Gough and Inaccessible Islands

Substantial threat to the important seabird colonies from invasive species (mice) (issue mentioned since 1999)

On 15 January 2016, the World Heritage Centre transmitted a letter to the State Party raising concern that two recent scientific papers reported an 87% chick mortality rate of Atlantic petrel and a breeding success rate of less than 10% of Tristan albatross on Gough Island, due to predation by invasive house mice. 

On 18 April 2016, the State Party submitted a state of conservation report, which is available at https://whc.unesco.org/en/list/740/documents/, and provides the following information:

• According to a 2015 peer-reviewed paper, Gough Island was identified as the top priority for invasive vertebrates in the United Kingdom Overseas Territories, and a recent feasibility study tested positive for successful mouse eradication from the island;
• The proposed mouse eradication programme will involve ground-based application as well as two applications of rat poison from four helicopters. Primary poisoning of other species on the island will be mitigated by taking representative individuals of each species into captivity, which ensures genetic viability in line with a newly developed captive management plan;
• The operational phase of the programme is expected to begin in 2018–2019, followed by two subsequent years of monitoring;
• The eradication programme is estimated to cost £7.5 million, of which the Royal Society for the Protection of Birds (RSPB) is anticipated to contribute 75% through its concerted fundraising campaign. The State Party foresees a bid in late 2016 to provide funding for the remainder of the budget.

The State Party also reports that the eradication programme for the invasive plant Sagina procumbens has been almost continuously implemented since 2009. A review of the programme in 2014 led to a proposal for the RSPB to lead a further five-year eradication campaign.

The rate of decline in seabird populations on Gough Island, primarily as a result of predation by invasive mice, is noted with significant concern. The critically endangered Tristan albatross (Diomedea dabbenena) in particular appears to have experienced a major decline in breeding success rate predominately due to low fledgling survival rate. Other affected species include the critically endangered Gough finch (Rowettia goughensis) and the endemic Atlantic petrel (Pterodroma incerta). The scientific reports note that the smaller petrel species are particularly vulnerable to extinction from the island in the near future if mice are not eradicated, and urgent actions are therefore required to reverse this declining trend in bird populations.

Whilst noting that allocation of three-quarters of the eradication programme budget is anticipated through RSPB’s fundraising campaign, it is of concern that the remaining funding source has not yet been confirmed. Considering the urgent need to address the threat, which is directly impacting the property’s Outstanding Universal Value (OUV), and recalling Decision 33 COM 7B.32 adopted at the 33rd session (Seville, 2009), which requested the State Party to eradicate mice within five years, it is recommended that the Committee request the State Party to urgently allocate sufficient funds for the rapid implementation of the eradication programme.

Also recalling decision 33 COM 7B.32 in which the State Party was requested to ensure continuous programmes of eradication of procumbent pearlwort (Sagina procumbens) for at least the next three years, it is appreciated that the programme has been almost continuously implemented since 2009, led by the Tristan da Cunha government and RSPB, through John Ellerman Foundation funding. It is recommended that the Committee request the State Party to submit an update on the current status of the procumbent pearlwort on the island, as well as further details on the further five-year eradication campaign.