New Zealand's North Island sea bird population in 'serious decline'
An estimated 90 percent of seabirds in the North island are at risk of extinction according to the Northern New Zealand Seabird Trust report.
More than 28 species, including five that are found nowhere else in the world, live in northern New Zealand with very little known about the status of them and the specific threats to them, the report said.
"We must first understand what threats these seabirds are up against before we can establish a baseline from which to work on researching and conserving them," lead author of the report and doctoral student at the University of Auckland, Eden Whitehead said.
Six of the main threats for the birds were, invasive species, fisheries, pollution, climate change, disease and direct human impacts, Whitehead said.
Report co-author Chris Gaskin, who is also project coordinator of the trust, said some seabird species had only recently been discovered.
"For example, the New Zealand storm petrel breeding on Te Hauturu-o-Toi/Little Barrier Island - it's quite possible that if the eradication of rats and cats on the island had not happened, we may never have known they were there."
Some of the most vulnerable seabirds include black petrels, threatened by fisheries by-catch, and the fairy tern, New Zealand's most endangered bird, which is down to around a dozen breeding pairs restricted to an area between Whangarei and Auckland.
The tern is intensively managed during the breeding season and its population directly threatened by human impacts, the report said.
While some threats to seabird populations are well known, such as introduced mammalian predators and fisheries, others are only just emerging, such as climate change, pollution and disease, University of Auckland Associate Professor and report co-author James Russell said.
"Although there has been some progress in eradicating invasive species from islands to restore seabird populations, this isn't enough when they are facing multiple threats both on land and at sea."