleri | Buller's Albatross | - | Vulnerable |
| Thalassarche carteri | Indian Yellow-nosed Albatross | - | Vulnerable |
| Thalassarche cauta | Shy Albatross | - | Vulnerable |
| Thalassarche chrysostoma | Grey-headed Albatross | - | Vulnerable |
| Thalassarche impavida | Campbell Albatross | - | Vulnerable |
| Thalassarche nov. sp. | Pacific Albatross | - | Vulnerable |
| Thalassarche salvini | Salvin's Albatross | - | Vulnerable |
| Thalassarche steadi | White-capped Albatross | - | Vulnerable |
Islands are significant habitats for seabirds. Lord Howe Island is said to be home to the most diverse and largest number of seabirds in Australia. Macquarie Island supports an estimate of 850 000 pairs of royal penguins and four species of albatross - one of the greatest concentration of seabirds in the world. Figure 11 identifies important breeding sites for seabirds.
Figure 11: Important breeding sites for seabirds.
Source: Environment Australia (2000)
Shorebirds [CO Indicator 1.3]
Shorebirds, are also known as waders, and can often be seen feeding on coastal mudflats, estuaries, coastal shorelines, reefs, and along the edges of inland wetlands. They are birds of the seashore, rather than the sea.
Many of the 73 species of Australian shorebirds are dependent upon coastal habitat, either as migrant or permanent residents. Watkins (1993) estimates that Australia has a minimum population of 2 million migrant and 1.1 million resident shorebirds.
The Action Plan for Australian Birds 2000 (Garnett and Crowley 2000) lists seven species of shorebirds, including the Hooded Plover (eastern) as vulnerable and the Hooded Plover (western) as near threatened.
Migratory birds depend heavily on preservation of habitat along their migration routes, both in Australia and overseas. The conservation of migratory birds and their habitats is the subject of several international treaties.
All migratory waterbirds (including shorebirds) listed under the international agreements have now been listed under the EPBC Act; this includes more than 35 species of shorebirds. Prior to the Act no species of international migratory shorebirds were protected by national legislation.
One hundred sites of international significance for migratory shorebirds have been identified in Australia; four sites are of outstanding importance, being recognised for up to 20 species. These are the south-eastern Gulf of Carpentaria, Roebuck Bay, Eighty Mile Beach and the Coorong (Figure 12). About a quarter of the identified internationally or nationally important shorebird habitat is protected within conservation reserves, but this does not include the four most important sites.
Figure 12: Important sites for migratory shorebirds.
Source: Environment Australia (2000)
There has been a significant decline in shorebird numbers at some sites. An example is at the Coorong in South Australia (Figure 13) (Wilson 2000). However, the survey does not show whether the decline in six most numerous species is caused by local or external factors or by climatic or seasonal effects.
Figure 13: Estimated total counts of shorebirds at the Coorong.
Source: Wilson (2000)
There are a number of pressures or threats to birds and their habitats, such as:
- urban development, mineral exploration, mining,
- infrastructure such as airports,
- off-road vehicles,
- introduced rats, cats and foxes on offshore islands,
- tourism,
- some fishing methods such as longlining, and
- discarded fishing gear.
In the Torres Strait islands, traditional harvesting of eggs and birds has affected bird survival. Gathering of seabird eggs and chicks reduced the breeding seabird population in the Torres Strait, for example Brown Boobies no longer breed successfully on Bramble Cay and on Booby Island (King 1996).
Initiatives
There have been a number of initiatives to address the various pressures on bird populations.
All migratory species of shorebirds are now protected under national legislation; some resident species are also protected by legislation in each State and Territory. The Commonwealth developed a Threat Abatement Plan in August 1998 for the Incidental Catch (or bycatch) of Seabirds during Oceanic Longline Fishing. Under this plan, domestic and foreign fishing vessels must adopt measures to reduce the bycatch of these birds.
The Abbott's Booby Recovery Plan (March 1998) is the only recovery plan for seabirds currently developed under the EPBC Act.
Public buy-back of land has occurred in some instances where critical habitat for a species has been lost to development. In 1985 the Victorian Government committed $1 million per year for 15 years to progressively buy back land and properties in the Summerland estate on Phillip Island, where development threatened Little Penguin habitat.
Initiatives are under way to improve the knowledge of some species. Tasmania, with Commonwealth funding, is researching albatrosses, Victoria is studying gannets, and New South Wales has undertaken major studies into Gould's Petrel. On a national scale, there is work on terns under the Australian Bird and Bat Banding Scheme. The Natural Heritage Trust has provided funding for a range of initiatives and activities relating to site protection and rehabilitation, research, raising community awareness of migratory shorebird conservation, and furthering nominations to the East Asian-Australasian Shorebird Site Network.
