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Wildlife Scientific Advice, Natural Heritage Division
Environment Australia, October 2001
Note:This publication has been superseded by the National recovery plan for threatened albatrosses and giant petrels 2011—2016
This section identifies and describes the threats and/or issues relating to the conservation of albatrosses and giant-petrels. Some of the threats and issues identified within this section have not yet been sufficiently investigated or quantified. This lack of information serves to emphasise the need for further research into the factors affecting albatross and giant-petrel survival and reproduction.
Throughout all stages of their life history, albatrosses and giant-petrels are subject to an array of threats, both at sea and on land, that have the potential to reduce their survivorship and/or their capacity to reproduce successfully. In addition, modification of their foraging habitat (that is, the world's oceans) may also be limiting populations. In combination, these factors are putting the long-term viability of several species at risk. The threats and issues detailed in this section are grouped according to subject matter, and do not necessarily reflect their order of importance.
Longline fishing has been identified as the primary threat currently affecting albatrosses (Gales 1998) and giant-petrels (Patterson and Hunter 1998). Two main forms of mortality can occur: (i) through by-catch during line-setting, or (ii) by ingestion of (discarded) fishing hooks.
Since the 1950s longline fishing fleets have expanded into every major oceanic sector to the point that most individual albatrosses are likely to interact with longline fishing vessels at some stage in their lives. During line setting, baits attached to hooks are paid out from the stern of the ship. Albatrosses and giant-petrels habitually follow fishing vessels and aggressively compete for baits. However, the birds risk their lives each time they do so, for if hooked, they are drawn underwater by the weight of the sinking longline and drown (Alexander et al. 1997).
Between 50 and 100 million hooks are set each year in the Southern Ocean (Alexander et al. 1997) and as many as 1.1 billion hooks are set globally (AFMA unpubl. data). Furthermore, there is a broad overlap between seabird abundance and the world's most fished oceans. Both seabirds and fishing vessels concentrate in areas of high biological productivity (Brothers et al. 1999). Consequently, all five species of albatross breeding in Australian waters and both species of giant-petrel are seriously threatened by longline fishing (Gales and Brothers 1996; Gales 1998). This fishing practice has also been identified as a major threat to 15 of the 16 'foraging species' (Table 5.1: Gales 1998). Only the recently distinguished Pacific Albatross is yet to be recorded on longlines.
A substantial number of mitigation measures for reducing the incidental capture of seabirds in longline fisheries has been developed over the past five to ten years (reviewed in Brothers et al. 1999).
|Recorded on Longlines Within the AFZ||Recorded on Longlines Outside the AFZ|
|Atlantic Yellow-nosed Albatross||4|
|Indian Yellow-nosed Albatross||4||4|
|Northern Royal Albatross||4||4|
|Southern Royal Albatross||4||4|
4 Denotes species have been recorded killed on longliners
Sometimes albatrosses and giant-petrels captured on longline fishing hooks are still alive when hauled aboard the ship (Brothers 1991). The birds are often cut free by fishers during the hauling operation. However, the hooks may become embedded in the digestive tract or attached to the exterior of the bird, with lethal or sub-lethal consequences (Weimerskirch and Jouventin 1987; Murray et al. 1993; Huin and Croxall 1996). In addition, albatrosses and giant-petrels are particularly successful in scavenging large pieces of offal - some of which still contain discarded long-line hooks (Nel and Nel 1999) and probably cause the eventual death of the bird. Presumably, most instances of hook ingestion occur as a result of the processing procedures (notably the discarding of hooked fish heads by factory crew) undertaken on demersal longlining vessels operated by other countries and/or by illegal, unreported and unregulated fishers.
Wandering Albatrosses, Black-browed Albatrosses, Grey-headed Albatrosses, Northern Giant-Petrels and Southern Giant-Petrels have all been observed regurgitating fishing gear to their chicks (Huin and Croxall 1996; Fraser and Patterson unpubl. data in Patterson et al. in press). Dozens of Wandering Albatrosses have regurgitated hooks at South Georgia (Isla Georgia del Sur). Furthermore, approximately 20% of albatross chicks at these colonies ingest regurgitated hooks that had first been swallowed by the adults. A substantial number of adults retain the hooks in their own alimentary tract (Huin and Croxall 1996), which has been seen to cause the slow death of adults at their nests (Weimerskirch and Jouventin 1987). The frequency of longline hooks being regurgitated at South Georgian (Isla Georgia del Sur) nest sites of Wandering Albatrosses and Black-browed Albatrosses has increased six-fold in recent years (Cooper 1995; Huin and Croxall 1996). The incidence of long-line hooks found near Southern Giant-Petrel nests or embedded in adult birds breeding near Palmer Station (Anvers Island, Antarctic Peninsula) has also increased substantially over the last seven years (Fraser and Patterson unpubl. data in Patterson et al. in press). A considerable increase in the incidence of fishing gear near the nests of albatrosses and giant-petrels on Marion Island between May 1996 to April 1998 has also been reported (Nel and Nel 1999).
Since both giant-petrel species and almost all albatross species have been recorded on longline hooks, it is very likely that most or all albatross species also suffer from swallowing fishing equipment.
Furthermore, some birds can become entangled in longlines during the hauling procedure. These birds are typically 'cut away' and released alive. The fate of these birds is usually unknown. However, two albatrosses released from domestic longline vessels have been later retrieved. Both individuals suffered from extensive tendon damage and subsequently died (R. Gales pers. comm.).
The Commonwealth Government of Australia recognised the impact of longline fishing practices on albatrosses and giant-petrels, and accordingly listed longline fishing as a Key Threatening Process on Schedule 3 of the ESP Actin July 1995. The process is therefore listed under the EPBC Act (1999), which replaced the ESP Act as of 16 July 2000. A Threat Abatement Plan for the Incidental Catch (or By-Catch) of Seabirds During Oceanic Longline Fishing Operations (herein, Longline Fishing Threat Abatement Plan) has been in operation since August 1998. The Longline Fishing Threat Abatement Planstipulates the actions needed to minimise by-catch of all seabirds, especially threatened albatross and Petrel species, in longline fisheries. Successful implementation of the Longline Fishing Threat Abatement Planwill eliminate the threat of longline fishing from the entire AFZ, and is vital to the success of this Recovery Plan.
One of the criteria for measuring the success of the Longline Fishing Threat Abatement Plan is that seabird by-catch mortality must be reduced to below 0.05 birds per thousand hooks set in all fishing areas, seasons and fisheries at the current fishing level. The Longline Fishing Threat Abatement Plan(1998: p48) states that 'if seabird by-catch rates do not decrease throughout the initial five year life of the Plan, other mitigation measures, such as area or seasonal closures, will be investigated.' This Recovery Plan endorses area and/or seasonal closures, particularly around sensitive breeding colonies, if albatross or giant-petrel by-catch persists within the AFZ.
The Longline Fishing Threat Abatement Plan also encourages the voluntary adoption of a Code of Practice that specifically includes the safe release of all seabirds caught alive on longlines (TAP Action 2.1: p33). Moreover, the mitigation measures detailed in the Longline Fishing Threat Abatement Plan should remove the opportunity for albatrosses and giant-petrels to ingest fishing hooks whilst within the AFZ.
