A herb field on Campbell Island. Photo: DOC / Gregory Sherley
More extreme weather driven by climate change is likely to threaten taonga species like albatross and sea lions on the country's most southern subantarctic island, the Department of Conservation is warning.
A study focused on Campbell Island, 740km south of Dunedin, looked at 83 years of weather observations.
It found an increase in the average daily temperature, a decrease in the number of cold days, and an increase in annual rainfall since 1970.
The three warmest and four wettest years on record all occurred after 2011.
The light-mantled sooty albatross is one of six species of albatross living on Campbell Island. Photo: Supplied / Department of Conservation
The study predicted the trends to continue with further temperature rise, along with more intense rainfall and wind.
"The pattern we've observed is a general increase across all climate indicators related to warmer conditions. This is expected to continue into the future," DOC principal science advisor Drew Bingham said.
"Increases in temperatures, rainfall and wind are projected for Campbell Island. Winter rainfall is expected to be particularly heavy, with a warmer atmosphere storing more water vapour and increasing the severity and intensity of downpours."
Extensive rainfall events and slips would impact nesting birds, while sea level rise and storm surges could threaten the habitat of sea lions, Bingham said.
The climate projections had implications for conservation management on Campbell and other sub-Antarctic islands, and further research was needed to help taonga species adapt to climate change, he said.
"Increasing the resilience of the subantarctic islands and keeping them pest-free becomes even more important in the face of climate change, especially given the wealth of biodiversity on many of the islands."
Taonga species
Campbell Island is part of New Zealand's subantarctic World Heritage Site. It is made up of rugged and steep terrain and is covered in extensive peat.
It is home to six species of albatross, including black-browed, grey-headed, light-mantled sooty and a small population of Gibson's wandering albatross.
Several critically endangered birds, including the Campbell Island teal and Campbell Island snipe, are found nowhere else.
It has about 128 native vascular plants, which include several endemic herbs and grasses.
The island's rat-free status was confirmed in 2006, following rat eradications in the early 2000s.
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