Rationale (Changed due to Incorrect application of criteria)

The regional population of Northern Giant Petrel Macronectes halli has been quantified at c. 750 annual breeding pairs that breed at two locations in the region, namely Prince Edward Island and Marion Island. The regional population trend appears to be stable but satisfies the criterion for regionally Vulnerable under D2 (population with a very restricted area of occupancy or restricted to a small number of locations (typically five or fewer) such that it is prone to the effects of human activities or stochastic events within a very short time period in an uncertain future, and is thus capable of becoming Critically Endangered or even Extinct in a very short time period). However, it was felt that it was unlikely that stochastic events or human activities at the Prince Edward Islands would lead to the Northern Giant Petrel becoming severely threatened within one to two generations. As a result, it was assessed as regionally Near Threatened.

Distribution

The Northern Giant Petrel breeds on several islands in the Subantarctic zone including South Georgia, the Crozet and Kerguelen archipelagos, Macquarie Island, Auckland, the New Zealand islands of Campbell, Antipodes and Chatham as well as the Prince Edward Islands (ACAP 2010). At sea the species is wide-ranging, dispersing across the Southern Ocean, and also frequently venturing into continental shelf waters.

Habitat View more ecological information

Population

The global population has been quantified at 11 000-14 000 annual breeding individuals which is roughly equivalent to 17 000-21 000 individuals (ACAP 2010). South Georgia holds roughly 33% of the global population (ACAP 2010, BirdLife International 2014). The 2008 census of Prince Edward Island suggested a minimum of 350 pairs although Ryan et al. (2009) note that this is almost certainly an underestimate of the total population as nests are easily overlooked. In 2008, there were an estimated 400 pairs breeding at Marion Island. The regional population is at least 750 pairs (Ryan et al. 2009). Confidence in this estimate is low due to considerable extrapolation used in estimating population size.

Population trend

The global population has shown both decreases and dramatic increases across their breeding range (ACAP 2010). Similarly, the breeding population on Marion Island has fluctuated since 1985 with a period of annual increase of 3.9% until 1998, followed by a decline of 9.2% until 2005. Since 2005, the population has been recovering at 24.8% per year (Ryan et al. 2009). The population at Prince Edward Island, the smaller of the two, remains too infrequently counted to discern trends, but it is assumed to form a single meta-population with the much larger Marion Island sub-population (Crawford et al. 2003). The count at Prince Edward Island was 44% higher in 2008 than that in 2001. The regional population is assumed stable. Confidence in this trend estimate is high.

Threats

Commercial fishing activity (in particular, Patagonian Toothfish Dissostichus eleginoides fishery, which tends to be restricted around subantarctic breeding islands), is the primary threat, although the threat from regulated fishing has largely abated; illegal fishing remains a concern of unknown proportions. Potentially 7-16% of the breeding population around the Prince Edward Islands may have been killed by longline operations between 1996-2000 (Nel et al. 2002). Trawl fisheries, through collisions, also pose a threat to this species. There are no known threats on either Marion or Prince Edward Island although human disturbance at breeding sites near research stations or visitations to breeding sites could lead to a decrease in breeding success or even colony abandonment. A secondary threat is the ingestion of marine debris and fouling from oil spills (ACAP 2010).

Conservation

Underway

The sub-population breeding at the Prince Edward Islands is small but stable. Monitoring and tracking programmes to assess overlap with key fisheries should continue, and the existing measures to avoid seabird bycatch in the Patagonian Toothfish fishery should likewise continue. The species receives international protection under the Agreement on the Conservation of Albatrosses and Petrels (Annex 1) and the Convention on the Conservation of Migratory Species of Wild Animals (Appendix II). Within the region it is protected under the Sea Birds and Seals Protection Act, 1973 (Act No. 46 of 1973), Marine Living Resources Act (Act No. 18 of 1998): Publication of Policy on the Management of Seals, Seabirds and Shorebirds: 2007 and the National Plan of Action (NPOA) for Reducing the Incidental Catch on Seabirds in Longline Fisheries (2008). The Prince Edward Islands are listed as a Ramsar Wetland of International Importance, and a Special Nature Reserve under the Environment Conservation Act (No 73 of 1989) and managed under the Prince Edward Islands Management Plan of 1996. The Prince Edward Islands Marine Protected Area was proclaimed in 2013.

Proposed

No additional conservation action is recommended for this species because it appears to have been stable since monitoring at Marion Island began.

Research

* Differences in ecology, distribution and diet between this and the Southern Giant Petrel, which have differing population trajectories, should be explored.

* Sensitivity to foraging conditions and how those might change in response to climate change should be investigated.