The Longline Fishing Threat Abatement Planis concerned with mitigating the threat to seabirds by longline fishing within the AFZ. However, longline fishing occurs within every oceanic sector on earth. Hence, the threat to albatrosses and giant-petrels posed by longline fishing is global in nature. The recovery of albatrosses and giant-petrels will not be possible unless similar Threat Abatement Plans are designed and implemented across the globe by international conservation and fishing fora.
Several international agreements to reduce the incidental mortality of seabirds on longline fishing vessels have already been implemented. In 1992, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) adopted measures for its 23 member countries to reduce the by-catch of seabirds in the Southern Ocean. Under the auspices of the Commission for the Conservation of Southern Bluefin Tuna (CCSBT), Australia, Japan and New Zealand have examined seabird by-catch measures in the Southern Bluefin Tuna longline fishery since 1994. All member nations of the CCSBT have made the use of bird scaring poles (tori poles) mandatory in their fisheries. The United States of America has also adopted measures for reducing the incidental catch of seabirds in the Groundfish Longline Fisheries in the Bering Sea/Aleutian Islands and Gulf of Alaska in 1997, and for its halibut fishery in 1998. In addition, the USA is currently developing measures to mitigate the incidental catch of seabirds in the Hawaiian pelagic longline fisheries. Several other countries with longline fisheries have adopted similar mitigation measures.
In 1998 the Food and Agriculture Organisation of the United Nations (FAO) Committee of Fisheries (COFI) developed an International Plan of Action for Reducing Catch of Seabirds in Longline Fisheries. The objective of the International Plan of Action (IPOA) is to reduce the incidental catch of seabirds in longline fisheries wherever this occurs. FAO encourages all States and fishing entities to implement the voluntary IPOA. The IPOA stipulates that States with longline fisheries should conduct an assessment of these fisheries to determine if a by-catch problem exists. Wherever this is the case, a National Plan of Action (NPOA) for reducing the incidental catch of seabirds in longline fisheries should be adopted no later than the COFI Session in 2001. The Longline Fishing Threat Abatement Planis regarded as equivalent to Australia's FAO National Plan of Action.
The highly dispersive nature of albatrosses and giant-petrels (see specific entries in Section 2) makes them vulnerable to longline fishing both inside and outside of the AFZ. As discussed above, the Longline Fishing Threat Abatement Plan should minimise or eliminate this primary threat to albatrosses and giant-petrels within the AFZ. However, despite recent progress in international conservation actions (detailed above), there are still large areas of the globe which host longline fishing fleets that are operating in the absence of important by-catch mitigation measures. As a result, considerable numbers of albatrosses and giant-petrels breeding within the AFZ are still killed on longlines from vessels operating outside of the AFZ. This situation needs to be rectified through the development of cooperative agreements with nations whose vessels are interacting with albatrosses and giant-petrels (prescribed in Section 5.15).
Few data exist, however, on the at-sea movements of albatrosses and giant-petrels breeding within areas under Australian jurisdiction. Different species and populations are often exclusive in their pelagic distribution. At present, only the at-sea distribution of Shy Albatrosses from Albatross Island is well understood. This lack of data is one of the most pressing management issues facing albatross and giant-petrel conservation.
Reliable information on the at-sea dispersal strategies of albatrosses and giant-petrels is essential to enable the identification of key foraging areas and the countries likely to be interacting with them. Thus, this Recovery Plan places a high priority on studies of the at-sea distributions of albatross and giant-petrel populations breeding within areas under Australian jurisdiction.
Studying the at-sea movements of such highly dispersive species requires the use of satellite telemetry techniques (eg. Jouventin and Weimerskirch 1990; Prince et al. 1992; Weimerskirch et al. 1993; Brothers et al. 1998). The extreme distances covered by albatrosses and giant-petrels mean that satellite transmitters need to send powerful signals, and hence are often relatively heavy units. It is essential that the well-being of the birds be held in the highest regard. For these reasons, satellite-tracking studies funded through the Recovery Plan will use minimal-weight equipment and attachment methods approved by the Albatross and Giant-Petrel Recovery Team.
During the 1998/99 fishing season, almost 150 trawl vessels were operating and more than 46,000 trawl gear deployments or 'shots' were set within the AFZ south of 30° S (AFMA logbook databases).
Much of this trawl fishing occurs within areas used by albatrosses and giant-petrels, including areas near breeding colonies at Heard and McDonald Islands, Macquarie Island and Tasmania (Table 5.2). Hundreds of seabirds (including colour-marked albatrosses and giant-petrels from Macquarie Island) routinely attend fishing vessels during these and other trawling operations (Gales and Brothers 1996; Sagar et al. 2000; AFMA Observer Reports 1997, unpubl. data).
Clearly the potential exists for seabird/trawl vessel interactions. Indeed, some workers have speculated that vessels from the South East Trawl Fishery operating in close proximity to Shy Albatross breeding colonies around Tasmania could have an impact upon the albatrosses (Brothers et al. 1998), although the level of any potential impact remains unquantified.
Seabirds may interact with trawlers in a number of contexts. Birds may be injured or killed after becoming entangled in trawl nets, colliding with trawl apparatus, or by adhering to lubricated cables and dragged through trawl winches (N. Brothers pers. comm; Wienecke and Robertson, in prep.).
Many albatrosses and giant-petrels have learnt to scavenge prey caught within the trawl nets during the net-hauling process. However, some are injured or drown as they become entangled in the net itself (cod-end and wings), or in trawl gear, such as the float line or belly lines (Bartle 1991; Wienecke and Robertson, in prep.).
Albatrosses and giant-petrels have been observed coming into contact with various components of trawling equipment, particularly trawl warp wires, but also trawl doors, backstrops, bridles, sweeps or paravanes. This can cause injury or the death of the bird if the collision is sufficiently severe (Wienecke and Robertson, in prep.).
Albatrosses and giant-petrels can also suffer injury or death from colliding with the headline netsonde monitor cables sometimes used on trawlers (particularly outside of the AFZ). This stiff (7mm diameter) cable extends up to 20m behind the vessel. Seabirds sometimes strike the cable as the vessel pitches in the swell (Duhamel et al. 1997). This causes considerable mortality within the Exclusive Economic Zones (EEZs) of numerous countries and throughout the High Seas (Schlatter 1984; Bartle 1991; Adams 1992; Williams and Capdeville 1996). An estimated 2,300 Shy-type Albatrosses were killed as a result of colliding with netsonde monitor cables during trawling operations in the sub-Antarctic waters around New Zealand in 1990 alone (Bartle 1991).
The use of netsonde monitor cables or equivalent trawl warps is now prohibited within New Zealand's 200-mile EEZ and the CCAMLR Convention Area (Bartle 1991; Murray et al. 1993: see Map 1). They are also banned within Australian sub-Antarctic fisheries, but are still permitted elsewhere within the AFZ. However, very few (if any) domestic trawling vessels still use a netsonde cable. Instead, domestic trawl vessels use hull-mounted transducers or tow aquaplanes on which transducers are set (AFMA logbook databases).