The Commonwealth and States have jointly prepared and adopted guidelines for managing human visits to marine islands with breeding seabirds (Claridge 1997). Disturbance of birds by human visits to Great Barrier Reef islands has been addressed by seasonal closure during the breeding season, restrictions on visitor numbers or purpose (including a permit system), and restrictions on vehicles. For example, the waters surrounding two of the major seabird islands, Eshelby and Wreck Islands, are preservation zones and are closed to all forms of visit except approved research. Seventeen other seabird islands are within Reef Marine Park Seasonal Closure Areas, and if required may be closed during seabird breeding seasons.
Strict guidelines have been developed by the Australian Antarctic Division in cooperation with pilots, researchers, the Civil Aviation Safety Authority and others, for aircraft operations associated with scientific work in the Antarctic. The guidelines are continually evolving and are based on research into the response of fauna to aircraft flying at various heights and speeds.
Many important sites to migratory shorebirds are listed as Ramsar (Convention on Wetlands) sites. Australia currently has 56 sites of which 32 are classified as coastal; 16 of these are internationally significant for a number of species of migratory shorebirds. Ramsar sites are also protected under the EPBC Act and either have management plans in place or plans are being developed.
Another important initiative has been the Asia Pacific Migratory Waterbird Strategy 1996-2000 and 2001-2005 and the associated Shorebird Action Plans and East Asian-Australasian Shorebird Site Network. The Site Network is an informal arrangement which promotes the conservation of migratory shorebirds through the management of internationally significant sites. As of January 2001, Australia has 11 (also Ramsar listed) of the total 29 sites in eight countries in the region. A number of other sites are in the process of nomination, with a target of 25 sites to be nominated by 2005.
Albatrosses and longline fisheries
Since the early 1950s the world's longline fishing fleets targeting tuna (Thunnus spp.), broadbill (Xiphias sp.) and more recently Patagonian toothfish (Dissostichus eleginoides ) have expanded into most of the oceans of the world.
It is now likely that pelagic seabirds will interact with longline fishing vessels at some stage in their lives. This interaction can be fatal for the birds, and considerable concern has been raised about the effect of longlining on populations of albatrosses in particular, and on some species of petrels.
During line setting, albatrosses and petrels scavenge the baits attached to hooks on longlines paid out from the stern of the fishing ship before the lines sink beyond their reach. Once hooked, the birds are drawn underwater by the sinking longline and drown. The death rate of albatrosses may average only about 0.4 birds/1000 hooks deployed, but the number of hooks set annually is high: between 50 and 100 million in the world's southern oceans alone. Multiplying the two yields a casualty rate that is unsustainable for most populations.
Drowned albatross caught on pelagic longline.
Source: G Robertson, Australian Antarctic Division
The populations of albatrosses and petrels at some closely monitored sites have been decreasing in recent decades. The rate of decrease has been insidious, from 1-7%, and it took many years of observation to provide convincing evidence that the decreases were not part of natural cycles. Compounding matters was the lack of an obvious reason to explain the decreases being recorded.
Only in the late 1980s did compelling evidence emerge for the causes of their decline. Data collected on the Japanese tuna longline fleet operating out of Hobart indicated that thousands of albatrosses were being killed annually by this industry alone. This created the impetus for the First International Conference on the Biology and Conservation of Albatrosses, held in Hobart in 1995. The conference brought together seabird and fish scientists, wildlife managers, fisheries managers, representatives of non-governmental organisations, and fishing industry representatives. A series of mitigation measures were suggested, including the provision of bird-scaring lines and streamers, weighted lines to reduce the amount of time baits are near the surface, setting lines at night, and setting lines beneath the waters' surface.
Since this conference, the issue has received global attention. In 1998 the United Nation's Food and Agriculture Organisation (FAO) produced an International Plan of Action to reduce seabird mortality in longline fisheries. This calls for an assessment of the extent of seabird mortality, the species affected and the adoption of mitigation practices.
Another important initiative has been the Agreement on the Conservation of Albatrosses and Petrels, developed under the Convention on the Conservation of Migratory Species of Wild Animals which seeks to protect albatrosses and petrels throughout their entire breeding and migratory ranges. The implementation of this multilateral Agreement through coordinated and cooperative actions will contribute significantly to the conservation of Southern Hemisphere albatross and petrel species and their habitats.
In addition to these initiatives, many nations are currently testing new technologies to determine the most effective methods to reduce seabird deaths. Some of these show great promise, particularly work by New Zealand and Australia, in developing an underwater setting device for domestic tuna vessels. Longline fishing operators are now trialing a bait chute-launcher that will prevent bird losses. The United States and Norway have also trialled techniques for reducing seabird mortality in their coastal longline fisheries. Change is slow, but perhaps there is reason for mild optimism about the future prospects of many of the seabird species that interact with longline fisheries.
Source: Australian Antarctic Division (2001).