Scientific monitoring of trawling operations has increased appreciably in recent years (Table 5.2). Preliminary data from AFMA observers indicate that albatross and giant-petrel mortality does occur, although it appears to be a rare event. Many trawl vessels operating within the AFZ currently employ simple and effective mitigation measures to prevent seabird mortality. These include using minimal deck lighting, and keeping all splice ends well-wrapped and as short as possible (Knuckey and Liggins 1999; N. Brothers pers. comm.).
Over the last five years, the Integrated Scientific Monitoring Program (ISMP) has been conducting a pilot observer program for demersal trawling in the South East Fishery (SEF) which operates over a large area of south-eastern Australia. Up to 900 trawl shots per year are monitored on commercial vessels working across the SEF (I.A. Knuckey pers. comm). In a recent report on the SEF, the by-catch of birds was described as 'virtually non-existent' (Knuckey and Liggins 1999: p46). However, quantitative data for this fishery is lacking or yet to be published.
AFMA has also placed observers on factory vessels targeting Blue Grenadier Macruronus novaezelandiae off Tasmania. In addition, the Fisheries Research and Development Corporation has, under their Effects of Trawl Sub-Program, funded a one-year pilot study to assess by-catch in the Great Australian Bight Trawl Fishery. This pilot will be undertaken by the ISMP. Coverage in other fisheries has been largely opportunistic (AFMA, Pers. Comm.).
Further, sub-Antarctic trawl fisheries have been subject to 100% AFMA observer coverage since 1997 (AFMA logbook databases). This policy will continue under the management plan being prepared for Heard and McDonald Island fisheries. Data from this program have provided encouraging evidence that incidental catch on trawl vessels is limited in this fishery.
Since 1994/95, one trawl vessel (Austral Leader)has been targeting Patagonian Toothfish Dissostichus eliginoides, both around Macquarie Island (more than 3 nautical miles from the island) and around Heard and McDonald Islands (more than 13 nautical miles from the islands: Williams and Capdeville 1996; Wienecke and Robertson, in prep.). A second vessel (Southern Champion) also trawls for Patagonian Toothfish around the Heard and McDonald Island group (Wienecke and Robertson, in prep).
Some seabirds from Macquarie Island breeding populations follow these fishing vessels in large numbers during trawling operations. Indeed, up to 500 Northern Giant-Petrels, up to 225 Southern Giant-Petrels, and up to 106 Black-browed Albatrosses have been recorded following the Austral Leader at any one time. Most of the Black-browed Albatrosses observed around the vessels are adults. If most of these birds are breeding adults, they could represent as much as 50% of the island's breeding population attending the vessel (AFMA unpubl. Observer Reports 1997).
Both vessels employ simple mitigation measures and as a result very few serious interactions between trawl equipment and seabirds have occurred (Wienecke and Robertson, in prep). At Macquarie Island, 186 shots (34%) and 267 trawl gear recoveries or 'hauls' (49%) were observed between 1997 and 1999. No deaths or serious injuries were reported during observation periods. Around Heard and McDonald Islands, 503 shots (43%) and 583 hauls (50%) were observed. One giant-petrel (species undetermined) was killed during the shot. In addition, three to five Cape Petrels Daption capense were killed, and three more suffered serious injury. Several other seabirds, including albatrosses and giant-petrels made significant contact with trawl apparatus. It is not known if the birds subsequently died (for example, after suffering a broken wing: Wienecke and Robertson, in prep).
Preliminary data from observers attending the Austral Leader around Macquarie Island suggest that the majority of such collisions arise when a combination of two ship-related factors occur: (i) the ship is discharging offal (either macerated offal or water running from the floor of the factory) causing birds to be attracted close to the ship (see Section 5.9); and (ii) water currents cause the trawl net to be towed to the side of the vessel that the offal is discharged to. In the preliminary study, the birds that collided with the trawl equipment were all attempting to feed on the discharged offal (AFMA unpubl. Observer Reports 1997).
More data on the rates, causes, and factors contributing to seabird mortality as a result of trawling operations are required to determine if trawl fisheries are having an impact on seabird populations. This information should be assessed from observer programs and examination of logbook databases.
|Fishery||Location||Observer coverage||Target species||No. vessels||No. shots|
|South East Trawl||Adjacent to NSW (south of Barrenjoey Point), Victoria, Tasmania and South Australia (east of Cape Jervis)||Regular MAFRI (ISMP) and limited AFMA observer coverage||Finfish and deep water crustaceans||108||41,382|
|South Tasman Rise||South Tasman Rise (STR) outside the AFZ. Regulations to extend the application of the Fisheries Management Act 1991 to include the area of the STR came into force in 1998||Limited AFMA observer coverage||Orange Roughy and related species||13||466|
|Heard and McDonald Islands||Surrounding Heard and McDonald Islands out 13-200 nautical miles (1nm buffer zone) and exclusion from the Marine Protected Area||100% AFMA observer coverage||Patagonian Toothfish||2||*|
|Macquarie Island||Surrounding Macquarie Island out 3-200 nautical miles||100% AFMA observer coverage||Patagonian Toothfish||1||*|
|Great Australian Bight||From Cape Leeuwin, Western Australia, to Cape Jervis, South Australia||Limited AFMA observer coverage||Primarily inshore species with periodic trawling for deeper dwelling species||10||3,193|
|Western Deepwater||North West Cape to Cape Leeuwin off Western Australia||Poor||14||1,208|
|Total||148||> 46,249 *|
* The number of shots for the Macquarie Island Fishery and the Heard and McDonald Island Fishery is kept in commercial confidence. The Macquarie Island Fishery's Total Allowable Catch is 600 tonnes Patagonian Toothfish to be taken outside the Aurora Trough (set on the calender year). The Heard and McDonald Island Fishery's TAC is 3,690 tonnes Patagonian Toothfish, 1,160 tonnes Mackerel Icefish, 80 tonnes Grey Rockcod, 150 tonnes Unicorn Icefish, 50 tonnes each for other deepwater species.
Data from AFMA (Logbook databases).
Albatrosses are sometimes intentionally shot for sport by recreational fishers or to reduce scavenging from commercial fishing vessels both inside and outside of Australian waters (Adams 1992; Brothers et al. 1998; TASPAWS unpubl. data).
Knowledge of the rate of this form of mortality is limited. Considerable numbers of Wandering Albatrosses and Shy Albatrosses are known to have been illegally shot by personnel involved with the Tasmanian Dropline Fishery in an attempt to reduce bait loss (TASPAWS unpubl. data). Wandering Albatrosses have also been reported to be intentionally shot off the New South Wales east coast (Blakers et al. 1984; Tomkins 1985). It seems likely that other species of albatross and giant-petrels are shot for the same reasons.
Wandering, Black-browed, Shy and Grey-headed Albatrosses and many 'foraging species' are also illegally killed in South African waters by fishers for sport, food and for use as bait (Adams 1992). Wandering Albatrosses and Black-browed Albatrosses are also known to be deliberately shot off Uruguay (Stagi et al. 1996).
The commercial and recreational practice of trolling a fishing line at or near the surface (for pelagic species such as Albacore Thunnus alalunga) has the potential to cause albatross and giant-petrel mortality if birds are caught on hooks.
This practice is unlikely to cause significant levels of albatross or giant-petrel injury or mortality. However, it represents another potential source of injury, and one that could be eliminated if troll lines were set at least 2m below the surface of the water.
Introduced mammals are the foremost land-based threat to seabirds on sub-Antarctic islands (Jouventin and Weimerskirch 1991). Alien species may reduce seabird populations via nest predation, nest destruction and habitat modification. Albatrosses and giant-petrels are especially vulnerable to alien mammals for several reasons: specifically, their lack of effective anti-predator behaviour; their habit of building their nests on the ground; their habit of leaving nests unattended during long-range foraging bouts; and their low annual productivity.
Predation by introduced mammals (especially cats and rats) has brought about local extinctions or reductions in numerous populations of large seabirds (Moors and Atkinson 1984). Cats have been introduced to numerous breeding islands where they have proven exceedingly difficult to eradicate. They are excellent predators that are capable of preying upon the unattended chicks of albatrosses and giant-petrels (Moors and Atkinson 1984; Scott 1996; Patterson et al. in press). Three species of rat (Ship's Rat Rattus rattus, Brown Rats R. norvegicus and Polynesian Rats R. exulans) also prey upon the eggs and chicks of numerous species of albatross (Moors and Atkinson 1984; reviewed in Gales 1993) and giant-petrels (Patterson et al. in press). Polynesian Rats have even been recorded killing adult Laysan Albatrosses (Moors and Atkinson 1984).
Some 'foraging species' of albatrosses also suffer predation by feral dogs, coatimundis Nasua nasua, ferrets Mustela furo, pigs and stoats Mustela erminea (Moors and Atkinson 1984). In addition, rabbits, cattle, sheep, goats, reindeer, caribou Rangifer tarandus and pigs introduced to breeding islands may limit the colony size of several 'foraging species' by inadvertently trampling on nests, overgrazing vegetation and modifying habitat required for nesting (Croxall et al. 1984b; Robertson and Bell 1984).
Macquarie Island is the only albatross or giant-petrel breeding site in Australia containing introduced mammals. Cats, rats, rabbits and house mice, as well as redpolls, mallards and starlings all remain on the island (Section 4.1.1).
Feral cats have been reported preying upon the eggs or small, unattended chicks of all four albatross and both giant-petrel species breeding on Macquarie Island (Rousevell and Brothers 1984). Although predation events by cats are seldom observed and difficult to quantify, they are suspected to cause the death of numerous chicks, particularly those of the less colonial species such as Northern Giant-Petrels and Light-mantled Albatrosses (Selkirk et al. 1990).
Predation by feral cats is listed as a Key Threatening Process under Schedule 3 of the former ESP Act. It is, therefore, also listed on the EPBC Act (1999), which replaced the ESP Act as of 16 July 2000. Elimination of feral cats on Macquarie Island is now regarded as an urgent priority and has been the focus of an intensive eradication program since the late 1980s (Scott 1996; G. Copson pers. comm.). A Natural Heritage Trust grant provided funds to increase the number of staff and resources in the field since June 1998. An increased use of soft-catch leg-hold traps has contributed to a significant reduction in cat numbers on the island by autumn 1999. No albatrosses or giant-petrels were killed as by-catch in the leg-hold traps in the twelve months between July 1998 to June 1999. From July 1998 to April 1999, a further 28 cats were captured (G. Copson unpubl. data).
The introduction of rabbits to Macquarie Island in the 1870s has significantly modified the distribution of vegetation alliances, particularly the grasslands (Rousevell and Brothers 1984), and possibly limits the number of available nest sites on the island. Rabbit population control began in 1978, reducing numbers from in excess of 150,000 to approximately 8,000 by 1998 (G. Copson unpubl. data). This has precipitated an increase in tall tussock grassland and a more natural vegetation mosaic on the island (Brothers and Copson 1988; Copson 1995).
Rats inhabit the tussock grasslands utilised by most albatross and giant-petrel species on Macquarie Island, and could opportunistically prey upon eggs and unattended chicks (Copson unpubl. data). A draft rodent eradication plan for the island is currently under development. The NZ DoC has been carrying out trials on the feasibility of eradicating brown rats from Campbell Island, New Zealand. As cold temperate Campbell Island (11,000ha) is very similar to sub-Antarctic Macquarie Island (12,800ha), NZ DoC's experience will be very important in planning a cost-effective rodent control program for Macquarie Island.
The naturalisation of rabbits, rats and mice may have secondary effects on Macquarie Island's ecosystem resulting from the ecological relationships between predators and their prey. These naturalised species act as additional food sources for introduced predators, notably cats, as well as for natural predators such as sub-Antarctic Skuas. Skuas are opportunistic predators of seabird chicks and eggs. It has been suggested that the introduction of rabbits to Macquarie Island has allowed the sub-Antarctic Skua population to increase above normal levels, thereby increasing nest predation pressure on other seabirds. An increase in the sub-Antarctic Skua population could prevent albatrosses and giant-petrels from moving into traditional breeding areas other than along the protected coastal rocks (Rousevell and Brothers 1984). The subsequent reduction in rabbit numbers through eradication programs might force the elevated numbers of cats and skuas to further intensify predation pressure upon ground-nesting seabirds (Scott 1996).
The sum product of these introductions is a major modification of the local vegetation and a great reduction in the populations of several species of ground-nesting seabirds. Today some bird species are only found breeding on islets and seastacks adjacent to the main island that are uninhabited by feral species (G. Copson pers. comm.). It may be significant that only 40 pairs of Black-browed Albatrosses breed annually on Macquarie Island whereas about 140 pairs breed on nearby Bishop and Clerk Islets, which, though tiny in comparison to Macquarie Island itself, are predominantly free of introduced pests.
Although albatrosses may superficially appear to be undisturbed by the presence of humans, biotelemetric studies demonstrate that nesting seabirds become stressed (as indicated by a marked increase in heart rate and stress hormones, such as corticosterone) as soon as humans are visible (Holberton and Wingfield 1994). The presence of humans too close to the nest can cause breeding failure as the stressed adults abandon or inadvertently crush eggs or small chicks.
Of all albatross and giant-petrel breeding localities under Australian jurisdiction, Macquarie Island hosts the greatest number of visitors. Nesting colonies on Albatross Island, Pedra Branca, the Mewstone, Heard and McDonald Islands, and within the Australian Antarctic Territory receive considerably fewer visitors each year.
The Macquarie Island Nature Reserve is a restricted area under Section 25 of the Tasmanian National Parks and Wildlife Act 1970. As such, permits are required to enter the reserve. Visitors to Macquarie Island are not permitted to approach within 25m of a Wandering Albatross without specific permits to work on the species. The 25m boundary is pegged out around all vulnerable Wandering Albatross nests.
The ANARE research station and associated infrastructure has been largely confined to the Isthmus at the north-eastern extremity of Macquarie Island.
Both tourists and researchers alike have the potential to disturb the nesting attempts of albatrosses and giant-petrels.
The Macquarie Island Nature Reserve Management Plan 1991 sets stringent guidelines for tourist operations at Macquarie Island. A maximum of 600 tourists is permitted to visit Macquarie Island each year. Tourists are permitted to land at two sites on Macquarie Island, the Isthmus and at Sandy Bay on the east coast. Tourist parties are organised into groups of no more than ten individuals, including one leader/guide with each party. Access is allowed on short sections of the beach along tracks at the Isthmus and on boardwalks leading to viewing platforms.
The Macquarie Island Nature Reserve Management Plan 1991 allows for particular areas to be closed in order to give added protection to threatened species, special ecosystems or historical sites. The area closures may be set for all or part of a year and are stipulated on the entry permits. General access to albatross breeding sites around the Caroline Cove area is restricted from November 1 to April 30 each year. This closure period coincides with the egg laying and hatching stages of Wandering Albatrosses. However, Black-browed, Grey-headed and Light-mantled Albatrosses also nest around Caroline Cove. Egg laying for these species begins as early as September 25. These birds may be disturbed by the relatively large influx of visitors in the month before its closure (TASPAWS unpubl. data).
Most Wandering Albatross eggs laid in the area of Macquarie Island known as the Featherbeds usually fail, possibly due to disturbance by visitors approaching too close. The breeding success of some Southern Giant-Petrel colonies also appears to be affected by human impact. In many cases colonies that are close to walking tracks or are simply visible from walking tracks suffer significantly lower breeding success (Gales and Brothers 1996).
Photographic equipment is provided to allow expeditioners to photograph nesting albatrosses without breaching the 25m exclusion area. A poster and booklet have been produced to assist in educating expeditioners on the status of the Wandering Albatrosses on Macquarie Island.
Albatrosses and giant-petrels on Macquarie Island are banded as part of a long-term conservation and research project. Chicks are banded just prior to fledging to minimise the risk of nest disturbance. The main priority for researchers on Macquarie Island is always to minimise disturbance to the seabird populations. Full documentation of any deleterious disturbance is a feature of the program (Gales and Brothers 1996).
During the last two field seasons, some nest attempts have been abandoned as a consequence of scientific activity. It is possible that the disturbance to an adult Grey-headed Albatross caused the subsequent failure of its chick in 1995/96. Three Light-mantled Albatrosses abandoned their nests and one chick died during banding in 1995/96 (TASPAWS unpubl. data). Another three adults abandoned their nests during banding in 1996/97. One Black-browed Albatross egg failure can be directly attributed to nest disturbance while banding the adult in 1996/97 (TASPAWS unpubl. data). Research does not appear to have affected any nesting attempts made by Wandering Albatrosses, Northern Giant-Petrels or Southern Giant-Petrels on Macquarie Island in recent years.
Pedra Branca and the Mewstone are designated part of the Tasmanian World Heritage Area. Thus, access to these islands is via permit only. A management plan for Albatross Island is currently in preparation and will include provisions for limiting access to permit-holders only.
Research activities at certain phases of the nesting cycle stress the adults causing them to desert their chicks. To date, the impact of researchers on Shy Albatrosses breeding on Albatross Island, Pedra Branca and the Mewstone appear to be minimal (A. Hedd, unpubl. data). Due care must be taken to ensure that this record is maintained.
Access to Heard and McDonald Islands is restricted to permit holders only. The number of tourists visiting Heard Island is increasing. All tourist and scientific activities should act to minimise any effects on colonies of seabirds nesting on these islands. The Australian Antarctic Division (AAD) has established minimum permitted approach distances on foot of 100m for nesting albatrosses and giant-petrels and 50m for birds away from nests. Approach closer than these distances requires a permit (Heard Island Wilderness Reserve Management Plan 1995).
Southern Giant-Petrels can be nervous around humans and easily disturbed during nesting, often resulting in breeding failure. The site may be abandoned if a colony is persistently visited (Williams 1984; Bretaganolle 1989).
Activities associated with the presence of the three Australian research stations located within the AAT appear to have caused local population declines of Southern Giant-Petrels (Woehler et al. 1990; Woehler 1993). This pattern mirrors trends at other sites where the establishment of research bases has caused drastic or complete depletion of nearby breeding populations (eg. Jouventin et al. 1984; Rootes 1988). However, the Southern Giant-Petrel population at Heard Island has also declined markedly since the 1950s (Kirkwood et al. 1995), yet there has been virtually no human presence on the island. It seems unlikely then that direct human intervention at the breeding colonies is the sole cause of Southern Giant-Petrel population declines. Nonetheless, such localised disturbances appear to have exacerbated the global population decline.
The breeding success of albatrosses and giant-petrels may be reduced through natural agents, such as a high parasite load or disease.
An avian pox virus transmitted by fleas and ticks Ixodes spp.is a major cause of Shy Albatross chick mortality during some years at the Albatross Island breeding colony. Heavily infested nestlings carry ticks clustered around the gape and along the soft, exposed skin on the underside of the bill. Such chicks appear weak and underweight (Johnstone et al. 1975), and ultimately lead to the death of the chick. Infestations by the ticks can be so severe in some years that they represent a significant factor restricting the recovery of the Albatross Island population (Johnstone et al. 1975; N. Brothers pers. comm., in Gales 1993).
Ticks on adults and chicks at colonies of Black-browed Albatrosses at Falkland Islands (Islas Malvinas) are known to spread an avian pox-virus, causing localised sporadic mortality. These ticks are also present on Macquarie Island (Selkirk et al. 1990; G. Copson pers. comm., in Gales 1993) and quite possibly have the same effect on nesting albatrosses.
Albatrosses, giant-petrels and many other seabirds typically nest on isolated, relatively small islands. As a consequence, competition (both within- and between-species) for limited nest space can be extreme, particularly on smaller islands.
Interspecific competition for nest space has been identified as a potential threat to Shy Albatrosses nesting on Pedra Branca (N. Brothers pers. comm.). Australasian Gannets have been increasing in numbers on Pedra Branca for at least the last 15 years. The gannets appear to be more aggressive at nest interactions and tend to displace Shy Albatrosses from potential nesting sites, particularly in areas where gannets outnumber albatrosses (N. Brothers pers. comm.).
The relative abundance of gannets and Shy Albatrosses on Pedra Branca may be changing due to natural processes. Alternatively, it is possible that certain human activities (eg. commercial fishing) have a greater impact upon the albatrosses, giving the gannets a competitive advantage.
Some seabird species have become dependent upon the offal discarded from fishing vessels during operations and/or processing at sea.
There are essentially two issues arising from this dependence upon discards. First, the disposal of offal further encourages albatrosses and giant-petrels to follow fishing vessels, significantly increasing their likelihood of becoming injured or killed during fishing operations (see Sections 5.1 and 5.2).
Second, some populations have become habituated to the regular food source and have altered their foraging ranges and dynamics accordingly (Ryan and Moloney 1988; Adams 1992; Acros and Oro 1996; Weimerskirch 1998; Blaber et al. 1998). Recent evidence indicates that the additional food made available by commercial fishing operations may influence breeding success and hence population sizes in some seabird species (eg. Blaber et al. 1998). This departure from 'natural behaviour' is sometimes considered an unacceptable outcome of commercial fishing practices (eg. Birdlife International 1995).
Preliminary data from studies of colour-marked albatrosses from Macquarie Island suggest individuals from some populations appear to become habitually attracted to the offal discarded from fishing vessels. As a result, some of these birds may return less frequently to the nest during critical phases of the nesting period, causing the nesting attempt to fail (Terauds and Hamill 1999). This indirect threat has been specifically identified as potentially affecting Black-browed Albatrosses breeding on Macquarie Island (Terauds and Hamill 1999), large numbers of which (eg. sometimes 100 individuals) routinely follow fishing vessels operating in close proximity to the island (AFMA unpubl. Observer Reports 1997: see Section 5.2).
There are few available data to quantify this recently identified issue. Satellite-tracking studies (see Section 5.1) would provide valuable information on the foraging locations of breeding individuals. This data could then be compared with fishing effort data, such as AFMA Vessel Monitoring System (VMS) data, to determine the level of association between fishing vessels and albatrosses and giant-petrels.
More than 140 commercial tourist voyages to Antarctica are expected to take place during the period from November 2000 to March 2001 (IAATO unpubl. data). Some tourist boat operators throw 'chum' (such as frozen squid) to attract seabirds - particularly albatrosses - to the vessel. This technique is used to provide tourists with the opportunity to see flocks of seabirds feeding and competing at a close range.
This practice offers another artificial food source for the birds, and further encourages them to follow boats, again increasing their likelihood of interacting with fishing vessels. If this practice is increasing the chances of albatrosses and giant-petrels becoming injured or killed on fishing vessels, then it contravenes the second objective of the bylaws of the International Association of Antarctica Tour Operators (IAATO): 'To advocate, promote and practice safe and environmentally responsible travel to the Antarctic.' It is perhaps more appropriate for tourists to observe seabirds displaying their natural behaviours, rather than scavenging for an artificial food source. The practice needs to be prohibited through IAATO regulations.
The progressive degradation of the marine habitat, particularly via the potential global over-extraction of marine resources, may have long-term effects on the status of albatrosses and giant-petrels as serious as the more direct and acute pressures of longline fishing (Croxall 1998).
All of the world's major fishing grounds are being exploited at or beyond sustainable limits, and many have suffered serious declines. According to the FAO, 70% of the world's fish stocks are now fully exploited, overfished, depleted or rebuilding from prior overfishing. Production has fallen dramatically in 13 of the world's 15 major fishing areas (Birdlife International 1995).
Such over-extraction has profound implications for the marine ecosystem, particularly for the higher order predators such as albatrosses and giant-petrels. Seabird populations have and probably will continue to decline through direct competition with fisheries for prey (Croxall 1998). The ecological sustainability of fisheries is thus particularly crucial to albatrosses and giant-petrels.
The dietary requirements of albatross and giant-petrel populations need to be taken into account when management arrangements (eg. Total Allowable Catches or TACs) of fisheries that overlap with the foraging grounds of albatrosses and giant-petrels are being developed or revised. It is, however, particularly difficult to accurately determine the level (and the effects) of competition for food resources between seabird populations and fisheries. Any assessment of the effects of competition for food resources requires a thorough knowledge of:
The Recovery Team acknowledges that each of these factors is potentially difficult to determine with accuracy.
Responsibility for ensuring the ecological sustainability of fisheries rests with AFMA. The activities of AFMA are governed and guided by the legislative objectives contained in Section 3 of the Fisheries Management Act 1991. One of the objectives contained within the Act is that AFMA is responsible for 'ensuring that the exploitation of fisheries resources and the carrying on of any related activities are conducted in a manner consistent with the principles of ecologically sustainable development and the exercise of the precautionary principle, in particular the need to have regard to the impact of fishing activities on non-target species and the long term sustainability of the marine environment.'
Furthermore, the recent Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act) requires that two-thirds of the fisheries managed by AFMA will have been strategically assessed at a broad, ecosystem-level within three years of the EPBC Act coming into force (that is, by 16 July 2003). Strategic assessment must be commenced for the remaining fisheries in Commonwealth waters by 2005. The requirements of the EPBC Act and the Fisheries Management Act 1991 are compatible with the Specific Objectives and time frame of the Recovery Plan.
Chemical contaminants can be categorised into two broad types, persistent organic pollutants (POPs) and heavy metals. Persistent organic pollutants, such as polychlorinated biphenyls (PCBs) were first introduced into the environment in the 1930s for a variety of industrial purposes (notably the plastic industry). Chlorinated hydrocarbon insecticides (including DDT) were introduced soon after (Moriarty 1975). Heavy metals, such as arsenic, mercury and cadmium, were introduced into the environment, particularly prior to the 1970s through uncontrolled industrial wastes that were deposited or stored at a variety of land- and water-based disposal sites (reviewed in Moore and Ramamoorthy 1994). Both POPs and heavy metals continue to be deposited into the environment, through the use of insecticides, herbicides, fungicides, coal and petroleum byproducts, and for dozens of other industrial, rural and domestic purposes.
Contamination with these chemicals is now global in nature. Elevated levels of POPs and heavy metals can be found in the plasma of adults, chicks and eggs of seabirds from every continent (including Antarctica) and virtually all islands across the globe (Croxall et al. 1984a,c; Auman et al. 1997; Ludwig et al. 1998).
Organochlorines and heavy metals degrade very slowly in the environment. These chemical contaminants are retained by organisms and passed along the trophic levels of the food chain, becoming increasingly concentrated in the tissues of each higher consumer (a process known as biomagnification). Consequently, top order predators, such as albatrosses and giant-petrels, may consume potentially hazardous levels of synthetic chemicals in their tissues. Furthermore, because albatrosses and giant-petrels are long-lived and typically highly dispersive species, they have even greater opportunity to accumulate high levels of chemical contaminants (Muirhead and Furness 1988; Luke et al. 1989; Lock et al. 1992; Auman et al. 1997; Ludwig et al. 1998; Stewart et al. 1999).
Within twenty years of their introduction, persistent organic pollutants had been clearly implicated in the decline of a number of predatory seabirds (Moriarty 1975). Elevated levels of POPs can have deleterious population level effects through diminished reproductive success caused by eggshell thinning, embryo inviability and offspring deformities (Croxall et al. 1984a; Ludwig et al. 1998).
Residue levels of PCBs, other organochlorine products and mercury in the body tissues of Northern and Southern Giant-Petrels increased, and in some cases doubled, between 1978 and 1983. The increases in chemical contaminants have been explicitly implicated in their population declines (Luke et al.1989). Excessive loads of organochlorine compounds have also been located in the plasma of adults and chicks of Black-footed Albatrosses Diomedea nigripes on Midway Atoll, contributing to population declines (Auman et al. 1997; Ludwig et al. 1998).
Several studies have revealed that giant-petrels and a number of albatross species possess unusually high concentrations of certain heavy metals, in particular cadmium and mercury (Muirhead and Furness 1988; Luke et al.1989; Lock et al. 1992; Thompson et al. 1993; Stewart et al. 1999; Hindell et al. 1999). Mercury levels in the liver of long-lived species such as Wandering Albatrosses, Sooty Albatrosses and 'Royal Albatrosses' are among the highest recorded for free-living birds (Stewart et al. 1999). Indeed, the mercury concentration in the liver of one Wandering Albatross analysed is the highest recorded for any vertebrate (Muirhead and Furness 1988). Adult Wandering Albatrosses carry significantly higher mercury levels than juveniles. Similarly, cadmium levels in Shy Albatrosses are higher in adults than juveniles (Hindell et al. 1999).
The significance of heavy metals in the tissues of marine organisms is not well understood as trace amounts also occur naturally in marine ecosystems (Thompson et al. 1993). It is often difficult to determine if the concentrations measured in seabird tissues exceed natural background concentrations (Ludwig et al. 1998).
Bulk fuel and/or oil spills also have the potential to affect large numbers of seabirds. Birds coming into contact with oil can become physically smothered. The matting of the plumage by the oil allows water to penetrate the air spaces between the feathers and the skin, greatly reducing the bird's insulation and waterproofing, often resulting in mortality. The increased heat-loss results in an increased metabolism of food reserves in the body which, if not countered by a corresponding increase in the food intake, may lead to emaciation. The risk is starvation is further heightened, as a severely oiled bird is unable to hunt and capture prey efficiently. Furthermore, the matted plumage reduces the bird's buoyancy and may cause them to sink and drown (Baker 1983; GESAMP 1993).
On a broader ecological scale, oil may be retained in sediments for many years, leading to the temporary or permanent loss of species critical to the ecological balance of a habitat. In addition, crude oil is essentially a mixture of many hydrocarbon compounds, some of which are toxic and/or persistent. These can accumulate in the marine food chain (described above) and may potentially lead to lethal or sub-lethal changes in metabolic functions (Baker 1983; GESAMP 1993). Two large-scale diesel fuel spills (30,000 and 60,000 litres) have already occurred during re-supply of Australian Antarctic stations (Woehler 1993). Since albatrosses and giant-petrels spend much of their time on the sea surface, they are particularly vulnerable to the hazards of oil or fuel spills.
Marine debris can impact upon albatrosses and giant-petrels into ways, through ingestion or via entanglement. Most of the marine debris affecting albatrosses and giant-petrels appear to derive from material jettisoned by vessels at sea (Huin and Croxall 1996).
Many albatross and giant-petrel species ingest considerable quantities of plastic and other marine debris. Ingestion of debris has a wide range of lethal or sub-lethal effects. The debris can cause physical damage, or perforation, mechanical blockage or impairment of the digestive system, resulting in starvation. Some plastics are also a source of toxic pollutants, which are released into the blood stream as the bird's digestive system attempts to break down the substance (Ryan 1988; Ryan et al. 1988). The subsequent reduction in fitness can lower the bird's ability to reproduce successfully, catch prey and/or avoid predation (Fry et al. 1987; Sileo et al. 1990).
Albatross and giant-petrel chicks appear to be at greater risk than adults because of their high rates of ingestion and low frequency of regurgitative casting of indigestible material. When the plastics are regurgitated to chicks, the physical impaction and internal ulceration are likely to lower post-fledging survival. In addition, the chick receives less food, lowering its nutrient intake and increasing its chances of starvation (Fry et al. 1987; Sileo et al. 1990).
The problem of plastic ingestion affects many 'breeding species' of albatross and giant-petrel. In a study of the stomach contents of 540 Shy Albatross chicks that had recently died of natural causes, 1% of stomachs contained plastic debris, ranging from segments of plastic bags to solid, coloured pieces of plastic (Hedd and Gales, in press). Wandering, Black-browed, and Grey-headed Albatrosses and Southern Giant-Petrels have all been observed regurgitating plastic debris to their chicks on breeding sites outside of Australia (Huin and Croxall 1996).
This problem has also been observed affecting several 'foraging species', including Antipodean, Gibson's, Tristan, Laysan, Northern Royal, Southern Royal and Yellow-nosed Albatrosses (Fry et al. 1987; Ryan 1987; J. Cooper pers. comm., in Gales 1993; J.P. Croxall pers. comm., in Gales 1993; Robertson 1998; A. Wiltshire pers. comm.). Many of these species have been observed regurgitating plastic debris to their chicks. Ninety per cent of Laysan Albatross chicks had plastic items lodged within their upper gastrointestinal tract (Fry et al. 1987). It is likely that most or all other 'foraging species' ingest plastic debris without it being observed or documented.
Some seabirds are also killed after becoming entangled in marine debris (Nel and Nel 1999). Such entanglement can constrict growth and circulation, leading to asphyxiation. Entanglement may also increase the bird's drag coefficient through the water, causing the animal to die due to its reduced ability to catch prey or avoid predators. The rate of this source of mortality remains completely unknown.
The efficacy of this Recovery Plan can best be measured via a system of regular population monitoring programs. Such programs calculate current population sizes, and when conducted over several years allow an assessment of a population's status. Furthermore, monitoring programs allow quantification of juvenile recruitment rates to populations, providing fundamental information concerning the future viability of populations. Hence these programs supply the vital demographic information necessary for the recovery process.
The First International Workshop on Fisheries-Albatross Interactions (Hobart, September 1995) urged that 'the existing land based studies to monitor and understand albatross population processes should be continued, and similar studies should be initiated on additional populations.' This plan reinforces the primacy of this recommendation.
Around 140 breeding populations of albatross currently exist outside of the AFZ. Despite increased efforts in population monitoring, knowledge of the status of two-thirds of these populations is still lacking. About 50 albatross populations contain less than 100 annual breeding pairs, making them extremely vulnerable to stochastic events (see Sections 2.1 - 2.5: Gales 1998). There is little information regarding the current status of giant-petrel populations breeding outside of Australian territory. Many of the populations have not been surveyed for at least ten years, making any assessment of their current status unreliable. This is of concern as about 20 giant-petrel populations contain 100 or fewer breeding pairs (see Sections 2.6 and 2.7).
There are twelve breeding populations of albatross within areas under Australian jurisdiction (Table 5.3). At least six of these colonies contain critically low populations, numbering 200 or fewer breeding pairs. Seven populations are currently being monitored, which should provide essential information regarding their viability. At present, the current status of only two populations is known. Likewise, the current status is known for only two of the six giant-petrel breeding populations within areas under Australian jurisdiction. Four populations have not been surveyed for at least a decade. Consequently, their current status can not be accurately assessed (Table 5.3).
Annual population monitoring programs exist for albatrosses and giant-petrels breeding on Macquarie Island, Albatross Island, Pedra Branca and the Mewstone. Since the mid 1980s, the AAD has opportunistically visited and estimated the size and breeding success of Southern Giant-Petrel colonies breeding at Giganteus Island, Hawker Island and the Frazier Islands (within the AAT). The results of these and future surveys need to be systematically reported to the Albatross and Giant-Petrel Recovery Team to ensure Recovery Actions are appropriately prioritised, and to assess the efficacy of the recovery process.
There are currently no systematic monitoring programs for the populations breeding on Heard Island or the McDonald Islands. Systematic, non-intrusive surveys of colonies at these locations conducted over many years are needed to determine the size and long term status of all Australian breeding populations.
Preliminary investigations into remote monitoring techniques (such as aerial surveys) have returned encouraging results (N. Brothers pers. comm.). Such remote techniques should be further refined and employed wherever appropriate.
|Species||Breeding locality||Current monitoring program||Survey date||Annual breeding pairs||Population status||Reference|
|Wandering Albatross||Macquarie Island||Yes||1998/99||15||Stable*||Gales et al. (in press)|
|Black-browed Albatross||Macquarie Island||Yes||1998/99||45||?||Gales et al. (in press)|
|Bishop and Clerk Islets||No||1993||141||?||N. Brothers unpubl.|
|Heard Island||No||1987/88||600-700||?||Kirkwood and Mitchell (1992)|
|McDonald Islands||No||1981||82-89||?||P. Keage, pers. comm. in Gales (1998)|
|Shy Albatrosses||Albatross Island||Yes||1995||5,000||Increasing||Brothers et al. (1997)|
|The Mewstone||Yes||1995||7,000||?||Brothers et al. (1997)|
|Pedra Branca||Yes||1995||200||?||Brothers et al. (1997)|
|Grey-headed Albatross||Macquarie Island||Yes||1998/99||78||?||Gales et al. (in press)|
|Light-mantled Albatross||Macquarie Island||Yes||1994/95||1,000-1,150||?||Gales et al. (in press)|
|Heard Island||No||1954||200-500||?||Downes et al. (1959)|
|McDonald Islands||No||?||?||?||Woehler (1991)|
|Northern Giant-Petrel||Macquarie Island||Yes||1998/99||1,485||?||Gales et al. (in press)|
|Southern Giant-Petrel||Macquarie Island||Yes||1998/99||2,293||Decreasing||Gales et al. (in press)|
|Heard Island||No||1988||3,154||?||Kirkwood et al. (1995)|
|McDonald Island||No||1979||1,400||?||Patterson et al. (in press)|
|AAT: - Giganteus Island||Opportunistic||1993||2||Decreasing?||Patterson et al. (in press)|
|- Hawker Island||Opportunistic||1989||18||Decreasing?||Patterson et al. (in press)|
|- Frazier Islands||Opportunistic||1990||174||Increasing #||Patterson et al. (in press)|
? Population status is unknown due to a lack of recent or consistent population censuses
* Population is currently stable at low levels after previous population declines
# Population is possibly increasing at low levels after previous population declines
Large populations that are quickly reduced to small, isolated populations often suffer from reduced fecundity and viability, known as inbreeding depression. The average fitness cost in these remnant populations may be as high as a 33% reduction in viability (Harvey and Read 1988).
In addition, the long-term viability of remnant populations may also be endangered due to a lack of genetic variability within the population. In small populations random fluctuations in allele frequencies caused by genetic drift lead to a loss of rare alleles, increasing homozygosity. Reduced genetic variability inhibits the ability of a population to track a changing environment, and increases its susceptibility to the effects of disease.
The problems of reduced genetic fitness may be a very real threat to several 'breeding species' of albatross and giant-petrel populations. Some of the world's smallest and most vulnerable populations of Wandering Albatrosses, Black-browed Albatrosses, Grey-headed Albatrosses and Southern Giant-Petrels breed within the AFZ. Many of these populations have undergone substantial decreases in population size within the last 100 years. Furthermore, albatross and giant-petrel populations typically show extremely high levels of philopatry. Consequently, individuals nearly always only breed with birds from their own population, increasing the likelihood of inbreeding depression and homozygosity.
Education, public awareness and community involvement are critical components of the recovery process. The impact of several threats to albatrosses and giant-petrels can be greatly decreased via the development of educational strategies targeting (i) commercial and recreational fishers, (ii) visitors to breeding colonies, and (iii) the general public.
Commercial and recreational fishers need to be encouraged to employ effective by-catch mitigation measures. This can best be achieved by educating fishers of the ecological importance and economic gains of using such measures, and the central importance of albatrosses, giant-petrels and other wildlife. Objective 6 of the Longline Fishing Threat Abatement Plan 'implement a fisher extension and training program for longline fishers operating in the AFZ' (TAP Actions 6.1 and 6.2: p37).
This Recovery Plan has identified the need for additional education strategies targeting fishers. The intentional shooting of albatrosses and giant-petrels (and other wildlife) by recreational and commercial fishers needs to be discouraged (Section 5.3). In addition, troll fishers need to be encouraged to set their lines more than 2m below the surface of the water (Section 5.4).
Section 5.6 of this Recovery Plan highlighted the need for visitors to albatross and giant-petrel breeding colonies to be made aware of their potential impact upon nesting attempts. Educational material regarding the impacts of wildlife disturbance should (i) continue to be provided to all tourists and ANARE expeditioners prior to arrival on Macquarie Island and the AAT (ii) be designed, developed and provided to all visitors to Heard Island.
Marine pollution has been identified as a potential threat to albatrosses and giant-petrels (Section 5.11). The general public needs to be informed of (i) the environmental impacts of using industrial, agricultural and domestic chemicals, and (ii) the central importance of conserving albatrosses, giant-petrels and other wildlife.
Throughout this document the highly dispersive nature of albatrosses and giant-petrels has been emphasised. Populations that breed on Australian islands may spend a large proportion of their lives foraging outside of the AFZ. Thus it is significant that many of the threats affecting albatrosses and giant-petrels within the AFZ are also occurring outside of the AFZ.
In addition, some human-induced threats only occur outside of the AFZ. Large-scale driftnet fisheries operated until the end of 1992 when the UN General Assembly enforced a global moratorium on drift netting due to the excessive levels of by-catch. Despite this, it is possible that a significant level of illegal drift netting persists on the High Seas and in some EEZs and coastal regions (Alexander et al. 1997). This could continue to have a negative impact on the survival of albatrosses, giant-petrels and other marine birds and mammals.
For these reasons, it will be difficult or impossible to restore all populations breeding on Australian islands solely by eliminating threats occurring within the AFZ. It is imperative that international agreements are reached to ameliorate threats caused by human activity throughout the entire range of albatrosses and giant-petrels.
As discussed in Section 5.1, the FAO has recently implemented an International Plan of Action for Reducing Catch of Seabirds in Longline Fisheries (IPOA). The objective of the IPOA is to reduce the primary global threat to albatrosses and giant-petrels (the incidental catch of seabirds in longline fisheries) wherever it occurs. The Longline Fishing Threat Abatement Planfulfils Australia's obligation to the FAO's IPOA.
In 1997 Australia successfully proposed that all Southern Hemisphere albatross species be listed under the CMS. This was an important step toward promoting a cooperative framework for the conservation and management of Southern Hemisphere albatrosses. The November 1999 Conference of Parties to the CMS recommended that all range states actively participate in the development and successful conclusion of a regional agreement for the conservation of albatrosses.
The progress of the plan should be evaluated each year at a meeting of the Albatross and Giant-Petrel Recovery Team. The regular flow of information between recovery team participants is critical to the recovery process. Information from actions, particularly those quantifying the impact of threats, should be fed into the recovery process through annual reports from participants. These will be collated by Environment Australia (EA) for circulation to the recovery team at meetings. New members to the recovery team must be nominated by the stakeholder group that they are representing.
The EPBC Act provides for review of the Recovery Plan at any time at the discretion of the Director of Parks and Wildlife.